[FFmpeg-devel] [PATCH] lavfi/avfiltergraph: always reduce all_layouts to a single layout

Marton Balint cus at passwd.hu
Wed Nov 30 21:29:52 EET 2016

On Wed, 30 Nov 2016, Nicolas George wrote:

> Le nonidi 9 frimaire, an CCXXV, Marton Balint a écrit :
>> There can be filters where .query_format is defined and they still can refer
>> to all_formats and not all_counts, so i am not sure we can remove the
>> all_formats/all_counts logic so easily.
> There is no difference between these filters and those who just do not
> have the query_format method: they need small adjustments.
> Or do you think there are filters that can not be adapted to work with
> unknown layouts?

E.g. loudnorm or ebur128 cannot simply work with unkown layouts, since 
coefficients are channel dependant.

>> Anyway, how can we move forward here? Apparently there is not too much
>> interest in the topic... Since this can be easily changed later, I can also
>> rework the patch to add the .query_formats callback to all filters currently
>> not supporting unkown layouts until this is decided. What do you think?
>> Obviously I prefer my original approach, but since it is not too much work,
>> I can change the patch as well.
> At this point, the issue is no longer technical. I have summarized the
> pros and cons of both sides, and my role as "the guy who knows that part
> of the code best" ends here. Now people must decide which side is
> preferred, and I have no particular authority to do that.
> Once the direction is decided, we can discuss the implementation
> details.

Since nobody else commented, I assume they don't have strong 
opinions, therefore I suggest we decide. I prefer the all-accepting 
default, but if you disagree, I accept that as well. What do you prefer? 
If you don't have a preference, I will follow my own approach and apply 
the patch which changed the default.


More information about the ffmpeg-devel mailing list