ProRes alpha support is almost there

I’ve finally brought myself into looking at alpha plane decoding support for ProRes. It was a bit peculiar but rather easy to reverse engineer. Now I only need to update my ConsumerRes decoder to support it.

And that’s probably enough for the month of intermediate codecs.

4 Responses to “ProRes alpha support is almost there”

  1. Jonathan says:


    How are you coming along on this? It seems like no one has the ability to support transcoding from ex./ MOV wrapped Animation to MOV wrapped ProRes 4444. I’ve looked pretty hard for this functionality and have yet to find anything!
    Thanks for putting in the hours to resolve this crisis.


  2. Kostya says:

    It’s been committed and supported since the middle of May (including encoding support), I suspect that tools beside avconv should support it too if they are fresh enough.

  3. Hello!

    Thanks for this! This is getting really close to solving my QT-woes on PC. I do VFX in a win7-environment, using Nuke as the main tool. The usual workflow is various stuff in – 16bit rgba png out from nuke.

    I found a couple of issues I hope you could help me out with:
    1. Using “-vcodec prores_ks -profile:v 4444 -pix_fmt yuva444p10le -alpha_bits 16 -quant_mat hq -acodec copy” the alpha channel is not of high enough quality to be usable in the resulting .mov file.
    Check this example:

    2. As usual with quicktimes, theres a slight colorshift when bringing encoded .movs back into Nuke. This can be corrected setting the colorspace to REC601. Is there any way to specify this in the commandline?

  4. Kostya says:

    1. That is strange indeed. I’ll look if something can be done about it.
    2. -color_primaries 5 I suppose