[alsa-devel] Problems with pulseaudio / asla on PS3

[Takashi Iwai]

At Fri, 5 Sep 2008 08:42:08 +1000,
Kevin Gilbert wrote:
> 
> Hi,
> 
> I'm trying to get an jukebox application going on a Sony PlayStation3 using 
> Qt-Embedded, Phonon and PulseAudio. The application is working well on my KDE-
> based laptop where it appears that the application is using Phonon -> ALSA -> 
> PulseAudio. But there is no sound from the application when run on the PS3.
> 
> I initially reported this problem to the PulseAudio mailing list. The first 
> post on this topic is at https://tango.0pointer.de/pipermail/pulseaudio-
> discuss/2008-August/002249.html . In pacticular, see these posts:
> 
> 1) https://tango.0pointer.de/pipermail/pulseaudio-discuss/2008-
> September/002346.html where I detail the results of a final test using the 
> latest development version of PulseAudio; and
> 
> 2) https://tango.0pointer.de/pipermail/pulseaudio-discuss/2008-
> September/002347.html where a PulseAudio developer diagnoses the problem as 
> being within ALSA.
> 
> For convenience, the following is from the latter post:
> 
> "So, what happens here is this: your device can only do non-interleaved audio 
> and is hence configured for it (as we can see from that "slave setup" listing 
> above). Because your hardware lacks a hardware volume control ALSA puts 
> "softvol" on top of the hw device: the "Soft Volume PCM" you can see in the 
> first part. That device is initialized for interleaved audio as you can see. 
> Which is what PA supports and PA asked for.
> 
> Now, if softval takes non-interleaved from below and gives interleaved to the 
> layer above than it would need to rearrange those samples -- which it however 
> doesn't actually. PA hence checks with those asserts if the audio data is 
> properly arranged -- which it is not as we can see.
> 
> This is a bug in ALSA's softvol module. Please report this on alsa-devel. 
> softvol falsely claims to be able to rearrange non-interleaved audio to 
> interleaved."
> 
> Not sure what other information I should post here so I'll wait for any 
> feedback.

Well, it's no bug in softvol, at least.  The softvol doesn't do any
format or layout conversions.  The layout conversion is done via plug
plugin applied onto the softvol.


Takashi