avcodec.h

ffmpeg源码分析

     *
     * - 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
     */
    int 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;
} 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;
#if LIBAVCODEC_VERSION_INT < ((50<<16)+(0<<8)+0)
    void *dummy; // FIXME remove next time we break binary compatibility
#endif
    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.
 */
#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 */
    uint32_t num_rects;
    AVSubtitleRect *rects;
} AVSubtitle;

extern AVCodec ac3_encoder;
extern AVCodec mp2_encoder;
extern AVCodec mp3lame_encoder;
extern AVCodec oggvorbis_encoder;
extern AVCodec oggtheora_encoder;
extern AVCodec faac_encoder;
extern AVCodec xvid_encoder;
extern AVCodec mpeg1video_encoder;
extern AVCodec mpeg2video_encoder;
extern AVCodec h261_encoder;
extern AVCodec h263_encoder;
extern AVCodec h263p_encoder;
extern AVCodec flv_encoder;
extern AVCodec rv10_encoder;
extern AVCodec rv20_encoder;
extern AVCodec dvvideo_encoder;
extern AVCodec mjpeg_encoder;
extern AVCodec ljpeg_encoder;
extern AVCodec jpegls_encoder;
extern AVCodec png_encoder;
extern AVCodec ppm_encoder;
extern AVCodec pgm_encoder;
extern AVCodec pgmyuv_encoder;
extern AVCodec pbm_encoder;
extern AVCodec pam_encoder;
extern AVCodec mpeg4_encoder;
extern AVCodec msmpeg4v1_encoder;
extern AVCodec msmpeg4v2_encoder;
extern AVCodec msmpeg4v3_encoder;
extern AVCodec wmv1_encoder;
extern AVCodec wmv2_encoder;
extern AVCodec huffyuv_encoder;
extern AVCodec ffvhuff_encoder;
extern AVCodec h264_encoder;
extern AVCodec asv1_encoder;
extern AVCodec asv2_encoder;
extern AVCodec vcr1_encoder;
extern AVCodec ffv1_encoder;
extern AVCodec snow_encoder;
extern AVCodec mdec_encoder;
extern AVCodec zlib_encoder;
extern AVCodec sonic_encoder;
extern AVCodec sonic_ls_encoder;
extern AVCodec svq1_encoder;
extern AVCodec x264_encoder;

extern AVCodec h263_decoder;
extern AVCodec h261_decoder;
extern AVCodec mpeg4_decoder;
extern AVCodec msmpeg4v1_decoder;
extern AVCodec msmpeg4v2_decoder;
extern AVCodec msmpeg4v3_decoder;
extern AVCodec wmv1_decoder;
extern AVCodec wmv2_decoder;
extern AVCodec vc9_decoder;
extern AVCodec wmv3_decoder;
extern AVCodec mpeg1video_decoder;
extern AVCodec mpeg2video_decoder;
extern AVCodec mpegvideo_decoder;
extern AVCodec mpeg_xvmc_decoder;
extern AVCodec h263i_decoder;
extern AVCodec flv_decoder;
extern AVCodec rv10_decoder;
extern AVCodec rv20_decoder;
extern AVCodec rv30_decoder;
extern AVCodec rv40_decoder;
extern AVCodec svq1_decoder;
extern AVCodec svq3_decoder;
extern AVCodec dvvideo_decoder;
extern AVCodec wmav1_decoder;
extern AVCodec wmav2_decoder;
extern AVCodec mjpeg_decoder;
extern AVCodec mjpegb_decoder;
extern AVCodec sp5x_decoder;
extern AVCodec png_decoder;
extern AVCodec mp2_decoder;
extern AVCodec mp3_decoder;
extern AVCodec mp3adu_decoder;
extern AVCodec mp3on4_decoder;
extern AVCodec qdm2_decoder;
extern AVCodec cook_decoder;
extern AVCodec truespeech_decoder;
extern AVCodec tta_decoder;
extern AVCodec mace3_decoder;
extern AVCodec mace6_decoder;
extern AVCodec huffyuv_decoder;
extern AVCodec ffvhuff_decoder;
extern AVCodec oggvorbis_decoder;
extern AVCodec oggtheora_decoder;
extern AVCodec cyuv_decoder;
extern AVCodec h264_decoder;
extern AVCodec indeo3_decoder;
extern AVCodec vp3_decoder;
extern AVCodec theora_decoder;
extern AVCodec amr_nb_decoder;
extern AVCodec amr_nb_encoder;
extern AVCodec amr_wb_encoder;
extern AVCodec amr_wb_decoder;
extern AVCodec aac_decoder;
extern AVCodec mpeg4aac_decoder;
extern AVCodec asv1_decoder;
extern AVCodec asv2_decoder;
extern AVCodec vcr1_decoder;
extern AVCodec cljr_decoder;
extern AVCodec ffv1_decoder;
extern AVCodec snow_decoder;
extern AVCodec fourxm_decoder;
extern AVCodec mdec_decoder;
extern AVCodec roq_decoder;
extern AVCodec interplay_video_decoder;
extern AVCodec xan_wc3_decoder;
extern AVCodec rpza_decoder;
extern AVCodec cinepak_decoder;
extern AVCodec msrle_decoder;
extern AVCodec msvideo1_decoder;
extern AVCodec vqa_decoder;
extern AVCodec idcin_decoder;
extern AVCodec eightbps_decoder;
extern AVCodec smc_decoder;
extern AVCodec flic_decoder;
extern AVCodec vmdvideo_decoder;
extern AVCodec vmdaudio_decoder;
extern AVCodec truemotion1_decoder;
extern AVCodec truemotion2_decoder;
extern AVCodec mszh_decoder;
extern AVCodec zlib_decoder;
extern AVCodec ra_144_decoder;
extern AVCodec ra_288_decoder;
extern AVCodec roq_dpcm_decoder;
extern AVCodec interplay_dpcm_decoder;
extern AVCodec xan_dpcm_decoder;
extern AVCodec sol_dpcm_decoder;
extern AVCodec sonic_decoder;
extern AVCodec qtrle_decoder;
extern AVCodec flac_decoder;
extern AVCodec tscc_decoder;
extern AVCodec cscd_decoder;
extern AVCodec nuv_decoder;
extern AVCodec ulti_decoder;
extern AVCodec qdraw_decoder;
extern AVCodec xl_decoder;
extern AVCodec qpeg_decoder;
extern AVCodec shorten_decoder;
extern AVCodec loco_decoder;
extern AVCodec wnv1_decoder;
extern AVCodec aasc_decoder;
extern AVCodec alac_decoder;
extern AVCodec ws_snd1_decoder;
extern AVCodec indeo2_decoder;
extern AVCodec vorbis_decoder;
extern AVCodec fraps_decoder;
extern AVCodec libgsm_encoder;
extern AVCodec libgsm_decoder;
extern AVCodec bmp_decoder;
extern AVCodec mmvideo_decoder;
extern AVCodec zmbv_decoder;
extern AVCodec avs_decoder;
extern AVCodec smacker_decoder;
extern AVCodec smackaud_decoder;

/* pcm codecs */
#define PCM_CODEC(id, name) \
extern AVCodec name ## _decoder; \
extern AVCodec name ## _encoder

PCM_CODEC(CODEC_ID_PCM_S32LE, pcm_s32le);
PCM_CODEC(CODEC_ID_PCM_S32BE, pcm_s32be);
PCM_CODEC(CODEC_ID_PCM_U32LE, pcm_u32le);
PCM_CODEC(CODEC_ID_PCM_U32BE, pcm_u32be);
PCM_CODEC(CODEC_ID_PCM_S24LE, pcm_s24le);
PCM_CODEC(CODEC_ID_PCM_S24BE, pcm_s24be);
PCM_CODEC(CODEC_ID_PCM_U24LE, pcm_u24le);
PCM_CODEC(CODEC_ID_PCM_U24BE, pcm_u24be);
PCM_CODEC(CODEC_ID_PCM_S24DAUD, pcm_s24daud);
PCM_CODEC(CODEC_ID_PCM_S16LE, pcm_s16le);
PCM_CODEC(CODEC_ID_PCM_S16BE, pcm_s16be);
PCM_CODEC(CODEC_ID_PCM_U16LE, pcm_u16le);
PCM_CODEC(CODEC_ID_PCM_U16BE, pcm_u16be);
PCM_CODEC(CODEC_ID_PCM_S8, pcm_s8);
PCM_CODEC(CODEC_ID_PCM_U8, pcm_u8);
PCM_CODEC(CODEC_ID_PCM_ALAW, pcm_alaw);
PCM_CODEC(CODEC_ID_PCM_MULAW, pcm_mulaw);

/* adpcm codecs */

PCM_CODEC(CODEC_ID_ADPCM_IMA_QT, adpcm_ima_qt);
PCM_CODEC(CODEC_ID_ADPCM_IMA_WAV, adpcm_ima_wav);
PCM_CODEC(CODEC_ID_ADPCM_IMA_DK3, adpcm_ima_dk3);
PCM_CODEC(CODEC_ID_ADPCM_IMA_DK4, adpcm_ima_dk4);
PCM_CODEC(CODEC_ID_ADPCM_IMA_WS, adpcm_ima_ws);
PCM_CODEC(CODEC_ID_ADPCM_SMJPEG, adpcm_ima_smjpeg);
PCM_CODEC(CODEC_ID_ADPCM_MS, adpcm_ms);
PCM_CODEC(CODEC_ID_ADPCM_4XM, adpcm_4xm);
PCM_CODEC(CODEC_ID_ADPCM_XA, adpcm_xa);
PCM_CODEC(CODEC_ID_ADPCM_ADX, adpcm_adx);
PCM_CODEC(CODEC_ID_ADPCM_EA, adpcm_ea);
PCM_CODEC(CODEC_ID_ADPCM_G726, adpcm_g726);
PCM_CODEC(CODEC_ID_ADPCM_CT, adpcm_ct);
PCM_CODEC(CODEC_ID_ADPCM_SWF, adpcm_swf);
PCM_CODEC(CODEC_ID_ADPCM_YAMAHA, adpcm_yamaha);
PCM_CODEC(CODEC_ID_ADPCM_SBPRO_4, adpcm_sbpro_4);
PCM_CODEC(CODEC_ID_ADPCM_SBPRO_3, adpcm_sbpro_3);
PCM_CODEC(CODEC_ID_ADPCM_SBPRO_2, adpcm_sbpro_2);

#undef PCM_CODEC

/* dummy raw video codec */
extern AVCodec rawvideo_encoder;
extern AVCodec rawvideo_decoder;

/* the following codecs use external GPL libs */
extern AVCodec ac3_decoder;
extern AVCodec dts_decoder;

/* subtitles */
extern AVCodec dvdsub_encoder;
extern AVCodec dvdsub_decoder;
extern AVCodec dvbsub_encoder;
extern AVCodec dvbsub_decoder;

/* resample.c */

struct ReSampleContext;
struct AVResampleContext;

typedef struct ReSampleContext ReSampleContext;

ReSampleContext *audio_resample_init(int output_channels, int input_channels,
                                     int output_rate, int input_rate);
int audio_resample(ReSampleContext *s, short *output, short *input, int nb_samples);
void audio_resample_close(ReSampleContext *s);

struct AVResampleContext *av_resample_init(int out_rate, int in_rate, int filter_length, int log2_phase_count, int linear, double cutoff);
int av_resample(struct AVResampleContext *c, short *dst, short *src, int *consumed, int src_size, int dst_size, int update_ctx);
void av_resample_compensate(struct AVResampleContext *c, int sample_delta, int compensation_distance);
void av_resample_close(struct AVResampleContext *c);

/* YUV420 format is assumed ! */

struct ImgReSampleContext;

typedef struct ImgReSampleContext ImgReSampleContext;

ImgReSampleContext *img_resample_init(int output_width, int output_height,
                                      int input_width, int input_height);

ImgReSampleContext *img_resample_full_init(int owidth, int oheight,
                                      int iwidth, int iheight,
                                      int topBand, int bottomBand,
                                      int leftBand, int rightBand,
                                      int padtop, int padbottom,
                                      int padleft, int padright);


void img_resample(ImgReSampleContext *s,
                  AVPicture *output, const AVPicture *input);

void img_resample_close(ImgReSampleContext *s);

/**
 * Allocate memory for a picture.  Call avpicture_free to free it.
 *
 * @param pic