I need to play video files with alpha channel. I've built and linked VP8 decoder. According to variety of guides, it supports alpha channel.
But in fact, it wasn't possible to convert video to webm format with alpha channel preserved (using ffmpeg/libvpx). Source files definitely contain alpha channel. But no matter which format do I choose in options (yuva420p, rgba and so on), libvpx just forces encoder to pick yuv without alpha.
May you please provide me a hint on how to encode webm with alpha preserved, or are there some other way / codec which may do that?