+ if (type == AVIO_DATA_MARKER_SYNC_POINT || type == AVIO_DATA_MARKER_BOUNDARY_POINT) {
+ seen_sync_markers = true;
+ } else if (type == AVIO_DATA_MARKER_UNKNOWN && !seen_sync_markers) {
+ // We don't know if this is a keyframe or not (the muxer could
+ // avoid marking it), so we just have to make the best of it.
+ type = AVIO_DATA_MARKER_SYNC_POINT;
+ }
+