[Csnd] Buffer overrun / underrun

Date	2013-10-21 15:38
From	Eduardo Moguillansky
Subject	[Csnd] Buffer overrun / underrun
	Hi! Maybe someone with experience on low-performance linux hardware can jump in. I am setting up an installation with csound on 4 raspberry pi's. I am launching each with the following command line: $ chrt 10 csound -d -b512 -B1024 -iadc:plughw:K6,0 -odac:plughw:K6,0 -+rtaudio=alsa moire.csd For some time this runs very good attached to a 6 channel USB2 soundcard (only four channels are used). After around 10 minutes, CPU usage goes down (normally it is ~45%, goes down to 20%) and sound breaks with the message WARNING: Buffer overrun in real-time audio input WARNING: Buffer underrun in real-time audio input Has someone around here experience with this csound on this kind of hardware? (the soundcards work very good with, for example, PD) Thanks! Eduardo Moguillansky NB: I can't use --sched because that seems to break the serial opcodes. Without higher priority sound breaks right away.

Date	2013-10-21 16:54
From	Justin Smith
Subject	Re: [Csnd] Buffer overrun / underrun
	You should try using the device directly rather than the dmix plughw wrapper. If that is not an option, make sure your -b / -B values align exactly with the hardware and software buffering that alsa generates for the dmix interface. On Mon, Oct 21, 2013 at 7:38 AM, Eduardo Moguillansky <eduardo.moguillansky@gmail.com> wrote: Hi! Maybe someone with experience on low-performance linux hardware can jump in. I am setting up an installation with csound on 4 raspberry pi's. I am launching each with the following command line: $ chrt 10 csound -d -b512 -B1024 -iadc:plughw:K6,0 -odac:plughw:K6,0 -+rtaudio=alsa moire.csd For some time this runs very good attached to a 6 channel USB2 soundcard (only four channels are used). After around 10 minutes, CPU usage goes down (normally it is ~45%, goes down to 20%) and sound breaks with the message WARNING: Buffer overrun in real-time audio input WARNING: Buffer underrun in real-time audio input Has someone around here experience with this csound on this kind of hardware? (the soundcards work very good with, for example, PD) Thanks! Eduardo Moguillansky NB: I can't use --sched because that seems to break the serial opcodes. Without higher priority sound breaks right away.