[alsa-devel] Using UCM with PulseAudio

Arun Raghavan arun.raghavan at collabora.co.uk
Mon Jun 25 03:25:21 CEST 2012

On Wed, 2012-06-20 at 21:50 -0500, Gabriel M. Beddingfield wrote:
> On 06/20/2012 07:30 AM, Arun Raghavan wrote:
> >> UCM provides the "modifier" to allow ad-hoc modifications to the audio
> >> use case like above where we want to play an end of call tone. In this
> >> case the verb is still VoiceCall, but PA would enable the "PlayTone"
> >> modifer to play the tone (UCM can also tell Pulseaudio the sink PCM and
> >> volume control for the tone data).
> >
> > Just as an observation, I think the Android HAL just uses PCM 0 and not
> > the PCM 3, but in the PA case, I'll do it the way you describe since
> > that makes more sense.
> Yes, the Galaxy Nexus pretty much only uses PCM 0 -- but that's mostly a 
> reflection of AudioFlinger's design and limitations.

Ah, that's good to know. :)

-- Arun

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