[pulseaudio-discuss] pulseaudio-discuss Digest, Vol 5, Issue 52

[Sriram Gopalan]

Hello Everybody,
First of all Congrajulations on the release. Hopefully, we will turn in some
patches soon.

Please see additional comments inline.

> Date: Mon, 26 Sep 2011 20:41:26 +0100
> From: Colin Guthrie <gmane at colin.guthr.ie>
> Subject: Re: [pulseaudio-discuss] No audio heard from loopback
> To: pulseaudio-discuss at lists.freedesktop.org
> Message-ID: <j5qkh2$m66$1 at dough.gmane.org>
> Content-Type: text/plain; charset=UTF-8
>
> 'Twas brillig, and Sriram Gopalan at 26/09/11 19:35 did gyre and gimble:
> > We are facing an issue with loopback in pulse audio 0.9.22
>
> Just as a standard approach I'd generally recommend, have you tried
> 0.9.23? it includes several fixes that could certainly help.
>
> If you wait a day, you can also try the shiney new 1.0 release which
> will be escaping very soon....
[Sriram] Certainly

>
> Col
>
> --

> Date: Mon, 26 Sep 2011 22:02:41 +0200
> From: Maarten Bosmans <mkbosmans at gmail.com>
> Subject: Re: [pulseaudio-discuss] No audio heard from loopback
> To: General PulseAudio Discussion
>        <pulseaudio-discuss at lists.freedesktop.org>
> Message-ID:
>        <CA+CvcKQmQgRcZ5JSjbrKRr8Tzp1ao5trftGiq6DDjANLdQLyUg at mail.gmail.com>
> Content-Type: text/plain; charset=UTF-8
>
> 2011/9/26 Sriram Gopalan <mgsram at gmail.com>:
> > Hello everybody,
> > We are facing an issue with loopback in pulse audio 0.9.22. We recently
> > ported pulseaudio to an ARM 11 based evaluation board and are running
> > pulseaudio in system mode.
>
> Great. Did you find it easy to get pulse to run, did you need to patch
> anything to make it working? If so, please submit upstream.

[Sriram] Except for few glitches with the hal-detect module, there was no issue
If we develop a patch, we will certainly upstream it. As a matter of fact,
looking forward to it.

>
> > 3) However, when we attempt the followings, it does not work. We cannot hear
> > any audio, whereas the same works on my Ubuntu 10.10 desktop
> > #arecord | aplay
>
> Are you saying that this doesn't work, or is the silence expected? Are
> you sure you're recording from the alsa hardware card and not from the
> pulse virtual alsa device? (I'm sorry for using the wrong terminology
> here)
[Sriram] silence is not expected. I would expect a ramping up echo.

>
> > #gst-launch alsasrc ! alsasink
> > #pactl load-module module-loopback
>
> It would be good to know why you want to do this, as in general
> (especially on embedded devices) you would not want to use
> software-based loopback of the mic input.
[Sriram] True. the end goal is to looback 2 different alsa devices for
bluetooth functionality. We are using a bluetooth chipset which interfaces
with the host micro over I2S. The drivers are integrated under the asoc layer
of alsa. If I access the devices directly through alsa ( hw:0,0 and hw:0,1)
it works exactly as expected.

>
> That being said, here are some other things you should try:
> - set the resampler to trivial or some speex-integer variant
> - try running with PULSE_NO_SIMD=1 set
> - try to run the tests of make check and see whether they give a problem
[Sriram] Will surely try 1.0 now that it is launched and post the
results here :-)
>
> > With the first 2 commands, there is only silence. With the third option,
> > pulse audio dies after sometime with a floating point exception.
>
> A backtrace would be nice.
> (preferably running from git master)
>
> Maarten
>
>
> ------------------------------
>
> Message: 4
> Date: Tue, 27 Sep 2011 07:18:46 +0530
> From: Arun Raghavan <arun.raghavan at collabora.co.uk>
> Subject: Re: [pulseaudio-discuss] No audio heard from loopback
> To: General PulseAudio Discussion
>        <pulseaudio-discuss at lists.freedesktop.org>
> Message-ID: <1317088131.6608.6.camel at snowflake>
> Content-Type: text/plain; charset="UTF-8"
>
> On Tue, 2011-09-27 at 00:05 +0530, Sriram Gopalan wrote:
> > Hello everybody,
> > We are facing an issue with loopback in pulse audio 0.9.22. We
> > recently ported pulseaudio to an ARM 11 based evaluation board and are
> > running pulseaudio in system mode. The application being targeted is
> > In-vehicle-Infotainment and the board has a Mono Mic ( 16-bit, 1
> > channel) and a Stereo Speaker ( 2 channels, 16-bit, 44.1 Khz).
> >
> >
> > 1) With gstreamer we are able to playback audio to the speakers using
> > the following command. pulseaudio promptly gets into action and plays
> > the file at 44.1 Khz without a glitch -
> > #gst-launch filesrc location=/home/test/songs/test.mp3 ! mad !
> > alsasink
> >
> >
> > 2) When we do a capture with the mic using the command below, again it
> > works fine ( By default arecord and aplay use 8Khz, 8-bit mono channel
> > for capture and playback) -
> > #arecord test.wav
> > #aplay test.wav
> >
> >
> > 3) However, when we attempt the followings, it does not work. We
> > cannot hear any audio, whereas the same works on my Ubuntu 10.10
> > desktop
> > #arecord | aplay
> > #gst-launch alsasrc ! alsasink
> > #pactl load-module module-loopback
>
> Incidentally, why are all the tests with alsasrc/alsasink and not
> pulsesrc/pulsesink?

[Sriram] I will try pulsesrc and pulsesink as well. I have not done that

>
> -- Arun