Thanks for getting back to me Dan

On Fri, Jul 26, 2013 at 11:50 PM, Dan Wilcox <[email protected]> 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 <[email protected]> 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 <[email protected]>
> 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 <[email protected]> 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.html
>>
>> I 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, [email protected] wrote:
>>
>> *From: *John Canning <[email protected]>
>>  *Subject: **[PD] Raspberry Pi Behringer UCA222 boot problems*
>>  *Date: *July 26, 2013 5:40:49 PM EDT
>> *To: *Pure Data <[email protected]>
>>
>>
>>  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?
>>
>> Thanks,
>> John
>>
>>
>>  --------
>> Dan Wilcox
>> @danomatika
>> danomatika.com
>> robotcowboy.com
>>
>>
>>
>>
>>
>>
>
> --------
> Dan Wilcox
> @danomatika
> danomatika.com
> robotcowboy.com
>
>
>
>
>
>
> --------
> Dan Wilcox
> @danomatika
> danomatika.com
> robotcowboy.com
>
>
>
>
>
>
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