Alpha transparency in Android

[Dohyung Park]

What I want to do is just render a webm video file with alpha transparency on the opengl surface of the android app.

So far, we’ve developed a decoder with MediaCodec and it decodes webm video successfully, but the texture of opengl surface has no alpha value.

And I found out that there’s no supported YUVA color format in MediaCodec and it’s native code.

So I guess it loses alpha data during the internal decode process. As far as I know, the Android media library didn’t implement decoding vp8/vp9 video with alpha value properly according to Alpha Channel - wiki.

So I just want to know how to resolve this issue. If it’s feasible, I’m even thinking of developing a custom media library for decoding webm with alpha using Android NDK. So I just want to hear your opinions and a little guide about how to.