AVFormatContext

Format I/O context
使用 avformat_alloc_context() 创建一个 AVFormatContext

typedef struct AVFormatContext 
{
const AVClass *av_class;
const struct AVInputFormat *iformat;
const struct AVOutputFormat *oformat;
void *priv_data;
AVIOContext *pb;
int ctx_flags;
unsigned int nb_streams;
AVStream **streams;
char *url;
int64_t start_time;
int64_t duration;
int64_t bit_rate;
unsigned int packet_size;
int max_delay;
}

AVFrame

describes decoded (raw) audio or video data

typedef struct AVFrame 
{
#define AV_NUM_DATA_POINTERS 8
uint8_t *data[AV_NUM_DATA_POINTERS];
int linesize[AV_NUM_DATA_POINTERS];
uint8_t **extended_data;
int width, height;
int nb_samples;
int format;
}

AVCodec

typedef struct AVCodec 
{
const char *name;
const char *long_name;
enum AVMediaType type;
enum AVCodecID id;
void (*init_static_data)(struct AVCodec *codec);int (*init)(struct AVCodecContext *);
}

AVPacket

此结构存储压缩数据。 它通常由解复用器导出，然后作为输入传递给解码器，或者作为输出从编码器接收，然后传递给复用器。

typedef struct AVPacket 
{
AVBufferRef *buf;
int64_t pts;
int64_t dts;
uint8_t *data;
int   size;
int   stream_index;
}