[pulseaudio-discuss] No audio heard from loopback

[Maarten Bosmans]

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.

> 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)

> #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.

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

> 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