这里就简单罗列下，免得你都不知道有这些接口

/*** @defgroup lavf_misc Utility functions* @ingroup libavf* @{** Miscellaneous utility functions related to both muxing and demuxing* (or neither).*//*** Send a nice hexadecimal dump of a buffer to the specified file stream.** @param f The file stream pointer where the dump should be sent to.* @param buf buffer* @param size buffer size** @see av_hex_dump_log, av_pkt_dump2, av_pkt_dump_log2*/
void av_hex_dump(FILE *f, const uint8_t *buf, int size);/*** Send a nice hexadecimal dump of a buffer to the log.** @param avcl A pointer to an arbitrary struct of which the first field is a* pointer to an AVClass struct.* @param level The importance level of the message, lower values signifying* higher importance.* @param buf buffer* @param size buffer size** @see av_hex_dump, av_pkt_dump2, av_pkt_dump_log2*/
void av_hex_dump_log(void *avcl, int level, const uint8_t *buf, int size);/*** Send a nice dump of a packet to the specified file stream.** @param f The file stream pointer where the dump should be sent to.* @param pkt packet to dump* @param dump_payload True if the payload must be displayed, too.* @param st AVStream that the packet belongs to*/
void av_pkt_dump2(FILE *f, const AVPacket *pkt, int dump_payload, const AVStream *st);/*** Send a nice dump of a packet to the log.** @param avcl A pointer to an arbitrary struct of which the first field is a* pointer to an AVClass struct.* @param level The importance level of the message, lower values signifying* higher importance.* @param pkt packet to dump* @param dump_payload True if the payload must be displayed, too.* @param st AVStream that the packet belongs to*/
void av_pkt_dump_log2(void *avcl, int level, const AVPacket *pkt, int dump_payload,const AVStream *st);

这个单独罗列出来

/*** Print detailed information about the input or output format, such as* duration, bitrate, streams, container, programs, metadata, side data,* codec and time base.** @param ic        the context to analyze* @param index     index of the stream to dump information about* @param url       the URL to print, such as source or destination file* @param is_output Select whether the specified context is an input(0) or output(1)*/
void av_dump_format(AVFormatContext *ic,int index,const char *url,int is_output);