Alpha Channel Video

[Igor]

If you send me a sample video with H.264 YUV pixel format + alpha channel, we'll try to add support for that format.

[tom95521]

  On 2/27/2023 at 1:20 PM, Igor said:

You can send me sample file(s) in VP8/VP9 format with Alpha channel for checking.

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Hi Igor,

Here is 5 second rotating DNA with VP9 codec with alpha channel. I verified it works in another video editor.

https://we.tl/t-sZplazeBYk

Thanks,
Tom

[jienense]

 

 

  On 2/27/2023 at 3:27 PM, tom95521 said:

I verified it works in another video editor.

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This file in Premiere, AE and vegas, shows it without transparency.

I have created several files in VP8 / VP9 and in all the editors that I have tried it shows them without transparency, could it be a problem with this codec?

Parameters used to create vp9

 

 

according to this page it would have to be in 8 bits

https://www.digitalrebellion.com/blog/posts/list_of_video_formats_supporting_alpha_channels.html

[Igor]

  On 2/27/2023 at 3:27 PM, tom95521 said:

Hi Igor,

Here is 5 second rotating DNA with VP9 codec with alpha channel. I verified it works in another video editor.

https://we.tl/t-sZplazeBYk

Thanks,
Tom

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Hi Tom,

Thanks for sharing this sample file. I agree with previous comment above. This VP9 video doesn't include the Alpha channel.

[tom95521]

Hi Igor,

That is strange. I used Filmora X12 on Mac and the alpha channel is being detected. I did not apply chroma key. I will test on Windows.

Thanks,
Tom

 

[tom95521]

Hi Igor,

Downloaded the wetransfer link video above on Win 11 computer and tested again using Filmora X 12. I see the same results. Somehow they are using alpha channel. It's not a problem for me to use QT RLE instead if the alpha channel can not be detected in webm video file.

Thanks,
Tom

 

[jienense]

I have also tried in Windows with Filmora and it does show transparency in your file and in one that I had created in Adobe Media Encoder, I have no idea because it doesn't show it in the other editors.

[tom95521]

Interesting. Here is some information how VP8 encodes the alpha channel.

http://wiki.webmproject.org/alpha-channel

Tom