printf("MPEG4 description: tag=0x%02x len=%d\n", *tag, len);
av_log(NULL, AV_LOG_DEBUG, "MPEG4 description: tag=0x%02x len=%d\n", *tag, len);
static int mov_mp4_read_descr(ByteIOContext *pb, int *tag){    int len;    *tag = get_byte(pb);    len = mov_mp4_read_descr_len(pb);#ifdef DEBUG    printf("MPEG4 description: tag=0x%02x len=%d\n", *tag, len);#endif    return len;}