[FFmpeg-devel] [libav-devel] [PATCH] h264: update avctx width/height when flushing

[Andreas Cadhalpun]

On 14.06.2015 16:46, Luca Barbato wrote:
> On 14/06/15 15:07, Andreas Cadhalpun wrote:
>> It would require changing a lot of code to use the internal values, but
>> I think the same effect could be achieved by backing up/restoring the values.
>> And that would require significantly less code changes.
> 
> Sadly some codecs such as vdpau (thanks to wm4 for spotting) would
> possibly break if those parameters aren't set to the current decoding
> decoding set, so setting avctx->{those} to the last outputted frame
> could probably cause more problems.

That'd be unfortunate. What issues could it cause for vdpau?

> And probably other spots might have a similar issue.
> 
> As Anton put it in a really nice way, avctx->{those values} are an
> internal state that leaks to the user.

Yes, that's the root cause of the problem.

> Doesn't look that there are quick or simple solution and looks like it
> is better to just tell people not to do that and fix where somebody is
> doing that mistake.

That's less than ideal. :-/

Best regards,
Andreas