+
+start_sync:
+ memset(d, -1, sizeof(d));
+ for (i = sync = avio_tell(pb); !pb->eof_reached; i++) {
+ int j;
+
+ for (j = 0; j < 7; j++)
+ d[j] = d[j + 1];
+ d[7] = avio_r8(pb);
+
+ size = d[4] + (d[5] << 8) + (d[6] << 16) + (d[7] << 24);
+
+ n = get_stream_idx(d + 2);
+ av_dlog(s, "%X %X %X %X %X %X %X %X %"PRId64" %u %d\n",
+ d[0], d[1], d[2], d[3], d[4], d[5], d[6], d[7], i, size, n);
+ if (i + (uint64_t)size > avi->fsize || d[0] > 127)
+ continue;
+
+ // parse ix##
+ if ((d[0] == 'i' && d[1] == 'x' && n < s->nb_streams) ||
+ // parse JUNK
+ (d[0] == 'J' && d[1] == 'U' && d[2] == 'N' && d[3] == 'K') ||
+ (d[0] == 'i' && d[1] == 'd' && d[2] == 'x' && d[3] == '1')) {
+ avio_skip(pb, size);
+ goto start_sync;
+ }
+
+ // parse stray LIST
+ if (d[0] == 'L' && d[1] == 'I' && d[2] == 'S' && d[3] == 'T') {
+ avio_skip(pb, 4);
+ goto start_sync;
+ }
+
+ n = get_stream_idx(d);
+
+ if (!((i - avi->last_pkt_pos) & 1) &&
+ get_stream_idx(d + 1) < s->nb_streams)
+ continue;
+
+ // detect ##ix chunk and skip
+ if (d[2] == 'i' && d[3] == 'x' && n < s->nb_streams) {
+ avio_skip(pb, size);
+ goto start_sync;
+ }
+
+ // parse ##dc/##wb
+ if (n < s->nb_streams) {
+ AVStream *st;
+ AVIStream *ast;
+ st = s->streams[n];
+ ast = st->priv_data;
+
+ if (s->nb_streams >= 2) {
+ AVStream *st1 = s->streams[1];
+ AVIStream *ast1 = st1->priv_data;
+ // workaround for broken small-file-bug402.avi
+ if (d[2] == 'w' && d[3] == 'b' && n == 0 &&
+ st->codec->codec_type == AVMEDIA_TYPE_VIDEO &&
+ st1->codec->codec_type == AVMEDIA_TYPE_AUDIO &&
+ ast->prefix == 'd' * 256 + 'c' &&
+ (d[2] * 256 + d[3] == ast1->prefix ||
+ !ast1->prefix_count)) {
+ n = 1;
+ st = st1;
+ ast = ast1;
+ av_log(s, AV_LOG_WARNING,
+ "Invalid stream + prefix combination, assuming audio.\n");
+ }
+ }
+
+ if (!avi->dv_demux &&
+ ((st->discard >= AVDISCARD_DEFAULT && size == 0) /* ||
+ // FIXME: needs a little reordering
+ (st->discard >= AVDISCARD_NONKEY &&
+ !(pkt->flags & AV_PKT_FLAG_KEY)) */
+ || st->discard >= AVDISCARD_ALL)) {
+ if (!exit_early) {
+ ast->frame_offset += get_duration(ast, size);
+ }
+ avio_skip(pb, size);
+ goto start_sync;
+ }
+
+ if (d[2] == 'p' && d[3] == 'c' && size <= 4 * 256 + 4) {
+ int k = avio_r8(pb);
+ int last = (k + avio_r8(pb) - 1) & 0xFF;
+
+ avio_rl16(pb); // flags
+
+ // b + (g << 8) + (r << 16);
+ for (; k <= last; k++)
+ ast->pal[k] = avio_rb32(pb) >> 8;
+
+ ast->has_pal = 1;
+ goto start_sync;
+ } else if (((ast->prefix_count < 5 || sync + 9 > i) &&
+ d[2] < 128 && d[3] < 128) ||
+ d[2] * 256 + d[3] == ast->prefix /* ||
+ (d[2] == 'd' && d[3] == 'c') ||
+ (d[2] == 'w' && d[3] == 'b') */) {
+ if (exit_early)
+ return 0;
+ if (d[2] * 256 + d[3] == ast->prefix)
+ ast->prefix_count++;
+ else {
+ ast->prefix = d[2] * 256 + d[3];
+ ast->prefix_count = 0;
+ }
+
+ avi->stream_index = n;
+ ast->packet_size = size + 8;
+ ast->remaining = size;
+
+ if (size || !ast->sample_size) {
+ uint64_t pos = avio_tell(pb) - 8;
+ if (!st->index_entries || !st->nb_index_entries ||
+ st->index_entries[st->nb_index_entries - 1].pos < pos) {
+ av_add_index_entry(st, pos, ast->frame_offset, size,
+ 0, AVINDEX_KEYFRAME);
+ }
+ }
+ return 0;
+ }
+ }
+ }
+
+ return AVERROR_EOF;
+}
+
+static int avi_read_packet(AVFormatContext *s, AVPacket *pkt)
+{
+ AVIContext *avi = s->priv_data;
+ AVIOContext *pb = s->pb;
+ int err;
+#if FF_API_DESTRUCT_PACKET
+ void *dstr;
+#endif