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frame.h (28932B)


      1 /*
      2 * This file is part of FFmpeg.
      3 *
      4 * FFmpeg is free software; you can redistribute it and/or
      5 * modify it under the terms of the GNU Lesser General Public
      6 * License as published by the Free Software Foundation; either
      7 * version 2.1 of the License, or (at your option) any later version.
      8 *
      9 * FFmpeg is distributed in the hope that it will be useful,
     10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
     11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     12 * Lesser General Public License for more details.
     13 *
     14 * You should have received a copy of the GNU Lesser General Public
     15 * License along with FFmpeg; if not, write to the Free Software
     16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
     17 */
     18 
     19 /**
     20 * @file
     21 * @ingroup lavu_frame
     22 * reference-counted frame API
     23 */
     24 
     25 #ifndef AVUTIL_FRAME_H
     26 #define AVUTIL_FRAME_H
     27 
     28 #include <stddef.h>
     29 #include <stdint.h>
     30 
     31 #include "avutil.h"
     32 #include "buffer.h"
     33 #include "dict.h"
     34 #include "rational.h"
     35 #include "samplefmt.h"
     36 #include "pixfmt.h"
     37 #include "version.h"
     38 
     39 
     40 /**
     41 * @defgroup lavu_frame AVFrame
     42 * @ingroup lavu_data
     43 *
     44 * @{
     45 * AVFrame is an abstraction for reference-counted raw multimedia data.
     46 */
     47 
     48 enum AVFrameSideDataType {
     49    /**
     50     * The data is the AVPanScan struct defined in libavcodec.
     51     */
     52    AV_FRAME_DATA_PANSCAN,
     53    /**
     54     * ATSC A53 Part 4 Closed Captions.
     55     * A53 CC bitstream is stored as uint8_t in AVFrameSideData.data.
     56     * The number of bytes of CC data is AVFrameSideData.size.
     57     */
     58    AV_FRAME_DATA_A53_CC,
     59    /**
     60     * Stereoscopic 3d metadata.
     61     * The data is the AVStereo3D struct defined in libavutil/stereo3d.h.
     62     */
     63    AV_FRAME_DATA_STEREO3D,
     64    /**
     65     * The data is the AVMatrixEncoding enum defined in libavutil/channel_layout.h.
     66     */
     67    AV_FRAME_DATA_MATRIXENCODING,
     68    /**
     69     * Metadata relevant to a downmix procedure.
     70     * The data is the AVDownmixInfo struct defined in libavutil/downmix_info.h.
     71     */
     72    AV_FRAME_DATA_DOWNMIX_INFO,
     73    /**
     74     * ReplayGain information in the form of the AVReplayGain struct.
     75     */
     76    AV_FRAME_DATA_REPLAYGAIN,
     77    /**
     78     * This side data contains a 3x3 transformation matrix describing an affine
     79     * transformation that needs to be applied to the frame for correct
     80     * presentation.
     81     *
     82     * See libavutil/display.h for a detailed description of the data.
     83     */
     84    AV_FRAME_DATA_DISPLAYMATRIX,
     85    /**
     86     * Active Format Description data consisting of a single byte as specified
     87     * in ETSI TS 101 154 using AVActiveFormatDescription enum.
     88     */
     89    AV_FRAME_DATA_AFD,
     90    /**
     91     * Motion vectors exported by some codecs (on demand through the export_mvs
     92     * flag set in the libavcodec AVCodecContext flags2 option).
     93     * The data is the AVMotionVector struct defined in
     94     * libavutil/motion_vector.h.
     95     */
     96    AV_FRAME_DATA_MOTION_VECTORS,
     97    /**
     98     * Recommmends skipping the specified number of samples. This is exported
     99     * only if the "skip_manual" AVOption is set in libavcodec.
    100     * This has the same format as AV_PKT_DATA_SKIP_SAMPLES.
    101     * @code
    102     * u32le number of samples to skip from start of this packet
    103     * u32le number of samples to skip from end of this packet
    104     * u8    reason for start skip
    105     * u8    reason for end   skip (0=padding silence, 1=convergence)
    106     * @endcode
    107     */
    108    AV_FRAME_DATA_SKIP_SAMPLES,
    109    /**
    110     * This side data must be associated with an audio frame and corresponds to
    111     * enum AVAudioServiceType defined in avcodec.h.
    112     */
    113    AV_FRAME_DATA_AUDIO_SERVICE_TYPE,
    114    /**
    115     * Mastering display metadata associated with a video frame. The payload is
    116     * an AVMasteringDisplayMetadata type and contains information about the
    117     * mastering display color volume.
    118     */
    119    AV_FRAME_DATA_MASTERING_DISPLAY_METADATA,
    120    /**
    121     * The GOP timecode in 25 bit timecode format. Data format is 64-bit integer.
    122     * This is set on the first frame of a GOP that has a temporal reference of 0.
    123     */
    124    AV_FRAME_DATA_GOP_TIMECODE,
    125 
    126    /**
    127     * The data represents the AVSphericalMapping structure defined in
    128     * libavutil/spherical.h.
    129     */
    130    AV_FRAME_DATA_SPHERICAL,
    131 
    132    /**
    133     * Content light level (based on CTA-861.3). This payload contains data in
    134     * the form of the AVContentLightMetadata struct.
    135     */
    136    AV_FRAME_DATA_CONTENT_LIGHT_LEVEL,
    137 
    138    /**
    139     * The data contains an ICC profile as an opaque octet buffer following the
    140     * format described by ISO 15076-1 with an optional name defined in the
    141     * metadata key entry "name".
    142     */
    143    AV_FRAME_DATA_ICC_PROFILE,
    144 
    145 #if FF_API_FRAME_QP
    146    /**
    147     * Implementation-specific description of the format of AV_FRAME_QP_TABLE_DATA.
    148     * The contents of this side data are undocumented and internal; use
    149     * av_frame_set_qp_table() and av_frame_get_qp_table() to access this in a
    150     * meaningful way instead.
    151     */
    152    AV_FRAME_DATA_QP_TABLE_PROPERTIES,
    153 
    154    /**
    155     * Raw QP table data. Its format is described by
    156     * AV_FRAME_DATA_QP_TABLE_PROPERTIES. Use av_frame_set_qp_table() and
    157     * av_frame_get_qp_table() to access this instead.
    158     */
    159    AV_FRAME_DATA_QP_TABLE_DATA,
    160 #endif
    161 };
    162 
    163 enum AVActiveFormatDescription {
    164    AV_AFD_SAME         = 8,
    165    AV_AFD_4_3          = 9,
    166    AV_AFD_16_9         = 10,
    167    AV_AFD_14_9         = 11,
    168    AV_AFD_4_3_SP_14_9  = 13,
    169    AV_AFD_16_9_SP_14_9 = 14,
    170    AV_AFD_SP_4_3       = 15,
    171 };
    172 
    173 
    174 /**
    175 * Structure to hold side data for an AVFrame.
    176 *
    177 * sizeof(AVFrameSideData) is not a part of the public ABI, so new fields may be added
    178 * to the end with a minor bump.
    179 */
    180 typedef struct AVFrameSideData {
    181    enum AVFrameSideDataType type;
    182    uint8_t *data;
    183    int      size;
    184    AVDictionary *metadata;
    185    AVBufferRef *buf;
    186 } AVFrameSideData;
    187 
    188 /**
    189 * This structure describes decoded (raw) audio or video data.
    190 *
    191 * AVFrame must be allocated using av_frame_alloc(). Note that this only
    192 * allocates the AVFrame itself, the buffers for the data must be managed
    193 * through other means (see below).
    194 * AVFrame must be freed with av_frame_free().
    195 *
    196 * AVFrame is typically allocated once and then reused multiple times to hold
    197 * different data (e.g. a single AVFrame to hold frames received from a
    198 * decoder). In such a case, av_frame_unref() will free any references held by
    199 * the frame and reset it to its original clean state before it
    200 * is reused again.
    201 *
    202 * The data described by an AVFrame is usually reference counted through the
    203 * AVBuffer API. The underlying buffer references are stored in AVFrame.buf /
    204 * AVFrame.extended_buf. An AVFrame is considered to be reference counted if at
    205 * least one reference is set, i.e. if AVFrame.buf[0] != NULL. In such a case,
    206 * every single data plane must be contained in one of the buffers in
    207 * AVFrame.buf or AVFrame.extended_buf.
    208 * There may be a single buffer for all the data, or one separate buffer for
    209 * each plane, or anything in between.
    210 *
    211 * sizeof(AVFrame) is not a part of the public ABI, so new fields may be added
    212 * to the end with a minor bump.
    213 *
    214 * Fields can be accessed through AVOptions, the name string used, matches the
    215 * C structure field name for fields accessible through AVOptions. The AVClass
    216 * for AVFrame can be obtained from avcodec_get_frame_class()
    217 */
    218 typedef struct AVFrame {
    219 #define AV_NUM_DATA_POINTERS 8
    220    /**
    221     * pointer to the picture/channel planes.
    222     * This might be different from the first allocated byte
    223     *
    224     * Some decoders access areas outside 0,0 - width,height, please
    225     * see avcodec_align_dimensions2(). Some filters and swscale can read
    226     * up to 16 bytes beyond the planes, if these filters are to be used,
    227     * then 16 extra bytes must be allocated.
    228     *
    229     * NOTE: Except for hwaccel formats, pointers not needed by the format
    230     * MUST be set to NULL.
    231     */
    232    uint8_t *data[AV_NUM_DATA_POINTERS];
    233 
    234    /**
    235     * For video, size in bytes of each picture line.
    236     * For audio, size in bytes of each plane.
    237     *
    238     * For audio, only linesize[0] may be set. For planar audio, each channel
    239     * plane must be the same size.
    240     *
    241     * For video the linesizes should be multiples of the CPUs alignment
    242     * preference, this is 16 or 32 for modern desktop CPUs.
    243     * Some code requires such alignment other code can be slower without
    244     * correct alignment, for yet other it makes no difference.
    245     *
    246     * @note The linesize may be larger than the size of usable data -- there
    247     * may be extra padding present for performance reasons.
    248     */
    249    int linesize[AV_NUM_DATA_POINTERS];
    250 
    251    /**
    252     * pointers to the data planes/channels.
    253     *
    254     * For video, this should simply point to data[].
    255     *
    256     * For planar audio, each channel has a separate data pointer, and
    257     * linesize[0] contains the size of each channel buffer.
    258     * For packed audio, there is just one data pointer, and linesize[0]
    259     * contains the total size of the buffer for all channels.
    260     *
    261     * Note: Both data and extended_data should always be set in a valid frame,
    262     * but for planar audio with more channels that can fit in data,
    263     * extended_data must be used in order to access all channels.
    264     */
    265    uint8_t **extended_data;
    266 
    267    /**
    268     * @name Video dimensions
    269     * Video frames only. The coded dimensions (in pixels) of the video frame,
    270     * i.e. the size of the rectangle that contains some well-defined values.
    271     *
    272     * @note The part of the frame intended for display/presentation is further
    273     * restricted by the @ref cropping "Cropping rectangle".
    274     * @{
    275     */
    276    int width, height;
    277    /**
    278     * @}
    279     */
    280 
    281    /**
    282     * number of audio samples (per channel) described by this frame
    283     */
    284    int nb_samples;
    285 
    286    /**
    287     * format of the frame, -1 if unknown or unset
    288     * Values correspond to enum AVPixelFormat for video frames,
    289     * enum AVSampleFormat for audio)
    290     */
    291    int format;
    292 
    293    /**
    294     * 1 -> keyframe, 0-> not
    295     */
    296    int key_frame;
    297 
    298    /**
    299     * Picture type of the frame.
    300     */
    301    enum AVPictureType pict_type;
    302 
    303    /**
    304     * Sample aspect ratio for the video frame, 0/1 if unknown/unspecified.
    305     */
    306    AVRational sample_aspect_ratio;
    307 
    308    /**
    309     * Presentation timestamp in time_base units (time when frame should be shown to user).
    310     */
    311    int64_t pts;
    312 
    313 #if FF_API_PKT_PTS
    314    /**
    315     * PTS copied from the AVPacket that was decoded to produce this frame.
    316     * @deprecated use the pts field instead
    317     */
    318    attribute_deprecated
    319    int64_t pkt_pts;
    320 #endif
    321 
    322    /**
    323     * DTS copied from the AVPacket that triggered returning this frame. (if frame threading isn't used)
    324     * This is also the Presentation time of this AVFrame calculated from
    325     * only AVPacket.dts values without pts values.
    326     */
    327    int64_t pkt_dts;
    328 
    329    /**
    330     * picture number in bitstream order
    331     */
    332    int coded_picture_number;
    333    /**
    334     * picture number in display order
    335     */
    336    int display_picture_number;
    337 
    338    /**
    339     * quality (between 1 (good) and FF_LAMBDA_MAX (bad))
    340     */
    341    int quality;
    342 
    343    /**
    344     * for some private data of the user
    345     */
    346    void *opaque;
    347 
    348 #if FF_API_ERROR_FRAME
    349    /**
    350     * @deprecated unused
    351     */
    352    attribute_deprecated
    353    uint64_t error[AV_NUM_DATA_POINTERS];
    354 #endif
    355 
    356    /**
    357     * When decoding, this signals how much the picture must be delayed.
    358     * extra_delay = repeat_pict / (2*fps)
    359     */
    360    int repeat_pict;
    361 
    362    /**
    363     * The content of the picture is interlaced.
    364     */
    365    int interlaced_frame;
    366 
    367    /**
    368     * If the content is interlaced, is top field displayed first.
    369     */
    370    int top_field_first;
    371 
    372    /**
    373     * Tell user application that palette has changed from previous frame.
    374     */
    375    int palette_has_changed;
    376 
    377    /**
    378     * reordered opaque 64 bits (generally an integer or a double precision float
    379     * PTS but can be anything).
    380     * The user sets AVCodecContext.reordered_opaque to represent the input at
    381     * that time,
    382     * the decoder reorders values as needed and sets AVFrame.reordered_opaque
    383     * to exactly one of the values provided by the user through AVCodecContext.reordered_opaque
    384     * @deprecated in favor of pkt_pts
    385     */
    386    int64_t reordered_opaque;
    387 
    388    /**
    389     * Sample rate of the audio data.
    390     */
    391    int sample_rate;
    392 
    393    /**
    394     * Channel layout of the audio data.
    395     */
    396    uint64_t channel_layout;
    397 
    398    /**
    399     * AVBuffer references backing the data for this frame. If all elements of
    400     * this array are NULL, then this frame is not reference counted. This array
    401     * must be filled contiguously -- if buf[i] is non-NULL then buf[j] must
    402     * also be non-NULL for all j < i.
    403     *
    404     * There may be at most one AVBuffer per data plane, so for video this array
    405     * always contains all the references. For planar audio with more than
    406     * AV_NUM_DATA_POINTERS channels, there may be more buffers than can fit in
    407     * this array. Then the extra AVBufferRef pointers are stored in the
    408     * extended_buf array.
    409     */
    410    AVBufferRef *buf[AV_NUM_DATA_POINTERS];
    411 
    412    /**
    413     * For planar audio which requires more than AV_NUM_DATA_POINTERS
    414     * AVBufferRef pointers, this array will hold all the references which
    415     * cannot fit into AVFrame.buf.
    416     *
    417     * Note that this is different from AVFrame.extended_data, which always
    418     * contains all the pointers. This array only contains the extra pointers,
    419     * which cannot fit into AVFrame.buf.
    420     *
    421     * This array is always allocated using av_malloc() by whoever constructs
    422     * the frame. It is freed in av_frame_unref().
    423     */
    424    AVBufferRef **extended_buf;
    425    /**
    426     * Number of elements in extended_buf.
    427     */
    428    int        nb_extended_buf;
    429 
    430    AVFrameSideData **side_data;
    431    int            nb_side_data;
    432 
    433 /**
    434 * @defgroup lavu_frame_flags AV_FRAME_FLAGS
    435 * @ingroup lavu_frame
    436 * Flags describing additional frame properties.
    437 *
    438 * @{
    439 */
    440 
    441 /**
    442 * The frame data may be corrupted, e.g. due to decoding errors.
    443 */
    444 #define AV_FRAME_FLAG_CORRUPT       (1 << 0)
    445 /**
    446 * A flag to mark the frames which need to be decoded, but shouldn't be output.
    447 */
    448 #define AV_FRAME_FLAG_DISCARD   (1 << 2)
    449 /**
    450 * @}
    451 */
    452 
    453    /**
    454     * Frame flags, a combination of @ref lavu_frame_flags
    455     */
    456    int flags;
    457 
    458    /**
    459     * MPEG vs JPEG YUV range.
    460     * - encoding: Set by user
    461     * - decoding: Set by libavcodec
    462     */
    463    enum AVColorRange color_range;
    464 
    465    enum AVColorPrimaries color_primaries;
    466 
    467    enum AVColorTransferCharacteristic color_trc;
    468 
    469    /**
    470     * YUV colorspace type.
    471     * - encoding: Set by user
    472     * - decoding: Set by libavcodec
    473     */
    474    enum AVColorSpace colorspace;
    475 
    476    enum AVChromaLocation chroma_location;
    477 
    478    /**
    479     * frame timestamp estimated using various heuristics, in stream time base
    480     * - encoding: unused
    481     * - decoding: set by libavcodec, read by user.
    482     */
    483    int64_t best_effort_timestamp;
    484 
    485    /**
    486     * reordered pos from the last AVPacket that has been input into the decoder
    487     * - encoding: unused
    488     * - decoding: Read by user.
    489     */
    490    int64_t pkt_pos;
    491 
    492    /**
    493     * duration of the corresponding packet, expressed in
    494     * AVStream->time_base units, 0 if unknown.
    495     * - encoding: unused
    496     * - decoding: Read by user.
    497     */
    498    int64_t pkt_duration;
    499 
    500    /**
    501     * metadata.
    502     * - encoding: Set by user.
    503     * - decoding: Set by libavcodec.
    504     */
    505    AVDictionary *metadata;
    506 
    507    /**
    508     * decode error flags of the frame, set to a combination of
    509     * FF_DECODE_ERROR_xxx flags if the decoder produced a frame, but there
    510     * were errors during the decoding.
    511     * - encoding: unused
    512     * - decoding: set by libavcodec, read by user.
    513     */
    514    int decode_error_flags;
    515 #define FF_DECODE_ERROR_INVALID_BITSTREAM   1
    516 #define FF_DECODE_ERROR_MISSING_REFERENCE   2
    517 
    518    /**
    519     * number of audio channels, only used for audio.
    520     * - encoding: unused
    521     * - decoding: Read by user.
    522     */
    523    int channels;
    524 
    525    /**
    526     * size of the corresponding packet containing the compressed
    527     * frame.
    528     * It is set to a negative value if unknown.
    529     * - encoding: unused
    530     * - decoding: set by libavcodec, read by user.
    531     */
    532    int pkt_size;
    533 
    534 #if FF_API_FRAME_QP
    535    /**
    536     * QP table
    537     */
    538    attribute_deprecated
    539    int8_t *qscale_table;
    540    /**
    541     * QP store stride
    542     */
    543    attribute_deprecated
    544    int qstride;
    545 
    546    attribute_deprecated
    547    int qscale_type;
    548 
    549    attribute_deprecated
    550    AVBufferRef *qp_table_buf;
    551 #endif
    552    /**
    553     * For hwaccel-format frames, this should be a reference to the
    554     * AVHWFramesContext describing the frame.
    555     */
    556    AVBufferRef *hw_frames_ctx;
    557 
    558    /**
    559     * AVBufferRef for free use by the API user. FFmpeg will never check the
    560     * contents of the buffer ref. FFmpeg calls av_buffer_unref() on it when
    561     * the frame is unreferenced. av_frame_copy_props() calls create a new
    562     * reference with av_buffer_ref() for the target frame's opaque_ref field.
    563     *
    564     * This is unrelated to the opaque field, although it serves a similar
    565     * purpose.
    566     */
    567    AVBufferRef *opaque_ref;
    568 
    569    /**
    570     * @anchor cropping
    571     * @name Cropping
    572     * Video frames only. The number of pixels to discard from the the
    573     * top/bottom/left/right border of the frame to obtain the sub-rectangle of
    574     * the frame intended for presentation.
    575     * @{
    576     */
    577    size_t crop_top;
    578    size_t crop_bottom;
    579    size_t crop_left;
    580    size_t crop_right;
    581    /**
    582     * @}
    583     */
    584 
    585    /**
    586     * AVBufferRef for internal use by a single libav* library.
    587     * Must not be used to transfer data between libraries.
    588     * Has to be NULL when ownership of the frame leaves the respective library.
    589     *
    590     * Code outside the FFmpeg libs should never check or change the contents of the buffer ref.
    591     *
    592     * FFmpeg calls av_buffer_unref() on it when the frame is unreferenced.
    593     * av_frame_copy_props() calls create a new reference with av_buffer_ref()
    594     * for the target frame's private_ref field.
    595     */
    596    AVBufferRef *private_ref;
    597 } AVFrame;
    598 
    599 #if FF_API_FRAME_GET_SET
    600 /**
    601 * Accessors for some AVFrame fields. These used to be provided for ABI
    602 * compatibility, and do not need to be used anymore.
    603 */
    604 attribute_deprecated
    605 int64_t av_frame_get_best_effort_timestamp(const AVFrame *frame);
    606 attribute_deprecated
    607 void    av_frame_set_best_effort_timestamp(AVFrame *frame, int64_t val);
    608 attribute_deprecated
    609 int64_t av_frame_get_pkt_duration         (const AVFrame *frame);
    610 attribute_deprecated
    611 void    av_frame_set_pkt_duration         (AVFrame *frame, int64_t val);
    612 attribute_deprecated
    613 int64_t av_frame_get_pkt_pos              (const AVFrame *frame);
    614 attribute_deprecated
    615 void    av_frame_set_pkt_pos              (AVFrame *frame, int64_t val);
    616 attribute_deprecated
    617 int64_t av_frame_get_channel_layout       (const AVFrame *frame);
    618 attribute_deprecated
    619 void    av_frame_set_channel_layout       (AVFrame *frame, int64_t val);
    620 attribute_deprecated
    621 int     av_frame_get_channels             (const AVFrame *frame);
    622 attribute_deprecated
    623 void    av_frame_set_channels             (AVFrame *frame, int     val);
    624 attribute_deprecated
    625 int     av_frame_get_sample_rate          (const AVFrame *frame);
    626 attribute_deprecated
    627 void    av_frame_set_sample_rate          (AVFrame *frame, int     val);
    628 attribute_deprecated
    629 AVDictionary *av_frame_get_metadata       (const AVFrame *frame);
    630 attribute_deprecated
    631 void          av_frame_set_metadata       (AVFrame *frame, AVDictionary *val);
    632 attribute_deprecated
    633 int     av_frame_get_decode_error_flags   (const AVFrame *frame);
    634 attribute_deprecated
    635 void    av_frame_set_decode_error_flags   (AVFrame *frame, int     val);
    636 attribute_deprecated
    637 int     av_frame_get_pkt_size(const AVFrame *frame);
    638 attribute_deprecated
    639 void    av_frame_set_pkt_size(AVFrame *frame, int val);
    640 #if FF_API_FRAME_QP
    641 attribute_deprecated
    642 int8_t *av_frame_get_qp_table(AVFrame *f, int *stride, int *type);
    643 attribute_deprecated
    644 int av_frame_set_qp_table(AVFrame *f, AVBufferRef *buf, int stride, int type);
    645 #endif
    646 attribute_deprecated
    647 enum AVColorSpace av_frame_get_colorspace(const AVFrame *frame);
    648 attribute_deprecated
    649 void    av_frame_set_colorspace(AVFrame *frame, enum AVColorSpace val);
    650 attribute_deprecated
    651 enum AVColorRange av_frame_get_color_range(const AVFrame *frame);
    652 attribute_deprecated
    653 void    av_frame_set_color_range(AVFrame *frame, enum AVColorRange val);
    654 #endif
    655 
    656 /**
    657 * Get the name of a colorspace.
    658 * @return a static string identifying the colorspace; can be NULL.
    659 */
    660 const char *av_get_colorspace_name(enum AVColorSpace val);
    661 
    662 /**
    663 * Allocate an AVFrame and set its fields to default values.  The resulting
    664 * struct must be freed using av_frame_free().
    665 *
    666 * @return An AVFrame filled with default values or NULL on failure.
    667 *
    668 * @note this only allocates the AVFrame itself, not the data buffers. Those
    669 * must be allocated through other means, e.g. with av_frame_get_buffer() or
    670 * manually.
    671 */
    672 AVFrame *av_frame_alloc(void);
    673 
    674 /**
    675 * Free the frame and any dynamically allocated objects in it,
    676 * e.g. extended_data. If the frame is reference counted, it will be
    677 * unreferenced first.
    678 *
    679 * @param frame frame to be freed. The pointer will be set to NULL.
    680 */
    681 void av_frame_free(AVFrame **frame);
    682 
    683 /**
    684 * Set up a new reference to the data described by the source frame.
    685 *
    686 * Copy frame properties from src to dst and create a new reference for each
    687 * AVBufferRef from src.
    688 *
    689 * If src is not reference counted, new buffers are allocated and the data is
    690 * copied.
    691 *
    692 * @warning: dst MUST have been either unreferenced with av_frame_unref(dst),
    693 *           or newly allocated with av_frame_alloc() before calling this
    694 *           function, or undefined behavior will occur.
    695 *
    696 * @return 0 on success, a negative AVERROR on error
    697 */
    698 int av_frame_ref(AVFrame *dst, const AVFrame *src);
    699 
    700 /**
    701 * Create a new frame that references the same data as src.
    702 *
    703 * This is a shortcut for av_frame_alloc()+av_frame_ref().
    704 *
    705 * @return newly created AVFrame on success, NULL on error.
    706 */
    707 AVFrame *av_frame_clone(const AVFrame *src);
    708 
    709 /**
    710 * Unreference all the buffers referenced by frame and reset the frame fields.
    711 */
    712 void av_frame_unref(AVFrame *frame);
    713 
    714 /**
    715 * Move everything contained in src to dst and reset src.
    716 *
    717 * @warning: dst is not unreferenced, but directly overwritten without reading
    718 *           or deallocating its contents. Call av_frame_unref(dst) manually
    719 *           before calling this function to ensure that no memory is leaked.
    720 */
    721 void av_frame_move_ref(AVFrame *dst, AVFrame *src);
    722 
    723 /**
    724 * Allocate new buffer(s) for audio or video data.
    725 *
    726 * The following fields must be set on frame before calling this function:
    727 * - format (pixel format for video, sample format for audio)
    728 * - width and height for video
    729 * - nb_samples and channel_layout for audio
    730 *
    731 * This function will fill AVFrame.data and AVFrame.buf arrays and, if
    732 * necessary, allocate and fill AVFrame.extended_data and AVFrame.extended_buf.
    733 * For planar formats, one buffer will be allocated for each plane.
    734 *
    735 * @warning: if frame already has been allocated, calling this function will
    736 *           leak memory. In addition, undefined behavior can occur in certain
    737 *           cases.
    738 *
    739 * @param frame frame in which to store the new buffers.
    740 * @param align Required buffer size alignment. If equal to 0, alignment will be
    741 *              chosen automatically for the current CPU. It is highly
    742 *              recommended to pass 0 here unless you know what you are doing.
    743 *
    744 * @return 0 on success, a negative AVERROR on error.
    745 */
    746 int av_frame_get_buffer(AVFrame *frame, int align);
    747 
    748 /**
    749 * Check if the frame data is writable.
    750 *
    751 * @return A positive value if the frame data is writable (which is true if and
    752 * only if each of the underlying buffers has only one reference, namely the one
    753 * stored in this frame). Return 0 otherwise.
    754 *
    755 * If 1 is returned the answer is valid until av_buffer_ref() is called on any
    756 * of the underlying AVBufferRefs (e.g. through av_frame_ref() or directly).
    757 *
    758 * @see av_frame_make_writable(), av_buffer_is_writable()
    759 */
    760 int av_frame_is_writable(AVFrame *frame);
    761 
    762 /**
    763 * Ensure that the frame data is writable, avoiding data copy if possible.
    764 *
    765 * Do nothing if the frame is writable, allocate new buffers and copy the data
    766 * if it is not.
    767 *
    768 * @return 0 on success, a negative AVERROR on error.
    769 *
    770 * @see av_frame_is_writable(), av_buffer_is_writable(),
    771 * av_buffer_make_writable()
    772 */
    773 int av_frame_make_writable(AVFrame *frame);
    774 
    775 /**
    776 * Copy the frame data from src to dst.
    777 *
    778 * This function does not allocate anything, dst must be already initialized and
    779 * allocated with the same parameters as src.
    780 *
    781 * This function only copies the frame data (i.e. the contents of the data /
    782 * extended data arrays), not any other properties.
    783 *
    784 * @return >= 0 on success, a negative AVERROR on error.
    785 */
    786 int av_frame_copy(AVFrame *dst, const AVFrame *src);
    787 
    788 /**
    789 * Copy only "metadata" fields from src to dst.
    790 *
    791 * Metadata for the purpose of this function are those fields that do not affect
    792 * the data layout in the buffers.  E.g. pts, sample rate (for audio) or sample
    793 * aspect ratio (for video), but not width/height or channel layout.
    794 * Side data is also copied.
    795 */
    796 int av_frame_copy_props(AVFrame *dst, const AVFrame *src);
    797 
    798 /**
    799 * Get the buffer reference a given data plane is stored in.
    800 *
    801 * @param plane index of the data plane of interest in frame->extended_data.
    802 *
    803 * @return the buffer reference that contains the plane or NULL if the input
    804 * frame is not valid.
    805 */
    806 AVBufferRef *av_frame_get_plane_buffer(AVFrame *frame, int plane);
    807 
    808 /**
    809 * Add a new side data to a frame.
    810 *
    811 * @param frame a frame to which the side data should be added
    812 * @param type type of the added side data
    813 * @param size size of the side data
    814 *
    815 * @return newly added side data on success, NULL on error
    816 */
    817 AVFrameSideData *av_frame_new_side_data(AVFrame *frame,
    818                                        enum AVFrameSideDataType type,
    819                                        int size);
    820 
    821 /**
    822 * Add a new side data to a frame from an existing AVBufferRef
    823 *
    824 * @param frame a frame to which the side data should be added
    825 * @param type  the type of the added side data
    826 * @param buf   an AVBufferRef to add as side data. The ownership of
    827 *              the reference is transferred to the frame.
    828 *
    829 * @return newly added side data on success, NULL on error. On failure
    830 *         the frame is unchanged and the AVBufferRef remains owned by
    831 *         the caller.
    832 */
    833 AVFrameSideData *av_frame_new_side_data_from_buf(AVFrame *frame,
    834                                                 enum AVFrameSideDataType type,
    835                                                 AVBufferRef *buf);
    836 
    837 /**
    838 * @return a pointer to the side data of a given type on success, NULL if there
    839 * is no side data with such type in this frame.
    840 */
    841 AVFrameSideData *av_frame_get_side_data(const AVFrame *frame,
    842                                        enum AVFrameSideDataType type);
    843 
    844 /**
    845 * If side data of the supplied type exists in the frame, free it and remove it
    846 * from the frame.
    847 */
    848 void av_frame_remove_side_data(AVFrame *frame, enum AVFrameSideDataType type);
    849 
    850 
    851 /**
    852 * Flags for frame cropping.
    853 */
    854 enum {
    855    /**
    856     * Apply the maximum possible cropping, even if it requires setting the
    857     * AVFrame.data[] entries to unaligned pointers. Passing unaligned data
    858     * to FFmpeg API is generally not allowed, and causes undefined behavior
    859     * (such as crashes). You can pass unaligned data only to FFmpeg APIs that
    860     * are explicitly documented to accept it. Use this flag only if you
    861     * absolutely know what you are doing.
    862     */
    863    AV_FRAME_CROP_UNALIGNED     = 1 << 0,
    864 };
    865 
    866 /**
    867 * Crop the given video AVFrame according to its crop_left/crop_top/crop_right/
    868 * crop_bottom fields. If cropping is successful, the function will adjust the
    869 * data pointers and the width/height fields, and set the crop fields to 0.
    870 *
    871 * In all cases, the cropping boundaries will be rounded to the inherent
    872 * alignment of the pixel format. In some cases, such as for opaque hwaccel
    873 * formats, the left/top cropping is ignored. The crop fields are set to 0 even
    874 * if the cropping was rounded or ignored.
    875 *
    876 * @param frame the frame which should be cropped
    877 * @param flags Some combination of AV_FRAME_CROP_* flags, or 0.
    878 *
    879 * @return >= 0 on success, a negative AVERROR on error. If the cropping fields
    880 * were invalid, AVERROR(ERANGE) is returned, and nothing is changed.
    881 */
    882 int av_frame_apply_cropping(AVFrame *frame, int flags);
    883 
    884 /**
    885 * @return a string identifying the side data type
    886 */
    887 const char *av_frame_side_data_name(enum AVFrameSideDataType type);
    888 
    889 /**
    890 * @}
    891 */
    892 
    893 #endif /* AVUTIL_FRAME_H */