--- a/media/libstagefright/binding/MP4Metadata.cpp
+++ b/media/libstagefright/binding/MP4Metadata.cpp
@@ -825,17 +825,18 @@ MP4MetadataRust::GetNumberTracks(mozilla
   uint32_t total = 0;
   for (uint32_t i = 0; i < tracks; ++i) {
     mp4parse_track_info track_info;
     rv = mp4parse_get_track_info(mRustParser.get(), i, &track_info);
     if (rv != mp4parse_status_OK) {
       continue;
     }
     // JPEG 'video' decoder is not supported in media stack yet.
-    if (track_info.codec == mp4parse_codec::mp4parse_codec_JPEG) {
+    if (track_info.codec == mp4parse_codec::mp4parse_codec_JPEG ||
+        track_info.codec == mp4parse_codec::mp4parse_codec_UNKNOWN) {
       continue;
     }
     if (TrackTypeEqual(aType, track_info.track_type)) {
         total += 1;
     }
   }
 
   return {NS_OK, total};