[FFmpeg-devel] [PATCH] avutil/frame: Add avcodec_private_ref to AVFrame

[James Almer]

On 11/6/2017 9:19 AM, Timo Rothenpieler wrote:
> Am 05.11.2017 um 14:35 schrieb James Almer:
>> On 11/5/2017 9:34 AM, Michael Niedermayer wrote:
>>> This gives libavcodec a field that it can freely and safely use.
>>> Avoiding the need of wraping of a users opaque_ref field and its issues.
>>
>> Could this perhaps be in an opaque internal struct instead, much like
>> AVCodecInternal and whatnot? As wm4 said in the relevant discussion,
>> this approach is nonoptimal and *will* snowball into a mess of fields if
>> other libav* libraries start requiring their own buffers in a frame.
>> An internal field of an opaque struct being in a public header is much
>> cleaner and easier to maintain than adding such specific fields that may
>> at some point in the future need to be removed.
> 
> The problem here is that avcodec, due to nested decoders and the like,
> might potentially wrap this field multiple times internally, so it
> basically has to be something avcodec specific.

And an opaque internal struct would require avpriv_ symbols to be
accessed from outside libavutil, so it's an ugly solution nonetheless. I
already told Michael to discard the suggestion.