Re: [Alsa-user] Parallel playback on multiple USB cards
On Fri, Aug 14, 2020, 3:56 AM Clemens Ladisch via Alsa-user < alsa-user@lists.sourceforge.net> wrote: > Alexandre Bouillot wrote: > > ... Raspberry Pi > > > > I'm able to address each of the 6 cards independently correctly. > > However, when I'm trying to have a second channel - not to mention the > third - working in parallel with the first, I face problems. > > From what I've heard, the Pi's USB controller has limited bandwidth, and > its > driver is not able to distribute all of it among multiple streams. > > > Regards, > Clemens I wonder, if that's the problem, whether the Pi4 would handle it better. I have no direct experience, but my understanding is that bandwidth issues are a primary target addressed in the model 4, and very successfully. regards, -- John Kirk ___ Alsa-user mailing list Alsa-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/alsa-user
Re: [Alsa-user] Parallel playback on multiple USB cards
Hi Clemens, Thanks for the hint. On a standard PC all goes well. I have 3 streams playing and 3 recordings at the same time. Regards, Alexandre Le ven. 14 août 2020 à 12:56, Clemens Ladisch via Alsa-user < alsa-user@lists.sourceforge.net> a écrit : > Alexandre Bouillot wrote: > > ... Raspberry Pi > > > > I'm able to address each of the 6 cards independently correctly. > > However, when I'm trying to have a second channel - not to mention the > third - working in parallel with the first, I face problems. > > From what I've heard, the Pi's USB controller has limited bandwidth, and > its > driver is not able to distribute all of it among multiple streams. > > > Regards, > Clemens > > > ___ > Alsa-user mailing list > Alsa-user@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/alsa-user > ___ Alsa-user mailing list Alsa-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/alsa-user
Re: [Alsa-user] Parallel playback on multiple USB cards
Alexandre Bouillot wrote: > ... Raspberry Pi > > I'm able to address each of the 6 cards independently correctly. > However, when I'm trying to have a second channel - not to mention the third > - working in parallel with the first, I face problems. >From what I've heard, the Pi's USB controller has limited bandwidth, and its driver is not able to distribute all of it among multiple streams. Regards, Clemens ___ Alsa-user mailing list Alsa-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/alsa-user
[Alsa-user] Parallel playback on multiple USB cards
Hi, I'm trying to set up a system for audio measurements and I'm trying to have a 3 channels solution using one single host (currently a Raspberry Pi, might migrate to x86 later on if needed). I have the one channel system working with two USB audio cards - one for emitting the sound and the other to record the audio output. I'm using shell commands as aplay and arecord. I'm able to address each of the 6 cards independently correctly. However, when I'm trying to have a second channel - not to mention the third - working in parallel with the first, I face problems. I launch aplay instances in asynchronous mode with an & at the end of the command line. As soon as the second instance is running, there is no more sound issued on any boards. As soon as there is only one instance left running, the assigned card is properly emitting the sound. I'm wondering if it is possible to have parallel instances of aplay, each controlling one audio card. Not to spoil anything, the next step will be the same, but with arecord. Thanks for any pointers you can provide. Alexandre ___ Alsa-user mailing list Alsa-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/alsa-user