[x264-devel] Transparency is lost during encoding wifth ffmpeg and x264

[Jason Garrett-Glaser]

On Thu, Sep 11, 2008 at 6:08 AM, Mustafa Aldemir <m_aldemir at yahoo.com> wrote:
> Hello,
>
> I have a FLV video encoded by Adobe After Effects using On2 VP6 encoder. I want to re-encode this video using x264 codec. FFMPEG can decode VP6 video, and encode x264. But after re-encoding the alpha channel transparency of the video is lost and the background is black. I searched a solution in ffmpeg list but, there was no response.

There is no alpha channel in the YV12 colorspace.  Theoretically it is
possible to encode an alpha channel using H.264, but I don't know of
any encoder or decoder that implements such a thing.

Dark Shikari.