On Sep 15, 2017 9:49 AM, "Davood Falahati" <[email protected]> wrote:
Dear Michael, Thanks for your reply. I changed the codec to qrtle and I found that there is an alpha channel added. My problem, however, exists. I translate opencv Mat with alpha plane to AVFrame. But in the resultin video I don't see the added alpha plane. best, ______________________________________________________ Tel: +98 (913) 126-0265 <+98%20913%20126%200265> On Tue, Sep 12, 2017 at 8:24 PM, Michael IV <[email protected]> wrote: > As far as I know h264 doesn't support alpha. But VP8 does. > > On Sep 12, 2017 2:06 PM, "Davood Falahati" <[email protected]> > wrote: > >> Dear community, >> >> I have a opevCV Mat frame, call it mask. I decode frames into AVFrame, >> convert AVFrame to openCV Mat and encode them into AVPacket again. >> >> Now, I want to add an alpha channel to my resulting video. Can you help >> me with that? >> >> - FYI, I tried to add alpha channel to openCV Mat and convert it to >> AVFrame. But it fades whole the video and it mars the color distribution. >> >> Best >> Davood Falahati >> ______________________________________________________ >> >> >> _______________________________________________ >> Libav-user mailing list >> [email protected] >> http://ffmpeg.org/mailman/listinfo/libav-user >> >> > _______________________________________________ > Libav-user mailing list > [email protected] > http://ffmpeg.org/mailman/listinfo/libav-user > > _______________________________________________ Libav-user mailing list [email protected] http://ffmpeg.org/mailman/listinfo/libav-user hello. i would recommend writing your own pixel routine to composit the layers. its a good chance what does work in the libs is developed around a different use case. formats matter of course so one may want to go through the highest bits per pix such as 32 for the blend if its detailed and involves greenscreen types, but fidelity might be a thing and sometimes the warmth of the transform to rgba and back is undesired.
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