avcodec.h

从FFMPEG转换而来的H264解码程序,VC下编译..

     */
    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: unused
     */
    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  /* Analyse i4x4 */
#define X264_PART_I8X8 0x002  /* Analyse i8x8 (requires 8x8 transform) */
#define X264_PART_P8X8 0x010  /* Analyse p16x8, p8x16 and p8x8 */
#define X264_PART_P4X4 0x020  /* Analyse p8x4, p4x8, p4x4 */
#define X264_PART_B8X8 0x100  /* Analyse b16x8, b8x16 and b8x8 */

    /**
     * direct MV prediction mode - 0 (none), 1 (spatial), 2 (temporal)
     * - encoding: Set by user.
     * - decoding: unused
     */
    int directpred;

    /**
     * Audio cutoff bandwidth (0 means "automatic"), currently used only by FAAC.
     * - 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

    /**
     * Sets whether to use LPC mode - used by FLAC encoder.
     * - encoding: Set by user.
     * - decoding: unused
     */
    int use_lpc;

    /**
     * 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;
} AVCodecContext;

/**
 * AVCodec.
 */
typedef struct AVCodec {
    /**
     * Name of the codec implementation.
     * The name is globally unique among encoders and among decoders (but an
     * encoder and a decoder can share the same name).
     * This is the primary way to find a codec from the user perspective.
     */
    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 *);
    const AVRational *supported_framerates; ///array of supported framerates, or NULL if any, array is terminated by {0,0}
    const enum PixelFormat *pix_fmts;       ///array of supported pixel formats, or NULL if unknown, array is terminanted by -1
} 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.
 *
 * @deprecated Use AVPacket to send palette changes instead.
 * This is totally broken.
 */
#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 an IBM VGA native format, the component
     * data is probably 6 bits in size and needs to be scaled. */
    unsigned int palette[AVPALETTE_COUNT];

} AVPaletteControl;

/**
 * Allocate memory for a picture.  Call avpicture_free to free it.
 *
 * @param picture the picture to be filled in
 * @param pix_fmt the format of the picture
 * @param width the width of the picture
 * @param height the height of the picture
 * @return zero if successful, a negative value if not
 */
int avpicture_alloc(AVPicture *picture, int pix_fmt, int width, int height);

/**
 * Free a picture previously allocated by avpicture_alloc().
 *
 * @param picture the AVPicture to be freed
 */
void avpicture_free(AVPicture *picture);

/**
 * Fill in the AVPicture fields.
 * The fields of the given AVPicture are filled in by using the 'ptr' address
 * which points to the image data buffer. Depending on the specified picture
 * format, one or multiple image data pointers and line sizes will be set.
 * If a planar format is specified, several pointers will be set pointing to
 * the different picture planes and the line sizes of the different planes
 * will be stored in the lines_sizes array.
 *
 * @param picture AVPicture whose fields are to be filled in
 * @param ptr Buffer which will contain or contains the actual image data
 * @param pix_fmt The format in which the picture data is stored.
 * @param width the width of the image in pixels
 * @param height the height of the image in pixels
 * @return size of the image data in bytes
 */
int avpicture_fill(AVPicture *picture, uint8_t *ptr,
                   int pix_fmt, int width, int height);
int avpicture_layout(const AVPicture* src, int pix_fmt, int width, int height,
                     unsigned char *dest, int dest_size);

/**
 * Calculate the size in bytes that a picture of the given width and height
 * would occupy if stored in the given picture format.
 *
 * @param pix_fmt the given picture format
 * @param width the width of the image
 * @param height the height of the image
 * @return Image data size in bytes
 */
int avpicture_get_size(int pix_fmt, int width, int height);
void avcodec_get_chroma_sub_sample(int pix_fmt, int *h_shift, int *v_shift);
const char *avcodec_get_pix_fmt_name(int pix_fmt);
void avcodec_set_dimensions(AVCodecContext *s, int width, int height);
enum PixelFormat avcodec_get_pix_fmt(const char* name);
unsigned int avcodec_pix_fmt_to_codec_tag(enum PixelFormat p);

#define FF_LOSS_RESOLUTION  0x0001 /**< loss due to resolution change */
#define FF_LOSS_DEPTH       0x0002 /**< loss due to color depth change */
#define FF_LOSS_COLORSPACE  0x0004 /**< loss due to color space conversion */
#define FF_LOSS_ALPHA       0x0008 /**< loss of alpha bits */
#define FF_LOSS_COLORQUANT  0x0010 /**< loss due to color quantization */
#define FF_LOSS_CHROMA      0x0020 /**< loss of chroma (e.g. RGB to gray conversion) */

/**
 * Computes what kind of losses will occur when converting from one specific
 * pixel format to another.
 * When converting from one pixel format to another, information loss may occur.
 * For example, when converting from RGB24 to GRAY, the color information will
 * be lost. Similarly, other losses occur when converting from some formats to
 * other formats. These losses can involve loss of chroma, but also loss of
 * resolution, loss of color depth, loss due to the color space conversion, loss
 * of the alpha bits or loss due to color quantization.
 * avcodec_get_fix_fmt_loss() informs you about the various types of losses
 * which will occur when converting from one pixel format to another.
 *
 * @param[in] dst_pix_fmt destination pixel format
 * @param[in] src_pix_fmt source pixel format
 * @param[in] has_alpha Whether the source pixel format alpha channel is used.
 * @return Combination of flags informing you what kind of losses will occur.
 */
int avcodec_get_pix_fmt_loss(int dst_pix_fmt, int src_pix_fmt,
                             int has_alpha);

/**
 * Finds the best pixel format to convert to given a certain source pixel
 * format.  When converting from one pixel format to another, information loss
 * may occur.  For example, when converting from RGB24 to GRAY, the color
 * information will be lost. Similarly, other losses occur when converting from
 * some formats to other formats. avcodec_find_best_pix_fmt() searches which of
 * the given pixel formats should be used to suffer the least amount of loss.
 * The pixel formats from which it chooses one, are determined by the
 * \p pix_fmt_mask parameter.
 *
 * @code
 * src_pix_fmt = PIX_FMT_YUV420P;
 * pix_fmt_mask = (1 << PIX_FMT_YUV422P) || (1 << PIX_FMT_RGB24);
 * dst_pix_fmt = avcodec_find_best_pix_fmt(pix_fmt_mask, src_pix_fmt, alpha, &loss);
 * @endcode
 *
 * @param[in] pix_fmt_mask bitmask determining which pixel format to choose from
 * @param[in] src_pix_fmt source pixel format
 * @param[in] has_alpha Whether the source pixel format alpha channel is used.
 * @param[out] loss_ptr Combination of flags informing you what kind of losses will occur.
 * @return The best pixel format to convert to or -1 if none was found.
 */
int avcodec_find_best_pix_fmt(int pix_fmt_mask, int src_pix_fmt,
                              int has_alpha