avcodec.h

ffmpeg的完整源代码和作者自己写的文档。不但有在Linux的工程哦

#define FF_MM_SSSE3    0x0080 /* Conroe SSSE3 functions */
#define FF_MM_IWMMXT   0x0100 /* XScale IWMMXT */

    /**
     * bits per sample/pixel from the demuxer (needed for huffyuv).
     * - encoding: Set by libavcodec.
     * - decoding: Set by user.
     */
     int bits_per_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)
     * 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

    /**
     * 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;

#define FF_LAMBDA_SHIFT 7
#define FF_LAMBDA_SCALE (1<<FF_LAMBDA_SHIFT)
#define FF_QP2LAMBDA 118 ///< factor to convert from H.263 QP to lambda
#define FF_LAMBDA_MAX (256*128-1)

#define FF_QUALITY_SCALE FF_LAMBDA_SCALE //FIXME maybe remove
    /**
     * 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 distoration

    /**
     * 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;

    /**
     * palette control structure
     * - encoding: ??? (no palette-enabled encoder yet)
     * - decoding: Set by user.
     */
    struct AVPaletteControl *palctrl;

    /**
     * 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().
     * - 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);