[FFmpeg-devel] [WIP][RFC][PATCH] png: support for skiping decoding data

[Paul B Mahol]

On 8/10/13, Nicolas George <nicolas.george at normalesup.org> wrote:
> Le duodi 22 thermidor, an CCXXI, Paul B Mahol a ecrit :
>> Crude attempt at parsing only frame and not doing decoding.
>> It returns frames with data, not calling ff_get_video_buffer()
>> gives error.
>> Perhaps doing this from parser is better solution.
>
> I suppose this is about trac ticket #2845 and this recent discussion in
> -user:
> http://ffmpeg.org/pipermail/ffmpeg-user/2013-August/016685.html
>
> I see you are using AVDISCARD_ALL to implement this; it does seem like a
> good idea, but did you check whether the few codecs that support it handle
> it the same way? Ideally, this option could be enabled in
> avformat_find_stream_info() for all codecs.

What exactly you mean by this? Decoding single packet and use what is
in codec context?

Codecs that use AVDISCARD_ALL do not return frames at all, so that is why
I seek for better solution.

But how would one handle case when width/height/format changes midstream?