<div dir="auto"><div><br><div class="gmail_extra"><br><div class="gmail_quote">On Sep 15, 2017 9:49 AM, "Davood Falahati" <<a href="mailto:falahati.davood@gmail.com">falahati.davood@gmail.com</a>> wrote:<br type="attribution"><blockquote class="quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">Dear Michael,<div><br></div><div>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.</div><div><br></div><div>best,</div></div><div class="gmail_extra"><br clear="all"><div><div class="m_8628567764597543119gmail_signature" data-smartmail="gmail_signature"><div dir="ltr"><div><div dir="ltr"><div dir="ltr">______________________________<wbr>________________________<div><br></div><div>Tel: <a href="tel:+98%20913%20126%200265" value="+989131260265" target="_blank">+98 (913) 126-0265</a></div></div></div></div></div></div></div><div class="elided-text">
<br><div class="gmail_quote">On Tue, Sep 12, 2017 at 8:24 PM, Michael IV <span dir="ltr"><<a href="mailto:explomaster@gmail.com" target="_blank">explomaster@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="auto">As far as I know h264 doesn't support alpha. But  VP8 does. </div><div class="gmail_extra"><br><div class="gmail_quote"><div><div class="m_8628567764597543119h5">On Sep 12, 2017 2:06 PM, "Davood Falahati" <<a href="mailto:falahati.davood@gmail.com" target="_blank">falahati.davood@gmail.com</a>> wrote:<br type="attribution"></div></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div><div class="m_8628567764597543119h5"><div dir="ltr">Dear community,<div><br></div><div>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.</div><div><br></div><div>Now, I want to add an alpha channel to my resulting video. Can you help me with that?</div><div><br></div><div>- 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.</div><div><br></div><div>Best</div><div>Davood Falahati</div><div><div><div class="m_8628567764597543119m_4140203587560487414m_-284146918710071586gmail_signature" data-smartmail="gmail_signature"><div dir="ltr"><div dir="ltr"><div dir="ltr">______________________________<wbr>________________________<div><br></div></div></div></div></div></div>
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<br></blockquote></div>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.</div></div></div>