demux_mkv: index all packets

Instead of indexing only 1 packet per cluster (which is enough for
working seeking), add every packet to the index.

Since on seek, we go through every single index entry, this probably
makes seeking slower. On the other hand, this code is used for files
without index only (e.g. incomplete files), so it probably doesn't
matter much.

Preparation for the following commits.

1 files changed, 2 insertions, 4 deletions

diff --git a/demux/demux_mkv.c b/demux/demux_mkv.c
index a9230106f5..5ececb9edc 100644
--- a/demux/demux_mkv.c
+++ b/demux/demux_mkv.c
@@ -678,10 +678,8 @@ static void add_block_position(demuxer_t *demuxer, struct mkv_track *track,
         return;
     if (track->last_index_entry != (size_t)-1) {
         mkv_index_t *index = &mkv_d->indexes[track->last_index_entry];
-        // filepos is always the cluster position, which can contain multiple
-        // blocks with different timecodes - one is enough.
-        // Also, never add block which are already covered by the index.
-        if (index->filepos == filepos || index->timecode >= timecode)
+        // Never add blocks which are already covered by the index.
+        if (index->timecode >= timecode)
             return;
     }
     cue_index_add(demuxer, track->tnum, filepos, timecode);