[pulseaudio-discuss] [PATCH v4 05/23] echo-cancel: Relax restrictions on webrtc AEC stream config

[Arun Raghavan]

On Wed, 2016-02-24 at 17:22 +0200, Tanu Kaskinen wrote:
> On Mon, 2016-02-22 at 11:53 +0530, Arun Raghavan wrote:
> > On Sat, 2016-02-20 at 15:35 +0200, Tanu Kaskinen wrote:
> > > On Wed, 2016-02-17 at 19:46 +0530, arun at accosted.net wrote:
> > > > From: Arun Raghavan <git at arunraghavan.net>
> > > > 
> > > > This exposes the range of configurations the library actually supports
> > > > (8, 16, 32 and 48 kHz).
> > > 
> > > That doesn't seem to explain all changes in the code. I'll analyze all
> > > the variables:
> > > 
> > > play_ss.format is handled as before, fixed to s16le.
> > > 
> > > play_ss.rate was earlier set to out_ss.rate, now it's set to one of the
> > > four possible rates based on the initial rec_ss.rate value.
> > > 
> > > play_ss.channels and play_map were earlier set to out_map, now they are
> > > unchanged.
> > > 
> > > rec_ss.format is handled as before, fixed to s16le.
> > > 
> > > rec_ss.rate was earlier set to out_ss.rate, now it's set to one of the
> > > four possible rates based on the initial rec_ss.rate value.
> > > 
> > > rec_ss.channels and rec_map were earlier set to out_map, now they are
> > > unchanged.
> > > 
> > > out_ss.format is handled as before, fixed to s16le.
> > > 
> > > out_ss.rate was earlier kept unchanged, now it's set to one of the four
> > > possible rates based on the initial rec_ss.rate value.
> > > 
> > > out_ss.channels and out_map were earlier kept unchanged, now they are
> > > set to the original value of rec_map.
> > > 
> > > In summary: no changes in sample format configuration, rate is based on
> > > the original rec_ss instead of the original out_ss and limited to the
> > > four possible rates (earlier there was no such limitation, so is the
> > > commit message wrong saying "relax restrictions"?), channels are based
> > > on rec_map instead of out_map.
> > 
> > Functionally, there is no difference. out_ss/map and rec_ss/map
> > essentially had the same value, and I just used them interchangeably
> > (which now IMO is confusing).
> > 
> > In the refactoring, I'm expressing the constraints in what I see to be
> > a more natural way -- rec_ss expresses what we're feeding the
> > canceller, so it makes sense to apply the constraints on what the
> > canceller accepts there. This then propagates to the output spec.
> > 
> > This all seems fairly minor to me, but I can add it to the commit
> > message as well if you want.
> 
> Thanks, I think that would be good.
> 
> Do you have comments about the question of whether it's correct to say
> "relax restrictions" in the commit message, when it looks like you're
> rather adding restrictions?

Rephrased as "echo-cancel: Express restrictions correctly on webrtc AEC
stream config"

-- Arun