On Fri, Oct 19, 2012 at 2:28 PM, Clemens Ladisch clemens@ladisch.de wrote:
Mike Looijmans wrote:
From: Prasant J pj0585@gmail.com
Prasant J wrote:
I'm writing an alsa application for recording & playing 16 channel audio.
I'm working with Beaglebone (ARM Cortex-A8 720 MHz). (Currently failures are for 8 channels 32 bit / 16 bit, but our final target is 16 channels)
I have managed to get Audio capture working fine (after certain linux optimizations) but playback is giving under-runs (only when PLAYBACK & CAPTURE run together)
You must be doing something wrong. I'm doing 32-bit, 16-channel input at 51.2kHz on a OMAP-L138 (an ARM9 CPU at 450 MHz)
@Mike: I'm playing & recording at the same time, that should be the reason.
When I was using arecord (only capture) I was getting overruns and only after making some linux optimizations, I was able to record properly. Are you 100% sure you do not observe any errors? Did you do tests for longer durations?
Playback and capture at the same time seems to be harder for certain embedded devices. I don't know if this is a driver bug or a hardware limitation.
@Clemens: The bottle-neck is SD card access. Driver bug cannot be ruled out, but it is difficult to evaluate.
Regards, Praant
P.S.: How do I reply to a post whose mail I did not receive. (I have enabled alsa-devel mails only now, but if someone does not include me in cc, I do not receive the posts started by me)