matroska: warn against mismatching segments

Matroska ordered chapters require all segment files to have the same
layout. If a referenced file has more tracks than the main file or
misses some tracks, the file is invalid.

Also see issue #1553.

1 files changed, 49 insertions, 0 deletions

diff --git a/player/timeline/tl_matroska.c b/player/timeline/tl_matroska.c
index 8ced0ca7ac..a2cc43550a 100644
--- a/player/timeline/tl_matroska.c
+++ b/player/timeline/tl_matroska.c
@@ -471,6 +471,53 @@ static void build_timeline_loop(struct MPContext *mpctx,
         *missing_time += limit - local_starttime;
 }
 
+static void check_track_compatibility(struct MPContext *mpctx)
+{
+    struct demuxer *mainsrc = mpctx->track_layout;
+
+    for (int n = 0; n < mpctx->num_timeline_parts; n++) {
+        struct timeline_part *p = &mpctx->timeline[n];
+        if (p->source == mainsrc)
+            continue;
+
+        for (int i = 0; i < p->source->num_streams; i++) {
+            struct sh_stream *s = p->source->streams[i];
+            if (s->attached_picture)
+                continue;
+
+            if (!demuxer_stream_by_demuxer_id(mainsrc, s->type, s->demuxer_id)) {
+                MP_WARN(mpctx, "Source %s has %s stream with TID=%d, which "
+                               "is not present in the ordered chapters main "
+                               "file. This is a broken file. "
+                               "The additional stream is ignored.\n",
+                               p->source->filename, stream_type_name(s->type),
+                               s->demuxer_id);
+            }
+        }
+
+        for (int i = 0; i < mainsrc->num_streams; i++) {
+            struct sh_stream *m = mainsrc->streams[i];
+            if (m->attached_picture)
+                continue;
+
+            struct sh_stream *s =
+                demuxer_stream_by_demuxer_id(p->source, m->type, m->demuxer_id);
+            if (s) {
+                // There are actually many more things that in theory have to
+                // match (though mpv's implementation doesn't care).
+                if (s->codec && m->codec && strcmp(s->codec, m->codec) != 0)
+                    MP_WARN(mpctx, "Timeline segments have mismatching codec.\n");
+            } else {
+                MP_WARN(mpctx, "Source %s lacks %s stream with TID=%d, which "
+                               "is present in the ordered chapters main "
+                               "file. This is a broken file.\n",
+                               p->source->filename, stream_type_name(m->type),
+                               m->demuxer_id);
+            }
+        }
+    }
+}
+
 void build_ordered_chapter_timeline(struct MPContext *mpctx)
 {
     struct MPOpts *opts = mpctx->opts;
@@ -579,4 +626,6 @@ void build_ordered_chapter_timeline(struct MPContext *mpctx)
             break;
         }
     }
+
+    check_track_compatibility(mpctx);
 }