AVCodecContext 结构体

/** * 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. */ int width, height; #define FF_ASPECT_EXTENDED 15 /** * the number of pictures in a group of pictures, or 0 for intra_only * - encoding: Set by user. * - decoding: unused */ int gop_size; /** * Pixel format, see PIX_FMT_xxx. * May be set by the demuxer if known from headers. * May be overriden by the decoder if it knows better. * - encoding: Set by user. * - decoding: Set by user if known, overridden by libavcodec if known */ enum PixelFormat pix_fmt; /** * Frame rate emulation. If not zero, the lower layer (i.e. format handler) * has to read frames at native frame rate. * - encoding: Set by user. * - decoding: unused */ int rate_emu; /** * If non NULL, 'draw_horiz_band' is called by the libavcodec * decoder to draw a horizontal band. It improves cache usage. Not * all codecs can do that. You must check the codec capabilities * beforehand. * The function is also used by hardware acceleration APIs. * It is called at least once during frame decoding to pass * the data needed for hardware render. * In that mode instead of pixel data, AVFrame points to * a structure specific to the acceleration API. The application * reads the structure and can change some fields to indicate progress * or mark state. * - encoding: unused * - decoding: Set by user. * @param height the height of the slice * @param y the y position of the slice * @param type 1->top field, 2->bottom field, 3->frame * @param offset offset into the AVFrame.data from which the slice should be read */ void (*draw_horiz_band)(struct AVCodecContext *s, const AVFrame *src, int offset[4], int y, int type, int height); /* audio only */ int sample_rate; ///< samples per second int channels; ///< number of audio channels /** * audio sample format * - encoding: Set by user. * - decoding: Set by libavcodec. */ enum AVSampleFormat sample_fmt; ///< sample format /* The following data should not be initialized. */ /** * Samples per packet, initialized when calling 'init'. */ int frame_size; int frame_number; ///< audio or video frame number #if LIBAVCODEC_VERSION_MAJOR < 53 int real_pict_num; ///< Returns the real picture number of previous encoded frame. #endif /** * Number of frames the decoded output will be delayed relative to * the encoded input. * - encoding: Set by libavcodec. * - decoding: unused */ int delay; /* - encoding parameters */ float qcompress; ///< amount of qscale change between easy & hard scenes (0.0-1.0) float qblur; ///< amount of qscale smoothing over time (0.0-1.0) /** * minimum quantizer * - encoding: Set by user. * - decoding: unused */ int qmin; /** * maximum quantizer * - encoding: Set by user. * - decoding: unused */ int qmax; /** * maximum quantizer difference between frames * - encoding: Set by user. * - decoding: unused */ int max_qdiff; /** * maximum number of B-frames between non-B-frames * Note: The output will be delayed by max_b_frames+1 relative to the input. * - encoding: Set by user. * - decoding: unused */ int max_b_frames; /** * qscale factor between IP and B-frames * If > 0 then the last P-frame quantizer will be used (q= lastp_q*factor+offset). * If < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset). * - encoding: Set by user. * - decoding: unused */ float b_quant_factor; /** obsolete FIXME remove */ int rc_strategy; #define FF_RC_STRATEGY_XVID 1 int b_frame_strategy; /** * hurry up amount * - encoding: unused * - decoding: Set by user. 1-> Skip B-frames, 2-> Skip IDCT/dequant too, 5-> Skip everything except header * @deprecated Deprecated in favor of skip_idct and skip_frame. */ int hurry_up; struct AVCodec *codec; void *priv_data; int rtp_payload_size; /* The size of the RTP payload: the coder will */ /* do its best to deliver a chunk with size */ /* below rtp_payload_size, the chunk will start */ /* with a start code on some codecs like H.263. */ /* This doesn't take account of any particular */ /* headers inside the transmitted RTP payload. */ /* The RTP callback: This function is called */ /* every time the encoder has a packet to send. */ /* It depends on the encoder if the data starts */ /* with a Start Code (it should). H.263 does. */ /* mb_nb contains the number of macroblocks */ /* encoded in the RTP payload. */ void (*rtp_callback)(struct AVCodecContext *avctx, void *data, int size, int mb_nb); /* statistics, used for 2-pass encoding */ int mv_bits; int header_bits; int i_tex_bits; int p_tex_bits; int i_count; int p_count; int skip_count; int misc_bits; /** * number of bits used for the previously encoded frame * - encoding: Set by libavcodec. * - decoding: unused */ int frame_bits; /** * Private data of the user, can be used to carry app specific stuff. * - encoding: Set by user. * - decoding: Set by user. */ void *opaque; char codec_name[32]; enum AVMediaType codec_type; /* see AVMEDIA_TYPE_xxx */ enum CodecID codec_id; /* see CODEC_ID_xxx */ /** * fourcc (LSB first, so "ABCD" -> ('D'<<24) + ('C'<<16) + ('B'<<8) + 'A'). * This is used to work around some encoder bugs. * A demuxer should set this to what is stored in the field used to identify the codec. * If there are multiple such fields in a container then the demuxer should choose the one * which maximizes the information about the used codec. * If the codec tag field in a container is larger then 32 bits then the demuxer should * remap the longer ID to 32 bits with a table or other structure. Alternatively a new * extra_codec_tag + size could be added but for this a clear advantage must be demonstrated * first. * - encoding: Set by user, if not then the default based on codec_id will be used. * - decoding: Set by user, will be converted to uppercase by libavcodec during init. */ unsigned int codec_tag; /** * Work around bugs in encoders which sometimes cannot be detected automatically. * - encoding: Set by user * - decoding: Set by user */ int workaround_bugs; #define FF_BUG_AUTODETECT 1 ///< autodetection #define FF_BUG_OLD_MSMPEG4 2 #define FF_BUG_XVID_ILACE 4 #define FF_BUG_UMP4 8 #define FF_BUG_NO_PADDING 16 #define FF_BUG_AMV 32 #define FF_BUG_AC_VLC 0 ///< Will be removed, libavcodec can now handle these non-compliant files by default. #define FF_BUG_QPEL_CHROMA 64 #define FF_BUG_STD_QPEL 128 #define FF_BUG_QPEL_CHROMA2 256 #define FF_BUG_DIRECT_BLOCKSIZE 512 #define FF_BUG_EDGE 1024 #define FF_BUG_HPEL_CHROMA 2048 #define FF_BUG_DC_CLIP 4096 #define FF_BUG_MS 8192 ///< Work around various bugs in Microsoft's broken decoders. #define FF_BUG_TRUNCATED 16384 //#define FF_BUG_FAKE_SCALABILITY 16 //Autodetection should work 100%. /** * luma single coefficient elimination threshold * - encoding: Set by user. * - decoding: unused */ int luma_elim_threshold; /** * chroma single coeff elimination threshold * - encoding: Set by user. * - decoding: unused */ int chroma_elim_threshold; /** * strictly follow the standard (MPEG4, ...). * - encoding: Set by user. * - decoding: Set by user. * Setting this to STRICT or higher means the encoder and decoder will * generally do stupid things, whereas setting it to unofficial or lower * will mean the encoder might produce output that is not supported by all * spec-compliant decoders. Decoders don't differentiate between normal, * unofficial and experimental (that is, they always try to decode things * when they can) unless they are explicitly asked to behave stupidly * (=strictly conform to the specs) */ int strict_std_compliance; #define FF_COMPLIANCE_VERY_STRICT 2 ///< Strictly conform to an older more strict version of the spec or reference software. #define FF_COMPLIANCE_STRICT 1 ///< Strictly conform to all the things in the spec no matter what consequences. #define FF_COMPLIANCE_NORMAL 0 #if FF_API_INOFFICIAL #define FF_COMPLIANCE_INOFFICIAL -1 ///< Allow inofficial extensions (deprecated - use FF_COMPLIANCE_UNOFFICIAL instead). #endif #define FF_COMPLIANCE_UNOFFICIAL -1 ///< Allow unofficial extensions #define FF_COMPLIANCE_EXPERIMENTAL -2 ///< Allow nonstandardized experimental things. /** * qscale offset between IP and B-frames * - encoding: Set by user. * - decoding: unused */ float b_quant_offset; /** * Error recognization; higher values will detect more errors but may * misdetect some more or less valid parts as errors. * - encoding: unused * - decoding: Set by user. */ int error_recognition; #define FF_ER_CAREFUL 1 #define FF_ER_COMPLIANT 2 #define FF_ER_AGGRESSIVE 3 #define FF_ER_VERY_AGGRESSIVE 4 /** * Called at the beginning of each frame to get a buffer for it. * If pic.reference is set then the frame will be read later by libavcodec. * avcodec_align_dimensions2() should be used to find the required width and * height, as they normally need to be rounded up to the next multiple of 16. * if CODEC_CAP_DR1 is not set then get_buffer() must call * avcodec_default_get_buffer() instead of providing buffers allocated by * some other means. * - encoding: unused * - decoding: Set by libavcodec, user can override. */ int (*get_buffer)(struct AVCodecContext *c, AVFrame *pic); /** * Called to release buffers which were allocated with get_buffer. * A released buffer can be reused in get_buffer(). * pic.data[*] must be set to NULL. * - encoding: unused * - decoding: Set by libavcodec, user can override. */ void (*release_buffer)(struct AVCodecContext *c, AVFrame *pic); /** * Size of the frame reordering buffer in the decoder. * For MPEG-2 it is 1 IPB or 0 low delay IP. * - encoding: Set by libavcodec. * - decoding: Set by libavcodec. */ int has_b_frames; /** * number of bytes per packet if constant and known or 0 * Used by some WAV based audio codecs. */ int block_align; int parse_only; /* - decoding only: If true, only parsing is done (function avcodec_parse_frame()). The frame data is returned. Only MPEG codecs support this now. */ /** * 0-> h263 quant 1-> mpeg quant * - encoding: Set by user. * - decoding: unused */ int mpeg_quant; /** * pass1 encoding statistics output buffer * - encoding: Set by libavcodec. * - decoding: unused */ char *stats_out; /** * pass2 encoding statistics input buffer * Concatenated stuff from stats_out of pass1 should be placed here. * - encoding: Allocated/set/freed by user. * - decoding: unused */ char *stats_in; /** * ratecontrol qmin qmax limiting method * 0-> clipping, 1-> use a nice continous function to limit qscale wthin qmin/qmax. * - encoding: Set by user. * - decoding: unused */ float rc_qsquish; float rc_qmod_amp; int rc_qmod_freq; /** * ratecontrol override, see RcOverride * - encoding: Allocated/set/freed by user. * - decoding: unused */ RcOverride *rc_override; int rc_override_count; /** * rate control equation * - encoding: Set by user * - decoding: unused */ const char *rc_eq; /** * maximum bitrate * - encoding: Set by user. * - decoding: unused */ int rc_max_rate; /** * minimum bitrate * - encoding: Set by user. * - decoding: unused */ int rc_min_rate; /** * decoder bitstream buffer size * - encoding: Set by user. * - decoding: unused */ int rc_buffer_size; float rc_buffer_aggressivity; /** * qscale factor between P and I-frames * If > 0 then the last p frame quantizer will be used (q= lastp_q*factor+offset). * If < 0 then normal ratecontrol will be done (q= -normal_q*factor+offset). * - encoding: Set by user. * - decoding: unused */ float i_quant_factor; /** * qscale offset between P and I-frames * - encoding: Set by user. * - decoding: unused */ float i_quant_offset; /** * initial complexity for pass1 ratecontrol * - encoding: Set by user. * - decoding: unused */ float rc_initial_cplx; /** * DCT algorithm, see FF_DCT_* below * - encoding: Set by user. * - decoding: unused */ int dct_algo; #define FF_DCT_AUTO 0 #define FF_DCT_FASTINT 1 #define FF_DCT_INT 2 #define FF_DCT_MMX 3 #define FF_DCT_MLIB 4 #define FF_DCT_ALTIVEC 5 #define FF_DCT_FAAN 6 /** * luminance masking (0-> disabled) * - encoding: Set by user. * - decoding: unused */ float lumi_masking; /** * temporary complexity masking (0-> disabled) * - encoding: Set by user. * - decoding: unused */ float temporal_cplx_masking; /** * spatial complexity masking (0-> disabled) * - encoding: Set by user. * - decoding: unused */ float spatial_cplx_masking; /** * p block masking (0-> disabled) * - encoding: Set by user. * - decoding: unused */ float p_masking; /** * darkness masking (0-> disabled) * - encoding: Set by user. * - decoding: unused */ float dark_masking; /** * IDCT algorithm, see FF_IDCT_* below. * - encoding: Set by user. * - decoding: Set by user. */ int idct_algo; #define FF_IDCT_AUTO 0 #define FF_IDCT_INT 1 #define FF_IDCT_SIMPLE 2 #define FF_IDCT_SIMPLEMMX 3 #define FF_IDCT_LIBMPEG2MMX 4 #define FF_IDCT_PS2 5 #define FF_IDCT_MLIB 6 #define FF_IDCT_ARM 7 #define FF_IDCT_ALTIVEC 8 #define FF_IDCT_SH4 9 #define FF_IDCT_SIMPLEARM 10 #define FF_IDCT_H264 11 #define FF_IDCT_VP3 12 #define FF_IDCT_IPP 13 #define FF_IDCT_XVIDMMX 14 #define FF_IDCT_CAVS 15 #define FF_IDCT_SIMPLEARMV5TE 16 #define FF_IDCT_SIMPLEARMV6 17 #define FF_IDCT_SIMPLEVIS 18 #define FF_IDCT_WMV2 19 #define FF_IDCT_FAAN 20 #define FF_IDCT_EA 21 #define FF_IDCT_SIMPLENEON 22 #define FF_IDCT_SIMPLEALPHA 23 #define FF_IDCT_BINK 24 /** * slice count * - encoding: Set by libavcodec. * - decoding: Set by user (or 0). */ int slice_count; /** * slice offsets in the frame in bytes * - encoding: Set/allocated by libavcodec. * - decoding: Set/allocated by user (or NULL). */ int *slice_offset; /** * error concealment flags * - encoding: unused * - decoding: Set by user. */ int error_concealment; #define FF_EC_GUESS_MVS 1 #define FF_EC_DEBLOCK 2 /** * dsp_mask could be add used to disable unwanted CPU features * CPU features (i.e. MMX, SSE. ...) * * With the FORCE flag you may instead enable given CPU features. * (Dangerous: Usable in case of misdetection, improper usage however will * result into program crash.) */ unsigned dsp_mask; #if FF_API_MM_FLAGS #define FF_MM_FORCE AV_CPU_FLAG_FORCE #define FF_MM_MMX AV_CPU_FLAG_MMX #define FF_MM_3DNOW AV_CPU_FLAG_3DNOW #define FF_MM_MMXEXT AV_CPU_FLAG_MMX2 #define FF_MM_MMX2 AV_CPU_FLAG_MMX2 #define FF_MM_SSE AV_CPU_FLAG_SSE #define FF_MM_SSE2 AV_CPU_FLAG_SSE2 #define FF_MM_SSE2SLOW AV_CPU_FLAG_SSE2SLOW #define FF_MM_3DNOWEXT AV_CPU_FLAG_3DNOWEXT #define FF_MM_SSE3 AV_CPU_FLAG_SSE3 #define FF_MM_SSE3SLOW AV_CPU_FLAG_SSE3SLOW #define FF_MM_SSSE3 AV_CPU_FLAG_SSSE3 #define FF_MM_SSE4 AV_CPU_FLAG_SSE4 #define FF_MM_SSE42 AV_CPU_FLAG_SSE42 #define FF_MM_IWMMXT AV_CPU_FLAG_IWMMXT #define FF_MM_ALTIVEC AV_CPU_FLAG_ALTIVEC #endif /** * bits per sample/pixel from the demuxer (needed for huffyuv). * - encoding: Set by libavcodec. * - decoding: Set by user. */ int bits_per_coded_sample; /** * prediction method (needed for huffyuv) * - encoding: Set by user. * - decoding: unused */ int prediction_method; #define FF_PRED_LEFT 0 #define FF_PRED_PLANE 1 #define FF_PRED_MEDIAN 2 /** * sample aspect ratio (0 if unknown) * That is the width of a pixel divided by the height of the pixel. * Numerator and denominator must be relatively prime and smaller than 256 for some video standards. * - encoding: Set by user. * - decoding: Set by libavcodec. */ AVRational sample_aspect_ratio; /** * the picture in the bitstream * - encoding: Set by libavcodec. * - decoding: Set by libavcodec. */ AVFrame *coded_frame; /** * debug * - encoding: Set by user. * - decoding: Set by user. */ int debug; #define FF_DEBUG_PICT_INFO 1 #define FF_DEBUG_RC 2 #define FF_DEBUG_BITSTREAM 4 #define FF_DEBUG_MB_TYPE 8 #define FF_DEBUG_QP 16 #define FF_DEBUG_MV 32 #define FF_DEBUG_DCT_COEFF 0x00000040 #define FF_DEBUG_SKIP 0x00000080 #define FF_DEBUG_STARTCODE 0x00000100 #define FF_DEBUG_PTS 0x00000200 #define FF_DEBUG_ER 0x00000400 #define FF_DEBUG_MMCO 0x00000800 #define FF_DEBUG_BUGS 0x00001000 #define FF_DEBUG_VIS_QP 0x00002000 #define FF_DEBUG_VIS_MB_TYPE 0x00004000 #define FF_DEBUG_BUFFERS 0x00008000 /** * debug * - encoding: Set by user. * - decoding: Set by user. */ int debug_mv; #define FF_DEBUG_VIS_MV_P_FOR 0x00000001 //visualize forward predicted MVs of P frames #define FF_DEBUG_VIS_MV_B_FOR 0x00000002 //visualize forward predicted MVs of B frames #define FF_DEBUG_VIS_MV_B_BACK 0x00000004 //visualize backward predicted MVs of B frames /** * error * - encoding: Set by libavcodec if flags&CODEC_FLAG_PSNR. * - decoding: unused */ uint64_t error[4]; /** * minimum MB quantizer * - encoding: unused * - decoding: unused */ int mb_qmin; /** * maximum MB quantizer * - encoding: unused * - decoding: unused */ int mb_qmax; /** * motion estimation comparison function * - encoding: Set by user. * - decoding: unused */ int me_cmp; /** * subpixel motion estimation comparison function * - encoding: Set by user. * - decoding: unused */ int me_sub_cmp; /** * macroblock comparison function (not supported yet) * - encoding: Set by user. * - decoding: unused */ int mb_cmp; /** * interlaced DCT comparison function * - encoding: Set by user. * - decoding: unused */ int ildct_cmp; #define FF_CMP_SAD 0 #define FF_CMP_SSE 1 #define FF_CMP_SATD 2 #define FF_CMP_DCT 3 #define FF_CMP_PSNR 4 #define FF_CMP_BIT 5 #define FF_CMP_RD 6 #define FF_CMP_ZERO 7 #define FF_CMP_VSAD 8 #define FF_CMP_VSSE 9 #define FF_CMP_NSSE 10 #define FF_CMP_W53 11 #define FF_CMP_W97 12 #define FF_CMP_DCTMAX 13 #define FF_CMP_DCT264 14 #define FF_CMP_CHROMA 256 /** * ME diamond size & shape * - encoding: Set by user. * - decoding: unused */ int dia_size; /** * amount of previous MV predictors (2a+1 x 2a+1 square) * - encoding: Set by user. * - decoding: unused */ int last_predictor_count; /** * prepass for motion estimation * - encoding: Set by user. * - decoding: unused */ int pre_me; /** * motion estimation prepass comparison function * - encoding: Set by user. * - decoding: unused */ int me_pre_cmp; /** * ME prepass diamond size & shape * - encoding: Set by user. * - decoding: unused */ int pre_dia_size; /** * subpel ME quality * - encoding: Set by user. * - decoding: unused */ int me_subpel_quality; /** * callback to negotiate the pixelFormat * @param fmt is the list of formats which are supported by the codec, * it is terminated by -1 as 0 is a valid format, the formats are ordered by quality. * The first is always the native one. * @return the chosen format * - encoding: unused * - decoding: Set by user, if not set the native format will be chosen. */ enum PixelFormat (*get_format)(struct AVCodecContext *s, const enum PixelFormat * fmt); /** * DTG active format information (additional aspect ratio * information only used in DVB MPEG-2 transport streams) * 0 if not set. * * - encoding: unused * - decoding: Set by decoder. */ int dtg_active_format; #define FF_DTG_AFD_SAME 8 #define FF_DTG_AFD_4_3 9 #define FF_DTG_AFD_16_9 10 #define FF_DTG_AFD_14_9 11 #define FF_DTG_AFD_4_3_SP_14_9 13 #define FF_DTG_AFD_16_9_SP_14_9 14 #define FF_DTG_AFD_SP_4_3 15 /** * maximum motion estimation search range in subpel units * If 0 then no limit. * * - encoding: Set by user. * - decoding: unused */ int me_range; /** * intra quantizer bias * - encoding: Set by user. * - decoding: unused */ int intra_quant_bias; #define FF_DEFAULT_QUANT_BIAS 999999 /** * inter quantizer bias * - encoding: Set by user. * - decoding: unused */ int inter_quant_bias; /** * color table ID * - encoding: unused * - decoding: Which clrtable should be used for 8bit RGB images. * Tables have to be stored somewhere. FIXME */ int color_table_id; /** * internal_buffer count * Don't touch, used by libavcodec default_get_buffer(). */ int internal_buffer_count; /** * internal_buffers * Don't touch, used by libavcodec default_get_buffer(). */ void *internal_buffer; /** * Global quality for codecs which cannot change it per frame. * This should be proportional to MPEG-1/2/4 qscale. * - encoding: Set by user. * - decoding: unused */ int global_quality; #define FF_CODER_TYPE_VLC 0 #define FF_CODER_TYPE_AC 1 #define FF_CODER_TYPE_RAW 2 #define FF_CODER_TYPE_RLE 3 #define FF_CODER_TYPE_DEFLATE 4 /** * coder type * - encoding: Set by user. * - decoding: unused */ int coder_type; /** * context model * - encoding: Set by user. * - decoding: unused */ int context_model; #if 0 /** * * - encoding: unused * - decoding: Set by user. */ uint8_t * (*realloc)(struct AVCodecContext *s, uint8_t *buf, int buf_size); #endif /** * slice flags * - encoding: unused * - decoding: Set by user. */ int slice_flags; #define SLICE_FLAG_CODED_ORDER 0x0001 ///< draw_horiz_band() is called in coded order instead of display #define SLICE_FLAG_ALLOW_FIELD 0x0002 ///< allow draw_horiz_band() with field slices (MPEG2 field pics) #define SLICE_FLAG_ALLOW_PLANE 0x0004 ///< allow draw_horiz_band() with 1 component at a time (SVQ1) /** * XVideo Motion Acceleration * - encoding: forbidden * - decoding: set by decoder */ int xvmc_acceleration; /** * macroblock decision mode * - encoding: Set by user. * - decoding: unused */ int mb_decision; #define FF_MB_DECISION_SIMPLE 0 ///< uses mb_cmp #define FF_MB_DECISION_BITS 1 ///< chooses the one which needs the fewest bits #define FF_MB_DECISION_RD 2 ///< rate distortion /** * custom intra quantization matrix * - encoding: Set by user, can be NULL. * - decoding: Set by libavcodec. */ uint16_t *intra_matrix; /** * custom inter quantization matrix * - encoding: Set by user, can be NULL. * - decoding: Set by libavcodec. */ uint16_t *inter_matrix; /** * fourcc from the AVI stream header (LSB first, so "ABCD" -> ('D'<<24) + ('C'<<16) + ('B'<<8) + 'A'). * This is used to work around some encoder bugs. * - encoding: unused * - decoding: Set by user, will be converted to uppercase by libavcodec during init. */ unsigned int stream_codec_tag; /** * scene change detection threshold * 0 is default, larger means fewer detected scene changes. * - encoding: Set by user. * - decoding: unused */ int scenechange_threshold; /** * minimum Lagrange multipler * - encoding: Set by user. * - decoding: unused */ int lmin; /** * maximum Lagrange multipler * - encoding: Set by user. * - decoding: unused */ int lmax; #if FF_API_PALETTE_CONTROL /** * palette control structure * - encoding: ??? (no palette-enabled encoder yet) * - decoding: Set by user. */ struct AVPaletteControl *palctrl; #endif /** * noise reduction strength * - encoding: Set by user. * - decoding: unused */ int noise_reduction; /** * Called at the beginning of a frame to get cr buffer for it. * Buffer type (size, hints) must be the same. libavcodec won't check it. * libavcodec will pass previous buffer in pic, function should return * same buffer or new buffer with old frame "painted" into it. * If pic.data[0] == NULL must behave like get_buffer(). * if CODEC_CAP_DR1 is not set then reget_buffer() must call * avcodec_default_reget_buffer() instead of providing buffers allocated by * some other means. * - encoding: unused * - decoding: Set by libavcodec, user can override. */ int (*reget_buffer)(struct AVCodecContext *c, AVFrame *pic); /** * Number of bits which should be loaded into the rc buffer before decoding starts. * - encoding: Set by user. * - decoding: unused */ int rc_initial_buffer_occupancy; /** * * - encoding: Set by user. * - decoding: unused */ int inter_threshold; /** * CODEC_FLAG2_* * - encoding: Set by user. * - decoding: Set by user. */ int flags2; /** * Simulates errors in the bitstream to test error concealment. * - encoding: Set by user. * - decoding: unused */ int error_rate; /** * MP3 antialias algorithm, see FF_AA_* below. * - encoding: unused * - decoding: Set by user. */ int antialias_algo; #define FF_AA_AUTO 0 #define FF_AA_FASTINT 1 //not implemented yet #define FF_AA_INT 2 #define FF_AA_FLOAT 3 /** * quantizer noise shaping * - encoding: Set by user. * - decoding: unused */ int quantizer_noise_shaping; /** * thread count * is used to decide how many independent tasks should be passed to execute() * - encoding: Set by user. * - decoding: Set by user. */ int thread_count; /** * The codec may call this to execute several independent things. * It will return only after finishing all tasks. * The user may replace this with some multithreaded implementation, * the default implementation will execute the parts serially. * @param count the number of things to execute * - encoding: Set by libavcodec, user can override. * - decoding: Set by libavcodec, user can override. */ int (*execute)(struct AVCodecContext *c, int (*func)(struct AVCodecContext *c2, void *arg), void *arg2, int *ret, int count, int size); /** * thread opaque * Can be used by execute() to store some per AVCodecContext stuff. * - encoding: set by execute() * - decoding: set by execute() */ void *thread_opaque; /** * Motion estimation threshold below which no motion estimation is * performed, but instead the user specified motion vectors are used. * * - encoding: Set by user. * - decoding: unused */ int me_threshold; /** * Macroblock threshold below which the user specified macroblock types will be used. * - encoding: Set by user. * - decoding: unused */ int mb_threshold; /** * precision of the intra DC coefficient - 8 * - encoding: Set by user. * - decoding: unused */ int intra_dc_precision; /** * noise vs. sse weight for the nsse comparsion function * - encoding: Set by user. * - decoding: unused */ int nsse_weight; /** * Number of macroblock rows at the top which are skipped. * - encoding: unused * - decoding: Set by user. */ int skip_top; /** * Number of macroblock rows at the bottom which are skipped. * - encoding: unused * - decoding: Set by user. */ int skip_bottom; /** * profile * - encoding: Set by user. * - decoding: Set by libavcodec. */ int profile; #define FF_PROFILE_UNKNOWN -99 #define FF_PROFILE_AAC_MAIN 0 #define FF_PROFILE_AAC_LOW 1 #define FF_PROFILE_AAC_SSR 2 #define FF_PROFILE_AAC_LTP 3 #define FF_PROFILE_DTS 20 #define FF_PROFILE_DTS_ES 30 #define FF_PROFILE_DTS_96_24 40 #define FF_PROFILE_DTS_HD_HRA 50 #define FF_PROFILE_DTS_HD_MA 60 #define FF_PROFILE_H264_BASELINE 66 #define FF_PROFILE_H264_MAIN 77 #define FF_PROFILE_H264_EXTENDED 88 #define FF_PROFILE_H264_HIGH 100 #define FF_PROFILE_H264_HIGH_10 110 #define FF_PROFILE_H264_HIGH_422 122 #define FF_PROFILE_H264_HIGH_444 244 #define FF_PROFILE_H264_CAVLC_444 44 /** * level * - encoding: Set by user. * - decoding: Set by libavcodec. */ int level; #define FF_LEVEL_UNKNOWN -99 /** * low resolution decoding, 1-> 1/2 size, 2->1/4 size * - encoding: unused * - decoding: Set by user. */ int lowres; /** * Bitstream width / height, may be different from width/height if lowres * or other things are used. * - encoding: unused * - decoding: Set by user before init if known. Codec should override / dynamically change if needed. */ int coded_width, coded_height; /** * frame skip threshold * - encoding: Set by user. * - decoding: unused */ int frame_skip_threshold; /** * frame skip factor * - encoding: Set by user. * - decoding: unused */ int frame_skip_factor; /** * frame skip exponent * - encoding: Set by user. * - decoding: unused */ int frame_skip_exp; /** * frame skip comparison function * - encoding: Set by user. * - decoding: unused */ int frame_skip_cmp; /** * Border processing masking, raises the quantizer for mbs on the borders * of the picture. * - encoding: Set by user. * - decoding: unused */ float border_masking; /** * minimum MB lagrange multipler * - encoding: Set by user. * - decoding: unused */ int mb_lmin; /** * maximum MB lagrange multipler * - encoding: Set by user. * - decoding: unused */ int mb_lmax; /** * * - encoding: Set by user. * - decoding: unused */ int me_penalty_compensation; /** * * - encoding: unused * - decoding: Set by user. */ enum AVDiscard skip_loop_filter; /** * * - encoding: unused * - decoding: Set by user. */ enum AVDiscard skip_idct; /** * * - encoding: unused * - decoding: Set by user. */ enum AVDiscard skip_frame; /** * * - encoding: Set by user. * - decoding: unused */ int bidir_refine; /** * * - encoding: Set by user. * - decoding: unused */ int brd_scale; /** * constant rate factor - quality-based VBR - values ~correspond to qps * - encoding: Set by user. * - decoding: unused */ float crf; /** * constant quantization parameter rate control method * - encoding: Set by user. * - decoding: unused */ int cqp; /** * minimum GOP size * - encoding: Set by user. * - decoding: unused */ int keyint_min; /** * number of reference frames * - encoding: Set by user. * - decoding: Set by lavc. */ int refs; /** * chroma qp offset from luma * - encoding: Set by user. * - decoding: unused */ int chromaoffset; /** * Influences how often B-frames are used. * - encoding: Set by user. * - decoding: unused */ int bframebias; /** * trellis RD quantization * - encoding: Set by user. * - decoding: unused */ int trellis; /** * Reduce fluctuations in qp (before curve compression). * - encoding: Set by user. * - decoding: unused */ float complexityblur; /** * in-loop deblocking filter alphac0 parameter * alpha is in the range -6...6 * - encoding: Set by user. * - decoding: unused */ int deblockalpha; /** * in-loop deblocking filter beta parameter * beta is in the range -6...6 * - encoding: Set by user. * - decoding: unused */ int deblockbeta; /** * macroblock subpartition sizes to consider - p8x8, p4x4, b8x8, i8x8, i4x4 * - encoding: Set by user. * - decoding: unused */ int partitions; #define X264_PART_I4X4 0x001 /* Analyze i4x4 */ #define X264_PART_I8X8 0x002 /* Analyze i8x8 (requires 8x8 transform) */ #define X264_PART_P8X8 0x010 /* Analyze p16x8, p8x16 and p8x8 */ #define X264_PART_P4X4 0x020 /* Analyze p8x4, p4x8, p4x4 */ #define X264_PART_B8X8 0x100 /* Analyze b16x8, b8x16 and b8x8 */ /** * direct MV prediction mode - 0 (none), 1 (spatial), 2 (temporal), 3 (auto) * - encoding: Set by user. * - decoding: unused */ int directpred; /** * Audio cutoff bandwidth (0 means "automatic") * - encoding: Set by user. * - decoding: unused */ int cutoff; /** * Multiplied by qscale for each frame and added to scene_change_score. * - encoding: Set by user. * - decoding: unused */ int scenechange_factor; /** * * Note: Value depends upon the compare function used for fullpel ME. * - encoding: Set by user. * - decoding: unused */ int mv0_threshold; /** * Adjusts sensitivity of b_frame_strategy 1. * - encoding: Set by user. * - decoding: unused */ int b_sensitivity; /** * - encoding: Set by user. * - decoding: unused */ int compression_level; #define FF_COMPRESSION_DEFAULT -1 #if FF_API_USE_LPC /** * Sets whether to use LPC mode - used by FLAC encoder. * - encoding: Set by user. * - decoding: unused * @deprecated Deprecated in favor of lpc_type and lpc_passes. */ int use_lpc; #endif /** * LPC coefficient precision - used by FLAC encoder * - encoding: Set by user. * - decoding: unused */ int lpc_coeff_precision; /** * - encoding: Set by user. * - decoding: unused */ int min_prediction_order; /** * - encoding: Set by user. * - decoding: unused */ int max_prediction_order; /** * search method for selecting prediction order * - encoding: Set by user. * - decoding: unused */ int prediction_order_method; /** * - encoding: Set by user. * - decoding: unused */ int min_partition_order; /** * - encoding: Set by user. * - decoding: unused */ int max_partition_order; /** * GOP timecode frame start number, in non drop frame format * - encoding: Set by user. * - decoding: unused */ int64_t timecode_frame_start; #if LIBAVCODEC_VERSION_MAJOR < 53 /** * Decoder should decode to this many channels if it can (0 for default) * - encoding: unused * - decoding: Set by user. * @deprecated Deprecated in favor of request_channel_layout. */ int request_channels; #endif /** * Percentage of dynamic range compression to be applied by the decoder. * The default value is 1.0, corresponding to full compression. * - encoding: unused * - decoding: Set by user. */ float drc_scale; /** * opaque 64bit number (generally a PTS) that will be reordered and * output in AVFrame.reordered_opaque * @deprecated in favor of pkt_pts * - encoding: unused * - decoding: Set by user. */ int64_t reordered_opaque; /** * Bits per sample/pixel of internal libavcodec pixel/sample format. * This field is applicable only when sample_fmt is AV_SAMPLE_FMT_S32. * - encoding: set by user. * - decoding: set by libavcodec. */ int bits_per_raw_sample; /** * Audio channel layout. * - encoding: set by user. * - decoding: set by libavcodec. */ int64_t channel_layout; /** * Request decoder to use this channel layout if it can (0 for default) * - encoding: unused * - decoding: Set by user. */ int64_t request_channel_layout; /** * Ratecontrol attempt to use, at maximum, <value> of what can be used without an underflow. * - encoding: Set by user. * - decoding: unused. */ float rc_max_available_vbv_use; /** * Ratecontrol attempt to use, at least, <value> times the amount needed to prevent a vbv overflow. * - encoding: Set by user. * - decoding: unused. */ float rc_min_vbv_overflow_use; /** * Hardware accelerator in use * - encoding: unused. * - decoding: Set by libavcodec */ struct AVHWAccel *hwaccel; /** * For some codecs, the time base is closer to the field rate than the frame rate. * Most notably, H.264 and MPEG-2 specify time_base as half of frame duration * if no telecine is used ... * * Set to time_base ticks per frame. Default 1, e.g., H.264/MPEG-2 set it to 2. */ int ticks_per_frame; /** * Hardware accelerator context. * For some hardware accelerators, a global context needs to be * provided by the user. In that case, this holds display-dependent * data FFmpeg cannot instantiate itself. Please refer to the * FFmpeg HW accelerator documentation to know how to fill this * is. e.g. for VA API, this is a struct vaapi_context. * - encoding: unused * - decoding: Set by user */ void *hwaccel_context; /** * Chromaticity coordinates of the source primaries. * - encoding: Set by user * - decoding: Set by libavcodec */ enum AVColorPrimaries color_primaries; /** * Color Transfer Characteristic. * - encoding: Set by user * - decoding: Set by libavcodec */ enum AVColorTransferCharacteristic color_trc; /** * YUV colorspace type. * - encoding: Set by user * - decoding: Set by libavcodec */ enum AVColorSpace colorspace; /** * MPEG vs JPEG YUV range. * - encoding: Set by user * - decoding: Set by libavcodec */ enum AVColorRange color_range; /** * This defines the location of chroma samples. * - encoding: Set by user * - decoding: Set by libavcodec */ enum AVChromaLocation chroma_sample_location; /** * The codec may call this to execute several independent things. * It will return only after finishing all tasks. * The user may replace this with some multithreaded implementation, * the default implementation will execute the parts serially. * Also see avcodec_thread_init and e.g. the --enable-pthread configure option. * @param c context passed also to func * @param count the number of things to execute * @param arg2 argument passed unchanged to func * @param ret return values of executed functions, must have space for "count" values. May be NULL. * @param func function that will be called count times, with jobnr from 0 to count-1. * threadnr will be in the range 0 to c->thread_count-1 < MAX_THREADS and so that no * two instances of func executing at the same time will have the same threadnr. * @return always 0 currently, but code should handle a future improvement where when any call to func * returns < 0 no further calls to func may be done and < 0 is returned. * - encoding: Set by libavcodec, user can override. * - decoding: Set by libavcodec, user can override. */ int (*execute2)(struct AVCodecContext *c, int (*func)(struct AVCodecContext *c2, void *arg, int jobnr, int threadnr), void *arg2, int *ret, int count); /** * explicit P-frame weighted prediction analysis method * 0: off * 1: fast blind weighting (one reference duplicate with -1 offset) * 2: smart weighting (full fade detection analysis) * - encoding: Set by user. * - decoding: unused */ int weighted_p_pred; /** * AQ mode * 0: Disabled * 1: Variance AQ (complexity mask) * 2: Auto-variance AQ (experimental) * - encoding: Set by user * - decoding: unused */ int aq_mode; /** * AQ strength * Reduces blocking and blurring in flat and textured areas. * - encoding: Set by user * - decoding: unused */ float aq_strength; /** * PSY RD * Strength of psychovisual optimization * - encoding: Set by user * - decoding: unused */ float psy_rd; /** * PSY trellis * Strength of psychovisual optimization * - encoding: Set by user * - decoding: unused */ float psy_trellis; /** * RC lookahead * Number of frames for frametype and ratecontrol lookahead * - encoding: Set by user * - decoding: unused */ int rc_lookahead; /** * Constant rate factor maximum * With CRF encoding mode and VBV restrictions enabled, prevents quality from being worse * than crf_max, even if doing so would violate VBV restrictions. * - encoding: Set by user. * - decoding: unused */ float crf_max; int log_level_offset; /** * Determines which LPC analysis algorithm to use. * - encoding: Set by user * - decoding: unused */ enum AVLPCType lpc_type; /** * Number of passes to use for Cholesky factorization during LPC analysis * - encoding: Set by user * - decoding: unused */ int lpc_passes; /** * Number of slices. * Indicates number of picture subdivisions. Used for parallelized * decoding. * - encoding: Set by user * - decoding: unused */ int slices; /** * Header containing style information for text subtitles. * For SUBTITLE_ASS subtitle type, it should contain the whole ASS * [Script Info] and [V4+ Styles] section, plus the [Events] line and * the Format line following. It shouldn't include any Dialogue line. * - encoding: Set/allocated/freed by user (before avcodec_open()) * - decoding: Set/allocated/freed by libavcodec (by avcodec_open()) */ uint8_t *subtitle_header; int subtitle_header_size; /** * Current packet as passed into the decoder, to avoid having * to pass the packet into every function. Currently only valid * inside lavc and get/release_buffer callbacks. * - decoding: set by avcodec_decode_*, read by get_buffer() for setting pkt_pts * - encoding: unused */ AVPacket *pkt; } AVCodecContext;