[pulseaudio-discuss] [RFC PATCH] Log PCM samples to files

[Becker, VincentX]

>-----Original Message-----
>From: Maarten Bosmans [mailto:mkbosmans at gmail.com]
>Sent: Wednesday, March 23, 2011 7:44 PM
>To: General PulseAudio Discussion
>Cc: Becker, VincentX
>Subject: Re: [pulseaudio-discuss] [RFC PATCH] Log PCM samples to files
>
>2011/3/21 Vincent Becker <vincentx.becker at intel.com>:
>> Hi,
>>
>> I recently created a new PA module (module-log-pcm) which is able to
>log PCM samples from any source/sink and its corresponding
>outputs/inputs. For testing audio quality, checking signal processing or	
>verifying the right implementation of a sound device mixed in PA,
>application fields are many.
>
>What is the use case you are specifically interested in?

It can just be any use case that is related to audio and Pulseaudio. I am particulary interested to log audio before and after sound algorithms to check that the signal processing has been well applied (or filters).

>
>> One just needs to give a parameter list depending on what is wished to
>be logged. During the process, an audio tree, or parts of it, is probed
>and logged for post-treatment purposes.
>
>I'm sorry if I am being stuped here, but wat can the module do that
>you can't with parec from a monitor source?

The module does the exact same thing as parec but parec can just log one device at a time but not the inputs and/or outputs.
If you wanted to log the whole set of sinks/sources connected to Pulse, you would need to run as many parec commands as there are devices. Not very practical though.
With the module you can specify a list of sinks or sources and choose to log the inputs or outputs, thing that is impossible now with Pulseaudio. Ok that needs a modification in the Pulsecore 
to probe the chunks when they are peeked or pushed but I don't see any other way.

>
>> For design needs, sources and sinks are designated by "ends" and
>source outputs/sink inputs by "ports".
>
>Why introduce the new terminology here? I think it is confusing for
>people that know pulse already. Or is there perhaps some subtle
>difference between the pulse concept and your designation for it?

Just to group sinks and sources under one word, same for inputs/outputs. It does not exist in Pulseaudio, am I right? So it shouldn't confuse anybody, I hope.

>

I am pretty sure that this module can be useful, especially when big sets of sinks/sources are present and someone wants to analyze an audio tree part of these sets during a specific use case. Why not ? May be it will create some needs at least..

>Maarten
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