+/* XXX: we make the implicit supposition that the position are sorted
+ for each stream */
+static int avi_read_idx1(AVFormatContext *s, int size)
+{
+ AVIContext *avi = s->priv_data;
+ ByteIOContext *pb = &s->pb;
+ int nb_index_entries, i;
+ AVStream *st;
+ AVIStream *ast;
+ unsigned int index, tag, flags, pos, len;
+ unsigned last_pos= -1;
+
+ nb_index_entries = size / 16;
+ if (nb_index_entries <= 0)
+ return -1;
+
+ /* read the entries and sort them in each stream component */
+ for(i = 0; i < nb_index_entries; i++) {
+ tag = get_le32(pb);
+ flags = get_le32(pb);
+ pos = get_le32(pb);
+ len = get_le32(pb);
+#if defined(DEBUG_SEEK)
+ av_log(NULL, AV_LOG_DEBUG, "%d: tag=0x%x flags=0x%x pos=0x%x len=%d/",
+ i, tag, flags, pos, len);
+#endif
+ if(i==0 && pos > avi->movi_list)
+ avi->movi_list= 0; //FIXME better check
+ pos += avi->movi_list;
+
+ index = ((tag & 0xff) - '0') * 10;
+ index += ((tag >> 8) & 0xff) - '0';
+ if (index >= s->nb_streams)
+ continue;
+ st = s->streams[index];
+ ast = st->priv_data;
+
+#if defined(DEBUG_SEEK)
+ av_log(NULL, AV_LOG_DEBUG, "%d cum_len=%Ld\n", len, ast->cum_len);
+#endif
+ if(last_pos == pos)
+ avi->non_interleaved= 1;
+ else
+ av_add_index_entry(st, pos, ast->cum_len, len, 0, (flags&AVIIF_INDEX) ? AVINDEX_KEYFRAME : 0);
+ if(ast->sample_size)
+ ast->cum_len += len / ast->sample_size;
+ else
+ ast->cum_len ++;
+ last_pos= pos;
+ }
+ return 0;
+}
+
+static int guess_ni_flag(AVFormatContext *s){
+ int i;
+ int64_t last_start=0;
+ int64_t first_end= INT64_MAX;
+
+ for(i=0; i<s->nb_streams; i++){
+ AVStream *st = s->streams[i];
+ int n= st->nb_index_entries;
+
+ if(n <= 0)
+ continue;
+
+ if(st->index_entries[0].pos > last_start)
+ last_start= st->index_entries[0].pos;
+ if(st->index_entries[n-1].pos < first_end)
+ first_end= st->index_entries[n-1].pos;
+ }
+ return last_start > first_end;
+}
+
+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;
+}
+
+static int avi_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
+{
+ AVIContext *avi = s->priv_data;
+ AVStream *st;
+ int i, index;
+ int64_t pos;
+
+ if (!avi->index_loaded) {
+ /* we only load the index on demand */
+ avi_load_index(s);
+ avi->index_loaded = 1;
+ }
+ assert(stream_index>= 0);
+
+ st = s->streams[stream_index];
+ index= av_index_search_timestamp(st, timestamp, flags);
+ if(index<0)
+ return -1;
+
+ /* find the position */
+ pos = st->index_entries[index].pos;
+ timestamp = st->index_entries[index].timestamp;
+
+// av_log(NULL, AV_LOG_DEBUG, "XX %Ld %d %Ld\n", timestamp, index, st->index_entries[index].timestamp);
+
+ for(i = 0; i < s->nb_streams; i++) {
+ AVStream *st2 = s->streams[i];
+ AVIStream *ast2 = st2->priv_data;
+
+ ast2->packet_size=
+ ast2->remaining= 0;
+
+ if (st2->nb_index_entries <= 0)
+ continue;
+
+// assert(st2->codec->block_align);
+ assert(st2->time_base.den == ast2->rate);
+ assert(st2->time_base.num == ast2->scale);
+ index = av_index_search_timestamp(
+ st2,
+ av_rescale(timestamp, st2->time_base.den*(int64_t)st->time_base.num, st->time_base.den * (int64_t)st2->time_base.num),
+ flags | AVSEEK_FLAG_BACKWARD);
+ if(index<0)
+ index=0;
+
+ if(!avi->non_interleaved){
+ while(index>0 && st2->index_entries[index].pos > pos)
+ index--;
+ while(index+1 < st2->nb_index_entries && st2->index_entries[index].pos < pos)
+ index++;
+ }
+
+// av_log(NULL, AV_LOG_DEBUG, "%Ld %d %Ld\n", timestamp, index, st2->index_entries[index].timestamp);
+ /* extract the current frame number */
+ ast2->frame_offset = st2->index_entries[index].timestamp;
+ if(ast2->sample_size)
+ ast2->frame_offset *=ast2->sample_size;
+ }
+
+ if (avi->dv_demux)
+ dv_flush_audio_packets(avi->dv_demux);
+ /* do the seek */
+ url_fseek(&s->pb, pos, SEEK_SET);
+ avi->stream_index= -1;
+ return 0;
+}
+