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mirror of https://github.com/FFmpeg/FFmpeg.git synced 2024-12-23 12:43:46 +02:00

lavc doxy: add decoding functions to a doxy group.

This commit is contained in:
Anton Khirnov 2012-04-08 12:45:58 +02:00
parent 199ada4944
commit c8ef8464c2

View File

@ -425,6 +425,7 @@ enum CodecID {
#endif #endif
/** /**
* @ingroup lavc_decoding
* Required number of additionally allocated bytes at the end of the input bitstream for decoding. * 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 * This is mainly needed because some optimized bitstream readers read
* 32 or 64 bit at once and could read over the end.<br> * 32 or 64 bit at once and could read over the end.<br>
@ -456,6 +457,9 @@ enum Motion_Est_ID {
ME_TESA, ///< transformed exhaustive search algorithm ME_TESA, ///< transformed exhaustive search algorithm
}; };
/**
* @ingroup lavc_decoding
*/
enum AVDiscard{ enum AVDiscard{
/* We leave some space between them for extensions (drop some /* We leave some space between them for extensions (drop some
* keyframes for intra-only or drop just some bidir frames). */ * keyframes for intra-only or drop just some bidir frames). */
@ -3326,6 +3330,428 @@ uint8_t* av_packet_get_side_data(AVPacket *pkt, enum AVPacketSideDataType type,
* @} * @}
*/ */
/**
* @addtogroup lavc_decoding
* @{
*/
/**
* 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);
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]);
#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);
/**
* @defgroup lavc_parsing 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;
/**
* Duration of the current frame.
* For audio, this is in units of 1 / AVCodecContext.sample_rate.
* For all other types, this is in units of AVCodecContext.time_base.
*/
int duration;
} 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);
/**
* @}
* @}
*/
/* resample.c */ /* resample.c */
struct ReSampleContext; struct ReSampleContext;
@ -3576,21 +4002,6 @@ AVCodec *avcodec_find_encoder(enum CodecID id);
*/ */
AVCodec *avcodec_find_encoder_by_name(const char *name); 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); void avcodec_string(char *buf, int buf_size, AVCodecContext *enc, int encode);
/** /**
@ -3602,207 +4013,12 @@ void avcodec_string(char *buf, int buf_size, AVCodecContext *enc, int encode);
*/ */
const char *av_get_profile_name(const AVCodec *codec, int profile); const char *av_get_profile_name(const AVCodec *codec, int profile);
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); enum PixelFormat avcodec_default_get_format(struct AVCodecContext *s, const enum PixelFormat * fmt);
int avcodec_default_execute(AVCodecContext *c, int (*func)(AVCodecContext *c2, void *arg2),void *arg, int *ret, int count, int size); 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); int avcodec_default_execute2(AVCodecContext *c, int (*func)(AVCodecContext *c2, void *arg2, int, int),void *arg, int *ret, int count);
//FIXME func typedef //FIXME func typedef
#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);
#if FF_API_OLD_ENCODE_AUDIO #if FF_API_OLD_ENCODE_AUDIO
/** /**
* Encode an audio frame from samples into buf. * Encode an audio frame from samples into buf.
@ -3995,201 +4211,6 @@ int av_get_exact_bits_per_sample(enum CodecID codec_id);
*/ */
int av_get_audio_frame_duration(AVCodecContext *avctx, int frame_bytes); int av_get_audio_frame_duration(AVCodecContext *avctx, int frame_bytes);
/* 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;
/**
* Duration of the current frame.
* For audio, this is in units of 1 / AVCodecContext.sample_rate.
* For all other types, this is in units of AVCodecContext.time_base.
*/
int duration;
} 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 { typedef struct AVBitStreamFilterContext {
void *priv_data; void *priv_data;