Sound problems on ARM platform

Reply to Sound problems on ARM platform on Fri, 28 Nov 2014 12:10:30 GMT

smark — Fri, 28 Nov 2014 12:10:30 GMT

I'm trying to use pd-extended on an ARMv7 platform Radxa Rock Pro. This is a fairly powerful 4-core ARM Cortex-A9 based system with 2GB of RAM, running Debian Wheezy with kernel 3.0.36. The pd-extended version is 0.43.4-1, which I've compiled myself from source.

Unfortunately, I've so far been unable to make pd-extended produce any sound. Upon startup it always complains with either a ALSA output error (restart failed): Broken pipe error (when using -audiodev 1) or a error: audio I/O stuck... closing audio error (when using -audiodev 2). The available audio devices provided by -listdev are as follows:

audio input devices:
1. RK29_RK1000 (hardware)
2. RK29_RK1000 (plug-in)
3. ROCKCHIP-SPDIF (hardware)
4. ROCKCHIP-SPDIF (plug-in)
audio output devices:
1. RK29_RK1000 (hardware)
2. RK29_RK1000 (plug-in)
3. ROCKCHIP-SPDIF (hardware)
4. ROCKCHIP-SPDIF (plug-in)

(I have no way of testing the SPDIF output).

Note that running speaker-test -t wav -c 2 works as expected, and I've added my user to the audio group.

Anyway, has someone managed to get pd-extended running on an ARM-based device? Is the problem related to PD itself or could there be a bug in the sound driver for this particular board? Or is there something else I should try? Thanks in advance.

Reply to Sound problems on ARM platform on Fri, 28 Nov 2014 13:12:44 GMT

EEight — Fri, 28 Nov 2014 13:12:44 GMT

@smark Can you provide the full flags:
pd-extented -rt -alsa -channels 2 ...?

Also try to use Miller's version first:
http://msp.ucsd.edu/Software/pd-0.46-2.src.tar.gz (source)
http://msp.ucsd.edu/Software/pd-0.46-2.rpi.tar.gz (compiled)

Cheers~

Reply to Sound problems on ARM platform on Fri, 28 Nov 2014 14:32:01 GMT

smark — Fri, 28 Nov 2014 14:32:01 GMT

These are the two invocations I've tried:

pd-extended -path $PATH -open $PATCH -nogui -alsa -channels 2 -audiodev 1

and

pd-extended -path $PATH -open $PATCH -nogui -alsa -channels 2 -audiodev 2

(Where $PATH and $PATCH are my actual directory and file)

The first invocation produces the ALSA output error (restart failed): Broken pipe error, whereas the second produces the error: audio I/O stuck... closing audio error.

I've also just tried the vanilla PD you linked to. In the "Test audio and MIDI" dialog, I can make it output noise, but nothing else. Moreover, the debug console shows displays tried but couldn't sync A/D/A, which doesn't sound too encouraging...

Reply to Sound problems on ARM platform on Fri, 28 Nov 2014 14:47:53 GMT

EEight — Fri, 28 Nov 2014 14:47:53 GMT

@smark try with:
sudo pd-extended -rt -alsa -audiodev 1 -r 48000 -audiobuf 64 -channels 2 -stderr

-audiobuf is the latency setting, play with this value (the lower the better, but you might get glitches)
also be sure that no other application is using your soundcard
if you can, install a rt-kernel
run with sudo or tweak /etc/security/limits.conf

Good luck,
Cheers~

Reply to Sound problems on ARM platform on Fri, 28 Nov 2014 17:00:50 GMT

smark — Fri, 28 Nov 2014 17:00:50 GMT

Thanks for the suggestions. I've tried as you suggested but had no success, either when running as normal user or as root (using sudo). I'm now going to experiment with Faust -- if the error persists, then the problem is likely to be related to the audio layer itself.

Reply to Sound problems on ARM platform on Sun, 30 Nov 2014 14:29:49 GMT

alexandros — Sun, 30 Nov 2014 14:29:49 GMT

@smark "I can make it output noise, but nothing else"

this is a bit strange...are you sure? noise tends to sound much louder than the sine wave in the "test audio and midi" patch. I tried with a raspberry pi and had to turn the volume quite high to hear the sine wave, where I didn't need to do anything to hear the white noise.
I mean, why would Pd be able to output [noise~] to the sound card, but nothing else?