[FFmpeg-devel] [PATCH 3/3] lavfi: fix doxygen doc for AVFilterLink.time_base

[Stefano Sabatini]

On date Friday 2011-09-16 11:55:27 +0200, Stefano Sabatini encoded:
> On date Monday 2011-09-12 03:05:59 +0200, Michael Niedermayer encoded:
> > On Sun, Sep 11, 2011 at 01:47:29PM +0200, Stefano Sabatini wrote:
> [...]
> > > Subject: [PATCH] lavfi: drop AVFilterLink.sample_rate at the next major bump
> > > 
> > > Use time_base instead for storing such information.
> > > 
> > > This avoids duplication of information, and simplifies PTS handling for
> > > the unified API, as time_base can be used for computing both audio and
> > > video buffers timestamps.
> > 
> > iam ok with this, just one note to make sure we dont by mistake run in
> > an issue with it
> > 
> > mpeg-ps has a timebase of 90khz and samplerates of 44.1,48,22.05, ...
> > that means if we want to preserve this through the filter chains
> > (and i dont know if we want or dont want...)
> > then we need both timebase & sample_rate
> > otoh i dont mind at all to drop that extra complexity and use a
> > timebase equal to the samplerate
> 
> Uhm, no strong opinion on this, in general timebase can be different
> from 1/samplerate, so I'm not against keeping both fields if it makes
> sense (does it?).
> 
> In case we want to follow this path: how to set correctly the
> sample_rate/time_base in the link?
> 
> I suppose a possible approach may be:
> 
> 1. if both sample_rate and time_base are set, do nothing
> 
> 2. if the sample_rate is not set and time_base is, set the samplerate
>    to the value of time_base.den
> 
> 3. if time_base is not set and time_base is, set the time_base to
>    1/samplerate.
> 
> 4. fail otherwise
> 
> So a source may decide to set either only the sample_rate or only the
> time_base in an output link.
> 
> So it may set the time_base (in this case samplerate is set as
> time_base.den), or the samplerate (in this case timebase is
> set to 1/samplerate).

This one should be simpler.
-- 
FFmpeg = Fast & Furious Mournful Peaceless Elaborated Goblin
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