I'm using ffmpeg and while looking through the list of codes with ffmpeg -codecs I realized there are actually three different prores encoders:

  • prores
  • prores_aw
  • prores_ks

What are the differences between them?

1 Answer 1


I found the following explanation on the ffmpeg wiki:

Fmpeg comes with 3 different prores encodes: "prores", "prores_ks" (formerly named "prores_kostya") and "prores_aw" (formerly named "prores_anatolyi"). In our testing we've used the "prores" and the "prores_ks" encoders and found "prores_ks" to be the best encoder to use. It is the only one that supports the 4444 colorspace and although it may be slightly slower. The color quality of the videos produced by these two codecs was visually indistinguishable Because of the 4444 support we've decided to go with Kostya's version of prores.

So, if you want to do 4444 and need alpha channel support, prores_ks is the way to go.

This blog post also suggests that prores_ks has a smaller footprint, and that prores and prores_aw are basically the same.

  • Beware of 4444+alpha encoding.
    – Gyan
    Feb 1, 2017 at 9:57
  • 1
    @Gyan Heads up for new people, the 4444+alpha bug has been fixed. Just make sure you're running the latest FFmpeg build.
    – Mint
    Aug 20, 2019 at 0:02

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