tor-browser

avcodec.h (158429B)

---

/*
* copyright (c) 2001 Fabrice Bellard
*
* This file is part of Libav.
*
* Libav is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* Libav is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/

#ifndef AVCODEC_AVCODEC_H
#define AVCODEC_AVCODEC_H

/**
* @file
* external API header
*/

#include <errno.h>
#include "libavutil/samplefmt.h"
#include "libavutil/avutil.h"
#include "libavutil/cpu.h"
#include "libavutil/dict.h"
#include "libavutil/log.h"
#include "libavutil/pixfmt.h"
#include "libavutil/rational.h"

#include "libavcodec/version.h"
/**
* @defgroup libavc Encoding/Decoding Library
* @{
*
* @defgroup lavc_decoding Decoding
* @{
* @}
*
* @defgroup lavc_encoding Encoding
* @{
* @}
*
* @defgroup lavc_codec Codecs
* @{
* @defgroup lavc_codec_native Native Codecs
* @{
* @}
* @defgroup lavc_codec_wrappers External library wrappers
* @{
* @}
* @defgroup lavc_codec_hwaccel Hardware Accelerators bridge
* @{
* @}
* @}
* @defgroup lavc_internal Internal
* @{
* @}
* @}
*
*/


/**
* Identify the syntax and semantics of the bitstream.
* The principle is roughly:
* Two decoders with the same ID can decode the same streams.
* Two encoders with the same ID can encode compatible streams.
* There may be slight deviations from the principle due to implementation
* details.
*
* If you add a codec ID to this list, add it so that
* 1. no value of a existing codec ID changes (that would break ABI),
* 2. it is as close as possible to similar codecs.
*/
enum CodecID {
   CODEC_ID_NONE,

   /* video codecs */
   CODEC_ID_MPEG1VIDEO,
   CODEC_ID_MPEG2VIDEO, ///< preferred ID for MPEG-1/2 video decoding
   CODEC_ID_MPEG2VIDEO_XVMC,
   CODEC_ID_H261,
   CODEC_ID_H263,
   CODEC_ID_RV10,
   CODEC_ID_RV20,
   CODEC_ID_MJPEG,
   CODEC_ID_MJPEGB,
   CODEC_ID_LJPEG,
   CODEC_ID_SP5X,
   CODEC_ID_JPEGLS,
   CODEC_ID_MPEG4,
   CODEC_ID_RAWVIDEO,
   CODEC_ID_MSMPEG4V1,
   CODEC_ID_MSMPEG4V2,
   CODEC_ID_MSMPEG4V3,
   CODEC_ID_WMV1,
   CODEC_ID_WMV2,
   CODEC_ID_H263P,
   CODEC_ID_H263I,
   CODEC_ID_FLV1,
   CODEC_ID_SVQ1,
   CODEC_ID_SVQ3,
   CODEC_ID_DVVIDEO,
   CODEC_ID_HUFFYUV,
   CODEC_ID_CYUV,
   CODEC_ID_H264,
   CODEC_ID_INDEO3,
   CODEC_ID_VP3,
   CODEC_ID_THEORA,
   CODEC_ID_ASV1,
   CODEC_ID_ASV2,
   CODEC_ID_FFV1,
   CODEC_ID_4XM,
   CODEC_ID_VCR1,
   CODEC_ID_CLJR,
   CODEC_ID_MDEC,
   CODEC_ID_ROQ,
   CODEC_ID_INTERPLAY_VIDEO,
   CODEC_ID_XAN_WC3,
   CODEC_ID_XAN_WC4,
   CODEC_ID_RPZA,
   CODEC_ID_CINEPAK,
   CODEC_ID_WS_VQA,
   CODEC_ID_MSRLE,
   CODEC_ID_MSVIDEO1,
   CODEC_ID_IDCIN,
   CODEC_ID_8BPS,
   CODEC_ID_SMC,
   CODEC_ID_FLIC,
   CODEC_ID_TRUEMOTION1,
   CODEC_ID_VMDVIDEO,
   CODEC_ID_MSZH,
   CODEC_ID_ZLIB,
   CODEC_ID_QTRLE,
   CODEC_ID_SNOW,
   CODEC_ID_TSCC,
   CODEC_ID_ULTI,
   CODEC_ID_QDRAW,
   CODEC_ID_VIXL,
   CODEC_ID_QPEG,
   CODEC_ID_PNG,
   CODEC_ID_PPM,
   CODEC_ID_PBM,
   CODEC_ID_PGM,
   CODEC_ID_PGMYUV,
   CODEC_ID_PAM,
   CODEC_ID_FFVHUFF,
   CODEC_ID_RV30,
   CODEC_ID_RV40,
   CODEC_ID_VC1,
   CODEC_ID_WMV3,
   CODEC_ID_LOCO,
   CODEC_ID_WNV1,
   CODEC_ID_AASC,
   CODEC_ID_INDEO2,
   CODEC_ID_FRAPS,
   CODEC_ID_TRUEMOTION2,
   CODEC_ID_BMP,
   CODEC_ID_CSCD,
   CODEC_ID_MMVIDEO,
   CODEC_ID_ZMBV,
   CODEC_ID_AVS,
   CODEC_ID_SMACKVIDEO,
   CODEC_ID_NUV,
   CODEC_ID_KMVC,
   CODEC_ID_FLASHSV,
   CODEC_ID_CAVS,
   CODEC_ID_JPEG2000,
   CODEC_ID_VMNC,
   CODEC_ID_VP5,
   CODEC_ID_VP6,
   CODEC_ID_VP6F,
   CODEC_ID_TARGA,
   CODEC_ID_DSICINVIDEO,
   CODEC_ID_TIERTEXSEQVIDEO,
   CODEC_ID_TIFF,
   CODEC_ID_GIF,
#if LIBAVCODEC_VERSION_MAJOR == 53
   CODEC_ID_FFH264,
#endif
   CODEC_ID_DXA,
   CODEC_ID_DNXHD,
   CODEC_ID_THP,
   CODEC_ID_SGI,
   CODEC_ID_C93,
   CODEC_ID_BETHSOFTVID,
   CODEC_ID_PTX,
   CODEC_ID_TXD,
   CODEC_ID_VP6A,
   CODEC_ID_AMV,
   CODEC_ID_VB,
   CODEC_ID_PCX,
   CODEC_ID_SUNRAST,
   CODEC_ID_INDEO4,
   CODEC_ID_INDEO5,
   CODEC_ID_MIMIC,
   CODEC_ID_RL2,
#if LIBAVCODEC_VERSION_MAJOR == 53
   CODEC_ID_8SVX_EXP,
   CODEC_ID_8SVX_FIB,
#endif
   CODEC_ID_ESCAPE124,
   CODEC_ID_DIRAC,
   CODEC_ID_BFI,
   CODEC_ID_CMV,
   CODEC_ID_MOTIONPIXELS,
   CODEC_ID_TGV,
   CODEC_ID_TGQ,
   CODEC_ID_TQI,
   CODEC_ID_AURA,
   CODEC_ID_AURA2,
   CODEC_ID_V210X,
   CODEC_ID_TMV,
   CODEC_ID_V210,
   CODEC_ID_DPX,
   CODEC_ID_MAD,
   CODEC_ID_FRWU,
   CODEC_ID_FLASHSV2,
   CODEC_ID_CDGRAPHICS,
   CODEC_ID_R210,
   CODEC_ID_ANM,
   CODEC_ID_BINKVIDEO,
   CODEC_ID_IFF_ILBM,
   CODEC_ID_IFF_BYTERUN1,
   CODEC_ID_KGV1,
   CODEC_ID_YOP,
   CODEC_ID_VP8,
   CODEC_ID_PICTOR,
   CODEC_ID_ANSI,
   CODEC_ID_A64_MULTI,
   CODEC_ID_A64_MULTI5,
   CODEC_ID_R10K,
   CODEC_ID_MXPEG,
   CODEC_ID_LAGARITH,
   CODEC_ID_PRORES,
   CODEC_ID_JV,
   CODEC_ID_DFA,
   CODEC_ID_WMV3IMAGE,
   CODEC_ID_VC1IMAGE,
#if LIBAVCODEC_VERSION_MAJOR == 53
   CODEC_ID_G723_1,
   CODEC_ID_G729,
#endif
   CODEC_ID_UTVIDEO,
   CODEC_ID_BMV_VIDEO,
   CODEC_ID_VBLE,
   CODEC_ID_DXTORY,
   CODEC_ID_V410,

   /* various PCM "codecs" */
   CODEC_ID_FIRST_AUDIO = 0x10000,     ///< A dummy id pointing at the start of audio codecs
   CODEC_ID_PCM_S16LE = 0x10000,
   CODEC_ID_PCM_S16BE,
   CODEC_ID_PCM_U16LE,
   CODEC_ID_PCM_U16BE,
   CODEC_ID_PCM_S8,
   CODEC_ID_PCM_U8,
   CODEC_ID_PCM_MULAW,
   CODEC_ID_PCM_ALAW,
   CODEC_ID_PCM_S32LE,
   CODEC_ID_PCM_S32BE,
   CODEC_ID_PCM_U32LE,
   CODEC_ID_PCM_U32BE,
   CODEC_ID_PCM_S24LE,
   CODEC_ID_PCM_S24BE,
   CODEC_ID_PCM_U24LE,
   CODEC_ID_PCM_U24BE,
   CODEC_ID_PCM_S24DAUD,
   CODEC_ID_PCM_ZORK,
   CODEC_ID_PCM_S16LE_PLANAR,
   CODEC_ID_PCM_DVD,
   CODEC_ID_PCM_F32BE,
   CODEC_ID_PCM_F32LE,
   CODEC_ID_PCM_F64BE,
   CODEC_ID_PCM_F64LE,
   CODEC_ID_PCM_BLURAY,
   CODEC_ID_PCM_LXF,
   CODEC_ID_S302M,
   CODEC_ID_PCM_S8_PLANAR,

   /* various ADPCM codecs */
   CODEC_ID_ADPCM_IMA_QT = 0x11000,
   CODEC_ID_ADPCM_IMA_WAV,
   CODEC_ID_ADPCM_IMA_DK3,
   CODEC_ID_ADPCM_IMA_DK4,
   CODEC_ID_ADPCM_IMA_WS,
   CODEC_ID_ADPCM_IMA_SMJPEG,
   CODEC_ID_ADPCM_MS,
   CODEC_ID_ADPCM_4XM,
   CODEC_ID_ADPCM_XA,
   CODEC_ID_ADPCM_ADX,
   CODEC_ID_ADPCM_EA,
   CODEC_ID_ADPCM_G726,
   CODEC_ID_ADPCM_CT,
   CODEC_ID_ADPCM_SWF,
   CODEC_ID_ADPCM_YAMAHA,
   CODEC_ID_ADPCM_SBPRO_4,
   CODEC_ID_ADPCM_SBPRO_3,
   CODEC_ID_ADPCM_SBPRO_2,
   CODEC_ID_ADPCM_THP,
   CODEC_ID_ADPCM_IMA_AMV,
   CODEC_ID_ADPCM_EA_R1,
   CODEC_ID_ADPCM_EA_R3,
   CODEC_ID_ADPCM_EA_R2,
   CODEC_ID_ADPCM_IMA_EA_SEAD,
   CODEC_ID_ADPCM_IMA_EA_EACS,
   CODEC_ID_ADPCM_EA_XAS,
   CODEC_ID_ADPCM_EA_MAXIS_XA,
   CODEC_ID_ADPCM_IMA_ISS,
   CODEC_ID_ADPCM_G722,

   /* AMR */
   CODEC_ID_AMR_NB = 0x12000,
   CODEC_ID_AMR_WB,

   /* RealAudio codecs*/
   CODEC_ID_RA_144 = 0x13000,
   CODEC_ID_RA_288,

   /* various DPCM codecs */
   CODEC_ID_ROQ_DPCM = 0x14000,
   CODEC_ID_INTERPLAY_DPCM,
   CODEC_ID_XAN_DPCM,
   CODEC_ID_SOL_DPCM,

   /* audio codecs */
   CODEC_ID_MP2 = 0x15000,
   CODEC_ID_MP3, ///< preferred ID for decoding MPEG audio layer 1, 2 or 3
   CODEC_ID_AAC,
   CODEC_ID_AC3,
   CODEC_ID_DTS,
   CODEC_ID_VORBIS,
   CODEC_ID_DVAUDIO,
   CODEC_ID_WMAV1,
   CODEC_ID_WMAV2,
   CODEC_ID_MACE3,
   CODEC_ID_MACE6,
   CODEC_ID_VMDAUDIO,
#if LIBAVCODEC_VERSION_MAJOR == 53
   CODEC_ID_SONIC,
   CODEC_ID_SONIC_LS,
#endif
   CODEC_ID_FLAC,
   CODEC_ID_MP3ADU,
   CODEC_ID_MP3ON4,
   CODEC_ID_SHORTEN,
   CODEC_ID_ALAC,
   CODEC_ID_WESTWOOD_SND1,
   CODEC_ID_GSM, ///< as in Berlin toast format
   CODEC_ID_QDM2,
   CODEC_ID_COOK,
   CODEC_ID_TRUESPEECH,
   CODEC_ID_TTA,
   CODEC_ID_SMACKAUDIO,
   CODEC_ID_QCELP,
   CODEC_ID_WAVPACK,
   CODEC_ID_DSICINAUDIO,
   CODEC_ID_IMC,
   CODEC_ID_MUSEPACK7,
   CODEC_ID_MLP,
   CODEC_ID_GSM_MS, /* as found in WAV */
   CODEC_ID_ATRAC3,
   CODEC_ID_VOXWARE,
   CODEC_ID_APE,
   CODEC_ID_NELLYMOSER,
   CODEC_ID_MUSEPACK8,
   CODEC_ID_SPEEX,
   CODEC_ID_WMAVOICE,
   CODEC_ID_WMAPRO,
   CODEC_ID_WMALOSSLESS,
   CODEC_ID_ATRAC3P,
   CODEC_ID_EAC3,
   CODEC_ID_SIPR,
   CODEC_ID_MP1,
   CODEC_ID_TWINVQ,
   CODEC_ID_TRUEHD,
   CODEC_ID_MP4ALS,
   CODEC_ID_ATRAC1,
   CODEC_ID_BINKAUDIO_RDFT,
   CODEC_ID_BINKAUDIO_DCT,
   CODEC_ID_AAC_LATM,
   CODEC_ID_QDMC,
   CODEC_ID_CELT,
#if LIBAVCODEC_VERSION_MAJOR > 53
   CODEC_ID_G723_1,
   CODEC_ID_G729,
   CODEC_ID_8SVX_EXP,
   CODEC_ID_8SVX_FIB,
#endif
   CODEC_ID_BMV_AUDIO,

   /* subtitle codecs */
   CODEC_ID_FIRST_SUBTITLE = 0x17000,          ///< A dummy ID pointing at the start of subtitle codecs.
   CODEC_ID_DVD_SUBTITLE = 0x17000,
   CODEC_ID_DVB_SUBTITLE,
   CODEC_ID_TEXT,  ///< raw UTF-8 text
   CODEC_ID_XSUB,
   CODEC_ID_SSA,
   CODEC_ID_MOV_TEXT,
   CODEC_ID_HDMV_PGS_SUBTITLE,
   CODEC_ID_DVB_TELETEXT,
   CODEC_ID_SRT,

   /* other specific kind of codecs (generally used for attachments) */
   CODEC_ID_FIRST_UNKNOWN = 0x18000,           ///< A dummy ID pointing at the start of various fake codecs.
   CODEC_ID_TTF = 0x18000,

   CODEC_ID_PROBE = 0x19000, ///< codec_id is not known (like CODEC_ID_NONE) but lavf should attempt to identify it

   CODEC_ID_MPEG2TS = 0x20000, /**< _FAKE_ codec to indicate a raw MPEG-2 TS
                               * stream (only used by libavformat) */
   CODEC_ID_MPEG4SYSTEMS = 0x20001, /**< _FAKE_ codec to indicate a MPEG-4 Systems
                               * stream (only used by libavformat) */
   CODEC_ID_FFMETADATA = 0x21000,   ///< Dummy codec for streams containing only metadata information.
};

#if FF_API_OLD_SAMPLE_FMT
#define SampleFormat AVSampleFormat

#define SAMPLE_FMT_NONE AV_SAMPLE_FMT_NONE
#define SAMPLE_FMT_U8   AV_SAMPLE_FMT_U8
#define SAMPLE_FMT_S16  AV_SAMPLE_FMT_S16
#define SAMPLE_FMT_S32  AV_SAMPLE_FMT_S32
#define SAMPLE_FMT_FLT  AV_SAMPLE_FMT_FLT
#define SAMPLE_FMT_DBL  AV_SAMPLE_FMT_DBL
#define SAMPLE_FMT_NB   AV_SAMPLE_FMT_NB
#endif

#if FF_API_OLD_AUDIOCONVERT
#include "libavutil/audioconvert.h"

/* Audio channel masks */
#define CH_FRONT_LEFT            AV_CH_FRONT_LEFT
#define CH_FRONT_RIGHT           AV_CH_FRONT_RIGHT
#define CH_FRONT_CENTER          AV_CH_FRONT_CENTER
#define CH_LOW_FREQUENCY         AV_CH_LOW_FREQUENCY
#define CH_BACK_LEFT             AV_CH_BACK_LEFT
#define CH_BACK_RIGHT            AV_CH_BACK_RIGHT
#define CH_FRONT_LEFT_OF_CENTER  AV_CH_FRONT_LEFT_OF_CENTER
#define CH_FRONT_RIGHT_OF_CENTER AV_CH_FRONT_RIGHT_OF_CENTER
#define CH_BACK_CENTER           AV_CH_BACK_CENTER
#define CH_SIDE_LEFT             AV_CH_SIDE_LEFT
#define CH_SIDE_RIGHT            AV_CH_SIDE_RIGHT
#define CH_TOP_CENTER            AV_CH_TOP_CENTER
#define CH_TOP_FRONT_LEFT        AV_CH_TOP_FRONT_LEFT
#define CH_TOP_FRONT_CENTER      AV_CH_TOP_FRONT_CENTER
#define CH_TOP_FRONT_RIGHT       AV_CH_TOP_FRONT_RIGHT
#define CH_TOP_BACK_LEFT         AV_CH_TOP_BACK_LEFT
#define CH_TOP_BACK_CENTER       AV_CH_TOP_BACK_CENTER
#define CH_TOP_BACK_RIGHT        AV_CH_TOP_BACK_RIGHT
#define CH_STEREO_LEFT           AV_CH_STEREO_LEFT
#define CH_STEREO_RIGHT          AV_CH_STEREO_RIGHT

/** Channel mask value used for AVCodecContext.request_channel_layout
   to indicate that the user requests the channel order of the decoder output
   to be the native codec channel order. */
#define CH_LAYOUT_NATIVE         AV_CH_LAYOUT_NATIVE

/* Audio channel convenience macros */
#define CH_LAYOUT_MONO           AV_CH_LAYOUT_MONO
#define CH_LAYOUT_STEREO         AV_CH_LAYOUT_STEREO
#define CH_LAYOUT_2_1            AV_CH_LAYOUT_2_1
#define CH_LAYOUT_SURROUND       AV_CH_LAYOUT_SURROUND
#define CH_LAYOUT_4POINT0        AV_CH_LAYOUT_4POINT0
#define CH_LAYOUT_2_2            AV_CH_LAYOUT_2_2
#define CH_LAYOUT_QUAD           AV_CH_LAYOUT_QUAD
#define CH_LAYOUT_5POINT0        AV_CH_LAYOUT_5POINT0
#define CH_LAYOUT_5POINT1        AV_CH_LAYOUT_5POINT1
#define CH_LAYOUT_5POINT0_BACK   AV_CH_LAYOUT_5POINT0_BACK
#define CH_LAYOUT_5POINT1_BACK   AV_CH_LAYOUT_5POINT1_BACK
#define CH_LAYOUT_7POINT0        AV_CH_LAYOUT_7POINT0
#define CH_LAYOUT_7POINT1        AV_CH_LAYOUT_7POINT1
#define CH_LAYOUT_7POINT1_WIDE   AV_CH_LAYOUT_7POINT1_WIDE
#define CH_LAYOUT_STEREO_DOWNMIX AV_CH_LAYOUT_STEREO_DOWNMIX
#endif

#if FF_API_OLD_DECODE_AUDIO
/* in bytes */
#define AVCODEC_MAX_AUDIO_FRAME_SIZE 192000 // 1 second of 48khz 32bit audio
#endif

/**
* Required number of additionally allocated bytes at the end of the input bitstream for decoding.
* This is mainly needed because some optimized bitstream readers read
* 32 or 64 bit at once and could read over the end.<br>
* Note: If the first 23 bits of the additional bytes are not 0, then damaged
* MPEG bitstreams could cause overread and segfault.
*/
#define FF_INPUT_BUFFER_PADDING_SIZE 8

/**
* minimum encoding buffer size
* Used to avoid some checks during header writing.
*/
#define FF_MIN_BUFFER_SIZE 16384


/**
* motion estimation type.
*/
enum Motion_Est_ID {
   ME_ZERO = 1,    ///< no search, that is use 0,0 vector whenever one is needed
   ME_FULL,
   ME_LOG,
   ME_PHODS,
   ME_EPZS,        ///< enhanced predictive zonal search
   ME_X1,          ///< reserved for experiments
   ME_HEX,         ///< hexagon based search
   ME_UMH,         ///< uneven multi-hexagon search
   ME_ITER,        ///< iterative search
   ME_TESA,        ///< transformed exhaustive search algorithm
};

enum AVDiscard{
   /* We leave some space between them for extensions (drop some
    * keyframes for intra-only or drop just some bidir frames). */
   AVDISCARD_NONE   =-16, ///< discard nothing
   AVDISCARD_DEFAULT=  0, ///< discard useless packets like 0 size packets in avi
   AVDISCARD_NONREF =  8, ///< discard all non reference
   AVDISCARD_BIDIR  = 16, ///< discard all bidirectional frames
   AVDISCARD_NONKEY = 32, ///< discard all frames except keyframes
   AVDISCARD_ALL    = 48, ///< discard all
};

enum AVColorPrimaries{
   AVCOL_PRI_BT709      =1, ///< also ITU-R BT1361 / IEC 61966-2-4 / SMPTE RP177 Annex B
   AVCOL_PRI_UNSPECIFIED=2,
   AVCOL_PRI_BT470M     =4,
   AVCOL_PRI_BT470BG    =5, ///< also ITU-R BT601-6 625 / ITU-R BT1358 625 / ITU-R BT1700 625 PAL & SECAM
   AVCOL_PRI_SMPTE170M  =6, ///< also ITU-R BT601-6 525 / ITU-R BT1358 525 / ITU-R BT1700 NTSC
   AVCOL_PRI_SMPTE240M  =7, ///< functionally identical to above
   AVCOL_PRI_FILM       =8,
   AVCOL_PRI_NB           , ///< Not part of ABI
};

enum AVColorTransferCharacteristic{
   AVCOL_TRC_BT709      =1, ///< also ITU-R BT1361
   AVCOL_TRC_UNSPECIFIED=2,
   AVCOL_TRC_GAMMA22    =4, ///< also ITU-R BT470M / ITU-R BT1700 625 PAL & SECAM
   AVCOL_TRC_GAMMA28    =5, ///< also ITU-R BT470BG
   AVCOL_TRC_NB           , ///< Not part of ABI
};

enum AVColorSpace{
   AVCOL_SPC_RGB        =0,
   AVCOL_SPC_BT709      =1, ///< also ITU-R BT1361 / IEC 61966-2-4 xvYCC709 / SMPTE RP177 Annex B
   AVCOL_SPC_UNSPECIFIED=2,
   AVCOL_SPC_FCC        =4,
   AVCOL_SPC_BT470BG    =5, ///< also ITU-R BT601-6 625 / ITU-R BT1358 625 / ITU-R BT1700 625 PAL & SECAM / IEC 61966-2-4 xvYCC601
   AVCOL_SPC_SMPTE170M  =6, ///< also ITU-R BT601-6 525 / ITU-R BT1358 525 / ITU-R BT1700 NTSC / functionally identical to above
   AVCOL_SPC_SMPTE240M  =7,
   AVCOL_SPC_NB           , ///< Not part of ABI
};

enum AVColorRange{
   AVCOL_RANGE_UNSPECIFIED=0,
   AVCOL_RANGE_MPEG       =1, ///< the normal 219*2^(n-8) "MPEG" YUV ranges
   AVCOL_RANGE_JPEG       =2, ///< the normal     2^n-1   "JPEG" YUV ranges
   AVCOL_RANGE_NB           , ///< Not part of ABI
};

/**
*  X   X      3 4 X      X are luma samples,
*             1 2        1-6 are possible chroma positions
*  X   X      5 6 X      0 is undefined/unknown position
*/
enum AVChromaLocation{
   AVCHROMA_LOC_UNSPECIFIED=0,
   AVCHROMA_LOC_LEFT       =1, ///< mpeg2/4, h264 default
   AVCHROMA_LOC_CENTER     =2, ///< mpeg1, jpeg, h263
   AVCHROMA_LOC_TOPLEFT    =3, ///< DV
   AVCHROMA_LOC_TOP        =4,
   AVCHROMA_LOC_BOTTOMLEFT =5,
   AVCHROMA_LOC_BOTTOM     =6,
   AVCHROMA_LOC_NB           , ///< Not part of ABI
};

#if FF_API_FLAC_GLOBAL_OPTS
/**
* LPC analysis type
*/
enum AVLPCType {
   AV_LPC_TYPE_DEFAULT     = -1, ///< use the codec default LPC type
   AV_LPC_TYPE_NONE        =  0, ///< do not use LPC prediction or use all zero coefficients
   AV_LPC_TYPE_FIXED       =  1, ///< fixed LPC coefficients
   AV_LPC_TYPE_LEVINSON    =  2, ///< Levinson-Durbin recursion
   AV_LPC_TYPE_CHOLESKY    =  3, ///< Cholesky factorization
   AV_LPC_TYPE_NB              , ///< Not part of ABI
};
#endif

enum AVAudioServiceType {
   AV_AUDIO_SERVICE_TYPE_MAIN              = 0,
   AV_AUDIO_SERVICE_TYPE_EFFECTS           = 1,
   AV_AUDIO_SERVICE_TYPE_VISUALLY_IMPAIRED = 2,
   AV_AUDIO_SERVICE_TYPE_HEARING_IMPAIRED  = 3,
   AV_AUDIO_SERVICE_TYPE_DIALOGUE          = 4,
   AV_AUDIO_SERVICE_TYPE_COMMENTARY        = 5,
   AV_AUDIO_SERVICE_TYPE_EMERGENCY         = 6,
   AV_AUDIO_SERVICE_TYPE_VOICE_OVER        = 7,
   AV_AUDIO_SERVICE_TYPE_KARAOKE           = 8,
   AV_AUDIO_SERVICE_TYPE_NB                   , ///< Not part of ABI
};

typedef struct RcOverride{
   int start_frame;
   int end_frame;
   int qscale; // If this is 0 then quality_factor will be used instead.
   float quality_factor;
} RcOverride;

#define FF_MAX_B_FRAMES 16

/* encoding support
  These flags can be passed in AVCodecContext.flags before initialization.
  Note: Not everything is supported yet.
*/

#define CODEC_FLAG_QSCALE 0x0002  ///< Use fixed qscale.
#define CODEC_FLAG_4MV    0x0004  ///< 4 MV per MB allowed / advanced prediction for H.263.
#define CODEC_FLAG_QPEL   0x0010  ///< Use qpel MC.
#define CODEC_FLAG_GMC    0x0020  ///< Use GMC.
#define CODEC_FLAG_MV0    0x0040  ///< Always try a MB with MV=<0,0>.
/**
* The parent program guarantees that the input for B-frames containing
* streams is not written to for at least s->max_b_frames+1 frames, if
* this is not set the input will be copied.
*/
#define CODEC_FLAG_INPUT_PRESERVED 0x0100
#define CODEC_FLAG_PASS1           0x0200   ///< Use internal 2pass ratecontrol in first pass mode.
#define CODEC_FLAG_PASS2           0x0400   ///< Use internal 2pass ratecontrol in second pass mode.
#define CODEC_FLAG_GRAY            0x2000   ///< Only decode/encode grayscale.
#define CODEC_FLAG_EMU_EDGE        0x4000   ///< Don't draw edges.
#define CODEC_FLAG_PSNR            0x8000   ///< error[?] variables will be set during encoding.
#define CODEC_FLAG_TRUNCATED       0x00010000 /** Input bitstream might be truncated at a random
                                                 location instead of only at frame boundaries. */
#define CODEC_FLAG_NORMALIZE_AQP  0x00020000 ///< Normalize adaptive quantization.
#define CODEC_FLAG_INTERLACED_DCT 0x00040000 ///< Use interlaced DCT.
#define CODEC_FLAG_LOW_DELAY      0x00080000 ///< Force low delay.
#define CODEC_FLAG_GLOBAL_HEADER  0x00400000 ///< Place global headers in extradata instead of every keyframe.
#define CODEC_FLAG_BITEXACT       0x00800000 ///< Use only bitexact stuff (except (I)DCT).
/* Fx : Flag for h263+ extra options */
#define CODEC_FLAG_AC_PRED        0x01000000 ///< H.263 advanced intra coding / MPEG-4 AC prediction
#define CODEC_FLAG_CBP_RD         0x04000000 ///< Use rate distortion optimization for cbp.
#define CODEC_FLAG_QP_RD          0x08000000 ///< Use rate distortion optimization for qp selectioon.
#define CODEC_FLAG_LOOP_FILTER    0x00000800 ///< loop filter
#define CODEC_FLAG_INTERLACED_ME  0x20000000 ///< interlaced motion estimation
#define CODEC_FLAG_CLOSED_GOP     0x80000000
#define CODEC_FLAG2_FAST          0x00000001 ///< Allow non spec compliant speedup tricks.
#define CODEC_FLAG2_STRICT_GOP    0x00000002 ///< Strictly enforce GOP size.
#define CODEC_FLAG2_NO_OUTPUT     0x00000004 ///< Skip bitstream encoding.
#define CODEC_FLAG2_LOCAL_HEADER  0x00000008 ///< Place global headers at every keyframe instead of in extradata.
#define CODEC_FLAG2_SKIP_RD       0x00004000 ///< RD optimal MB level residual skipping
#define CODEC_FLAG2_CHUNKS        0x00008000 ///< Input bitstream might be truncated at a packet boundaries instead of only at frame boundaries.
/**
* @defgroup deprecated_flags Deprecated codec flags
* Use corresponding private codec options instead.
* @{
*/
#if FF_API_MPEGVIDEO_GLOBAL_OPTS
#define CODEC_FLAG_OBMC           0x00000001 ///< OBMC
#define CODEC_FLAG_H263P_AIV      0x00000008 ///< H.263 alternative inter VLC
#define CODEC_FLAG_PART   0x0080  ///< Use data partitioning.
#define CODEC_FLAG_ALT_SCAN       0x00100000 ///< Use alternate scan.
#define CODEC_FLAG_H263P_UMV      0x02000000 ///< unlimited motion vector
#define CODEC_FLAG_H263P_SLICE_STRUCT 0x10000000
#define CODEC_FLAG_SVCD_SCAN_OFFSET 0x40000000 ///< Will reserve space for SVCD scan offset user data.
#define CODEC_FLAG2_INTRA_VLC     0x00000800 ///< Use MPEG-2 intra VLC table.
#define CODEC_FLAG2_DROP_FRAME_TIMECODE 0x00002000 ///< timecode is in drop frame format.
#define CODEC_FLAG2_NON_LINEAR_QUANT 0x00010000 ///< Use MPEG-2 nonlinear quantizer.
#endif
#if FF_API_MJPEG_GLOBAL_OPTS
#define CODEC_FLAG_EXTERN_HUFF     0x1000   ///< Use external Huffman table (for MJPEG).
#endif
#if FF_API_X264_GLOBAL_OPTS
#define CODEC_FLAG2_BPYRAMID      0x00000010 ///< H.264 allow B-frames to be used as references.
#define CODEC_FLAG2_WPRED         0x00000020 ///< H.264 weighted biprediction for B-frames
#define CODEC_FLAG2_MIXED_REFS    0x00000040 ///< H.264 one reference per partition, as opposed to one reference per macroblock
#define CODEC_FLAG2_8X8DCT        0x00000080 ///< H.264 high profile 8x8 transform
#define CODEC_FLAG2_FASTPSKIP     0x00000100 ///< H.264 fast pskip
#define CODEC_FLAG2_AUD           0x00000200 ///< H.264 access unit delimiters
#define CODEC_FLAG2_BRDO          0x00000400 ///< B-frame rate-distortion optimization
#define CODEC_FLAG2_MBTREE        0x00040000 ///< Use macroblock tree ratecontrol (x264 only)
#define CODEC_FLAG2_PSY           0x00080000 ///< Use psycho visual optimizations.
#define CODEC_FLAG2_SSIM          0x00100000 ///< Compute SSIM during encoding, error[] values are undefined.
#define CODEC_FLAG2_INTRA_REFRESH 0x00200000 ///< Use periodic insertion of intra blocks instead of keyframes.
#endif
#if FF_API_SNOW_GLOBAL_OPTS
#define CODEC_FLAG2_MEMC_ONLY     0x00001000 ///< Only do ME/MC (I frames -> ref, P frame -> ME+MC).
#endif
#if FF_API_LAME_GLOBAL_OPTS
#define CODEC_FLAG2_BIT_RESERVOIR 0x00020000 ///< Use a bit reservoir when encoding if possible
#endif
/**
* @}
*/

/* Unsupported options :
*              Syntax Arithmetic coding (SAC)
*              Reference Picture Selection
*              Independent Segment Decoding */
/* /Fx */
/* codec capabilities */

#define CODEC_CAP_DRAW_HORIZ_BAND 0x0001 ///< Decoder can use draw_horiz_band callback.
/**
* Codec uses get_buffer() for allocating buffers and supports custom allocators.
* If not set, it might not use get_buffer() at all or use operations that
* assume the buffer was allocated by avcodec_default_get_buffer.
*/
#define CODEC_CAP_DR1             0x0002
#if FF_API_PARSE_FRAME
/* If 'parse_only' field is true, then avcodec_parse_frame() can be used. */
#define CODEC_CAP_PARSE_ONLY      0x0004
#endif
#define CODEC_CAP_TRUNCATED       0x0008
/* Codec can export data for HW decoding (XvMC). */
#define CODEC_CAP_HWACCEL         0x0010
/**
* Encoder or decoder requires flushing with NULL input at the end in order to
* give the complete and correct output.
*
* NOTE: If this flag is not set, the codec is guaranteed to never be fed with
*       with NULL data. The user can still send NULL data to the public encode
*       or decode function, but libavcodec will not pass it along to the codec
*       unless this flag is set.
*
* Decoders:
* The decoder has a non-zero delay and needs to be fed with avpkt->data=NULL,
* avpkt->size=0 at the end to get the delayed data until the decoder no longer
* returns frames.
*
* Encoders:
* The encoder needs to be fed with NULL data at the end of encoding until the
* encoder no longer returns data.
*
* NOTE: For encoders implementing the AVCodec.encode2() function, setting this
*       flag also means that the encoder must set the pts and duration for
*       each output packet. If this flag is not set, the pts and duration will
*       be determined by libavcodec from the input frame.
*/
#define CODEC_CAP_DELAY           0x0020
/**
* Codec can be fed a final frame with a smaller size.
* This can be used to prevent truncation of the last audio samples.
*/
#define CODEC_CAP_SMALL_LAST_FRAME 0x0040
/**
* Codec can export data for HW decoding (VDPAU).
*/
#define CODEC_CAP_HWACCEL_VDPAU    0x0080
/**
* Codec can output multiple frames per AVPacket
* Normally demuxers return one frame at a time, demuxers which do not do
* are connected to a parser to split what they return into proper frames.
* This flag is reserved to the very rare category of codecs which have a
* bitstream that cannot be split into frames without timeconsuming
* operations like full decoding. Demuxers carring such bitstreams thus
* may return multiple frames in a packet. This has many disadvantages like
* prohibiting stream copy in many cases thus it should only be considered
* as a last resort.
*/
#define CODEC_CAP_SUBFRAMES        0x0100
/**
* Codec is experimental and is thus avoided in favor of non experimental
* encoders
*/
#define CODEC_CAP_EXPERIMENTAL     0x0200
/**
* Codec should fill in channel configuration and samplerate instead of container
*/
#define CODEC_CAP_CHANNEL_CONF     0x0400
/**
* Codec is able to deal with negative linesizes
*/
#define CODEC_CAP_NEG_LINESIZES    0x0800
/**
* Codec supports frame-level multithreading.
*/
#define CODEC_CAP_FRAME_THREADS    0x1000
/**
* Codec supports slice-based (or partition-based) multithreading.
*/
#define CODEC_CAP_SLICE_THREADS    0x2000
/**
* Codec supports changed parameters at any point.
*/
#define CODEC_CAP_PARAM_CHANGE     0x4000
/**
* Codec supports avctx->thread_count == 0 (auto).
*/
#define CODEC_CAP_AUTO_THREADS     0x8000
/**
* Audio encoder supports receiving a different number of samples in each call.
*/
#define CODEC_CAP_VARIABLE_FRAME_SIZE 0x10000

//The following defines may change, don't expect compatibility if you use them.
#define MB_TYPE_INTRA4x4   0x0001
#define MB_TYPE_INTRA16x16 0x0002 //FIXME H.264-specific
#define MB_TYPE_INTRA_PCM  0x0004 //FIXME H.264-specific
#define MB_TYPE_16x16      0x0008
#define MB_TYPE_16x8       0x0010
#define MB_TYPE_8x16       0x0020
#define MB_TYPE_8x8        0x0040
#define MB_TYPE_INTERLACED 0x0080
#define MB_TYPE_DIRECT2    0x0100 //FIXME
#define MB_TYPE_ACPRED     0x0200
#define MB_TYPE_GMC        0x0400
#define MB_TYPE_SKIP       0x0800
#define MB_TYPE_P0L0       0x1000
#define MB_TYPE_P1L0       0x2000
#define MB_TYPE_P0L1       0x4000
#define MB_TYPE_P1L1       0x8000
#define MB_TYPE_L0         (MB_TYPE_P0L0 | MB_TYPE_P1L0)
#define MB_TYPE_L1         (MB_TYPE_P0L1 | MB_TYPE_P1L1)
#define MB_TYPE_L0L1       (MB_TYPE_L0   | MB_TYPE_L1)
#define MB_TYPE_QUANT      0x00010000
#define MB_TYPE_CBP        0x00020000
//Note bits 24-31 are reserved for codec specific use (h264 ref0, mpeg1 0mv, ...)

/**
* Pan Scan area.
* This specifies the area which should be displayed.
* Note there may be multiple such areas for one frame.
*/
typedef struct AVPanScan{
   /**
    * id
    * - encoding: Set by user.
    * - decoding: Set by libavcodec.
    */
   int id;

   /**
    * width and height in 1/16 pel
    * - encoding: Set by user.
    * - decoding: Set by libavcodec.
    */
   int width;
   int height;

   /**
    * position of the top left corner in 1/16 pel for up to 3 fields/frames
    * - encoding: Set by user.
    * - decoding: Set by libavcodec.
    */
   int16_t position[3][2];
}AVPanScan;

#define FF_QSCALE_TYPE_MPEG1 0
#define FF_QSCALE_TYPE_MPEG2 1
#define FF_QSCALE_TYPE_H264  2
#define FF_QSCALE_TYPE_VP56  3

#define FF_BUFFER_TYPE_INTERNAL 1
#define FF_BUFFER_TYPE_USER     2 ///< direct rendering buffers (image is (de)allocated by user)
#define FF_BUFFER_TYPE_SHARED   4 ///< Buffer from somewhere else; don't deallocate image (data/base), all other tables are not shared.
#define FF_BUFFER_TYPE_COPY     8 ///< Just a (modified) copy of some other buffer, don't deallocate anything.

#if FF_API_OLD_FF_PICT_TYPES
/* DEPRECATED, directly use the AV_PICTURE_TYPE_* enum values */
#define FF_I_TYPE  AV_PICTURE_TYPE_I  ///< Intra
#define FF_P_TYPE  AV_PICTURE_TYPE_P  ///< Predicted
#define FF_B_TYPE  AV_PICTURE_TYPE_B  ///< Bi-dir predicted
#define FF_S_TYPE  AV_PICTURE_TYPE_S  ///< S(GMC)-VOP MPEG4
#define FF_SI_TYPE AV_PICTURE_TYPE_SI ///< Switching Intra
#define FF_SP_TYPE AV_PICTURE_TYPE_SP ///< Switching Predicted
#define FF_BI_TYPE AV_PICTURE_TYPE_BI
#endif

#define FF_BUFFER_HINTS_VALID    0x01 // Buffer hints value is meaningful (if 0 ignore).
#define FF_BUFFER_HINTS_READABLE 0x02 // Codec will read from buffer.
#define FF_BUFFER_HINTS_PRESERVE 0x04 // User must not alter buffer content.
#define FF_BUFFER_HINTS_REUSABLE 0x08 // Codec will reuse the buffer (update).

enum AVPacketSideDataType {
   AV_PKT_DATA_PALETTE,
   AV_PKT_DATA_NEW_EXTRADATA,
   AV_PKT_DATA_PARAM_CHANGE,
};

typedef struct AVPacket {
   /**
    * Presentation timestamp in AVStream->time_base units; the time at which
    * the decompressed packet will be presented to the user.
    * Can be AV_NOPTS_VALUE if it is not stored in the file.
    * pts MUST be larger or equal to dts as presentation cannot happen before
    * decompression, unless one wants to view hex dumps. Some formats misuse
    * the terms dts and pts/cts to mean something different. Such timestamps
    * must be converted to true pts/dts before they are stored in AVPacket.
    */
   int64_t pts;
   /**
    * Decompression timestamp in AVStream->time_base units; the time at which
    * the packet is decompressed.
    * Can be AV_NOPTS_VALUE if it is not stored in the file.
    */
   int64_t dts;
   uint8_t *data;
   int   size;
   int   stream_index;
   /**
    * A combination of AV_PKT_FLAG values
    */
   int   flags;
   /**
    * Additional packet data that can be provided by the container.
    * Packet can contain several types of side information.
    */
   struct {
       uint8_t *data;
       int      size;
       enum AVPacketSideDataType type;
   } *side_data;
   int side_data_elems;

   /**
    * Duration of this packet in AVStream->time_base units, 0 if unknown.
    * Equals next_pts - this_pts in presentation order.
    */
   int   duration;
   void  (*destruct)(struct AVPacket *);
   void  *priv;
   int64_t pos;                            ///< byte position in stream, -1 if unknown

   /**
    * Time difference in AVStream->time_base units from the pts of this
    * packet to the point at which the output from the decoder has converged
    * independent from the availability of previous frames. That is, the
    * frames are virtually identical no matter if decoding started from
    * the very first frame or from this keyframe.
    * Is AV_NOPTS_VALUE if unknown.
    * This field is not the display duration of the current packet.
    * This field has no meaning if the packet does not have AV_PKT_FLAG_KEY
    * set.
    *
    * The purpose of this field is to allow seeking in streams that have no
    * keyframes in the conventional sense. It corresponds to the
    * recovery point SEI in H.264 and match_time_delta in NUT. It is also
    * essential for some types of subtitle streams to ensure that all
    * subtitles are correctly displayed after seeking.
    */
   int64_t convergence_duration;
} AVPacket;
#define AV_PKT_FLAG_KEY     0x0001 ///< The packet contains a keyframe
#define AV_PKT_FLAG_CORRUPT 0x0002 ///< The packet content is corrupted

/**
* An AV_PKT_DATA_PARAM_CHANGE side data packet is laid out as follows:
* u32le param_flags
* if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_COUNT)
*     s32le channel_count
* if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_LAYOUT)
*     u64le channel_layout
* if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_SAMPLE_RATE)
*     s32le sample_rate
* if (param_flags & AV_SIDE_DATA_PARAM_CHANGE_DIMENSIONS)
*     s32le width
*     s32le height
*/

enum AVSideDataParamChangeFlags {
   AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_COUNT  = 0x0001,
   AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_LAYOUT = 0x0002,
   AV_SIDE_DATA_PARAM_CHANGE_SAMPLE_RATE    = 0x0004,
   AV_SIDE_DATA_PARAM_CHANGE_DIMENSIONS     = 0x0008,
};

/**
* Audio Video Frame.
* New fields can be added to the end of AVFRAME with minor version
* bumps. Removal, reordering and changes to existing fields require
* a major version bump.
* sizeof(AVFrame) must not be used outside libav*.
*/
typedef struct AVFrame {
#if FF_API_DATA_POINTERS
#define AV_NUM_DATA_POINTERS 4
#else
#define AV_NUM_DATA_POINTERS 8
#endif
   /**
    * pointer to the picture/channel planes.
    * This might be different from the first allocated byte
    * - encoding: Set by user
    * - decoding: set by AVCodecContext.get_buffer()
    */
   uint8_t *data[AV_NUM_DATA_POINTERS];

   /**
    * Size, in bytes, of the data for each picture/channel plane.
    *
    * For audio, only linesize[0] may be set. For planar audio, each channel
    * plane must be the same size.
    *
    * - encoding: Set by user (video only)
    * - decoding: set by AVCodecContext.get_buffer()
    */
   int linesize[AV_NUM_DATA_POINTERS];

   /**
    * pointer to the first allocated byte of the picture. Can be used in get_buffer/release_buffer.
    * This isn't used by libavcodec unless the default get/release_buffer() is used.
    * - encoding:
    * - decoding:
    */
   uint8_t *base[AV_NUM_DATA_POINTERS];
   /**
    * 1 -> keyframe, 0-> not
    * - encoding: Set by libavcodec.
    * - decoding: Set by libavcodec.
    */
   int key_frame;

   /**
    * Picture type of the frame, see ?_TYPE below.
    * - encoding: Set by libavcodec. for coded_picture (and set by user for input).
    * - decoding: Set by libavcodec.
    */
   enum AVPictureType pict_type;

   /**
    * presentation timestamp in time_base units (time when frame should be shown to user)
    * If AV_NOPTS_VALUE then frame_rate = 1/time_base will be assumed.
    * - encoding: MUST be set by user.
    * - decoding: Set by libavcodec.
    */
   int64_t pts;

   /**
    * picture number in bitstream order
    * - encoding: set by
    * - decoding: Set by libavcodec.
    */
   int coded_picture_number;
   /**
    * picture number in display order
    * - encoding: set by
    * - decoding: Set by libavcodec.
    */
   int display_picture_number;

   /**
    * quality (between 1 (good) and FF_LAMBDA_MAX (bad))
    * - encoding: Set by libavcodec. for coded_picture (and set by user for input).
    * - decoding: Set by libavcodec.
    */
   int quality;

#if FF_API_AVFRAME_AGE
   /**
    * @deprecated unused
    */
   attribute_deprecated int age;
#endif

   /**
    * is this picture used as reference
    * The values for this are the same as the MpegEncContext.picture_structure
    * variable, that is 1->top field, 2->bottom field, 3->frame/both fields.
    * Set to 4 for delayed, non-reference frames.
    * - encoding: unused
    * - decoding: Set by libavcodec. (before get_buffer() call)).
    */
   int reference;

   /**
    * QP table
    * - encoding: unused
    * - decoding: Set by libavcodec.
    */
   int8_t *qscale_table;
   /**
    * QP store stride
    * - encoding: unused
    * - decoding: Set by libavcodec.
    */
   int qstride;

   /**
    * mbskip_table[mb]>=1 if MB didn't change
    * stride= mb_width = (width+15)>>4
    * - encoding: unused
    * - decoding: Set by libavcodec.
    */
   uint8_t *mbskip_table;

   /**
    * motion vector table
    * @code
    * example:
    * int mv_sample_log2= 4 - motion_subsample_log2;
    * int mb_width= (width+15)>>4;
    * int mv_stride= (mb_width << mv_sample_log2) + 1;
    * motion_val[direction][x + y*mv_stride][0->mv_x, 1->mv_y];
    * @endcode
    * - encoding: Set by user.
    * - decoding: Set by libavcodec.
    */
   int16_t (*motion_val[2])[2];

   /**
    * macroblock type table
    * mb_type_base + mb_width + 2
    * - encoding: Set by user.
    * - decoding: Set by libavcodec.
    */
   uint32_t *mb_type;

   /**
    * log2 of the size of the block which a single vector in motion_val represents:
    * (4->16x16, 3->8x8, 2-> 4x4, 1-> 2x2)
    * - encoding: unused
    * - decoding: Set by libavcodec.
    */
   uint8_t motion_subsample_log2;

   /**
    * for some private data of the user
    * - encoding: unused
    * - decoding: Set by user.
    */
   void *opaque;

   /**
    * error
    * - encoding: Set by libavcodec. if flags&CODEC_FLAG_PSNR.
    * - decoding: unused
    */
   uint64_t error[AV_NUM_DATA_POINTERS];

   /**
    * type of the buffer (to keep track of who has to deallocate data[*])
    * - encoding: Set by the one who allocates it.
    * - decoding: Set by the one who allocates it.
    * Note: User allocated (direct rendering) & internal buffers cannot coexist currently.
    */
   int type;

   /**
    * When decoding, this signals how much the picture must be delayed.
    * extra_delay = repeat_pict / (2*fps)
    * - encoding: unused
    * - decoding: Set by libavcodec.
    */
   int repeat_pict;

   /**
    *
    */
   int qscale_type;

   /**
    * The content of the picture is interlaced.
    * - encoding: Set by user.
    * - decoding: Set by libavcodec. (default 0)
    */
   int interlaced_frame;

   /**
    * If the content is interlaced, is top field displayed first.
    * - encoding: Set by user.
    * - decoding: Set by libavcodec.
    */
   int top_field_first;

   /**
    * Pan scan.
    * - encoding: Set by user.
    * - decoding: Set by libavcodec.
    */
   AVPanScan *pan_scan;

   /**
    * Tell user application that palette has changed from previous frame.
    * - encoding: ??? (no palette-enabled encoder yet)
    * - decoding: Set by libavcodec. (default 0).
    */
   int palette_has_changed;

   /**
    * codec suggestion on buffer type if != 0
    * - encoding: unused
    * - decoding: Set by libavcodec. (before get_buffer() call)).
    */
   int buffer_hints;

   /**
    * DCT coefficients
    * - encoding: unused
    * - decoding: Set by libavcodec.
    */
   short *dct_coeff;

   /**
    * motion reference frame index
    * the order in which these are stored can depend on the codec.
    * - encoding: Set by user.
    * - decoding: Set by libavcodec.
    */
   int8_t *ref_index[2];

   /**
    * reordered opaque 64bit (generally an integer or a double precision float
    * PTS but can be anything).
    * The user sets AVCodecContext.reordered_opaque to represent the input at
    * that time,
    * the decoder reorders values as needed and sets AVFrame.reordered_opaque
    * to exactly one of the values provided by the user through AVCodecContext.reordered_opaque
    * @deprecated in favor of pkt_pts
    * - encoding: unused
    * - decoding: Read by user.
    */
   int64_t reordered_opaque;

   /**
    * hardware accelerator private data (Libav-allocated)
    * - encoding: unused
    * - decoding: Set by libavcodec
    */
   void *hwaccel_picture_private;

   /**
    * reordered pts from the last AVPacket that has been input into the decoder
    * - encoding: unused
    * - decoding: Read by user.
    */
   int64_t pkt_pts;

   /**
    * dts from the last AVPacket that has been input into the decoder
    * - encoding: unused
    * - decoding: Read by user.
    */
   int64_t pkt_dts;

   /**
    * the AVCodecContext which ff_thread_get_buffer() was last called on
    * - encoding: Set by libavcodec.
    * - decoding: Set by libavcodec.
    */
   struct AVCodecContext *owner;

   /**
    * used by multithreading to store frame-specific info
    * - encoding: Set by libavcodec.
    * - decoding: Set by libavcodec.
    */
   void *thread_opaque;

   /**
    * number of audio samples (per channel) described by this frame
    * - encoding: unused
    * - decoding: Set by libavcodec
    */
   int nb_samples;

   /**
    * pointers to the data planes/channels.
    *
    * For video, this should simply point to data[].
    *
    * For planar audio, each channel has a separate data pointer, and
    * linesize[0] contains the size of each channel buffer.
    * For packed audio, there is just one data pointer, and linesize[0]
    * contains the total size of the buffer for all channels.
    *
    * Note: Both data and extended_data will always be set by get_buffer(),
    * but for planar audio with more channels that can fit in data,
    * extended_data must be used by the decoder in order to access all
    * channels.
    *
    * encoding: unused
    * decoding: set by AVCodecContext.get_buffer()
    */
   uint8_t **extended_data;

   /**
    * sample aspect ratio for the video frame, 0/1 if unknown\unspecified
    * - encoding: unused
    * - decoding: Read by user.
    */
   AVRational sample_aspect_ratio;

   /**
    * width and height of the video frame
    * - encoding: unused
    * - decoding: Read by user.
    */
   int width, height;

   /**
    * format of the frame, -1 if unknown or unset
    * Values correspond to enum PixelFormat for video frames,
    * enum AVSampleFormat for audio)
    * - encoding: unused
    * - decoding: Read by user.
    */
   int format;
} AVFrame;

struct AVCodecInternal;

enum AVFieldOrder {
   AV_FIELD_UNKNOWN,
   AV_FIELD_PROGRESSIVE,
   AV_FIELD_TT,          //< Top coded_first, top displayed first
   AV_FIELD_BB,          //< Bottom coded first, bottom displayed first
   AV_FIELD_TB,          //< Top coded first, bottom displayed first
   AV_FIELD_BT,          //< Bottom coded first, top displayed first
};

/**
* main external API structure.
* New fields can be added to the end with minor version bumps.
* Removal, reordering and changes to existing fields require a major
* version bump.
* sizeof(AVCodecContext) must not be used outside libav*.
*/
typedef struct AVCodecContext {
   /**
    * information on struct for av_log
    * - set by avcodec_alloc_context3
    */
   const AVClass *av_class;
   /**
    * the average bitrate
    * - encoding: Set by user; unused for constant quantizer encoding.
    * - decoding: Set by libavcodec. 0 or some bitrate if this info is available in the stream.
    */
   int bit_rate;

   /**
    * number of bits the bitstream is allowed to diverge from the reference.
    *           the reference can be CBR (for CBR pass1) or VBR (for pass2)
    * - encoding: Set by user; unused for constant quantizer encoding.
    * - decoding: unused
    */
   int bit_rate_tolerance;

   /**
    * CODEC_FLAG_*.
    * - encoding: Set by user.
    * - decoding: Set by user.
    */
   int flags;

   /**
    * Some codecs need additional format info. It is stored here.
    * If any muxer uses this then ALL demuxers/parsers AND encoders for the
    * specific codec MUST set it correctly otherwise stream copy breaks.
    * In general use of this field by muxers is not recommended.
    * - encoding: Set by libavcodec.
    * - decoding: Set by libavcodec. (FIXME: Is this OK?)
    */
   int sub_id;

   /**
    * Motion estimation algorithm used for video coding.
    * 1 (zero), 2 (full), 3 (log), 4 (phods), 5 (epzs), 6 (x1), 7 (hex),
    * 8 (umh), 9 (iter), 10 (tesa) [7, 8, 10 are x264 specific, 9 is snow specific]
    * - encoding: MUST be set by user.
    * - decoding: unused
    */
   int me_method;

   /**
    * some codecs need / can use extradata like Huffman tables.
    * mjpeg: Huffman tables
    * rv10: additional flags
    * mpeg4: global headers (they can be in the bitstream or here)
    * The allocated memory should be FF_INPUT_BUFFER_PADDING_SIZE bytes larger
    * than extradata_size to avoid prolems if it is read with the bitstream reader.
    * The bytewise contents of extradata must not depend on the architecture or CPU endianness.
    * - encoding: Set/allocated/freed by libavcodec.
    * - decoding: Set/allocated/freed by user.
    */
   uint8_t *extradata;
   int extradata_size;

   /**
    * This is the fundamental unit of time (in seconds) in terms
    * of which frame timestamps are represented. For fixed-fps content,
    * timebase should be 1/framerate and timestamp increments should be
    * identically 1.
    * - encoding: MUST be set by user.
    * - decoding: Set by libavcodec.
    */
   AVRational time_base;

   /* video only */
   /**
    * picture width / height.
    * - encoding: MUST be set by user.
    * - decoding: Set by libavcodec.
    * Note: For compatibility it is possible to set this instead of
    * coded_width/height before decoding.
    */
   int width, height;

#define FF_ASPECT_EXTENDED 15

   /**
    * the number of pictures in a group of pictures, or 0 for intra_only
    * - encoding: Set by user.
    * - decoding: unused
    */
   int gop_size;

   /**
    * Pixel format, see PIX_FMT_xxx.
    * May be set by the demuxer if known from headers.
    * May be overriden by the decoder if it knows better.
    * - encoding: Set by user.
    * - decoding: Set by user if known, overridden by libavcodec if known
    */
   enum PixelFormat pix_fmt;

   /**
    * If non NULL, 'draw_horiz_band' is called by the libavcodec
    * decoder to draw a horizontal band. It improves cache usage. Not
    * all codecs can do that. You must check the codec capabilities
    * beforehand.
    * When multithreading is used, it may be called from multiple threads
    * at the same time; threads might draw different parts of the same AVFrame,
    * or multiple AVFrames, and there is no guarantee that slices will be drawn
    * in order.
    * The function is also used by hardware acceleration APIs.
    * It is called at least once during frame decoding to pass
    * the data needed for hardware render.
    * In that mode instead of pixel data, AVFrame points to
    * a structure specific to the acceleration API. The application
    * reads the structure and can change some fields to indicate progress
    * or mark state.
    * - encoding: unused
    * - decoding: Set by user.
    * @param height the height of the slice
    * @param y the y position of the slice
    * @param type 1->top field, 2->bottom field, 3->frame
    * @param offset offset into the AVFrame.data from which the slice should be read
    */
   void (*draw_horiz_band)(struct AVCodecContext *s,
                           const AVFrame *src, int offset[AV_NUM_DATA_POINTERS],
                           int y, int type, int height);

   /* audio only */
   int sample_rate; ///< samples per second
   int channels;    ///< number of audio channels

   /**
    * audio sample format
    * - encoding: Set by user.
    * - decoding: Set by libavcodec.
    */
   enum AVSampleFormat sample_fmt;  ///< sample format

   /* The following data should not be initialized. */
   /**
    * Samples per packet, initialized when calling 'init'.
    */
   int frame_size;
   int frame_number;   ///< audio or video frame number

   /**
    * Number of frames the decoded output will be delayed relative to
    * the encoded input.
    * - encoding: Set by libavcodec.
    * - decoding: unused
    */
   int delay;

   /* - encoding parameters */
   float qcompress;  ///< amount of qscale change between easy & hard scenes (0.0-1.0)
   float qblur;      ///< amount of qscale smoothing over time (0.0-1.0)

   /**
    * minimum quantizer
    * - encoding: Set by user.
    * - decoding: unused
    */
   int qmin;

   /**
    * maximum quantizer
    * - encoding: Set by user.
    * - decoding: unused
    */
   int qmax;

   /**
    * maximum quantizer difference between frames
    * - encoding: Set by user.
    * - decoding: unused
    */
   int max_qdiff;

   /**
    * maximum number of B-frames between non-B-frames
    * Note: The output will be delayed by max_b_frames+1 relative to the input.
    * - encoding: Set by user.
    * - decoding: unused
    */
   int max_b_frames;

   /**
    * qscale factor between IP and B-frames
    * If > 0 then the last P-frame quantizer will be used (q= lastp_q*factor+offset).
    * If < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset).
    * - encoding: Set by user.
    * - decoding: unused
    */
   float b_quant_factor;

   /** obsolete FIXME remove */
   int rc_strategy;
#define FF_RC_STRATEGY_XVID 1

   int b_frame_strategy;

   struct AVCodec *codec;

   void *priv_data;

   int rtp_payload_size;   /* The size of the RTP payload: the coder will  */
                           /* do its best to deliver a chunk with size     */
                           /* below rtp_payload_size, the chunk will start */
                           /* with a start code on some codecs like H.263. */
                           /* This doesn't take account of any particular  */
                           /* headers inside the transmitted RTP payload.  */


   /* The RTP callback: This function is called    */
   /* every time the encoder has a packet to send. */
   /* It depends on the encoder if the data starts */
   /* with a Start Code (it should). H.263 does.   */
   /* mb_nb contains the number of macroblocks     */
   /* encoded in the RTP payload.                  */
   void (*rtp_callback)(struct AVCodecContext *avctx, void *data, int size, int mb_nb);

   /* statistics, used for 2-pass encoding */
   int mv_bits;
   int header_bits;
   int i_tex_bits;
   int p_tex_bits;
   int i_count;
   int p_count;
   int skip_count;
   int misc_bits;

   /**
    * number of bits used for the previously encoded frame
    * - encoding: Set by libavcodec.
    * - decoding: unused
    */
   int frame_bits;

   /**
    * Private data of the user, can be used to carry app specific stuff.
    * - encoding: Set by user.
    * - decoding: Set by user.
    */
   void *opaque;

   char codec_name[32];
   enum AVMediaType codec_type; /* see AVMEDIA_TYPE_xxx */
   enum CodecID codec_id; /* see CODEC_ID_xxx */

   /**
    * fourcc (LSB first, so "ABCD" -> ('D'<<24) + ('C'<<16) + ('B'<<8) + 'A').
    * This is used to work around some encoder bugs.
    * A demuxer should set this to what is stored in the field used to identify the codec.
    * If there are multiple such fields in a container then the demuxer should choose the one
    * which maximizes the information about the used codec.
    * If the codec tag field in a container is larger than 32 bits then the demuxer should
    * remap the longer ID to 32 bits with a table or other structure. Alternatively a new
    * extra_codec_tag + size could be added but for this a clear advantage must be demonstrated
    * first.
    * - encoding: Set by user, if not then the default based on codec_id will be used.
    * - decoding: Set by user, will be converted to uppercase by libavcodec during init.
    */
   unsigned int codec_tag;

   /**
    * Work around bugs in encoders which sometimes cannot be detected automatically.
    * - encoding: Set by user
    * - decoding: Set by user
    */
   int workaround_bugs;
#define FF_BUG_AUTODETECT       1  ///< autodetection
#define FF_BUG_OLD_MSMPEG4      2
#define FF_BUG_XVID_ILACE       4
#define FF_BUG_UMP4             8
#define FF_BUG_NO_PADDING       16
#define FF_BUG_AMV              32
#define FF_BUG_AC_VLC           0  ///< Will be removed, libavcodec can now handle these non-compliant files by default.
#define FF_BUG_QPEL_CHROMA      64
#define FF_BUG_STD_QPEL         128
#define FF_BUG_QPEL_CHROMA2     256
#define FF_BUG_DIRECT_BLOCKSIZE 512
#define FF_BUG_EDGE             1024
#define FF_BUG_HPEL_CHROMA      2048
#define FF_BUG_DC_CLIP          4096
#define FF_BUG_MS               8192 ///< Work around various bugs in Microsoft's broken decoders.
#define FF_BUG_TRUNCATED       16384
//#define FF_BUG_FAKE_SCALABILITY 16 //Autodetection should work 100%.

   /**
    * luma single coefficient elimination threshold
    * - encoding: Set by user.
    * - decoding: unused
    */
   int luma_elim_threshold;

   /**
    * chroma single coeff elimination threshold
    * - encoding: Set by user.
    * - decoding: unused
    */
   int chroma_elim_threshold;

   /**
    * strictly follow the standard (MPEG4, ...).
    * - encoding: Set by user.
    * - decoding: Set by user.
    * Setting this to STRICT or higher means the encoder and decoder will
    * generally do stupid things, whereas setting it to unofficial or lower
    * will mean the encoder might produce output that is not supported by all
    * spec-compliant decoders. Decoders don't differentiate between normal,
    * unofficial and experimental (that is, they always try to decode things
    * when they can) unless they are explicitly asked to behave stupidly
    * (=strictly conform to the specs)
    */
   int strict_std_compliance;
#define FF_COMPLIANCE_VERY_STRICT   2 ///< Strictly conform to an older more strict version of the spec or reference software.
#define FF_COMPLIANCE_STRICT        1 ///< Strictly conform to all the things in the spec no matter what consequences.
#define FF_COMPLIANCE_NORMAL        0
#define FF_COMPLIANCE_UNOFFICIAL   -1 ///< Allow unofficial extensions
#define FF_COMPLIANCE_EXPERIMENTAL -2 ///< Allow nonstandardized experimental things.

   /**
    * qscale offset between IP and B-frames
    * - encoding: Set by user.
    * - decoding: unused
    */
   float b_quant_offset;

#if FF_API_ER
   /**
    * Error recognition; higher values will detect more errors but may
    * misdetect some more or less valid parts as errors.
    * - encoding: unused
    * - decoding: Set by user.
    */
   attribute_deprecated int error_recognition;
#define FF_ER_CAREFUL         1
#define FF_ER_COMPLIANT       2
#define FF_ER_AGGRESSIVE      3
#define FF_ER_VERY_AGGRESSIVE 4
#define FF_ER_EXPLODE         5
#endif /* FF_API_ER */

   /**
    * Called at the beginning of each frame to get a buffer for it.
    *
    * The function will set AVFrame.data[], AVFrame.linesize[].
    * AVFrame.extended_data[] must also be set, but it should be the same as
    * AVFrame.data[] except for planar audio with more channels than can fit
    * in AVFrame.data[]. In that case, AVFrame.data[] shall still contain as
    * many data pointers as it can hold.
    *
    * if CODEC_CAP_DR1 is not set then get_buffer() must call
    * avcodec_default_get_buffer() instead of providing buffers allocated by
    * some other means.
    *
    * AVFrame.data[] should be 32- or 16-byte-aligned unless the CPU doesn't
    * need it. avcodec_default_get_buffer() aligns the output buffer properly,
    * but if get_buffer() is overridden then alignment considerations should
    * be taken into account.
    *
    * @see avcodec_default_get_buffer()
    *
    * Video:
    *
    * If pic.reference is set then the frame will be read later by libavcodec.
    * avcodec_align_dimensions2() should be used to find the required width and
    * height, as they normally need to be rounded up to the next multiple of 16.
    *
    * If frame multithreading is used and thread_safe_callbacks is set,
    * it may be called from a different thread, but not from more than one at
    * once. Does not need to be reentrant.
    *
    * @see release_buffer(), reget_buffer()
    * @see avcodec_align_dimensions2()
    *
    * Audio:
    *
    * Decoders request a buffer of a particular size by setting
    * AVFrame.nb_samples prior to calling get_buffer(). The decoder may,
    * however, utilize only part of the buffer by setting AVFrame.nb_samples
    * to a smaller value in the output frame.
    *
    * Decoders cannot use the buffer after returning from
    * avcodec_decode_audio4(), so they will not call release_buffer(), as it
    * is assumed to be released immediately upon return.
    *
    * As a convenience, av_samples_get_buffer_size() and
    * av_samples_fill_arrays() in libavutil may be used by custom get_buffer()
    * functions to find the required data size and to fill data pointers and
    * linesize. In AVFrame.linesize, only linesize[0] may be set for audio
    * since all planes must be the same size.
    *
    * @see av_samples_get_buffer_size(), av_samples_fill_arrays()
    *
    * - encoding: unused
    * - decoding: Set by libavcodec, user can override.
    */
   int (*get_buffer)(struct AVCodecContext *c, AVFrame *pic);

   /**
    * Called to release buffers which were allocated with get_buffer.
    * A released buffer can be reused in get_buffer().
    * pic.data[*] must be set to NULL.
    * May be called from a different thread if frame multithreading is used,
    * but not by more than one thread at once, so does not need to be reentrant.
    * - encoding: unused
    * - decoding: Set by libavcodec, user can override.
    */
   void (*release_buffer)(struct AVCodecContext *c, AVFrame *pic);

   /**
    * Size of the frame reordering buffer in the decoder.
    * For MPEG-2 it is 1 IPB or 0 low delay IP.
    * - encoding: Set by libavcodec.
    * - decoding: Set by libavcodec.
    */
   int has_b_frames;

   /**
    * number of bytes per packet if constant and known or 0
    * Used by some WAV based audio codecs.
    */
   int block_align;

#if FF_API_PARSE_FRAME
   /**
    * If true, only parsing is done. The frame data is returned.
    * Only MPEG audio decoders support this now.
    * - encoding: unused
    * - decoding: Set by user
    */
   attribute_deprecated int parse_only;
#endif

   /**
    * 0-> h263 quant 1-> mpeg quant
    * - encoding: Set by user.
    * - decoding: unused
    */
   int mpeg_quant;

   /**
    * pass1 encoding statistics output buffer
    * - encoding: Set by libavcodec.
    * - decoding: unused
    */
   char *stats_out;

   /**
    * pass2 encoding statistics input buffer
    * Concatenated stuff from stats_out of pass1 should be placed here.
    * - encoding: Allocated/set/freed by user.
    * - decoding: unused
    */
   char *stats_in;

   /**
    * ratecontrol qmin qmax limiting method
    * 0-> clipping, 1-> use a nice continous function to limit qscale wthin qmin/qmax.
    * - encoding: Set by user.
    * - decoding: unused
    */
   float rc_qsquish;

   float rc_qmod_amp;
   int rc_qmod_freq;

   /**
    * ratecontrol override, see RcOverride
    * - encoding: Allocated/set/freed by user.
    * - decoding: unused
    */
   RcOverride *rc_override;
   int rc_override_count;

   /**
    * rate control equation
    * - encoding: Set by user
    * - decoding: unused
    */
   const char *rc_eq;

   /**
    * maximum bitrate
    * - encoding: Set by user.
    * - decoding: unused
    */
   int rc_max_rate;

   /**
    * minimum bitrate
    * - encoding: Set by user.
    * - decoding: unused
    */
   int rc_min_rate;

   /**
    * decoder bitstream buffer size
    * - encoding: Set by user.
    * - decoding: unused
    */
   int rc_buffer_size;
   float rc_buffer_aggressivity;

   /**
    * qscale factor between P and I-frames
    * If > 0 then the last p frame quantizer will be used (q= lastp_q*factor+offset).
    * If < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset).
    * - encoding: Set by user.
    * - decoding: unused
    */
   float i_quant_factor;

   /**
    * qscale offset between P and I-frames
    * - encoding: Set by user.
    * - decoding: unused
    */
   float i_quant_offset;

   /**
    * initial complexity for pass1 ratecontrol
    * - encoding: Set by user.
    * - decoding: unused
    */
   float rc_initial_cplx;

   /**
    * DCT algorithm, see FF_DCT_* below
    * - encoding: Set by user.
    * - decoding: unused
    */
   int dct_algo;
#define FF_DCT_AUTO    0
#define FF_DCT_FASTINT 1
#define FF_DCT_INT     2
#define FF_DCT_MMX     3
#define FF_DCT_MLIB    4
#define FF_DCT_ALTIVEC 5
#define FF_DCT_FAAN    6

   /**
    * luminance masking (0-> disabled)
    * - encoding: Set by user.
    * - decoding: unused
    */
   float lumi_masking;

   /**
    * temporary complexity masking (0-> disabled)
    * - encoding: Set by user.
    * - decoding: unused
    */
   float temporal_cplx_masking;

   /**
    * spatial complexity masking (0-> disabled)
    * - encoding: Set by user.
    * - decoding: unused
    */
   float spatial_cplx_masking;

   /**
    * p block masking (0-> disabled)
    * - encoding: Set by user.
    * - decoding: unused
    */
   float p_masking;

   /**
    * darkness masking (0-> disabled)
    * - encoding: Set by user.
    * - decoding: unused
    */
   float dark_masking;

   /**
    * IDCT algorithm, see FF_IDCT_* below.
    * - encoding: Set by user.
    * - decoding: Set by user.
    */
   int idct_algo;
#define FF_IDCT_AUTO          0
#define FF_IDCT_INT           1
#define FF_IDCT_SIMPLE        2
#define FF_IDCT_SIMPLEMMX     3
#define FF_IDCT_LIBMPEG2MMX   4
#define FF_IDCT_PS2           5
#define FF_IDCT_MLIB          6
#define FF_IDCT_ARM           7
#define FF_IDCT_ALTIVEC       8
#define FF_IDCT_SH4           9
#define FF_IDCT_SIMPLEARM     10
#define FF_IDCT_H264          11
#define FF_IDCT_VP3           12
#define FF_IDCT_IPP           13
#define FF_IDCT_XVIDMMX       14
#define FF_IDCT_CAVS          15
#define FF_IDCT_SIMPLEARMV5TE 16
#define FF_IDCT_SIMPLEARMV6   17
#define FF_IDCT_SIMPLEVIS     18
#define FF_IDCT_WMV2          19
#define FF_IDCT_FAAN          20
#define FF_IDCT_EA            21
#define FF_IDCT_SIMPLENEON    22
#define FF_IDCT_SIMPLEALPHA   23
#define FF_IDCT_BINK          24

   /**
    * slice count
    * - encoding: Set by libavcodec.
    * - decoding: Set by user (or 0).
    */
   int slice_count;
   /**
    * slice offsets in the frame in bytes
    * - encoding: Set/allocated by libavcodec.
    * - decoding: Set/allocated by user (or NULL).
    */
   int *slice_offset;

   /**
    * error concealment flags
    * - encoding: unused
    * - decoding: Set by user.
    */
   int error_concealment;
#define FF_EC_GUESS_MVS   1
#define FF_EC_DEBLOCK     2

   /**
    * dsp_mask could be add used to disable unwanted CPU features
    * CPU features (i.e. MMX, SSE. ...)
    *
    * With the FORCE flag you may instead enable given CPU features.
    * (Dangerous: Usable in case of misdetection, improper usage however will
    * result into program crash.)
    */
   unsigned dsp_mask;

   /**
    * bits per sample/pixel from the demuxer (needed for huffyuv).
    * - encoding: Set by libavcodec.
    * - decoding: Set by user.
    */
    int bits_per_coded_sample;

   /**
    * prediction method (needed for huffyuv)
    * - encoding: Set by user.
    * - decoding: unused
    */
    int prediction_method;
#define FF_PRED_LEFT   0
#define FF_PRED_PLANE  1
#define FF_PRED_MEDIAN 2

   /**
    * sample aspect ratio (0 if unknown)
    * That is the width of a pixel divided by the height of the pixel.
    * Numerator and denominator must be relatively prime and smaller than 256 for some video standards.
    * - encoding: Set by user.
    * - decoding: Set by libavcodec.
    */
   AVRational sample_aspect_ratio;

   /**
    * the picture in the bitstream
    * - encoding: Set by libavcodec.
    * - decoding: Set by libavcodec.
    */
   AVFrame *coded_frame;

   /**
    * debug
    * - encoding: Set by user.
    * - decoding: Set by user.
    */
   int debug;
#define FF_DEBUG_PICT_INFO   1
#define FF_DEBUG_RC          2
#define FF_DEBUG_BITSTREAM   4
#define FF_DEBUG_MB_TYPE     8
#define FF_DEBUG_QP          16
#define FF_DEBUG_MV          32
#define FF_DEBUG_DCT_COEFF   0x00000040
#define FF_DEBUG_SKIP        0x00000080
#define FF_DEBUG_STARTCODE   0x00000100
#define FF_DEBUG_PTS         0x00000200
#define FF_DEBUG_ER          0x00000400
#define FF_DEBUG_MMCO        0x00000800
#define FF_DEBUG_BUGS        0x00001000
#define FF_DEBUG_VIS_QP      0x00002000
#define FF_DEBUG_VIS_MB_TYPE 0x00004000
#define FF_DEBUG_BUFFERS     0x00008000
#define FF_DEBUG_THREADS     0x00010000

   /**
    * debug
    * - encoding: Set by user.
    * - decoding: Set by user.
    */
   int debug_mv;
#define FF_DEBUG_VIS_MV_P_FOR  0x00000001 //visualize forward predicted MVs of P frames
#define FF_DEBUG_VIS_MV_B_FOR  0x00000002 //visualize forward predicted MVs of B frames
#define FF_DEBUG_VIS_MV_B_BACK 0x00000004 //visualize backward predicted MVs of B frames

   /**
    * error
    * - encoding: Set by libavcodec if flags&CODEC_FLAG_PSNR.
    * - decoding: unused
    */
   uint64_t error[AV_NUM_DATA_POINTERS];

   /**
    * motion estimation comparison function
    * - encoding: Set by user.
    * - decoding: unused
    */
   int me_cmp;
   /**
    * subpixel motion estimation comparison function
    * - encoding: Set by user.
    * - decoding: unused
    */
   int me_sub_cmp;
   /**
    * macroblock comparison function (not supported yet)
    * - encoding: Set by user.
    * - decoding: unused
    */
   int mb_cmp;
   /**
    * interlaced DCT comparison function
    * - encoding: Set by user.
    * - decoding: unused
    */
   int ildct_cmp;
#define FF_CMP_SAD    0
#define FF_CMP_SSE    1
#define FF_CMP_SATD   2
#define FF_CMP_DCT    3
#define FF_CMP_PSNR   4
#define FF_CMP_BIT    5
#define FF_CMP_RD     6
#define FF_CMP_ZERO   7
#define FF_CMP_VSAD   8
#define FF_CMP_VSSE   9
#define FF_CMP_NSSE   10
#define FF_CMP_W53    11
#define FF_CMP_W97    12
#define FF_CMP_DCTMAX 13
#define FF_CMP_DCT264 14
#define FF_CMP_CHROMA 256

   /**
    * ME diamond size & shape
    * - encoding: Set by user.
    * - decoding: unused
    */
   int dia_size;

   /**
    * amount of previous MV predictors (2a+1 x 2a+1 square)
    * - encoding: Set by user.
    * - decoding: unused
    */
   int last_predictor_count;

   /**
    * prepass for motion estimation
    * - encoding: Set by user.
    * - decoding: unused
    */
   int pre_me;

   /**
    * motion estimation prepass comparison function
    * - encoding: Set by user.
    * - decoding: unused
    */
   int me_pre_cmp;

   /**
    * ME prepass diamond size & shape
    * - encoding: Set by user.
    * - decoding: unused
    */
   int pre_dia_size;

   /**
    * subpel ME quality
    * - encoding: Set by user.
    * - decoding: unused
    */
   int me_subpel_quality;

   /**
    * callback to negotiate the pixelFormat
    * @param fmt is the list of formats which are supported by the codec,
    * it is terminated by -1 as 0 is a valid format, the formats are ordered by quality.
    * The first is always the native one.
    * @return the chosen format
    * - encoding: unused
    * - decoding: Set by user, if not set the native format will be chosen.
    */
   enum PixelFormat (*get_format)(struct AVCodecContext *s, const enum PixelFormat * fmt);

   /**
    * DTG active format information (additional aspect ratio
    * information only used in DVB MPEG-2 transport streams)
    * 0 if not set.
    *
    * - encoding: unused
    * - decoding: Set by decoder.
    */
   int dtg_active_format;
#define FF_DTG_AFD_SAME         8
#define FF_DTG_AFD_4_3          9
#define FF_DTG_AFD_16_9         10
#define FF_DTG_AFD_14_9         11
#define FF_DTG_AFD_4_3_SP_14_9  13
#define FF_DTG_AFD_16_9_SP_14_9 14
#define FF_DTG_AFD_SP_4_3       15

   /**
    * maximum motion estimation search range in subpel units
    * If 0 then no limit.
    *
    * - encoding: Set by user.
    * - decoding: unused
    */
   int me_range;

   /**
    * intra quantizer bias
    * - encoding: Set by user.
    * - decoding: unused
    */
   int intra_quant_bias;
#define FF_DEFAULT_QUANT_BIAS 999999

   /**
    * inter quantizer bias
    * - encoding: Set by user.
    * - decoding: unused
    */
   int inter_quant_bias;

   /**
    * color table ID
    * - encoding: unused
    * - decoding: Which clrtable should be used for 8bit RGB images.
    *             Tables have to be stored somewhere. FIXME
    */
   int color_table_id;

#if FF_API_INTERNAL_CONTEXT
   /**
    * internal_buffer count
    * Don't touch, used by libavcodec default_get_buffer().
    * @deprecated this field was moved to an internal context
    */
   attribute_deprecated int internal_buffer_count;

   /**
    * internal_buffers
    * Don't touch, used by libavcodec default_get_buffer().
    * @deprecated this field was moved to an internal context
    */
   attribute_deprecated void *internal_buffer;
#endif

   /**
    * Global quality for codecs which cannot change it per frame.
    * This should be proportional to MPEG-1/2/4 qscale.
    * - encoding: Set by user.
    * - decoding: unused
    */
   int global_quality;

#define FF_CODER_TYPE_VLC       0
#define FF_CODER_TYPE_AC        1
#define FF_CODER_TYPE_RAW       2
#define FF_CODER_TYPE_RLE       3
#define FF_CODER_TYPE_DEFLATE   4
   /**
    * coder type
    * - encoding: Set by user.
    * - decoding: unused
    */
   int coder_type;

   /**
    * context model
    * - encoding: Set by user.
    * - decoding: unused
    */
   int context_model;
#if 0
   /**
    *
    * - encoding: unused
    * - decoding: Set by user.
    */
   uint8_t * (*realloc)(struct AVCodecContext *s, uint8_t *buf, int buf_size);
#endif

   /**
    * slice flags
    * - encoding: unused
    * - decoding: Set by user.
    */
   int slice_flags;
#define SLICE_FLAG_CODED_ORDER    0x0001 ///< draw_horiz_band() is called in coded order instead of display
#define SLICE_FLAG_ALLOW_FIELD    0x0002 ///< allow draw_horiz_band() with field slices (MPEG2 field pics)
#define SLICE_FLAG_ALLOW_PLANE    0x0004 ///< allow draw_horiz_band() with 1 component at a time (SVQ1)

   /**
    * XVideo Motion Acceleration
    * - encoding: forbidden
    * - decoding: set by decoder
    */
   int xvmc_acceleration;

   /**
    * macroblock decision mode
    * - encoding: Set by user.
    * - decoding: unused
    */
   int mb_decision;
#define FF_MB_DECISION_SIMPLE 0        ///< uses mb_cmp
#define FF_MB_DECISION_BITS   1        ///< chooses the one which needs the fewest bits
#define FF_MB_DECISION_RD     2        ///< rate distortion

   /**
    * custom intra quantization matrix
    * - encoding: Set by user, can be NULL.
    * - decoding: Set by libavcodec.
    */
   uint16_t *intra_matrix;

   /**
    * custom inter quantization matrix
    * - encoding: Set by user, can be NULL.
    * - decoding: Set by libavcodec.
    */
   uint16_t *inter_matrix;

   /**
    * fourcc from the AVI stream header (LSB first, so "ABCD" -> ('D'<<24) + ('C'<<16) + ('B'<<8) + 'A').
    * This is used to work around some encoder bugs.
    * - encoding: unused
    * - decoding: Set by user, will be converted to uppercase by libavcodec during init.
    */
   unsigned int stream_codec_tag;

   /**
    * scene change detection threshold
    * 0 is default, larger means fewer detected scene changes.
    * - encoding: Set by user.
    * - decoding: unused
    */
   int scenechange_threshold;

   /**
    * minimum Lagrange multipler
    * - encoding: Set by user.
    * - decoding: unused
    */
   int lmin;

   /**
    * maximum Lagrange multipler
    * - encoding: Set by user.
    * - decoding: unused
    */
   int lmax;

#if FF_API_PALETTE_CONTROL
   /**
    * palette control structure
    * - encoding: ??? (no palette-enabled encoder yet)
    * - decoding: Set by user.
    */
   struct AVPaletteControl *palctrl;
#endif

   /**
    * noise reduction strength
    * - encoding: Set by user.
    * - decoding: unused
    */
   int noise_reduction;

   /**
    * Called at the beginning of a frame to get cr buffer for it.
    * Buffer type (size, hints) must be the same. libavcodec won't check it.
    * libavcodec will pass previous buffer in pic, function should return
    * same buffer or new buffer with old frame "painted" into it.
    * If pic.data[0] == NULL must behave like get_buffer().
    * if CODEC_CAP_DR1 is not set then reget_buffer() must call
    * avcodec_default_reget_buffer() instead of providing buffers allocated by
    * some other means.
    * - encoding: unused
    * - decoding: Set by libavcodec, user can override.
    */
   int (*reget_buffer)(struct AVCodecContext *c, AVFrame *pic);

   /**
    * Number of bits which should be loaded into the rc buffer before decoding starts.
    * - encoding: Set by user.
    * - decoding: unused
    */
   int rc_initial_buffer_occupancy;

   /**
    *
    * - encoding: Set by user.
    * - decoding: unused
    */
   int inter_threshold;

   /**
    * CODEC_FLAG2_*
    * - encoding: Set by user.
    * - decoding: Set by user.
    */
   int flags2;

   /**
    * Simulates errors in the bitstream to test error concealment.
    * - encoding: Set by user.
    * - decoding: unused
    */
   int error_rate;

#if FF_API_ANTIALIAS_ALGO
   /**
    * MP3 antialias algorithm, see FF_AA_* below.
    * - encoding: unused
    * - decoding: Set by user.
    */
   attribute_deprecated int antialias_algo;
#define FF_AA_AUTO    0
#define FF_AA_FASTINT 1 //not implemented yet
#define FF_AA_INT     2
#define FF_AA_FLOAT   3
#endif

   /**
    * quantizer noise shaping
    * - encoding: Set by user.
    * - decoding: unused
    */
   int quantizer_noise_shaping;

   /**
    * thread count
    * is used to decide how many independent tasks should be passed to execute()
    * - encoding: Set by user.
    * - decoding: Set by user.
    */
   int thread_count;

   /**
    * The codec may call this to execute several independent things.
    * It will return only after finishing all tasks.
    * The user may replace this with some multithreaded implementation,
    * the default implementation will execute the parts serially.
    * @param count the number of things to execute
    * - encoding: Set by libavcodec, user can override.
    * - decoding: Set by libavcodec, user can override.
    */
   int (*execute)(struct AVCodecContext *c, int (*func)(struct AVCodecContext *c2, void *arg), void *arg2, int *ret, int count, int size);

   /**
    * thread opaque
    * Can be used by execute() to store some per AVCodecContext stuff.
    * - encoding: set by execute()
    * - decoding: set by execute()
    */
   void *thread_opaque;

   /**
    * Motion estimation threshold below which no motion estimation is
    * performed, but instead the user specified motion vectors are used.
    *
    * - encoding: Set by user.
    * - decoding: unused
    */
    int me_threshold;

   /**
    * Macroblock threshold below which the user specified macroblock types will be used.
    * - encoding: Set by user.
    * - decoding: unused
    */
    int mb_threshold;

   /**
    * precision of the intra DC coefficient - 8
    * - encoding: Set by user.
    * - decoding: unused
    */
    int intra_dc_precision;

   /**
    * noise vs. sse weight for the nsse comparsion function
    * - encoding: Set by user.
    * - decoding: unused
    */
    int nsse_weight;

   /**
    * Number of macroblock rows at the top which are skipped.
    * - encoding: unused
    * - decoding: Set by user.
    */
    int skip_top;

   /**
    * Number of macroblock rows at the bottom which are skipped.
    * - encoding: unused
    * - decoding: Set by user.
    */
    int skip_bottom;

   /**
    * profile
    * - encoding: Set by user.
    * - decoding: Set by libavcodec.
    */
    int profile;
#define FF_PROFILE_UNKNOWN -99
#define FF_PROFILE_RESERVED -100

#define FF_PROFILE_AAC_MAIN 0
#define FF_PROFILE_AAC_LOW  1
#define FF_PROFILE_AAC_SSR  2
#define FF_PROFILE_AAC_LTP  3

#define FF_PROFILE_DTS         20
#define FF_PROFILE_DTS_ES      30
#define FF_PROFILE_DTS_96_24   40
#define FF_PROFILE_DTS_HD_HRA  50
#define FF_PROFILE_DTS_HD_MA   60

#define FF_PROFILE_MPEG2_422    0
#define FF_PROFILE_MPEG2_HIGH   1
#define FF_PROFILE_MPEG2_SS     2
#define FF_PROFILE_MPEG2_SNR_SCALABLE  3
#define FF_PROFILE_MPEG2_MAIN   4
#define FF_PROFILE_MPEG2_SIMPLE 5

#define FF_PROFILE_H264_CONSTRAINED  (1<<9)  // 8+1; constraint_set1_flag
#define FF_PROFILE_H264_INTRA        (1<<11) // 8+3; constraint_set3_flag

#define FF_PROFILE_H264_BASELINE             66
#define FF_PROFILE_H264_CONSTRAINED_BASELINE (66|FF_PROFILE_H264_CONSTRAINED)
#define FF_PROFILE_H264_MAIN                 77
#define FF_PROFILE_H264_EXTENDED             88
#define FF_PROFILE_H264_HIGH                 100
#define FF_PROFILE_H264_HIGH_10              110
#define FF_PROFILE_H264_HIGH_10_INTRA        (110|FF_PROFILE_H264_INTRA)
#define FF_PROFILE_H264_HIGH_422             122
#define FF_PROFILE_H264_HIGH_422_INTRA       (122|FF_PROFILE_H264_INTRA)
#define FF_PROFILE_H264_HIGH_444             144
#define FF_PROFILE_H264_HIGH_444_PREDICTIVE  244
#define FF_PROFILE_H264_HIGH_444_INTRA       (244|FF_PROFILE_H264_INTRA)
#define FF_PROFILE_H264_CAVLC_444            44

#define FF_PROFILE_VC1_SIMPLE   0
#define FF_PROFILE_VC1_MAIN     1
#define FF_PROFILE_VC1_COMPLEX  2
#define FF_PROFILE_VC1_ADVANCED 3

#define FF_PROFILE_MPEG4_SIMPLE                     0
#define FF_PROFILE_MPEG4_SIMPLE_SCALABLE            1
#define FF_PROFILE_MPEG4_CORE                       2
#define FF_PROFILE_MPEG4_MAIN                       3
#define FF_PROFILE_MPEG4_N_BIT                      4
#define FF_PROFILE_MPEG4_SCALABLE_TEXTURE           5
#define FF_PROFILE_MPEG4_SIMPLE_FACE_ANIMATION      6
#define FF_PROFILE_MPEG4_BASIC_ANIMATED_TEXTURE     7
#define FF_PROFILE_MPEG4_HYBRID                     8
#define FF_PROFILE_MPEG4_ADVANCED_REAL_TIME         9
#define FF_PROFILE_MPEG4_CORE_SCALABLE             10
#define FF_PROFILE_MPEG4_ADVANCED_CODING           11
#define FF_PROFILE_MPEG4_ADVANCED_CORE             12
#define FF_PROFILE_MPEG4_ADVANCED_SCALABLE_TEXTURE 13
#define FF_PROFILE_MPEG4_SIMPLE_STUDIO             14
#define FF_PROFILE_MPEG4_ADVANCED_SIMPLE           15

   /**
    * level
    * - encoding: Set by user.
    * - decoding: Set by libavcodec.
    */
    int level;
#define FF_LEVEL_UNKNOWN -99

   /**
    * low resolution decoding, 1-> 1/2 size, 2->1/4 size
    * - encoding: unused
    * - decoding: Set by user.
    */
    int lowres;

   /**
    * Bitstream width / height, may be different from width/height if lowres enabled.
    * - encoding: unused
    * - decoding: Set by user before init if known. Codec should override / dynamically change if needed.
    */
   int coded_width, coded_height;

   /**
    * frame skip threshold
    * - encoding: Set by user.
    * - decoding: unused
    */
   int frame_skip_threshold;

   /**
    * frame skip factor
    * - encoding: Set by user.
    * - decoding: unused
    */
   int frame_skip_factor;

   /**
    * frame skip exponent
    * - encoding: Set by user.
    * - decoding: unused
    */
   int frame_skip_exp;

   /**
    * frame skip comparison function
    * - encoding: Set by user.
    * - decoding: unused
    */
   int frame_skip_cmp;

   /**
    * Border processing masking, raises the quantizer for mbs on the borders
    * of the picture.
    * - encoding: Set by user.
    * - decoding: unused
    */
   float border_masking;

   /**
    * minimum MB lagrange multipler
    * - encoding: Set by user.
    * - decoding: unused
    */
   int mb_lmin;

   /**
    * maximum MB lagrange multipler
    * - encoding: Set by user.
    * - decoding: unused
    */
   int mb_lmax;

   /**
    *
    * - encoding: Set by user.
    * - decoding: unused
    */
   int me_penalty_compensation;

   /**
    *
    * - encoding: unused
    * - decoding: Set by user.
    */
   enum AVDiscard skip_loop_filter;

   /**
    *
    * - encoding: unused
    * - decoding: Set by user.
    */
   enum AVDiscard skip_idct;

   /**
    *
    * - encoding: unused
    * - decoding: Set by user.
    */
   enum AVDiscard skip_frame;

   /**
    *
    * - encoding: Set by user.
    * - decoding: unused
    */
   int bidir_refine;

   /**
    *
    * - encoding: Set by user.
    * - decoding: unused
    */
   int brd_scale;

#if FF_API_X264_GLOBAL_OPTS
   /**
    * constant rate factor - quality-based VBR - values ~correspond to qps
    * - encoding: Set by user.
    * - decoding: unused
    *   @deprecated use 'crf' libx264 private option
    */
   attribute_deprecated float crf;

   /**
    * constant quantization parameter rate control method
    * - encoding: Set by user.
    * - decoding: unused
    *   @deprecated use 'cqp' libx264 private option
    */
   attribute_deprecated int cqp;
#endif

   /**
    * minimum GOP size
    * - encoding: Set by user.
    * - decoding: unused
    */
   int keyint_min;

   /**
    * number of reference frames
    * - encoding: Set by user.
    * - decoding: Set by lavc.
    */
   int refs;

   /**
    * chroma qp offset from luma
    * - encoding: Set by user.
    * - decoding: unused
    */
   int chromaoffset;

#if FF_API_X264_GLOBAL_OPTS
   /**
    * Influence how often B-frames are used.
    * - encoding: Set by user.
    * - decoding: unused
    */
   attribute_deprecated int bframebias;
#endif

   /**
    * trellis RD quantization
    * - encoding: Set by user.
    * - decoding: unused
    */
   int trellis;

#if FF_API_X264_GLOBAL_OPTS
   /**
    * Reduce fluctuations in qp (before curve compression).
    * - encoding: Set by user.
    * - decoding: unused
    */
   attribute_deprecated float complexityblur;

   /**
    * in-loop deblocking filter alphac0 parameter
    * alpha is in the range -6...6
    * - encoding: Set by user.
    * - decoding: unused
    */
   attribute_deprecated int deblockalpha;

   /**
    * in-loop deblocking filter beta parameter
    * beta is in the range -6...6
    * - encoding: Set by user.
    * - decoding: unused
    */
   attribute_deprecated int deblockbeta;

   /**
    * macroblock subpartition sizes to consider - p8x8, p4x4, b8x8, i8x8, i4x4
    * - encoding: Set by user.
    * - decoding: unused
    */
   attribute_deprecated int partitions;
#define X264_PART_I4X4 0x001  /* Analyze i4x4 */
#define X264_PART_I8X8 0x002  /* Analyze i8x8 (requires 8x8 transform) */
#define X264_PART_P8X8 0x010  /* Analyze p16x8, p8x16 and p8x8 */
#define X264_PART_P4X4 0x020  /* Analyze p8x4, p4x8, p4x4 */
#define X264_PART_B8X8 0x100  /* Analyze b16x8, b8x16 and b8x8 */

   /**
    * direct MV prediction mode - 0 (none), 1 (spatial), 2 (temporal), 3 (auto)
    * - encoding: Set by user.
    * - decoding: unused
    */
   attribute_deprecated int directpred;
#endif

   /**
    * Audio cutoff bandwidth (0 means "automatic")
    * - encoding: Set by user.
    * - decoding: unused
    */
   int cutoff;

   /**
    * Multiplied by qscale for each frame and added to scene_change_score.
    * - encoding: Set by user.
    * - decoding: unused
    */
   int scenechange_factor;

   /**
    *
    * Note: Value depends upon the compare function used for fullpel ME.
    * - encoding: Set by user.
    * - decoding: unused
    */
   int mv0_threshold;

   /**
    * Adjust sensitivity of b_frame_strategy 1.
    * - encoding: Set by user.
    * - decoding: unused
    */
   int b_sensitivity;

   /**
    * - encoding: Set by user.
    * - decoding: unused
    */
   int compression_level;
#define FF_COMPRESSION_DEFAULT -1

   /**
    * - encoding: Set by user.
    * - decoding: unused
    */
   int min_prediction_order;

   /**
    * - encoding: Set by user.
    * - decoding: unused
    */
   int max_prediction_order;

#if FF_API_FLAC_GLOBAL_OPTS
   /**
    * @name FLAC options
    * @deprecated Use FLAC encoder private options instead.
    * @{
    */

   /**
    * LPC coefficient precision - used by FLAC encoder
    * - encoding: Set by user.
    * - decoding: unused
    */
   attribute_deprecated int lpc_coeff_precision;

   /**
    * search method for selecting prediction order
    * - encoding: Set by user.
    * - decoding: unused
    */
   attribute_deprecated int prediction_order_method;

   /**
    * - encoding: Set by user.
    * - decoding: unused
    */
   attribute_deprecated int min_partition_order;

   /**
    * - encoding: Set by user.
    * - decoding: unused
    */
   attribute_deprecated int max_partition_order;
   /**
    * @}
    */
#endif

   /**
    * GOP timecode frame start number, in non drop frame format
    * - encoding: Set by user.
    * - decoding: unused
    */
   int64_t timecode_frame_start;

#if FF_API_REQUEST_CHANNELS
   /**
    * Decoder should decode to this many channels if it can (0 for default)
    * - encoding: unused
    * - decoding: Set by user.
    * @deprecated Deprecated in favor of request_channel_layout.
    */
   int request_channels;
#endif

#if FF_API_DRC_SCALE
   /**
    * Percentage of dynamic range compression to be applied by the decoder.
    * The default value is 1.0, corresponding to full compression.
    * - encoding: unused
    * - decoding: Set by user.
    * @deprecated use AC3 decoder private option instead.
    */
   attribute_deprecated float drc_scale;
#endif

   /**
    * opaque 64bit number (generally a PTS) that will be reordered and
    * output in AVFrame.reordered_opaque
    * @deprecated in favor of pkt_pts
    * - encoding: unused
    * - decoding: Set by user.
    */
   int64_t reordered_opaque;

   /**
    * Bits per sample/pixel of internal libavcodec pixel/sample format.
    * - encoding: set by user.
    * - decoding: set by libavcodec.
    */
   int bits_per_raw_sample;

   /**
    * Audio channel layout.
    * - encoding: set by user.
    * - decoding: set by libavcodec.
    */
   uint64_t channel_layout;

   /**
    * Request decoder to use this channel layout if it can (0 for default)
    * - encoding: unused
    * - decoding: Set by user.
    */
   uint64_t request_channel_layout;

   /**
    * Ratecontrol attempt to use, at maximum, <value> of what can be used without an underflow.
    * - encoding: Set by user.
    * - decoding: unused.
    */
   float rc_max_available_vbv_use;

   /**
    * Ratecontrol attempt to use, at least, <value> times the amount needed to prevent a vbv overflow.
    * - encoding: Set by user.
    * - decoding: unused.
    */
   float rc_min_vbv_overflow_use;

   /**
    * Hardware accelerator in use
    * - encoding: unused.
    * - decoding: Set by libavcodec
    */
   struct AVHWAccel *hwaccel;

   /**
    * For some codecs, the time base is closer to the field rate than the frame rate.
    * Most notably, H.264 and MPEG-2 specify time_base as half of frame duration
    * if no telecine is used ...
    *
    * Set to time_base ticks per frame. Default 1, e.g., H.264/MPEG-2 set it to 2.
    */
   int ticks_per_frame;

   /**
    * Hardware accelerator context.
    * For some hardware accelerators, a global context needs to be
    * provided by the user. In that case, this holds display-dependent
    * data Libav cannot instantiate itself. Please refer to the
    * Libav HW accelerator documentation to know how to fill this
    * is. e.g. for VA API, this is a struct vaapi_context.
    * - encoding: unused
    * - decoding: Set by user
    */
   void *hwaccel_context;

   /**
    * Chromaticity coordinates of the source primaries.
    * - encoding: Set by user
    * - decoding: Set by libavcodec
    */
   enum AVColorPrimaries color_primaries;

   /**
    * Color Transfer Characteristic.
    * - encoding: Set by user
    * - decoding: Set by libavcodec
    */
   enum AVColorTransferCharacteristic color_trc;

   /**
    * YUV colorspace type.
    * - encoding: Set by user
    * - decoding: Set by libavcodec
    */
   enum AVColorSpace colorspace;

   /**
    * MPEG vs JPEG YUV range.
    * - encoding: Set by user
    * - decoding: Set by libavcodec
    */
   enum AVColorRange color_range;

   /**
    * This defines the location of chroma samples.
    * - encoding: Set by user
    * - decoding: Set by libavcodec
    */
   enum AVChromaLocation chroma_sample_location;

   /**
    * The codec may call this to execute several independent things.
    * It will return only after finishing all tasks.
    * The user may replace this with some multithreaded implementation,
    * the default implementation will execute the parts serially.
    * Also see avcodec_thread_init and e.g. the --enable-pthread configure option.
    * @param c context passed also to func
    * @param count the number of things to execute
    * @param arg2 argument passed unchanged to func
    * @param ret return values of executed functions, must have space for "count" values. May be NULL.
    * @param func function that will be called count times, with jobnr from 0 to count-1.
    *             threadnr will be in the range 0 to c->thread_count-1 < MAX_THREADS and so that no
    *             two instances of func executing at the same time will have the same threadnr.
    * @return always 0 currently, but code should handle a future improvement where when any call to func
    *         returns < 0 no further calls to func may be done and < 0 is returned.
    * - encoding: Set by libavcodec, user can override.
    * - decoding: Set by libavcodec, user can override.
    */
   int (*execute2)(struct AVCodecContext *c, int (*func)(struct AVCodecContext *c2, void *arg, int jobnr, int threadnr), void *arg2, int *ret, int count);

#if FF_API_X264_GLOBAL_OPTS
   /**
    * explicit P-frame weighted prediction analysis method
    * 0: off
    * 1: fast blind weighting (one reference duplicate with -1 offset)
    * 2: smart weighting (full fade detection analysis)
    * - encoding: Set by user.
    * - decoding: unused
    */
   attribute_deprecated int weighted_p_pred;

   /**
    * AQ mode
    * 0: Disabled
    * 1: Variance AQ (complexity mask)
    * 2: Auto-variance AQ (experimental)
    * - encoding: Set by user
    * - decoding: unused
    */
   attribute_deprecated int aq_mode;

   /**
    * AQ strength
    * Reduces blocking and blurring in flat and textured areas.
    * - encoding: Set by user
    * - decoding: unused
    */
   attribute_deprecated float aq_strength;

   /**
    * PSY RD
    * Strength of psychovisual optimization
    * - encoding: Set by user
    * - decoding: unused
    */
   attribute_deprecated float psy_rd;

   /**
    * PSY trellis
    * Strength of psychovisual optimization
    * - encoding: Set by user
    * - decoding: unused
    */
   attribute_deprecated float psy_trellis;

   /**
    * RC lookahead
    * Number of frames for frametype and ratecontrol lookahead
    * - encoding: Set by user
    * - decoding: unused
    */
   attribute_deprecated int rc_lookahead;

   /**
    * Constant rate factor maximum
    * With CRF encoding mode and VBV restrictions enabled, prevents quality from being worse
    * than crf_max, even if doing so would violate VBV restrictions.
    * - encoding: Set by user.
    * - decoding: unused
    */
   attribute_deprecated float crf_max;
#endif

   int log_level_offset;

#if FF_API_FLAC_GLOBAL_OPTS
   /**
    * Determine which LPC analysis algorithm to use.
    * - encoding: Set by user
    * - decoding: unused
    */
   attribute_deprecated enum AVLPCType lpc_type;

   /**
    * Number of passes to use for Cholesky factorization during LPC analysis
    * - encoding: Set by user
    * - decoding: unused
    */
   attribute_deprecated int lpc_passes;
#endif

   /**
    * Number of slices.
    * Indicates number of picture subdivisions. Used for parallelized
    * decoding.
    * - encoding: Set by user
    * - decoding: unused
    */
   int slices;

   /**
    * Header containing style information for text subtitles.
    * For SUBTITLE_ASS subtitle type, it should contain the whole ASS
    * [Script Info] and [V4+ Styles] section, plus the [Events] line and
    * the Format line following. It shouldn't include any Dialogue line.
    * - encoding: Set/allocated/freed by user (before avcodec_open2())
    * - decoding: Set/allocated/freed by libavcodec (by avcodec_open2())
    */
   uint8_t *subtitle_header;
   int subtitle_header_size;

   /**
    * Current packet as passed into the decoder, to avoid having
    * to pass the packet into every function. Currently only valid
    * inside lavc and get/release_buffer callbacks.
    * - decoding: set by avcodec_decode_*, read by get_buffer() for setting pkt_pts
    * - encoding: unused
    */
   AVPacket *pkt;

#if FF_API_INTERNAL_CONTEXT
   /**
    * Whether this is a copy of the context which had init() called on it.
    * This is used by multithreading - shared tables and picture pointers
    * should be freed from the original context only.
    * - encoding: Set by libavcodec.
    * - decoding: Set by libavcodec.
    *
    * @deprecated this field has been moved to an internal context
    */
   attribute_deprecated int is_copy;
#endif

   /**
    * Which multithreading methods to use.
    * Use of FF_THREAD_FRAME will increase decoding delay by one frame per thread,
    * so clients which cannot provide future frames should not use it.
    *
    * - encoding: Set by user, otherwise the default is used.
    * - decoding: Set by user, otherwise the default is used.
    */
   int thread_type;
#define FF_THREAD_FRAME   1 ///< Decode more than one frame at once
#define FF_THREAD_SLICE   2 ///< Decode more than one part of a single frame at once

   /**
    * Which multithreading methods are in use by the codec.
    * - encoding: Set by libavcodec.
    * - decoding: Set by libavcodec.
    */
   int active_thread_type;

   /**
    * Set by the client if its custom get_buffer() callback can be called
    * from another thread, which allows faster multithreaded decoding.
    * draw_horiz_band() will be called from other threads regardless of this setting.
    * Ignored if the default get_buffer() is used.
    * - encoding: Set by user.
    * - decoding: Set by user.
    */
   int thread_safe_callbacks;

   /**
    * VBV delay coded in the last frame (in periods of a 27 MHz clock).
    * Used for compliant TS muxing.
    * - encoding: Set by libavcodec.
    * - decoding: unused.
    */
   uint64_t vbv_delay;

   /**
    * Type of service that the audio stream conveys.
    * - encoding: Set by user.
    * - decoding: Set by libavcodec.
    */
   enum AVAudioServiceType audio_service_type;

   /**
    * Used to request a sample format from the decoder.
    * - encoding: unused.
    * - decoding: Set by user.
    */
   enum AVSampleFormat request_sample_fmt;

   /**
    * Error recognition; may misdetect some more or less valid parts as errors.
    * - encoding: unused
    * - decoding: Set by user.
    */
   int err_recognition;
#define AV_EF_CRCCHECK  (1<<0)
#define AV_EF_BITSTREAM (1<<1)
#define AV_EF_BUFFER    (1<<2)
#define AV_EF_EXPLODE   (1<<3)

   /**
    * Private context used for internal data.
    *
    * Unlike priv_data, this is not codec-specific. It is used in general
    * libavcodec functions.
    */
   struct AVCodecInternal *internal;

   /** Field order
    * - encoding: set by libavcodec
    * - decoding: Set by libavcodec
    */
   enum AVFieldOrder field_order;
} AVCodecContext;

/**
* AVProfile.
*/
typedef struct AVProfile {
   int profile;
   const char *name; ///< short name for the profile
} AVProfile;

typedef struct AVCodecDefault AVCodecDefault;

/**
* AVCodec.
*/
typedef struct AVCodec {
   /**
    * Name of the codec implementation.
    * The name is globally unique among encoders and among decoders (but an
    * encoder and a decoder can share the same name).
    * This is the primary way to find a codec from the user perspective.
    */
   const char *name;
   enum AVMediaType type;
   enum CodecID id;
   int priv_data_size;
   int (*init)(AVCodecContext *);
   int (*encode)(AVCodecContext *, uint8_t *buf, int buf_size, void *data);
   int (*close)(AVCodecContext *);
   int (*decode)(AVCodecContext *, void *outdata, int *outdata_size, AVPacket *avpkt);
   /**
    * Codec capabilities.
    * see CODEC_CAP_*
    */
   int capabilities;
   struct AVCodec *next;
   /**
    * Flush buffers.
    * Will be called when seeking
    */
   void (*flush)(AVCodecContext *);
   const AVRational *supported_framerates; ///< array of supported framerates, or NULL if any, array is terminated by {0,0}
   const enum PixelFormat *pix_fmts;       ///< array of supported pixel formats, or NULL if unknown, array is terminated by -1
   /**
    * Descriptive name for the codec, meant to be more human readable than name.
    * You should use the NULL_IF_CONFIG_SMALL() macro to define it.
    */
   const char *long_name;
   const int *supported_samplerates;       ///< array of supported audio samplerates, or NULL if unknown, array is terminated by 0
   const enum AVSampleFormat *sample_fmts; ///< array of supported sample formats, or NULL if unknown, array is terminated by -1
   const uint64_t *channel_layouts;         ///< array of support channel layouts, or NULL if unknown. array is terminated by 0
   uint8_t max_lowres;                     ///< maximum value for lowres supported by the decoder
   const AVClass *priv_class;              ///< AVClass for the private context
   const AVProfile *profiles;              ///< array of recognized profiles, or NULL if unknown, array is terminated by {FF_PROFILE_UNKNOWN}

   /**
    * @name Frame-level threading support functions
    * @{
    */
   /**
    * If defined, called on thread contexts when they are created.
    * If the codec allocates writable tables in init(), re-allocate them here.
    * priv_data will be set to a copy of the original.
    */
   int (*init_thread_copy)(AVCodecContext *);
   /**
    * Copy necessary context variables from a previous thread context to the current one.
    * If not defined, the next thread will start automatically; otherwise, the codec
    * must call ff_thread_finish_setup().
    *
    * dst and src will (rarely) point to the same context, in which case memcpy should be skipped.
    */
   int (*update_thread_context)(AVCodecContext *dst, const AVCodecContext *src);
   /** @} */

   /**
    * Private codec-specific defaults.
    */
   const AVCodecDefault *defaults;

   /**
    * Initialize codec static data, called from avcodec_register().
    */
   void (*init_static_data)(struct AVCodec *codec);

   /**
    * Encode data to an AVPacket.
    *
    * @param      avctx          codec context
    * @param      avpkt          output AVPacket (may contain a user-provided buffer)
    * @param[in]  frame          AVFrame containing the raw data to be encoded
    * @param[out] got_packet_ptr encoder sets to 0 or 1 to indicate that a
    *                            non-empty packet was returned in avpkt.
    * @return 0 on success, negative error code on failure
    */
   int (*encode2)(AVCodecContext *avctx, AVPacket *avpkt, const AVFrame *frame,
                  int *got_packet_ptr);
} AVCodec;

/**
* AVHWAccel.
*/
typedef struct AVHWAccel {
   /**
    * Name of the hardware accelerated codec.
    * The name is globally unique among encoders and among decoders (but an
    * encoder and a decoder can share the same name).
    */
   const char *name;

   /**
    * Type of codec implemented by the hardware accelerator.
    *
    * See AVMEDIA_TYPE_xxx
    */
   enum AVMediaType type;

   /**
    * Codec implemented by the hardware accelerator.
    *
    * See CODEC_ID_xxx
    */
   enum CodecID id;

   /**
    * Supported pixel format.
    *
    * Only hardware accelerated formats are supported here.
    */
   enum PixelFormat pix_fmt;

   /**
    * Hardware accelerated codec capabilities.
    * see FF_HWACCEL_CODEC_CAP_*
    */
   int capabilities;

   struct AVHWAccel *next;

   /**
    * Called at the beginning of each frame or field picture.
    *
    * Meaningful frame information (codec specific) is guaranteed to
    * be parsed at this point. This function is mandatory.
    *
    * Note that buf can be NULL along with buf_size set to 0.
    * Otherwise, this means the whole frame is available at this point.
    *
    * @param avctx the codec context
    * @param buf the frame data buffer base
    * @param buf_size the size of the frame in bytes
    * @return zero if successful, a negative value otherwise
    */
   int (*start_frame)(AVCodecContext *avctx, const uint8_t *buf, uint32_t buf_size);

   /**
    * Callback for each slice.
    *
    * Meaningful slice information (codec specific) is guaranteed to
    * be parsed at this point. This function is mandatory.
    *
    * @param avctx the codec context
    * @param buf the slice data buffer base
    * @param buf_size the size of the slice in bytes
    * @return zero if successful, a negative value otherwise
    */
   int (*decode_slice)(AVCodecContext *avctx, const uint8_t *buf, uint32_t buf_size);

   /**
    * Called at the end of each frame or field picture.
    *
    * The whole picture is parsed at this point and can now be sent
    * to the hardware accelerator. This function is mandatory.
    *
    * @param avctx the codec context
    * @return zero if successful, a negative value otherwise
    */
   int (*end_frame)(AVCodecContext *avctx);

   /**
    * Size of HW accelerator private data.
    *
    * Private data is allocated with av_mallocz() before
    * AVCodecContext.get_buffer() and deallocated after
    * AVCodecContext.release_buffer().
    */
   int priv_data_size;
} AVHWAccel;

/**
* four components are given, that's all.
* the last component is alpha
*/
typedef struct AVPicture {
   uint8_t *data[AV_NUM_DATA_POINTERS];
   int linesize[AV_NUM_DATA_POINTERS];     ///< number of bytes per line
} AVPicture;

#define AVPALETTE_SIZE 1024
#define AVPALETTE_COUNT 256
#if FF_API_PALETTE_CONTROL
/**
* AVPaletteControl
* This structure defines a method for communicating palette changes
* between and demuxer and a decoder.
*
* @deprecated Use AVPacket to send palette changes instead.
* This is totally broken.
*/
typedef struct AVPaletteControl {

   /* Demuxer sets this to 1 to indicate the palette has changed;
    * decoder resets to 0. */
   int palette_changed;

   /* 4-byte ARGB palette entries, stored in native byte order; note that
    * the individual palette components should be on a 8-bit scale; if
    * the palette data comes from an IBM VGA native format, the component
    * data is probably 6 bits in size and needs to be scaled. */
   unsigned int palette[AVPALETTE_COUNT];

} AVPaletteControl attribute_deprecated;
#endif

enum AVSubtitleType {
   SUBTITLE_NONE,

   SUBTITLE_BITMAP,                ///< A bitmap, pict will be set

   /**
    * Plain text, the text field must be set by the decoder and is
    * authoritative. ass and pict fields may contain approximations.
    */
   SUBTITLE_TEXT,

   /**
    * Formatted text, the ass field must be set by the decoder and is
    * authoritative. pict and text fields may contain approximations.
    */
   SUBTITLE_ASS,
};

typedef struct AVSubtitleRect {
   int x;         ///< top left corner  of pict, undefined when pict is not set
   int y;         ///< top left corner  of pict, undefined when pict is not set
   int w;         ///< width            of pict, undefined when pict is not set
   int h;         ///< height           of pict, undefined when pict is not set
   int nb_colors; ///< number of colors in pict, undefined when pict is not set

   /**
    * data+linesize for the bitmap of this subtitle.
    * can be set for text/ass as well once they where rendered
    */
   AVPicture pict;
   enum AVSubtitleType type;

   char *text;                     ///< 0 terminated plain UTF-8 text

   /**
    * 0 terminated ASS/SSA compatible event line.
    * The pressentation of this is unaffected by the other values in this
    * struct.
    */
   char *ass;
} AVSubtitleRect;

typedef struct AVSubtitle {
   uint16_t format; /* 0 = graphics */
   uint32_t start_display_time; /* relative to packet pts, in ms */
   uint32_t end_display_time; /* relative to packet pts, in ms */
   unsigned num_rects;
   AVSubtitleRect **rects;
   int64_t pts;    ///< Same as packet pts, in AV_TIME_BASE
} AVSubtitle;

/* packet functions */

/**
* @deprecated use NULL instead
*/
attribute_deprecated void av_destruct_packet_nofree(AVPacket *pkt);

/**
* Default packet destructor.
*/
void av_destruct_packet(AVPacket *pkt);

/**
* Initialize optional fields of a packet with default values.
*
* @param pkt packet
*/
void av_init_packet(AVPacket *pkt);

/**
* Allocate the payload of a packet and initialize its fields with
* default values.
*
* @param pkt packet
* @param size wanted payload size
* @return 0 if OK, AVERROR_xxx otherwise
*/
int av_new_packet(AVPacket *pkt, int size);

/**
* Reduce packet size, correctly zeroing padding
*
* @param pkt packet
* @param size new size
*/
void av_shrink_packet(AVPacket *pkt, int size);

/**
* Increase packet size, correctly zeroing padding
*
* @param pkt packet
* @param grow_by number of bytes by which to increase the size of the packet
*/
int av_grow_packet(AVPacket *pkt, int grow_by);

/**
* @warning This is a hack - the packet memory allocation stuff is broken. The
* packet is allocated if it was not really allocated.
*/
int av_dup_packet(AVPacket *pkt);

/**
* Free a packet.
*
* @param pkt packet to free
*/
void av_free_packet(AVPacket *pkt);

/**
* Allocate new information of a packet.
*
* @param pkt packet
* @param type side information type
* @param size side information size
* @return pointer to fresh allocated data or NULL otherwise
*/
uint8_t* av_packet_new_side_data(AVPacket *pkt, enum AVPacketSideDataType type,
                                int size);

/**
* Get side information from packet.
*
* @param pkt packet
* @param type desired side information type
* @param size pointer for side information size to store (optional)
* @return pointer to data if present or NULL otherwise
*/
uint8_t* av_packet_get_side_data(AVPacket *pkt, enum AVPacketSideDataType type,
                                int *size);

/* resample.c */

struct ReSampleContext;
struct AVResampleContext;

typedef struct ReSampleContext ReSampleContext;

/**
*  Initialize audio resampling context.
*
* @param output_channels  number of output channels
* @param input_channels   number of input channels
* @param output_rate      output sample rate
* @param input_rate       input sample rate
* @param sample_fmt_out   requested output sample format
* @param sample_fmt_in    input sample format
* @param filter_length    length of each FIR filter in the filterbank relative to the cutoff frequency
* @param log2_phase_count log2 of the number of entries in the polyphase filterbank
* @param linear           if 1 then the used FIR filter will be linearly interpolated
                          between the 2 closest, if 0 the closest will be used
* @param cutoff           cutoff frequency, 1.0 corresponds to half the output sampling rate
* @return allocated ReSampleContext, NULL if error occurred
*/
ReSampleContext *av_audio_resample_init(int output_channels, int input_channels,
                                       int output_rate, int input_rate,
                                       enum AVSampleFormat sample_fmt_out,
                                       enum AVSampleFormat sample_fmt_in,
                                       int filter_length, int log2_phase_count,
                                       int linear, double cutoff);

int audio_resample(ReSampleContext *s, short *output, short *input, int nb_samples);

/**
* Free resample context.
*
* @param s a non-NULL pointer to a resample context previously
*          created with av_audio_resample_init()
*/
void audio_resample_close(ReSampleContext *s);


/**
* Initialize an audio resampler.
* Note, if either rate is not an integer then simply scale both rates up so they are.
* @param filter_length length of each FIR filter in the filterbank relative to the cutoff freq
* @param log2_phase_count log2 of the number of entries in the polyphase filterbank
* @param linear If 1 then the used FIR filter will be linearly interpolated
                between the 2 closest, if 0 the closest will be used
* @param cutoff cutoff frequency, 1.0 corresponds to half the output sampling rate
*/
struct AVResampleContext *av_resample_init(int out_rate, int in_rate, int filter_length, int log2_phase_count, int linear, double cutoff);

/**
* Resample an array of samples using a previously configured context.
* @param src an array of unconsumed samples
* @param consumed the number of samples of src which have been consumed are returned here
* @param src_size the number of unconsumed samples available
* @param dst_size the amount of space in samples available in dst
* @param update_ctx If this is 0 then the context will not be modified, that way several channels can be resampled with the same context.
* @return the number of samples written in dst or -1 if an error occurred
*/
int av_resample(struct AVResampleContext *c, short *dst, short *src, int *consumed, int src_size, int dst_size, int update_ctx);


/**
* Compensate samplerate/timestamp drift. The compensation is done by changing
* the resampler parameters, so no audible clicks or similar distortions occur
* @param compensation_distance distance in output samples over which the compensation should be performed
* @param sample_delta number of output samples which should be output less
*
* example: av_resample_compensate(c, 10, 500)
* here instead of 510 samples only 500 samples would be output
*
* note, due to rounding the actual compensation might be slightly different,
* especially if the compensation_distance is large and the in_rate used during init is small
*/
void av_resample_compensate(struct AVResampleContext *c, int sample_delta, int compensation_distance);
void av_resample_close(struct AVResampleContext *c);

/**
* Allocate memory for a picture.  Call avpicture_free() to free it.
*
* @see avpicture_fill()
*
* @param picture the picture to be filled in
* @param pix_fmt the format of the picture
* @param width the width of the picture
* @param height the height of the picture
* @return zero if successful, a negative value if not
*/
int avpicture_alloc(AVPicture *picture, enum PixelFormat pix_fmt, int width, int height);

/**
* Free a picture previously allocated by avpicture_alloc().
* The data buffer used by the AVPicture is freed, but the AVPicture structure
* itself is not.
*
* @param picture the AVPicture to be freed
*/
void avpicture_free(AVPicture *picture);

/**
* Fill in the AVPicture fields.
* The fields of the given AVPicture are filled in by using the 'ptr' address
* which points to the image data buffer. Depending on the specified picture
* format, one or multiple image data pointers and line sizes will be set.
* If a planar format is specified, several pointers will be set pointing to
* the different picture planes and the line sizes of the different planes
* will be stored in the lines_sizes array.
* Call with ptr == NULL to get the required size for the ptr buffer.
*
* To allocate the buffer and fill in the AVPicture fields in one call,
* use avpicture_alloc().
*
* @param picture AVPicture whose fields are to be filled in
* @param ptr Buffer which will contain or contains the actual image data
* @param pix_fmt The format in which the picture data is stored.
* @param width the width of the image in pixels
* @param height the height of the image in pixels
* @return size of the image data in bytes
*/
int avpicture_fill(AVPicture *picture, uint8_t *ptr,
                  enum PixelFormat pix_fmt, int width, int height);

/**
* Copy pixel data from an AVPicture into a buffer.
* The data is stored compactly, without any gaps for alignment or padding
* which may be applied by avpicture_fill().
*
* @see avpicture_get_size()
*
* @param[in] src AVPicture containing image data
* @param[in] pix_fmt The format in which the picture data is stored.
* @param[in] width the width of the image in pixels.
* @param[in] height the height of the image in pixels.
* @param[out] dest A buffer into which picture data will be copied.
* @param[in] dest_size The size of 'dest'.
* @return The number of bytes written to dest, or a negative value (error code) on error.
*/
int avpicture_layout(const AVPicture* src, enum PixelFormat pix_fmt, int width, int height,
                    unsigned char *dest, int dest_size);

/**
* Calculate the size in bytes that a picture of the given width and height
* would occupy if stored in the given picture format.
* Note that this returns the size of a compact representation as generated
* by avpicture_layout(), which can be smaller than the size required for e.g.
* avpicture_fill().
*
* @param pix_fmt the given picture format
* @param width the width of the image
* @param height the height of the image
* @return Image data size in bytes or -1 on error (e.g. too large dimensions).
*/
int avpicture_get_size(enum PixelFormat pix_fmt, int width, int height);
void avcodec_get_chroma_sub_sample(enum PixelFormat pix_fmt, int *h_shift, int *v_shift);

#if FF_API_GET_PIX_FMT_NAME
/**
* @deprecated Deprecated in favor of av_get_pix_fmt_name().
*/
attribute_deprecated
const char *avcodec_get_pix_fmt_name(enum PixelFormat pix_fmt);
#endif

void avcodec_set_dimensions(AVCodecContext *s, int width, int height);

/**
* Return a value representing the fourCC code associated to the
* pixel format pix_fmt, or 0 if no associated fourCC code can be
* found.
*/
unsigned int avcodec_pix_fmt_to_codec_tag(enum PixelFormat pix_fmt);

/**
* Put a string representing the codec tag codec_tag in buf.
*
* @param buf_size size in bytes of buf
* @return the length of the string that would have been generated if
* enough space had been available, excluding the trailing null
*/
size_t av_get_codec_tag_string(char *buf, size_t buf_size, unsigned int codec_tag);

#define FF_LOSS_RESOLUTION  0x0001 /**< loss due to resolution change */
#define FF_LOSS_DEPTH       0x0002 /**< loss due to color depth change */
#define FF_LOSS_COLORSPACE  0x0004 /**< loss due to color space conversion */
#define FF_LOSS_ALPHA       0x0008 /**< loss of alpha bits */
#define FF_LOSS_COLORQUANT  0x0010 /**< loss due to color quantization */
#define FF_LOSS_CHROMA      0x0020 /**< loss of chroma (e.g. RGB to gray conversion) */

/**
* Compute what kind of losses will occur when converting from one specific
* pixel format to another.
* When converting from one pixel format to another, information loss may occur.
* For example, when converting from RGB24 to GRAY, the color information will
* be lost. Similarly, other losses occur when converting from some formats to
* other formats. These losses can involve loss of chroma, but also loss of
* resolution, loss of color depth, loss due to the color space conversion, loss
* of the alpha bits or loss due to color quantization.
* avcodec_get_fix_fmt_loss() informs you about the various types of losses
* which will occur when converting from one pixel format to another.
*
* @param[in] dst_pix_fmt destination pixel format
* @param[in] src_pix_fmt source pixel format
* @param[in] has_alpha Whether the source pixel format alpha channel is used.
* @return Combination of flags informing you what kind of losses will occur.
*/
int avcodec_get_pix_fmt_loss(enum PixelFormat dst_pix_fmt, enum PixelFormat src_pix_fmt,
                            int has_alpha);

/**
* Find the best pixel format to convert to given a certain source pixel
* format.  When converting from one pixel format to another, information loss
* may occur.  For example, when converting from RGB24 to GRAY, the color
* information will be lost. Similarly, other losses occur when converting from
* some formats to other formats. avcodec_find_best_pix_fmt() searches which of
* the given pixel formats should be used to suffer the least amount of loss.
* The pixel formats from which it chooses one, are determined by the
* pix_fmt_mask parameter.
*
* @code
* src_pix_fmt = PIX_FMT_YUV420P;
* pix_fmt_mask = (1 << PIX_FMT_YUV422P) || (1 << PIX_FMT_RGB24);
* dst_pix_fmt = avcodec_find_best_pix_fmt(pix_fmt_mask, src_pix_fmt, alpha, &loss);
* @endcode
*
* @param[in] pix_fmt_mask bitmask determining which pixel format to choose from
* @param[in] src_pix_fmt source pixel format
* @param[in] has_alpha Whether the source pixel format alpha channel is used.
* @param[out] loss_ptr Combination of flags informing you what kind of losses will occur.
* @return The best pixel format to convert to or -1 if none was found.
*/
enum PixelFormat avcodec_find_best_pix_fmt(int64_t pix_fmt_mask, enum PixelFormat src_pix_fmt,
                             int has_alpha, int *loss_ptr);

#if FF_API_GET_ALPHA_INFO
#define FF_ALPHA_TRANSP       0x0001 /* image has some totally transparent pixels */
#define FF_ALPHA_SEMI_TRANSP  0x0002 /* image has some transparent pixels */

/**
* Tell if an image really has transparent alpha values.
* @return ored mask of FF_ALPHA_xxx constants
*/
attribute_deprecated
int img_get_alpha_info(const AVPicture *src,
                      enum PixelFormat pix_fmt, int width, int height);
#endif

/* deinterlace a picture */
/* deinterlace - if not supported return -1 */
int avpicture_deinterlace(AVPicture *dst, const AVPicture *src,
                         enum PixelFormat pix_fmt, int width, int height);

/* external high level API */

/**
* If c is NULL, returns the first registered codec,
* if c is non-NULL, returns the next registered codec after c,
* or NULL if c is the last one.
*/
AVCodec *av_codec_next(AVCodec *c);

/**
* Return the LIBAVCODEC_VERSION_INT constant.
*/
unsigned avcodec_version(void);

/**
* Return the libavcodec build-time configuration.
*/
const char *avcodec_configuration(void);

/**
* Return the libavcodec license.
*/
const char *avcodec_license(void);

#if FF_API_AVCODEC_INIT
/**
* @deprecated this function is called automatically from avcodec_register()
* and avcodec_register_all(), there is no need to call it manually
*/
attribute_deprecated
void avcodec_init(void);
#endif

/**
* Register the codec codec and initialize libavcodec.
*
* @warning either this function or avcodec_register_all() must be called
* before any other libavcodec functions.
*
* @see avcodec_register_all()
*/
void avcodec_register(AVCodec *codec);

/**
* Find a registered encoder with a matching codec ID.
*
* @param id CodecID of the requested encoder
* @return An encoder if one was found, NULL otherwise.
*/
AVCodec *avcodec_find_encoder(enum CodecID id);

/**
* Find a registered encoder with the specified name.
*
* @param name name of the requested encoder
* @return An encoder if one was found, NULL otherwise.
*/
AVCodec *avcodec_find_encoder_by_name(const char *name);

/**
* Find a registered decoder with a matching codec ID.
*
* @param id CodecID of the requested decoder
* @return A decoder if one was found, NULL otherwise.
*/
AVCodec *avcodec_find_decoder(enum CodecID id);

/**
* Find a registered decoder with the specified name.
*
* @param name name of the requested decoder
* @return A decoder if one was found, NULL otherwise.
*/
AVCodec *avcodec_find_decoder_by_name(const char *name);
void avcodec_string(char *buf, int buf_size, AVCodecContext *enc, int encode);

/**
* Return a name for the specified profile, if available.
*
* @param codec the codec that is searched for the given profile
* @param profile the profile value for which a name is requested
* @return A name for the profile if found, NULL otherwise.
*/
const char *av_get_profile_name(const AVCodec *codec, int profile);

#if FF_API_ALLOC_CONTEXT
/**
* Set the fields of the given AVCodecContext to default values.
*
* @param s The AVCodecContext of which the fields should be set to default values.
* @deprecated use avcodec_get_context_defaults3
*/
attribute_deprecated
void avcodec_get_context_defaults(AVCodecContext *s);

/** THIS FUNCTION IS NOT YET PART OF THE PUBLIC API!
*  we WILL change its arguments and name a few times! */
attribute_deprecated
void avcodec_get_context_defaults2(AVCodecContext *s, enum AVMediaType);
#endif

/**
* Set the fields of the given AVCodecContext to default values corresponding
* to the given codec (defaults may be codec-dependent).
*
* Do not call this function if a non-NULL codec has been passed
* to avcodec_alloc_context3() that allocated this AVCodecContext.
* If codec is non-NULL, it is illegal to call avcodec_open2() with a
* different codec on this AVCodecContext.
*/
int avcodec_get_context_defaults3(AVCodecContext *s, AVCodec *codec);

#if FF_API_ALLOC_CONTEXT
/**
* Allocate an AVCodecContext and set its fields to default values.  The
* resulting struct can be deallocated by simply calling av_free().
*
* @return An AVCodecContext filled with default values or NULL on failure.
* @see avcodec_get_context_defaults
*
* @deprecated use avcodec_alloc_context3()
*/
attribute_deprecated
AVCodecContext *avcodec_alloc_context(void);

/** THIS FUNCTION IS NOT YET PART OF THE PUBLIC API!
*  we WILL change its arguments and name a few times! */
attribute_deprecated
AVCodecContext *avcodec_alloc_context2(enum AVMediaType);
#endif

/**
* Allocate an AVCodecContext and set its fields to default values.  The
* resulting struct can be deallocated by calling avcodec_close() on it followed
* by av_free().
*
* @param codec if non-NULL, allocate private data and initialize defaults
*              for the given codec. It is illegal to then call avcodec_open2()
*              with a different codec.
*
* @return An AVCodecContext filled with default values or NULL on failure.
* @see avcodec_get_context_defaults
*/
AVCodecContext *avcodec_alloc_context3(AVCodec *codec);

/**
* Copy the settings of the source AVCodecContext into the destination
* AVCodecContext. The resulting destination codec context will be
* unopened, i.e. you are required to call avcodec_open2() before you
* can use this AVCodecContext to decode/encode video/audio data.
*
* @param dest target codec context, should be initialized with
*             avcodec_alloc_context3(), but otherwise uninitialized
* @param src source codec context
* @return AVERROR() on error (e.g. memory allocation error), 0 on success
*/
int avcodec_copy_context(AVCodecContext *dest, const AVCodecContext *src);

/**
* Set the fields of the given AVFrame to default values.
*
* @param pic The AVFrame of which the fields should be set to default values.
*/
void avcodec_get_frame_defaults(AVFrame *pic);

/**
* Allocate an AVFrame and set its fields to default values.  The resulting
* struct can be deallocated by simply calling av_free().
*
* @return An AVFrame filled with default values or NULL on failure.
* @see avcodec_get_frame_defaults
*/
AVFrame *avcodec_alloc_frame(void);

int avcodec_default_get_buffer(AVCodecContext *s, AVFrame *pic);
void avcodec_default_release_buffer(AVCodecContext *s, AVFrame *pic);
int avcodec_default_reget_buffer(AVCodecContext *s, AVFrame *pic);

/**
* Return the amount of padding in pixels which the get_buffer callback must
* provide around the edge of the image for codecs which do not have the
* CODEC_FLAG_EMU_EDGE flag.
*
* @return Required padding in pixels.
*/
unsigned avcodec_get_edge_width(void);
/**
* Modify width and height values so that they will result in a memory
* buffer that is acceptable for the codec if you do not use any horizontal
* padding.
*
* May only be used if a codec with CODEC_CAP_DR1 has been opened.
* If CODEC_FLAG_EMU_EDGE is not set, the dimensions must have been increased
* according to avcodec_get_edge_width() before.
*/
void avcodec_align_dimensions(AVCodecContext *s, int *width, int *height);
/**
* Modify width and height values so that they will result in a memory
* buffer that is acceptable for the codec if you also ensure that all
* line sizes are a multiple of the respective linesize_align[i].
*
* May only be used if a codec with CODEC_CAP_DR1 has been opened.
* If CODEC_FLAG_EMU_EDGE is not set, the dimensions must have been increased
* according to avcodec_get_edge_width() before.
*/
void avcodec_align_dimensions2(AVCodecContext *s, int *width, int *height,
                              int linesize_align[AV_NUM_DATA_POINTERS]);

enum PixelFormat avcodec_default_get_format(struct AVCodecContext *s, const enum PixelFormat * fmt);

#if FF_API_THREAD_INIT
/**
* @deprecated Set s->thread_count before calling avcodec_open2() instead of calling this.
*/
attribute_deprecated
int avcodec_thread_init(AVCodecContext *s, int thread_count);
#endif

int avcodec_default_execute(AVCodecContext *c, int (*func)(AVCodecContext *c2, void *arg2),void *arg, int *ret, int count, int size);
int avcodec_default_execute2(AVCodecContext *c, int (*func)(AVCodecContext *c2, void *arg2, int, int),void *arg, int *ret, int count);
//FIXME func typedef

#if FF_API_AVCODEC_OPEN
/**
* Initialize the AVCodecContext to use the given AVCodec. Prior to using this
* function the context has to be allocated.
*
* The functions avcodec_find_decoder_by_name(), avcodec_find_encoder_by_name(),
* avcodec_find_decoder() and avcodec_find_encoder() provide an easy way for
* retrieving a codec.
*
* @warning This function is not thread safe!
*
* @code
* avcodec_register_all();
* codec = avcodec_find_decoder(CODEC_ID_H264);
* if (!codec)
*     exit(1);
*
* context = avcodec_alloc_context3(codec);
*
* if (avcodec_open(context, codec) < 0)
*     exit(1);
* @endcode
*
* @param avctx The context which will be set up to use the given codec.
* @param codec The codec to use within the context.
* @return zero on success, a negative value on error
* @see avcodec_alloc_context3, avcodec_find_decoder, avcodec_find_encoder, avcodec_close
*
* @deprecated use avcodec_open2
*/
attribute_deprecated
int avcodec_open(AVCodecContext *avctx, AVCodec *codec);
#endif

/**
* Initialize the AVCodecContext to use the given AVCodec. Prior to using this
* function the context has to be allocated with avcodec_alloc_context3().
*
* The functions avcodec_find_decoder_by_name(), avcodec_find_encoder_by_name(),
* avcodec_find_decoder() and avcodec_find_encoder() provide an easy way for
* retrieving a codec.
*
* @warning This function is not thread safe!
*
* @code
* avcodec_register_all();
* av_dict_set(&opts, "b", "2.5M", 0);
* codec = avcodec_find_decoder(CODEC_ID_H264);
* if (!codec)
*     exit(1);
*
* context = avcodec_alloc_context3(codec);
*
* if (avcodec_open2(context, codec, opts) < 0)
*     exit(1);
* @endcode
*
* @param avctx The context to initialize.
* @param codec The codec to open this context for. If a non-NULL codec has been
*              previously passed to avcodec_alloc_context3() or
*              avcodec_get_context_defaults3() for this context, then this
*              parameter MUST be either NULL or equal to the previously passed
*              codec.
* @param options A dictionary filled with AVCodecContext and codec-private options.
*                On return this object will be filled with options that were not found.
*
* @return zero on success, a negative value on error
* @see avcodec_alloc_context3(), avcodec_find_decoder(), avcodec_find_encoder(),
*      av_dict_set(), av_opt_find().
*/
int avcodec_open2(AVCodecContext *avctx, AVCodec *codec, AVDictionary **options);

#if FF_API_OLD_DECODE_AUDIO
/**
* Wrapper function which calls avcodec_decode_audio4.
*
* @deprecated Use avcodec_decode_audio4 instead.
*
* Decode the audio frame of size avpkt->size from avpkt->data into samples.
* Some decoders may support multiple frames in a single AVPacket, such
* decoders would then just decode the first frame. In this case,
* avcodec_decode_audio3 has to be called again with an AVPacket that contains
* the remaining data in order to decode the second frame etc.
* If no frame
* could be outputted, frame_size_ptr is zero. Otherwise, it is the
* decompressed frame size in bytes.
*
* @warning You must set frame_size_ptr to the allocated size of the
* output buffer before calling avcodec_decode_audio3().
*
* @warning The input buffer must be FF_INPUT_BUFFER_PADDING_SIZE larger than
* the actual read bytes because some optimized bitstream readers read 32 or 64
* bits at once and could read over the end.
*
* @warning The end of the input buffer avpkt->data should be set to 0 to ensure that
* no overreading happens for damaged MPEG streams.
*
* @warning You must not provide a custom get_buffer() when using
* avcodec_decode_audio3().  Doing so will override it with
* avcodec_default_get_buffer.  Use avcodec_decode_audio4() instead,
* which does allow the application to provide a custom get_buffer().
*
* @note You might have to align the input buffer avpkt->data and output buffer
* samples. The alignment requirements depend on the CPU: On some CPUs it isn't
* necessary at all, on others it won't work at all if not aligned and on others
* it will work but it will have an impact on performance.
*
* In practice, avpkt->data should have 4 byte alignment at minimum and
* samples should be 16 byte aligned unless the CPU doesn't need it
* (AltiVec and SSE do).
*
* @note Codecs which have the CODEC_CAP_DELAY capability set have a delay
* between input and output, these need to be fed with avpkt->data=NULL,
* avpkt->size=0 at the end to return the remaining frames.
*
* @param avctx the codec context
* @param[out] samples the output buffer, sample type in avctx->sample_fmt
*                     If the sample format is planar, each channel plane will
*                     be the same size, with no padding between channels.
* @param[in,out] frame_size_ptr the output buffer size in bytes
* @param[in] avpkt The input AVPacket containing the input buffer.
*            You can create such packet with av_init_packet() and by then setting
*            data and size, some decoders might in addition need other fields.
*            All decoders are designed to use the least fields possible though.
* @return On error a negative value is returned, otherwise the number of bytes
* used or zero if no frame data was decompressed (used) from the input AVPacket.
*/
attribute_deprecated int avcodec_decode_audio3(AVCodecContext *avctx, int16_t *samples,
                        int *frame_size_ptr,
                        AVPacket *avpkt);
#endif

/**
* Decode the audio frame of size avpkt->size from avpkt->data into frame.
*
* Some decoders may support multiple frames in a single AVPacket. Such
* decoders would then just decode the first frame. In this case,
* avcodec_decode_audio4 has to be called again with an AVPacket containing
* the remaining data in order to decode the second frame, etc...
* Even if no frames are returned, the packet needs to be fed to the decoder
* with remaining data until it is completely consumed or an error occurs.
*
* @warning The input buffer, avpkt->data must be FF_INPUT_BUFFER_PADDING_SIZE
*          larger than the actual read bytes because some optimized bitstream
*          readers read 32 or 64 bits at once and could read over the end.
*
* @note You might have to align the input buffer. The alignment requirements
*       depend on the CPU and the decoder.
*
* @param      avctx the codec context
* @param[out] frame The AVFrame in which to store decoded audio samples.
*                   Decoders request a buffer of a particular size by setting
*                   AVFrame.nb_samples prior to calling get_buffer(). The
*                   decoder may, however, only utilize part of the buffer by
*                   setting AVFrame.nb_samples to a smaller value in the
*                   output frame.
* @param[out] got_frame_ptr Zero if no frame could be decoded, otherwise it is
*                           non-zero.
* @param[in]  avpkt The input AVPacket containing the input buffer.
*                   At least avpkt->data and avpkt->size should be set. Some
*                   decoders might also require additional fields to be set.
* @return A negative error code is returned if an error occurred during
*         decoding, otherwise the number of bytes consumed from the input
*         AVPacket is returned.
*/
int avcodec_decode_audio4(AVCodecContext *avctx, AVFrame *frame,
                         int *got_frame_ptr, AVPacket *avpkt);

/**
* Decode the video frame of size avpkt->size from avpkt->data into picture.
* Some decoders may support multiple frames in a single AVPacket, such
* decoders would then just decode the first frame.
*
* @warning The input buffer must be FF_INPUT_BUFFER_PADDING_SIZE larger than
* the actual read bytes because some optimized bitstream readers read 32 or 64
* bits at once and could read over the end.
*
* @warning The end of the input buffer buf should be set to 0 to ensure that
* no overreading happens for damaged MPEG streams.
*
* @note You might have to align the input buffer avpkt->data.
* The alignment requirements depend on the CPU: on some CPUs it isn't
* necessary at all, on others it won't work at all if not aligned and on others
* it will work but it will have an impact on performance.
*
* In practice, avpkt->data should have 4 byte alignment at minimum.
*
* @note Codecs which have the CODEC_CAP_DELAY capability set have a delay
* between input and output, these need to be fed with avpkt->data=NULL,
* avpkt->size=0 at the end to return the remaining frames.
*
* @param avctx the codec context
* @param[out] picture The AVFrame in which the decoded video frame will be stored.
*             Use avcodec_alloc_frame to get an AVFrame, the codec will
*             allocate memory for the actual bitmap.
*             with default get/release_buffer(), the decoder frees/reuses the bitmap as it sees fit.
*             with overridden get/release_buffer() (needs CODEC_CAP_DR1) the user decides into what buffer the decoder
*                   decodes and the decoder tells the user once it does not need the data anymore,
*                   the user app can at this point free/reuse/keep the memory as it sees fit.
*
* @param[in] avpkt The input AVpacket containing the input buffer.
*            You can create such packet with av_init_packet() and by then setting
*            data and size, some decoders might in addition need other fields like
*            flags&AV_PKT_FLAG_KEY. All decoders are designed to use the least
*            fields possible.
* @param[in,out] got_picture_ptr Zero if no frame could be decompressed, otherwise, it is nonzero.
* @return On error a negative value is returned, otherwise the number of bytes
* used or zero if no frame could be decompressed.
*/
int avcodec_decode_video2(AVCodecContext *avctx, AVFrame *picture,
                        int *got_picture_ptr,
                        AVPacket *avpkt);

/**
* Decode a subtitle message.
* Return a negative value on error, otherwise return the number of bytes used.
* If no subtitle could be decompressed, got_sub_ptr is zero.
* Otherwise, the subtitle is stored in *sub.
* Note that CODEC_CAP_DR1 is not available for subtitle codecs. This is for
* simplicity, because the performance difference is expect to be negligible
* and reusing a get_buffer written for video codecs would probably perform badly
* due to a potentially very different allocation pattern.
*
* @param avctx the codec context
* @param[out] sub The AVSubtitle in which the decoded subtitle will be stored, must be
                  freed with avsubtitle_free if *got_sub_ptr is set.
* @param[in,out] got_sub_ptr Zero if no subtitle could be decompressed, otherwise, it is nonzero.
* @param[in] avpkt The input AVPacket containing the input buffer.
*/
int avcodec_decode_subtitle2(AVCodecContext *avctx, AVSubtitle *sub,
                           int *got_sub_ptr,
                           AVPacket *avpkt);

/**
* Free all allocated data in the given subtitle struct.
*
* @param sub AVSubtitle to free.
*/
void avsubtitle_free(AVSubtitle *sub);

#if FF_API_OLD_ENCODE_AUDIO
/**
* Encode an audio frame from samples into buf.
*
* @deprecated Use avcodec_encode_audio2 instead.
*
* @note The output buffer should be at least FF_MIN_BUFFER_SIZE bytes large.
* However, for codecs with avctx->frame_size equal to 0 (e.g. PCM) the user
* will know how much space is needed because it depends on the value passed
* in buf_size as described below. In that case a lower value can be used.
*
* @param avctx the codec context
* @param[out] buf the output buffer
* @param[in] buf_size the output buffer size
* @param[in] samples the input buffer containing the samples
* The number of samples read from this buffer is frame_size*channels,
* both of which are defined in avctx.
* For codecs which have avctx->frame_size equal to 0 (e.g. PCM) the number of
* samples read from samples is equal to:
* buf_size * 8 / (avctx->channels * av_get_bits_per_sample(avctx->codec_id))
* This also implies that av_get_bits_per_sample() must not return 0 for these
* codecs.
* @return On error a negative value is returned, on success zero or the number
* of bytes used to encode the data read from the input buffer.
*/
int attribute_deprecated avcodec_encode_audio(AVCodecContext *avctx,
                                             uint8_t *buf, int buf_size,
                                             const short *samples);
#endif

/**
* Encode a frame of audio.
*
* Takes input samples from frame and writes the next output packet, if
* available, to avpkt. The output packet does not necessarily contain data for
* the most recent frame, as encoders can delay, split, and combine input frames
* internally as needed.
*
* @param avctx     codec context
* @param avpkt     output AVPacket.
*                  The user can supply an output buffer by setting
*                  avpkt->data and avpkt->size prior to calling the
*                  function, but if the size of the user-provided data is not
*                  large enough, encoding will fail. All other AVPacket fields
*                  will be reset by the encoder using av_init_packet(). If
*                  avpkt->data is NULL, the encoder will allocate it.
*                  The encoder will set avpkt->size to the size of the
*                  output packet.
* @param[in] frame AVFrame containing the raw audio data to be encoded.
*                  May be NULL when flushing an encoder that has the
*                  CODEC_CAP_DELAY capability set.
*                  There are 2 codec capabilities that affect the allowed
*                  values of frame->nb_samples.
*                  If CODEC_CAP_SMALL_LAST_FRAME is set, then only the final
*                  frame may be smaller than avctx->frame_size, and all other
*                  frames must be equal to avctx->frame_size.
*                  If CODEC_CAP_VARIABLE_FRAME_SIZE is set, then each frame
*                  can have any number of samples.
*                  If neither is set, frame->nb_samples must be equal to
*                  avctx->frame_size for all frames.
* @param[out] got_packet_ptr This field is set to 1 by libavcodec if the
*                            output packet is non-empty, and to 0 if it is
*                            empty. If the function returns an error, the
*                            packet can be assumed to be invalid, and the
*                            value of got_packet_ptr is undefined and should
*                            not be used.
* @return          0 on success, negative error code on failure
*/
int avcodec_encode_audio2(AVCodecContext *avctx, AVPacket *avpkt,
                         const AVFrame *frame, int *got_packet_ptr);

/**
* Fill audio frame data and linesize.
* AVFrame extended_data channel pointers are allocated if necessary for
* planar audio.
*
* @param frame       the AVFrame
*                    frame->nb_samples must be set prior to calling the
*                    function. This function fills in frame->data,
*                    frame->extended_data, frame->linesize[0].
* @param nb_channels channel count
* @param sample_fmt  sample format
* @param buf         buffer to use for frame data
* @param buf_size    size of buffer
* @param align       plane size sample alignment
* @return            0 on success, negative error code on failure
*/
int avcodec_fill_audio_frame(AVFrame *frame, int nb_channels,
                            enum AVSampleFormat sample_fmt, const uint8_t *buf,
                            int buf_size, int align);

/**
* Encode a video frame from pict into buf.
* The input picture should be
* stored using a specific format, namely avctx.pix_fmt.
*
* @param avctx the codec context
* @param[out] buf the output buffer for the bitstream of encoded frame
* @param[in] buf_size the size of the output buffer in bytes
* @param[in] pict the input picture to encode
* @return On error a negative value is returned, on success zero or the number
* of bytes used from the output buffer.
*/
int avcodec_encode_video(AVCodecContext *avctx, uint8_t *buf, int buf_size,
                        const AVFrame *pict);
int avcodec_encode_subtitle(AVCodecContext *avctx, uint8_t *buf, int buf_size,
                           const AVSubtitle *sub);

/**
* Close a given AVCodecContext and free all the data associated with it
* (but not the AVCodecContext itself).
*
* Calling this function on an AVCodecContext that hasn't been opened will free
* the codec-specific data allocated in avcodec_alloc_context3() /
* avcodec_get_context_defaults3() with a non-NULL codec. Subsequent calls will
* do nothing.
*/
int avcodec_close(AVCodecContext *avctx);

/**
* Register all the codecs, parsers and bitstream filters which were enabled at
* configuration time. If you do not call this function you can select exactly
* which formats you want to support, by using the individual registration
* functions.
*
* @see avcodec_register
* @see av_register_codec_parser
* @see av_register_bitstream_filter
*/
void avcodec_register_all(void);

/**
* Flush buffers, should be called when seeking or when switching to a different stream.
*/
void avcodec_flush_buffers(AVCodecContext *avctx);

void avcodec_default_free_buffers(AVCodecContext *s);

/* misc useful functions */

#if FF_API_OLD_FF_PICT_TYPES
/**
* Return a single letter to describe the given picture type pict_type.
*
* @param[in] pict_type the picture type
* @return A single character representing the picture type.
* @deprecated Use av_get_picture_type_char() instead.
*/
attribute_deprecated
char av_get_pict_type_char(int pict_type);
#endif

/**
* Return codec bits per sample.
*
* @param[in] codec_id the codec
* @return Number of bits per sample or zero if unknown for the given codec.
*/
int av_get_bits_per_sample(enum CodecID codec_id);

#if FF_API_OLD_SAMPLE_FMT
/**
* @deprecated Use av_get_bytes_per_sample() instead.
*/
attribute_deprecated
int av_get_bits_per_sample_format(enum AVSampleFormat sample_fmt);
#endif

/* frame parsing */
typedef struct AVCodecParserContext {
   void *priv_data;
   struct AVCodecParser *parser;
   int64_t frame_offset; /* offset of the current frame */
   int64_t cur_offset; /* current offset
                          (incremented by each av_parser_parse()) */
   int64_t next_frame_offset; /* offset of the next frame */
   /* video info */
   int pict_type; /* XXX: Put it back in AVCodecContext. */
   /**
    * This field is used for proper frame duration computation in lavf.
    * It signals, how much longer the frame duration of the current frame
    * is compared to normal frame duration.
    *
    * frame_duration = (1 + repeat_pict) * time_base
    *
    * It is used by codecs like H.264 to display telecined material.
    */
   int repeat_pict; /* XXX: Put it back in AVCodecContext. */
   int64_t pts;     /* pts of the current frame */
   int64_t dts;     /* dts of the current frame */

   /* private data */
   int64_t last_pts;
   int64_t last_dts;
   int fetch_timestamp;

#define AV_PARSER_PTS_NB 4
   int cur_frame_start_index;
   int64_t cur_frame_offset[AV_PARSER_PTS_NB];
   int64_t cur_frame_pts[AV_PARSER_PTS_NB];
   int64_t cur_frame_dts[AV_PARSER_PTS_NB];

   int flags;
#define PARSER_FLAG_COMPLETE_FRAMES           0x0001
#define PARSER_FLAG_ONCE                      0x0002
/// Set if the parser has a valid file offset
#define PARSER_FLAG_FETCHED_OFFSET            0x0004

   int64_t offset;      ///< byte offset from starting packet start
   int64_t cur_frame_end[AV_PARSER_PTS_NB];

   /**
    * Set by parser to 1 for key frames and 0 for non-key frames.
    * It is initialized to -1, so if the parser doesn't set this flag,
    * old-style fallback using AV_PICTURE_TYPE_I picture type as key frames
    * will be used.
    */
   int key_frame;

   /**
    * Time difference in stream time base units from the pts of this
    * packet to the point at which the output from the decoder has converged
    * independent from the availability of previous frames. That is, the
    * frames are virtually identical no matter if decoding started from
    * the very first frame or from this keyframe.
    * Is AV_NOPTS_VALUE if unknown.
    * This field is not the display duration of the current frame.
    * This field has no meaning if the packet does not have AV_PKT_FLAG_KEY
    * set.
    *
    * The purpose of this field is to allow seeking in streams that have no
    * keyframes in the conventional sense. It corresponds to the
    * recovery point SEI in H.264 and match_time_delta in NUT. It is also
    * essential for some types of subtitle streams to ensure that all
    * subtitles are correctly displayed after seeking.
    */
   int64_t convergence_duration;

   // Timestamp generation support:
   /**
    * Synchronization point for start of timestamp generation.
    *
    * Set to >0 for sync point, 0 for no sync point and <0 for undefined
    * (default).
    *
    * For example, this corresponds to presence of H.264 buffering period
    * SEI message.
    */
   int dts_sync_point;

   /**
    * Offset of the current timestamp against last timestamp sync point in
    * units of AVCodecContext.time_base.
    *
    * Set to INT_MIN when dts_sync_point unused. Otherwise, it must
    * contain a valid timestamp offset.
    *
    * Note that the timestamp of sync point has usually a nonzero
    * dts_ref_dts_delta, which refers to the previous sync point. Offset of
    * the next frame after timestamp sync point will be usually 1.
    *
    * For example, this corresponds to H.264 cpb_removal_delay.
    */
   int dts_ref_dts_delta;

   /**
    * Presentation delay of current frame in units of AVCodecContext.time_base.
    *
    * Set to INT_MIN when dts_sync_point unused. Otherwise, it must
    * contain valid non-negative timestamp delta (presentation time of a frame
    * must not lie in the past).
    *
    * This delay represents the difference between decoding and presentation
    * time of the frame.
    *
    * For example, this corresponds to H.264 dpb_output_delay.
    */
   int pts_dts_delta;

   /**
    * Position of the packet in file.
    *
    * Analogous to cur_frame_pts/dts
    */
   int64_t cur_frame_pos[AV_PARSER_PTS_NB];

   /**
    * Byte position of currently parsed frame in stream.
    */
   int64_t pos;

   /**
    * Previous frame byte position.
    */
   int64_t last_pos;
} AVCodecParserContext;

typedef struct AVCodecParser {
   int codec_ids[5]; /* several codec IDs are permitted */
   int priv_data_size;
   int (*parser_init)(AVCodecParserContext *s);
   int (*parser_parse)(AVCodecParserContext *s,
                       AVCodecContext *avctx,
                       const uint8_t **poutbuf, int *poutbuf_size,
                       const uint8_t *buf, int buf_size);
   void (*parser_close)(AVCodecParserContext *s);
   int (*split)(AVCodecContext *avctx, const uint8_t *buf, int buf_size);
   struct AVCodecParser *next;
} AVCodecParser;

AVCodecParser *av_parser_next(AVCodecParser *c);

void av_register_codec_parser(AVCodecParser *parser);
AVCodecParserContext *av_parser_init(int codec_id);

/**
* Parse a packet.
*
* @param s             parser context.
* @param avctx         codec context.
* @param poutbuf       set to pointer to parsed buffer or NULL if not yet finished.
* @param poutbuf_size  set to size of parsed buffer or zero if not yet finished.
* @param buf           input buffer.
* @param buf_size      input length, to signal EOF, this should be 0 (so that the last frame can be output).
* @param pts           input presentation timestamp.
* @param dts           input decoding timestamp.
* @param pos           input byte position in stream.
* @return the number of bytes of the input bitstream used.
*
* Example:
* @code
*   while(in_len){
*       len = av_parser_parse2(myparser, AVCodecContext, &data, &size,
*                                        in_data, in_len,
*                                        pts, dts, pos);
*       in_data += len;
*       in_len  -= len;
*
*       if(size)
*          decode_frame(data, size);
*   }
* @endcode
*/
int av_parser_parse2(AVCodecParserContext *s,
                    AVCodecContext *avctx,
                    uint8_t **poutbuf, int *poutbuf_size,
                    const uint8_t *buf, int buf_size,
                    int64_t pts, int64_t dts,
                    int64_t pos);

int av_parser_change(AVCodecParserContext *s,
                    AVCodecContext *avctx,
                    uint8_t **poutbuf, int *poutbuf_size,
                    const uint8_t *buf, int buf_size, int keyframe);
void av_parser_close(AVCodecParserContext *s);


typedef struct AVBitStreamFilterContext {
   void *priv_data;
   struct AVBitStreamFilter *filter;
   AVCodecParserContext *parser;
   struct AVBitStreamFilterContext *next;
} AVBitStreamFilterContext;


typedef struct AVBitStreamFilter {
   const char *name;
   int priv_data_size;
   int (*filter)(AVBitStreamFilterContext *bsfc,
                 AVCodecContext *avctx, const char *args,
                 uint8_t **poutbuf, int *poutbuf_size,
                 const uint8_t *buf, int buf_size, int keyframe);
   void (*close)(AVBitStreamFilterContext *bsfc);
   struct AVBitStreamFilter *next;
} AVBitStreamFilter;

void av_register_bitstream_filter(AVBitStreamFilter *bsf);
AVBitStreamFilterContext *av_bitstream_filter_init(const char *name);
int av_bitstream_filter_filter(AVBitStreamFilterContext *bsfc,
                              AVCodecContext *avctx, const char *args,
                              uint8_t **poutbuf, int *poutbuf_size,
                              const uint8_t *buf, int buf_size, int keyframe);
void av_bitstream_filter_close(AVBitStreamFilterContext *bsf);

AVBitStreamFilter *av_bitstream_filter_next(AVBitStreamFilter *f);

/* memory */

/**
* Reallocate the given block if it is not large enough, otherwise do nothing.
*
* @see av_realloc
*/
void *av_fast_realloc(void *ptr, unsigned int *size, size_t min_size);

/**
* Allocate a buffer, reusing the given one if large enough.
*
* Contrary to av_fast_realloc the current buffer contents might not be
* preserved and on error the old buffer is freed, thus no special
* handling to avoid memleaks is necessary.
*
* @param ptr pointer to pointer to already allocated buffer, overwritten with pointer to new buffer
* @param size size of the buffer *ptr points to
* @param min_size minimum size of *ptr buffer after returning, *ptr will be NULL and
*                 *size 0 if an error occurred.
*/
void av_fast_malloc(void *ptr, unsigned int *size, size_t min_size);

/**
* Copy image src to dst. Wraps av_picture_data_copy() above.
*/
void av_picture_copy(AVPicture *dst, const AVPicture *src,
                    enum PixelFormat pix_fmt, int width, int height);

/**
* Crop image top and left side.
*/
int av_picture_crop(AVPicture *dst, const AVPicture *src,
                   enum PixelFormat pix_fmt, int top_band, int left_band);

/**
* Pad image.
*/
int av_picture_pad(AVPicture *dst, const AVPicture *src, int height, int width, enum PixelFormat pix_fmt,
           int padtop, int padbottom, int padleft, int padright, int *color);

/**
* Encode extradata length to a buffer. Used by xiph codecs.
*
* @param s buffer to write to; must be at least (v/255+1) bytes long
* @param v size of extradata in bytes
* @return number of bytes written to the buffer.
*/
unsigned int av_xiphlacing(unsigned char *s, unsigned int v);

/**
* Log a generic warning message about a missing feature. This function is
* intended to be used internally by Libav (libavcodec, libavformat, etc.)
* only, and would normally not be used by applications.
* @param[in] avc a pointer to an arbitrary struct of which the first field is
* a pointer to an AVClass struct
* @param[in] feature string containing the name of the missing feature
* @param[in] want_sample indicates if samples are wanted which exhibit this feature.
* If want_sample is non-zero, additional verbage will be added to the log
* message which tells the user how to report samples to the development
* mailing list.
*/
void av_log_missing_feature(void *avc, const char *feature, int want_sample);

/**
* Log a generic warning message asking for a sample. This function is
* intended to be used internally by Libav (libavcodec, libavformat, etc.)
* only, and would normally not be used by applications.
* @param[in] avc a pointer to an arbitrary struct of which the first field is
* a pointer to an AVClass struct
* @param[in] msg string containing an optional message, or NULL if no message
*/
void av_log_ask_for_sample(void *avc, const char *msg, ...) av_printf_format(2, 3);

/**
* Register the hardware accelerator hwaccel.
*/
void av_register_hwaccel(AVHWAccel *hwaccel);

/**
* If hwaccel is NULL, returns the first registered hardware accelerator,
* if hwaccel is non-NULL, returns the next registered hardware accelerator
* after hwaccel, or NULL if hwaccel is the last one.
*/
AVHWAccel *av_hwaccel_next(AVHWAccel *hwaccel);


/**
* Lock operation used by lockmgr
*/
enum AVLockOp {
 AV_LOCK_CREATE,  ///< Create a mutex
 AV_LOCK_OBTAIN,  ///< Lock the mutex
 AV_LOCK_RELEASE, ///< Unlock the mutex
 AV_LOCK_DESTROY, ///< Free mutex resources
};

/**
* Register a user provided lock manager supporting the operations
* specified by AVLockOp. mutex points to a (void *) where the
* lockmgr should store/get a pointer to a user allocated mutex. It's
* NULL upon AV_LOCK_CREATE and != NULL for all other ops.
*
* @param cb User defined callback. Note: Libav may invoke calls to this
*           callback during the call to av_lockmgr_register().
*           Thus, the application must be prepared to handle that.
*           If cb is set to NULL the lockmgr will be unregistered.
*           Also note that during unregistration the previously registered
*           lockmgr callback may also be invoked.
*/
int av_lockmgr_register(int (*cb)(void **mutex, enum AVLockOp op));

/**
* Get the type of the given codec.
*/
enum AVMediaType avcodec_get_type(enum CodecID codec_id);

/**
* Get the AVClass for AVCodecContext. It can be used in combination with
* AV_OPT_SEARCH_FAKE_OBJ for examining options.
*
* @see av_opt_find().
*/
const AVClass *avcodec_get_class(void);

/**
* @return a positive value if s is open (i.e. avcodec_open2() was called on it
* with no corresponding avcodec_close()), 0 otherwise.
*/
int avcodec_is_open(AVCodecContext *s);

#endif /* AVCODEC_AVCODEC_H */