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--;
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--;