On Fri, Jul 26, 2013 at 11:50 PM, Dan Wilcox <danomatika@gmail.com> wrote:
Actually I miss-typed. The issue is with "Isochronous" usb mode: http://www.raspberrypi.org/phpBB3/viewtopic.php?f=28&t=29226 Looks like things should be better for USB 2 audio devices, but still issues with USB 1.1 devices (aka mine :P):While Isoc has improved for pretty much everyone using USB2.0 devices (USB1.1 will still suffer from lost packets due to split transaction breakage noted elsewhere) I'm still annoyed at my webcams "kinda working" - I get 1-2 seconds of uninterrupted video and then a half-garbled frame.
On Jul 26, 2013, at 6:35 PM, Dan Wilcox <danomatika@gmail.com> wrote:Sure, but that's only for certain types of USB devices. Some are working and others aren't. More "professional" sound cards require lower-latency/burst mode over USB which the PI firmware currently doesn't allow and/or doesn't set the correct priority for. The issue AFAICT is that essentially the usb host is software defined on the SOC and they haven't optimized it for usb audio, or something like that.For instance, I can get stereo out in Pd working fine with my Edirol UA-25 . If I enable an audio input, I get instant dropouts. Yeah, I guess it "works", but not well enough for me.On Jul 26, 2013, at 6:27 PM, John Canning <johnnyboy7777@hotmail.co.uk> wrote:Hi Dan,Thanks for getting back to me. I'm still very new to the Pi but have found this post that seems to say that it can work. I'm confused. What do you reckon?
On Fri, Jul 26, 2013 at 11:02 PM, Dan Wilcox <danomatika@gmail.com> wrote:Simply put, the RPI firmware does not work with USB audio correctly yet. See this thread: http://lists.puredata.info/pipermail/pd-list/2013-07/103261.htmlI keep looking for fixes, but the way USB is handled, the only way for it to work without dropouts is to have *nothing* else plugged into the usb bus and ethernet disabled ... sucks.On Jul 26, 2013, at 5:41 PM, pd-list-request@iem.at wrote:From: John Canning <johnnyboy7777@hotmail.co.uk>
Subject: [PD] Raspberry Pi Behringer UCA222 boot problems
Date: July 26, 2013 5:40:49 PM EDTTo: Pure Data <pd-list@iem.at>
JohnThanks,Hi Folks,I have been trying for quite a while to get my Raspberry Pi to work in full duplex with Pd. I have installed the OS on the PdPi site and updated it. I am using a Behringer UCA222 for audio. When I change the USB speed down to 1 (dwc_otg.speed=1) in /boot/cmdline.txt my Pi won't boot with the soundcard plugged in. If I unplug the soundcard the Pi will boot but as soon as I plug it in the Pi crashes. Has anyone got any suggestions about why this is happening?
