[FFmpeg-user] ProRes encoding: Question about FFmpeg docs

Peter B. pb at das-werkstatt.com
Mon Mar 12 09:24:26 EET 2018

On 2018-03-12 00:50, Moritz Barsnick wrote:
> On Sun, Mar 11, 2018 at 09:33:29 +0100, Peter B. wrote:
>> 2) Docs say "profile/quantmat" is "integer", but only list strings:
>> ========================================
> You can use the strings instead of numbers. I believe it used to be
> *only* integers, nowadays strings mostly also map to the same values.
> The docs could list the integers, but if they don't, I don't think it
> matters. But I do understand your confusion.

My confusion was *before* Carl's answer :)
I assumed that strings will be mapped to integers, but trying any
profile string (I found) with prores (=prores_aw?) resulted in this:

[prores @ 0x28b2fc0] [Eval @ 0x7ffc00f9e2c0] Undefined constant or
missing '(' in 'lt'
[prores @ 0x28b2fc0] Unable to parse option value "lt"
[prores @ 0x28b2fc0] Error setting option profile to value lt.

But now I know:

  * -c:v prores_ks: uses the documented profile strings
  * -c:v prores_aw (=prores): seems to work only with integers (not in
the documentation/nor help)

btw: Trying an invalid profile number with prores_aw, gives some

[prores_aw @ 0x36fdc40] unknown profile -1, use [0 - apco, 1 - apcs, 2 -
apcn (default), 3 - apch]

Where "apco, apcs, apcn, apch" are explained in:

> You can (sometimes) see the mapping if you use "ffmpeg -h", e.g.
> $ ffmpeg -h encoder=prores_ks

Thanks again! :)

btw: for "encoder=prores" or "encoder=prores_aw", this doesn't provide
much information:

Encoder prores_aw [Apple ProRes]:
    General capabilities: threads
    Threading capabilities: frame
    Supported pixel formats: yuv422p10le

> Those seven values map to -1 .. 5, in case you do want to use digits. I
> don't see a reason for doing that though.

Completely agree! Strings are way better (to remember and use).
They just don't work for the default encoder :(

Again: Thanks for clearing things up!

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