Hi Chen, For modules/libimg/png, mozilla products use aPNG which was rejected by upstream. http://en.wikipedia.org/wiki/APNG So we have to use internal png. For media/libvorbis, mozilla has custom patches in the source tree. https://bugzilla.mozilla.org/show_bug.cgi?id=517422 Fro media/libvpx, I don't know well. However you are welcome to file the issue to bugzilla.mozilla.org. Takanori -- devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxxx https://admin.fedoraproject.org/mailman/listinfo/devel