[FFmpeg-devel] [PATCH] Make avfilter_config_links() propagate audio information of the source link if it is not explicitely set by the filter.

[Måns Rullgård]

Stefano Sabatini <stefano.sabatini-lala at poste.it> writes:

> On date Monday 2011-02-14 12:36:56 +0000, M?ns Rullg?rd encoded:
>> Stefano Sabatini <stefano.sabatini-lala at poste.it> writes:
>> 
>> > ---
>> >  libavfilter/avfilter.c |    6 ++++++
>> >  1 files changed, 6 insertions(+), 0 deletions(-)
>> >
>> > diff --git a/libavfilter/avfilter.c b/libavfilter/avfilter.c
>> > index 31af890..1c400a6 100644
>> > --- a/libavfilter/avfilter.c
>> > +++ b/libavfilter/avfilter.c
>> > @@ -194,6 +194,12 @@ int avfilter_config_links(AVFilterContext *filter)
>> >                  link->time_base = link->src && link->src->input_count ?
>> >                      link->src->inputs[0]->time_base : AV_TIME_BASE_Q;
>> >
>> > +            if (link->sample_rate == 0 && link->src && link->src->input_count)
>> > +                link->sample_rate = link->src->inputs[0]->sample_rate;
>> > +
>> > +            if (link->channel_layout == 0 && link->src && link->src->input_count)
>> > +                link->channel_layout = link->src->inputs[0]->channel_layout;
>> > +
>> 
>> What if there is more than one input?  Are more complex cases assumed to
>> provide explicit parameters? 
>
> Yes, if a filter doesn't explicitely set the values they're set using
> the values in the first input link. This is a quite safe assumption
> and works fine for most 1-input/1-output filters.
>
>> Is this input certain to be an audio input?
>
> No, it is set anyway, a check may be added but right now it would be
> quite pointless anyway since the value is not used by video filters.

OK, it certainly can't be worse than not setting it at all.

However, the patch doesn't apply to current master.  Could you please
rebase and resend it?

-- 
M?ns Rullg?rd
mans at mansr.com