KaxSemantic.cpp: make KaxVideoAlphaMode mandatory

See https://github.com/ietf-wg-cellar/matroska-specification/commit/5aa6c928caac5300b0ab1a65522e9be31710b2b0

diff --git a/src/KaxSemantic.cpp b/src/KaxSemantic.cpp
index b91a05c1ee275e07f57f617dade3876424b3eb3d..cdb8621b243d67fe47a3eee57ffd9e2ea1cbba23 100644 (file)
--- a/src/KaxSemantic.cpp
+++ b/src/KaxSemantic.cpp
@@ -322,7 +322,7 @@ DEFINE_START_SEMANTIC(KaxTrackVideo)
 DEFINE_SEMANTIC_ITEM(true, true, KaxVideoFlagInterlaced)
 DEFINE_SEMANTIC_ITEM(true, true, KaxVideoFieldOrder)
 DEFINE_SEMANTIC_ITEM(true, true, KaxVideoStereoMode)
-DEFINE_SEMANTIC_ITEM(false, true, KaxVideoAlphaMode)
+DEFINE_SEMANTIC_ITEM(true, true, KaxVideoAlphaMode)
 DEFINE_SEMANTIC_ITEM(false, true, KaxOldStereoMode) // not supported
 DEFINE_SEMANTIC_ITEM(true, true, KaxVideoPixelWidth)
 DEFINE_SEMANTIC_ITEM(true, true, KaxVideoPixelHeight)