1 files changed, 13 insertions, 4 deletions

diff --git a/demux/demux_mkv.c b/demux/demux_mkv.c
index 3e902c0ea3..a391dde5a6 100644
--- a/demux/demux_mkv.c
+++ b/demux/demux_mkv.c
@@ -188,7 +188,7 @@ typedef struct mkv_demuxer {
 
     uint64_t skip_to_timecode;
     int v_skip_to_keyframe, a_skip_to_keyframe;
-    bool subtitle_preroll;
+    int subtitle_preroll;
 } mkv_demuxer_t;
 
 #define REALHEADER_SIZE    16
@@ -196,6 +196,9 @@ typedef struct mkv_demuxer {
 #define RAPROPERTIES4_SIZE 56
 #define RAPROPERTIES5_SIZE 70
 
+// Maximum number of subtitle packets that are accepted for pre-roll.
+#define NUM_SUB_PREROLL_PACKETS 100
+
 /**
  * \brief ensures there is space for at least one additional element
  * \param array array to grow
@@ -2269,7 +2272,10 @@ static int handle_block(demuxer_t *demuxer, struct block_info *block_info)
         if (mkv_d->v_skip_to_keyframe)
             use_this_block = 0;
     } else if (track->type == MATROSKA_TRACK_SUBTITLE) {
-        use_this_block |= mkv_d->subtitle_preroll;
+        if (!use_this_block && mkv_d->subtitle_preroll) {
+            mkv_d->subtitle_preroll--;
+            use_this_block = 1;
+        }
         if (use_this_block) {
             if (laces > 1) {
                 mp_msg(MSGT_DEMUX, MSGL_WARN, "[mkv] Subtitles use Matroska "
@@ -2316,7 +2322,7 @@ static int handle_block(demuxer_t *demuxer, struct block_info *block_info)
         if (stream->type == STREAM_VIDEO) {
             mkv_d->v_skip_to_keyframe = 0;
             mkv_d->skip_to_timecode = 0;
-            mkv_d->subtitle_preroll = false;
+            mkv_d->subtitle_preroll = 0;
         } else if (stream->type == STREAM_AUDIO)
             mkv_d->a_skip_to_keyframe = 0;
 
@@ -2596,7 +2602,10 @@ static void demux_mkv_seek(demuxer_t *demuxer, float rel_seek_secs, int flags)
                 a_tnum = track->tnum;
         }
     }
-    mkv_d->subtitle_preroll = (flags & SEEK_SUBPREROLL) && st_active[STREAM_SUB];
+    mkv_d->subtitle_preroll = 0;
+    if ((flags & SEEK_SUBPREROLL) && st_active[STREAM_SUB] &&
+        st_active[STREAM_VIDEO])
+        mkv_d->subtitle_preroll = NUM_SUB_PREROLL_PACKETS;
     if (!(flags & (SEEK_BACKWARD | SEEK_FORWARD))) {
         if (flags & SEEK_ABSOLUTE || rel_seek_secs < 0)
             flags |= SEEK_BACKWARD;