let vp8/vp9 support alpha?

  • Make webm support alpha?

    When choosing vp8 or vp9 for video, choose vorbis for sound

    Output can choose webm.

    But the output webm file does not support transparency

    I checked the logs and found pixelFormat=yuv420p

    Can you add pixelFormat options of vp8 and vp9?

    I know it can be transparent if the pixelFormat is set to yuva420p

    I don't want export to ffv1 and manually convert it with ffmpeg.


  • Vouk

    Approved the thread.
  • Vouk

    Changed the title of the thread from “let webm support alpha?” to “let vp8/vp9 support alpha?”.
  • Hello,

    I appreciate your great work, and would like to make an additional request here. Could you please make this VP8/VP9 alpha channel work in Davinci Resolve. Most people do not know how to render an alpha channel in Davinci, so here is how to do it.

    1) On the Edit page, place the clip that has the Alpha channel on Video Track 1. It MUST be on Video Track 1; it will not work on any other Video Track.

    2) On the Deliver page, set Render to "Individual clips". This is another MUST. If Render is set to "Single clip", Davinci will never render an Alpha Channel.

    3) Choose a Codec that supports Alpha Channel.

    A good one is Quicktime/Grass Valley/HQX.

    An "Export Alpha" check box will appear under the Resolution popup menu. Check it. Below that is the "Alpha Mode" where you can choose Premultiplied or Straight.

    Hope that helps you in figuring out how to hook in Voukoder.