matroskadec: full seeking support in index-less files

when trying to seek past the last index entry, just parse more clusters to add them to the index, until an index entry match the desired position


git-svn-id: file:///var/local/repositories/ffmpeg/trunk@14959 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

libavformat/matroskadec.c

@@ -1657,11 +1657,15 @@ static int matroska_read_seek(AVFormatContext *s, int stream_index,
     if (timestamp < 0)
         timestamp = 0;
 
-    index = av_index_search_timestamp(st, timestamp, flags);
-    if (index < 0)
-        return 0;
+    while ((index = av_index_search_timestamp(st, timestamp, flags)) < 0) {
+        matroska_clear_queue(matroska);
+        if (matroska_parse_cluster(matroska) < 0)
+            break;
+    }
 
     matroska_clear_queue(matroska);
+    if (index < 0)
+        return 0;
 
     url_fseek(s->pb, st->index_entries[index].pos, SEEK_SET);
     matroska->skip_to_keyframe = !(flags & AVSEEK_FLAG_ANY);