Hi,
on a RME 9632 PCI card using the AES input/output, I'd like to get playback/recording without any software mixing, rate conversion etc. simultaneously. The goal is to check for transmission errors during signal processing.
For a start, I'd like to get some sort of proof of concept using simple tools like aplay/arecord from ALSA and some postprocessing for comparision.
Sadly, it looks like I can't figure out how to select the channels I want to record from.
Everything looks ok in hdspmixer and hdscpconfig (SPDIF input is synced to the record source and the input meter shows the signal to record).
Can anyone point me to some document describing this or give some hints what I could try?
Regards,
Tino
RME HDSP/LInux: Playback/recording usage hints needed
Moderators: MattKingUSA, khz
Re: RME HDSP/LInux: Playback/recording usage hints needed
Hi!
I never tried to use AES, so I don't really know much about it. Just wondering whether you tried to use Ecasound or Sox. In the past I tried to use them for simultaneous playback-recording for transfer function measurements. I was not too happy with Ecasound (I think it converts all streams to its own internal format). However, you might want to give it a go. These utilities should make you able to specify channels as parameters, if I recall correctly.
I never tried to use AES, so I don't really know much about it. Just wondering whether you tried to use Ecasound or Sox. In the past I tried to use them for simultaneous playback-recording for transfer function measurements. I was not too happy with Ecasound (I think it converts all streams to its own internal format). However, you might want to give it a go. These utilities should make you able to specify channels as parameters, if I recall correctly.
Re: RME HDSP/LInux: Playback/recording usage hints needed
Hi,
thanks for the reply. I only found tools where I can specify the number of channels I want to record. The AES input is on channels 9 and 10.
Furthermore, I can't get simultaneous record and playback to work.
I tried to record in audacity, but then I wasn't able to play anything (set_params
Unable to install hw params). The same happens when I try to record with other tools (e.g. arecord).
My next try was jack. I was able to play a sample and record specific channels using jack_rec. However, the result looks dithered. The sample was a clean square sample, the recording looked like it went though some bad DA/AD conversion.
This is how I started jack:
jackd -R -d alsa -d hw:DSP -z none -M -H
thanks for the reply. I only found tools where I can specify the number of channels I want to record. The AES input is on channels 9 and 10.
Furthermore, I can't get simultaneous record and playback to work.
I tried to record in audacity, but then I wasn't able to play anything (set_params
Unable to install hw params). The same happens when I try to record with other tools (e.g. arecord).My next try was jack. I was able to play a sample and record specific channels using jack_rec. However, the result looks dithered. The sample was a clean square sample, the recording looked like it went though some bad DA/AD conversion.
This is how I started jack:
jackd -R -d alsa -d hw:DSP -z none -M -H