libmatroska2: 0 duration frames can be keyframes

The part of the Matroska specifications that claimed that Blocks from a BlockGroup with duration zero are no keyframes has been dropped in 9313a00f7391a285f95e9d6f0a5f8f3f80ed4779. This commit brings libmatroska2 in line with this change. The earlier version e.g. made mkvalidator warn about files muxed by FFmpeg that contained pgs subtitles (which are muxed as zero-duration subtitles, which is spec-compliant). Signed-off-by: Andreas Rheinhardt <[email protected]>
Matroska-Org · Dec 31, 2024 · 16a25aa · 16a25aa
1 parent 3f2782b
commit 16a25aa
Showing 1 changed file with 1 addition and 9 deletions.
diff --git a/libmatroska2/matroskamain.c b/libmatroska2/matroskamain.c
@@ -698,7 +698,6 @@ uint16_t MATROSKA_BlockTrackNum(const matroska_block *Block)
 bool_t MATROSKA_BlockKeyframe(const matroska_block *Block)
 {
     ebml_master *BlockGroup;
-    ebml_integer *Duration;
 
     assert(Node_IsPartOf(Block,MATROSKA_BLOCK_CLASS));
     if (Block->IsKeyframe)
@@ -711,14 +710,7 @@ bool_t MATROSKA_BlockKeyframe(const matroska_block *Block)
     if (!BlockGroup || !Node_IsPartOf(BlockGroup,MATROSKA_BLOCKGROUP_CLASS))
         return 0;
 
-    if (EBML_MasterFindChild(BlockGroup,MATROSKA_getContextReferenceBlock()))
-        return 0;
-
-    Duration = (ebml_integer*)EBML_MasterFindChild(BlockGroup,MATROSKA_getContextBlockDuration());
-    if (Duration!=NULL && EBML_IntegerValue(Duration)==0)
-        return 0;
-
-    return 1;
+    return EBML_MasterFindChild(BlockGroup,MATROSKA_getContextReferenceBlock()) == NULL;
 }
 
 bool_t MATROSKA_BlockDiscardable(const matroska_block *Block)