tracks[i].stream, st->index_entries[index].timestamp,
AVSEEK_FLAG_BACKWARD);
while (index_sub >= 0 &&
- index_min >= 0 &&
+ index_min > 0 &&
tracks[i].stream->index_entries[index_sub].pos < st->index_entries[index_min].pos &&
st->index_entries[index].timestamp - tracks[i].stream->index_entries[index_sub].timestamp < 30000000000 / matroska->time_scale)
index_min--;