avi->non_interleaved |= guess_ni_flag(s);
static int avi_load_index(AVFormatContext *s){    AVIContext *avi = s->priv_data;    ByteIOContext *pb = &s->pb;    uint32_t tag, size;    offset_t pos= url_ftell(pb);        url_fseek(pb, avi->movi_end, SEEK_SET);#ifdef DEBUG_SEEK    printf("movi_end=0x%llx\n", avi->movi_end);#endif    for(;;) {        if (url_feof(pb))            break;        tag = get_le32(pb);        size = get_le32(pb);#ifdef DEBUG_SEEK        printf("tag=%c%c%c%c size=0x%x\n",               tag & 0xff,               (tag >> 8) & 0xff,               (tag >> 16) & 0xff,               (tag >> 24) & 0xff,               size);#endif        switch(tag) {        case MKTAG('i', 'd', 'x', '1'):            if (avi_read_idx1(s, size) < 0)                goto skip;            else                goto the_end;            break;        default:        skip:            size += (size & 1);            url_fskip(pb, size);            break;        }    } the_end:    url_fseek(pb, pos, SEEK_SET);    return 0;}