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KrispyKreative
Participating Frequently
March 16, 2023
Question

Encoding video to HEVC H.265 with alpha channel - can't get transparency

  • March 16, 2023
  • 1 reply
  • 36690 views

I'm trying to convert ProRes 4444 with alpha to a HEVC H265 with Alpha. I'm on an M1 Mac Studio (running Ventura 13.2.1). I've seen people say "hardware encoding" needs to be selected in Media Encoder (23.2.1), but it is not selectable. I've tried this conversion using Premiere and in also Mac finder using "Encode Selected Files"; everything seems to work correctly, but when I test the finished HEVC in AE or Pr, they never have alpha channels. Just black where there should be transparency. What am I doing wrong? Thanks.

    1 reply

    Warren Heaton
    Community Expert
    Warren HeatonCommunity Expert
    Community Expert
    March 18, 2023

    The specification for ProRes supports an alpha channel while the specificaion for HEVC does not.  

     

    When something goes against file format specifications, like having transparancy in a HEVC,  it is often referred to as "out of spec".

     

    Howevever, the Apple AV Foundation Frameworks Team figured out a way to include transparency with HEVC even though it's out of spec.

     

    Right-click on an Apple ProRes 4444 with alpha file in the Finder and choose Encode Selected Video Files.  When the Encode Media dialog box appears choose one of the HEVC options from the Settings pop-up menu and enable "Preserve Transparency".  Then click Continue.

     

    The resulting file will be HEVC H265 with alpha.

     

    Since this is out of spec, be sure to double-check that the application that the resulting file will be used in recognizes the transparancy as expected.

     

     

      3
      3dron
      Participant
      March 12, 2024

      Can this be done in the Windows version of Adobe Media Encoder (I've tried 2022 and 2023?)  I cannot find where to right click on "Apple ProRes 4444" and get "Encode Selected Video Files"  when you say in the finder where should that be in Windows?  In Windows the only place I can right click on "Apple ProRes 4444" is in the Queue and only get Export Settings, Skip Selection, Duplicate and Remove.

      S
      Synyster27062305aswn
      Participant
      October 17, 2024

      As far as I am aware, having transparency with h265 encoding is a feature exclusive to AV Foundation Frameworks.  As such, it's limited to macOS.

       

       


      if the data is in the container is there no way to seperate the channels, data in whatever format is data, i find it wierd as i can write cuda to process any matrix or set of matricies in anyway i choose to write. i find it strange that channel splitting isnt an option in adobe software, rgba is rgba regardless, if the data is there, the issue is the reader of the data not the writer. back to blenders vfx editor and good'ol python for me 🙂 et 'el hard-mode 😛

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