[FFmpeg-devel] [PATCH] avformat/apngenc: use the stream parameters extradata if no updated one is made available

[Andreas Cadhalpun]

On 03.11.2016 09:52, Hendrik Leppkes wrote:
> Hence my point about trying to stick to a common behavior scheme
> without looking at what *OUR* decoder needs - there could be others,
> after all.
> Its common to write extradata into codecpar if its present. You can
> try to dispute that as long as you wish, but that doesn't make it any
> less true.
> 
> avcodec is not the only thing people use avformat with, and
> vice-versa, so sticking to common patterns makes the life easier for
> those.
> 
> Do we really need to write this down somewhere to convince you, what
> do we have the ML for then if we can't inform contributors about
> common practice?

What you need to convince me are good arguments.
The reason why I asked about documentation is that if it's not documented,
your argument about other decoders, that you repeated above, is void,
because others shouldn't rely on undocumented behavior, as our
documentation states clearly [1]:
"Behavior in undocumented situations may change slightly (and be documented)."

So if you want to be able to rely on the behavior you describe, you'll
have to get it documented.
As you seem to care about this a lot, I don't understand why you appear
to be opposed to the idea of documenting it.

Best regards,
Andreas

1: https://ffmpeg.org/doxygen/3.2/index.html