av_fourcc_make_string  348 libavutil/avutil.h #define av_fourcc2str(fourcc) av_fourcc_make_string((char[AV_FOURCC_MAX_STRING_SIZE]){0}, fourcc)
av_fourcc_make_string  358 libavutil/avutil.h char *av_fourcc_make_string(char *buf, uint32_t fourcc);