📄 avcodec.h
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#define CODEC_FLAG_OBMC 0x00000001 ///< OBMC
#define CODEC_FLAG_LOOP_FILTER 0x00000800 ///< loop filter
#define CODEC_FLAG_H263P_SLICE_STRUCT 0x10000000
#define CODEC_FLAG_INTERLACED_ME 0x20000000 ///< interlaced motion estimation
#define CODEC_FLAG_SVCD_SCAN_OFFSET 0x40000000 ///< Will reserve space for SVCD scan offset user data.
#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_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_INTRA_VLC 0x00000800 ///< Use MPEG-2 intra VLC table.
#define CODEC_FLAG2_MEMC_ONLY 0x00001000 ///< Only do ME/MC (I frames -> ref, P frame -> ME+MC).
#define CODEC_FLAG2_DROP_FRAME_TIMECODE 0x00002000 ///< timecode is in drop frame format.
#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.
#define CODEC_FLAG2_NON_LINEAR_QUANT 0x00010000 ///< Use MPEG-2 nonlinear quantizer.
#define CODEC_FLAG2_BIT_RESERVOIR 0x00020000 ///< Use a bit reservoir when encoding if possible
/* 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.
* direct rendering method 1
*/
#define CODEC_CAP_DR1 0x0002
/* If 'parse_only' field is true, then avcodec_parse_frame() can be used. */
#define CODEC_CAP_PARSE_ONLY 0x0004
#define CODEC_CAP_TRUNCATED 0x0008
/* Codec can export data for HW decoding (XvMC). */
#define CODEC_CAP_HWACCEL 0x0010
/**
* Codec has a nonzero delay and needs to be fed with NULL at the end to get the delayed data.
* If this is not set, the codec is guaranteed to never be fed with NULL data.
*/
#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
//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_COMMON_FRAME \
/**\
* pointer to the picture planes.\
* This might be different from the first allocated byte\
* - encoding: \
* - decoding: \
*/\
uint8_t *data[4];\
int linesize[4];\
/**\
* 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[4];\
/**\
* 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.\
*/\
int 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; \
\
/**\
* buffer age (1->was last buffer and dint change, 2->..., ...).\
* Set to INT_MAX if the buffer has not been used yet.\
* - encoding: unused\
* - decoding: MUST be set by get_buffer().\
*/\
int age;\
\
/**\
* 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.\
* - 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[4];\
\
/**\
* 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 referece frame index\
* - encoding: Set by user.\
* - decoding: Set by libavcodec.\
*/\
int8_t *ref_index[2];
#define FF_QSCALE_TYPE_MPEG1 0
#define FF_QSCALE_TYPE_MPEG2 1
#define FF_QSCALE_TYPE_H264 2
#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.
#define FF_I_TYPE 1 ///< Intra
#define FF_P_TYPE 2 ///< Predicted
#define FF_B_TYPE 3 ///< Bi-dir predicted
#define FF_S_TYPE 4 ///< S(GMC)-VOP MPEG4
#define FF_SI_TYPE 5 ///< Switching Intra
#define FF_SP_TYPE 6 ///< Switching Predicted
#define FF_BI_TYPE 7
#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).
/**
* Audio Video Frame.
* New fields can be added to the end of FF_COMMON_FRAME with minor version
* bumps.
* Removal, reordering and changes to existing fields require a major
* version bump. No fields should be added into AVFrame before or after
* FF_COMMON_FRAME!
* sizeof(AVFrame) must not be used outside libav*.
*/
typedef struct AVFrame {
FF_COMMON_FRAME
} AVFrame;
#define DEFAULT_FRAME_RATE_BASE 1001000
/**
* 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_context
*/
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 recommanded.
* - 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.
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