avcodec.h

mpeg4 video codec mpeg4 video codec

     */
    int context_model;
    
    /**
     * 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 lavc
     */
    uint16_t *intra_matrix,*intra_matrix_luma,*intra_matrix_chroma;

    /**
     * custom inter quantization matrix
     * - encoding: set by user, can be NULL
     * - decoding: set by lavc
     */
    uint16_t *inter_matrix,*inter_matrix_luma,*inter_matrix_chroma;
    
    /**
     * fourcc from the AVI stream header (LSB first, so "ABCD" -> ('D'<<24) + ('C'<<16) + ('B'<<8) + 'A').
     * this is used to workaround some encoder bugs
     * - encoding: unused
     * - decoding: set by user, will be converted to upper case by lavc 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 and maxminum quantizer for I frames. If 0, derived from qmin, i_quant_factor, i_quant_offset
     * - encoding: set by user.
     * - decoding: unused
     */
    int qmin_i,qmax_i;

    /**
     * minimum and maximum quantizer for B frames. If 0, derived from qmin, b_quant_factor, b_quant_offset
     * - encoding: set by user.
     * - decoding: unused
     */
    int qmin_b,qmax_b;

    /**
     * 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. lavc won't check it.
     * lavc 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 lavc, 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 independant 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 independant 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 lavc, user can override
     * - decoding: set by lavc, user can override
     */
    int (*execute)(struct AVCodecContext *c, int (*func)(struct AVCodecContext *c2, void *arg), void **arg2, int *ret, int count);
    
    /**
     * 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. under 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. under 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 lavc
     */
     int profile;
#define FF_PROFILE_UNKNOWN -99

    /**
     * level
     * - encoding: set by user
     * - decoding: set by lavc
     */
     int level;
#define FF_LEVEL_UNKNOWN -99
    int xvid_build;
    /* lavc specific stuff, used to workaround bugs in libavcodec */
    int lavc_build;
    /* divx specific, used to workaround (many) bugs in divx5 */
    int divx_version;
    int divx_build;
    int ac3mode,ac3lfe;
    int ac3channels[6];
    int nal_length_size;
    int h264_deblocking_filter,h264_slice_alpha_c0_offset,h264_slice_beta_offset;
    int vorbis_header_size[3];
    int64_t granulepos;
    int64_t *parserRtStart;
    void (*handle_user_data)(struct AVCodecContext *c,const uint8_t *buf,int buf_size);
    /**
     * low resolution decoding. 1-> 1/2 size, 2->1/4 size
     * - encoding: unused
     * - decoding: set by user
     */
     int lowres;

    /**
     * bitsream 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 comparission 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;

    /**
     * multiplied by qscale for each frame and added to scene_change_score
     * - encoding: set by user.
     * - decoding: unused
     */
    int scenechange_factor;
} AVCodecContext;

/**
 * AVCodec.
 */
typedef struct AVCodec {
    const char *name;
    enum CodecType type;
    enum CodecID id;
    int priv_data_size;
    int (*init)(AVCodecContext *);
    int (*encode)(AVCodecContext *, uint8_t *buf, int buf_size, void *data);
    int (*close)(AVCodecContext *);
    int (*decode)(AVCodecContext *, void *outdata, int *outdata_size, 
                  uint8_t *buf, int buf_size);
    int capabilities;
    struct AVCodec *next;
    void (*flush)(AVCodecContext *);
} AVCodec;

/** 
 * four components are given, that's all.
 * the last component is alpha
 */
typedef struct AVPicture {
    uint8_t *data[4];
    int linesize[4];       ///< number of bytes per line
} AVPicture;

/**
 * AVPaletteControl
 * This structure defines a method for communicating palette changes
 * between and demuxer and a decoder.
 */
#define AVPALETTE_SIZE 1024
#define AVPALETTE_COUNT 256
typedef struct AVPaletteControl {

    /* demuxer sets this to 1 to indicate the palette has changed;
     * decoder resets to 0 */
    int palette_changed;

    /* 4-byte ARGB palette entries, stored in native byte order; note that
     * the individual palette components should be on a 8-bit scale; if
     * the palette data comes from a IBM VGA native format, the component
     * data is probably 6 bits in size and needs to be scaled */
    unsigned int palette[AVPALETTE_COUNT];

} AVPaletteControl;

typedef struct AVSubtitleRect {
    uint16_t x;
    uint16_t y;
    uint16_t w;
    uint16_t h;
    uint16_t nb_colors;
    int linesize;
    uint32_t *rgba_palette;
    uint8_t *bitmap;
} AVSubtitleRect;

typedef struct AVSubtitle {
    uint16_t format; /* 0 = graphics */
    uint32_t start_display_time; /* relative to packet pts, in ms */
    uint32_t end_display_time; /* relative to packet pts, in ms */