Re: [PATCH 0/2] Document memory-to-memory video codec interfaces

[Hans Verkuil]

Hi Tomasz,

On 07/24/2018 04:06 PM, Tomasz Figa wrote:
> This series attempts to add the documentation of what was discussed
> during Media Workshops at LinuxCon Europe 2012 in Barcelona and then
> later Embedded Linux Conference Europe 2014 in DÃsseldorf and then
> eventually written down by Pawel Osciak and tweaked a bit by Chrome OS
> video team (but mostly in a cosmetic way or making the document more
> precise), during the several years of Chrome OS using the APIs in
> production.
> 
> Note that most, if not all, of the API is already implemented in
> existing mainline drivers, such as s5p-mfc or mtk-vcodec. Intention of
> this series is just to formalize what we already have.
> 
> It is an initial conversion from Google Docs to RST, so formatting is
> likely to need some further polishing. It is also the first time for me
> to create such long RST documention. I could not find any other instance
> of similar userspace sequence specifications among our Media documents,
> so I mostly followed what was there in the source. Feel free to suggest
> a better format.
> 
> Much of credits should go to Pawel Osciak, for writing most of the
> original text of the initial RFC.

I'm adding this here as a result of an irc discussion, since it applies
to both encoders and decoders:

How to handle non-square pixel aspect ratios?

Decoders would have to report it through VIDIOC_CROPCAP, so this needs
to be documented when the application should call this, but I don't
think we can provide this information today for encoders.

Regards,

	Hans