tor-browser

codec.h (17274B)

---

/*
* AVCodec public API
*
* This file is part of FFmpeg.
*
* FFmpeg 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.
*
* FFmpeg 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 FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/

#ifndef AVCODEC_CODEC_H
#define AVCODEC_CODEC_H

#include <stdint.h>

#include "libavutil/avutil.h"
#include "libavutil/hwcontext.h"
#include "libavutil/log.h"
#include "libavutil/pixfmt.h"
#include "libavutil/rational.h"
#include "libavutil/samplefmt.h"

#include "libavcodec/codec_id.h"
#include "libavcodec/version.h"

/**
* @addtogroup lavc_core
* @{
*/

/**
* Decoder can use draw_horiz_band callback.
*/
#define AV_CODEC_CAP_DRAW_HORIZ_BAND     (1 <<  0)
/**
* Codec uses get_buffer() or get_encode_buffer() for allocating buffers and
* supports custom allocators.
* If not set, it might not use get_buffer() or get_encode_buffer() at all, or
* use operations that assume the buffer was allocated by
* avcodec_default_get_buffer2 or avcodec_default_get_encode_buffer.
*/
#define AV_CODEC_CAP_DR1                 (1 <<  1)
#define AV_CODEC_CAP_TRUNCATED           (1 <<  3)
/**
* 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 AV_CODEC_CAP_DELAY               (1 <<  5)
/**
* Codec can be fed a final frame with a smaller size.
* This can be used to prevent truncation of the last audio samples.
*/
#define AV_CODEC_CAP_SMALL_LAST_FRAME    (1 <<  6)

/**
* 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 carrying 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 AV_CODEC_CAP_SUBFRAMES           (1 <<  8)
/**
* Codec is experimental and is thus avoided in favor of non experimental
* encoders
*/
#define AV_CODEC_CAP_EXPERIMENTAL        (1 <<  9)
/**
* Codec should fill in channel configuration and samplerate instead of container
*/
#define AV_CODEC_CAP_CHANNEL_CONF        (1 << 10)
/**
* Codec supports frame-level multithreading.
*/
#define AV_CODEC_CAP_FRAME_THREADS       (1 << 12)
/**
* Codec supports slice-based (or partition-based) multithreading.
*/
#define AV_CODEC_CAP_SLICE_THREADS       (1 << 13)
/**
* Codec supports changed parameters at any point.
*/
#define AV_CODEC_CAP_PARAM_CHANGE        (1 << 14)
/**
* Codec supports multithreading through a method other than slice- or
* frame-level multithreading. Typically this marks wrappers around
* multithreading-capable external libraries.
*/
#define AV_CODEC_CAP_OTHER_THREADS       (1 << 15)
#if FF_API_AUTO_THREADS
#define AV_CODEC_CAP_AUTO_THREADS        AV_CODEC_CAP_OTHER_THREADS
#endif
/**
* Audio encoder supports receiving a different number of samples in each call.
*/
#define AV_CODEC_CAP_VARIABLE_FRAME_SIZE (1 << 16)
/**
* Decoder is not a preferred choice for probing.
* This indicates that the decoder is not a good choice for probing.
* It could for example be an expensive to spin up hardware decoder,
* or it could simply not provide a lot of useful information about
* the stream.
* A decoder marked with this flag should only be used as last resort
* choice for probing.
*/
#define AV_CODEC_CAP_AVOID_PROBING       (1 << 17)

#if FF_API_UNUSED_CODEC_CAPS
/**
* Deprecated and unused. Use AVCodecDescriptor.props instead
*/
#define AV_CODEC_CAP_INTRA_ONLY       0x40000000
/**
* Deprecated and unused. Use AVCodecDescriptor.props instead
*/
#define AV_CODEC_CAP_LOSSLESS         0x80000000
#endif

/**
* Codec is backed by a hardware implementation. Typically used to
* identify a non-hwaccel hardware decoder. For information about hwaccels, use
* avcodec_get_hw_config() instead.
*/
#define AV_CODEC_CAP_HARDWARE            (1 << 18)

/**
* Codec is potentially backed by a hardware implementation, but not
* necessarily. This is used instead of AV_CODEC_CAP_HARDWARE, if the
* implementation provides some sort of internal fallback.
*/
#define AV_CODEC_CAP_HYBRID              (1 << 19)

/**
* This codec takes the reordered_opaque field from input AVFrames
* and returns it in the corresponding field in AVCodecContext after
* encoding.
*/
#define AV_CODEC_CAP_ENCODER_REORDERED_OPAQUE (1 << 20)

/**
* This encoder can be flushed using avcodec_flush_buffers(). If this flag is
* not set, the encoder must be closed and reopened to ensure that no frames
* remain pending.
*/
#define AV_CODEC_CAP_ENCODER_FLUSH   (1 << 21)

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

typedef struct AVCodecDefault AVCodecDefault;

struct AVCodecContext;
struct AVSubtitle;
struct AVPacket;

/**
* 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;
   /**
    * 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;
   enum AVMediaType type;
   enum AVCodecID id;
   /**
    * Codec capabilities.
    * see AV_CODEC_CAP_*
    */
   int capabilities;
   const AVRational *supported_framerates; ///< array of supported framerates, or NULL if any, array is terminated by {0,0}
   const enum AVPixelFormat *pix_fmts;     ///< array of supported pixel formats, or NULL if unknown, array is terminated by -1
   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}

   /**
    * Group name of the codec implementation.
    * This is a short symbolic name of the wrapper backing this codec. A
    * wrapper uses some kind of external implementation for the codec, such
    * as an external library, or a codec implementation provided by the OS or
    * the hardware.
    * If this field is NULL, this is a builtin, libavcodec native codec.
    * If non-NULL, this will be the suffix in AVCodec.name in most cases
    * (usually AVCodec.name will be of the form "<codec_name>_<wrapper_name>").
    */
   const char *wrapper_name;

   /*****************************************************************
    * No fields below this line are part of the public API. They
    * may not be used outside of libavcodec and can be changed and
    * removed at will.
    * New public fields should be added right above.
    *****************************************************************
    */
   int priv_data_size;
#if FF_API_NEXT
   struct AVCodec *next;
#endif
   /**
    * @name Frame-level threading support functions
    * @{
    */
   /**
    * 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)(struct AVCodecContext *dst, const struct AVCodecContext *src);
   /** @} */

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

   /**
    * Initialize codec static data, called from av_codec_iterate().
    *
    * This is not intended for time consuming operations as it is
    * run for every codec regardless of that codec being used.
    */
   void (*init_static_data)(struct AVCodec *codec);

   int (*init)(struct AVCodecContext *);
   int (*encode_sub)(struct AVCodecContext *, uint8_t *buf, int buf_size,
                     const struct AVSubtitle *sub);
   /**
    * Encode data to an AVPacket.
    *
    * @param      avctx          codec context
    * @param      avpkt          output AVPacket
    * @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)(struct AVCodecContext *avctx, struct AVPacket *avpkt,
                  const struct AVFrame *frame, int *got_packet_ptr);
   /**
    * Decode picture or subtitle data.
    *
    * @param      avctx          codec context
    * @param      outdata        codec type dependent output struct
    * @param[out] got_frame_ptr  decoder sets to 0 or 1 to indicate that a
    *                            non-empty frame or subtitle was returned in
    *                            outdata.
    * @param[in]  avpkt          AVPacket containing the data to be decoded
    * @return amount of bytes read from the packet on success, negative error
    *         code on failure
    */
   int (*decode)(struct AVCodecContext *avctx, void *outdata,
                 int *got_frame_ptr, struct AVPacket *avpkt);
   int (*close)(struct AVCodecContext *);
   /**
    * Encode API with decoupled frame/packet dataflow. This function is called
    * to get one output packet. It should call ff_encode_get_frame() to obtain
    * input data.
    */
   int (*receive_packet)(struct AVCodecContext *avctx, struct AVPacket *avpkt);

   /**
    * Decode API with decoupled packet/frame dataflow. This function is called
    * to get one output frame. It should call ff_decode_get_packet() to obtain
    * input data.
    */
   int (*receive_frame)(struct AVCodecContext *avctx, struct AVFrame *frame);
   /**
    * Flush buffers.
    * Will be called when seeking
    */
   void (*flush)(struct AVCodecContext *);
   /**
    * Internal codec capabilities.
    * See FF_CODEC_CAP_* in internal.h
    */
   int caps_internal;

   /**
    * Decoding only, a comma-separated list of bitstream filters to apply to
    * packets before decoding.
    */
   const char *bsfs;

   /**
    * Array of pointers to hardware configurations supported by the codec,
    * or NULL if no hardware supported.  The array is terminated by a NULL
    * pointer.
    *
    * The user can only access this field via avcodec_get_hw_config().
    */
   const struct AVCodecHWConfigInternal *const *hw_configs;

   /**
    * List of supported codec_tags, terminated by FF_CODEC_TAGS_END.
    */
   const uint32_t *codec_tags;
} AVCodec;

/**
* Iterate over all registered codecs.
*
* @param opaque a pointer where libavcodec will store the iteration state. Must
*               point to NULL to start the iteration.
*
* @return the next registered codec or NULL when the iteration is
*         finished
*/
const AVCodec *av_codec_iterate(void **opaque);

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

/**
* Find a registered encoder with a matching codec ID.
*
* @param id AVCodecID of the requested encoder
* @return An encoder if one was found, NULL otherwise.
*/
AVCodec *avcodec_find_encoder(enum AVCodecID 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);
/**
* @return a non-zero number if codec is an encoder, zero otherwise
*/
int av_codec_is_encoder(const AVCodec *codec);

/**
* @return a non-zero number if codec is a decoder, zero otherwise
*/
int av_codec_is_decoder(const AVCodec *codec);

enum {
   /**
    * The codec supports this format via the hw_device_ctx interface.
    *
    * When selecting this format, AVCodecContext.hw_device_ctx should
    * have been set to a device of the specified type before calling
    * avcodec_open2().
    */
   AV_CODEC_HW_CONFIG_METHOD_HW_DEVICE_CTX = 0x01,
   /**
    * The codec supports this format via the hw_frames_ctx interface.
    *
    * When selecting this format for a decoder,
    * AVCodecContext.hw_frames_ctx should be set to a suitable frames
    * context inside the get_format() callback.  The frames context
    * must have been created on a device of the specified type.
    *
    * When selecting this format for an encoder,
    * AVCodecContext.hw_frames_ctx should be set to the context which
    * will be used for the input frames before calling avcodec_open2().
    */
   AV_CODEC_HW_CONFIG_METHOD_HW_FRAMES_CTX = 0x02,
   /**
    * The codec supports this format by some internal method.
    *
    * This format can be selected without any additional configuration -
    * no device or frames context is required.
    */
   AV_CODEC_HW_CONFIG_METHOD_INTERNAL      = 0x04,
   /**
    * The codec supports this format by some ad-hoc method.
    *
    * Additional settings and/or function calls are required.  See the
    * codec-specific documentation for details.  (Methods requiring
    * this sort of configuration are deprecated and others should be
    * used in preference.)
    */
   AV_CODEC_HW_CONFIG_METHOD_AD_HOC        = 0x08,
};

typedef struct AVCodecHWConfig {
   /**
    * For decoders, a hardware pixel format which that decoder may be
    * able to decode to if suitable hardware is available.
    *
    * For encoders, a pixel format which the encoder may be able to
    * accept.  If set to AV_PIX_FMT_NONE, this applies to all pixel
    * formats supported by the codec.
    */
   enum AVPixelFormat pix_fmt;
   /**
    * Bit set of AV_CODEC_HW_CONFIG_METHOD_* flags, describing the possible
    * setup methods which can be used with this configuration.
    */
   int methods;
   /**
    * The device type associated with the configuration.
    *
    * Must be set for AV_CODEC_HW_CONFIG_METHOD_HW_DEVICE_CTX and
    * AV_CODEC_HW_CONFIG_METHOD_HW_FRAMES_CTX, otherwise unused.
    */
   enum AVHWDeviceType device_type;
} AVCodecHWConfig;

/**
* Retrieve supported hardware configurations for a codec.
*
* Values of index from zero to some maximum return the indexed configuration
* descriptor; all other values return NULL.  If the codec does not support
* any hardware configurations then it will always return NULL.
*/
const AVCodecHWConfig *avcodec_get_hw_config(const AVCodec *codec, int index);

/**
* @}
*/

#endif /* AVCODEC_CODEC_H */