avcodec.h

gaca源码

    /**
     * hurry up amount.
     * deprecated in favor of skip_idct and skip_frame
     * - encoding: unused
     * - decoding: set by user. 1-> skip b frames, 2-> skip idct/dequant too, 5-> skip everything except header
     */
    int hurry_up;
    
    struct AVCodec *codec;
    
    void *priv_data;

    /* unused, FIXME remove*/
    int rtp_mode;
    
    int rtp_payload_size;   /* The size of the RTP payload: the coder will  */
                            /* do it's 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 transmited RTP payload    */

    
    /* The RTP callback: This function is called   */
    /* every time the encoder has a packet to send */
    /* 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 lavc
     * - 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 CodecType codec_type; /* see CODEC_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 workaround some encoder bugs
     * - encoding: set by user, if not then the default based on codec_id will be used
     * - decoding: set by user, will be converted to upper case by lavc during init
     */
    unsigned int codec_tag;
    
    /**
     * workaround 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 ///< workaround various bugs in microsofts broken decoders
//#define FF_BUG_FAKE_SCALABILITY 16 //autodetection should work 100%
        
    /**
     * luma single coeff 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 std (MPEG4, ...).
     * - encoding: set by user
     * - decoding: unused
     */
    int strict_std_compliance;
#define FF_COMPLIANCE_VERY_STRICT   2 ///< strictly conform to a 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
#define FF_COMPLIANCE_INOFFICIAL   -1 ///< allow inofficial extensions
#define FF_COMPLIANCE_EXPERIMENTAL -2 ///< allow non standarized experimental things

    /**
     * qscale offset 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_offset;
    
    /**
     * error resilience higher values will detect more errors but may missdetect
     * some more or less valid parts as errors.
     * - encoding: unused
     * - decoding: set by user
     */
    int error_resilience;
#define FF_ER_CAREFULL        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 lavc
     * avcodec_align_dimensions() should be used to find the required width and
     * height, as they normally need to be rounded up to the next multiple of 16
     * - encoding: unused
     * - decoding: set by lavc, user can override
     */
    int (*get_buffer)(struct AVCodecContext *c, AVFrame *pic);
    
    /**
     * called to release buffers which where 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 lavc, user can override
     */
    void (*release_buffer)(struct AVCodecContext *c, AVFrame *pic);

    /**
     * if 1 the stream has a 1 frame delay during decoding.
     * - encoding: set by lavc
     * - decoding: set by lavc
     */
    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 lavc
     * - 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
     */
    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;
    
    
    /* for binary compatibility */
    int unused;
    
    /**
     * 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

    /**
     * slice count.
     * - encoding: set by lavc
     * - decoding: set by user (or 0)
     */
    int slice_count;
    /**
     * slice offsets in the frame in bytes.
     * - encoding: set/allocated by lavc
     * - 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 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;
#define FF_MM_FORCE	0x80000000 /* force usage of selected flags (OR) */
    /* lower 16 bits - CPU features */
#ifdef HAVE_MMX
#define FF_MM_MMX	0x0001 /* standard MMX */
#define FF_MM_3DNOW	0x0004 /* AMD 3DNOW */
#define FF_MM_MMXEXT	0x0002 /* SSE integer functions or AMD MMX ext */
#define FF_MM_SSE	0x0008 /* SSE functions */
#define FF_MM_SSE2	0x0010 /* PIV SSE2 functions */
#define FF_MM_3DNOWEXT	0x0020 /* AMD 3DNowExt */
#endif /* HAVE_MMX */
#ifdef HAVE_IWMMXT
#define FF_MM_IWMMXT	0x0100 /* XScale IWMMXT */
#endif /* HAVE_IWMMXT */

    /**
     * bits per sample/pixel from the demuxer (needed for huffyuv).
     * - encoding: set by lavc
     * - 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 relative prime and smaller then 256 for some video standards
     * - encoding: set by user.
     * - decoding: set by lavc.
     */
    AVRational sample_aspect_ratio;

    /**
     * the picture in the bitstream.
     * - encoding: set by lavc
     * - decoding: set by lavc
     */
    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