[LAU] ffado streaming mode

Pieter Palmers pieterp at joow.be
Fri Sep 26 08:09:43 EDT 2008


porl sheean wrote:
> thanks for the reply Pieter.
> 
> after sending you the message i realised how stupid i waws regarding
> jack. i was thinking that the latency had to be low so that the live
> output wouldn't be too delayed, but completely forgot the whole point
> of the 'input mix' part :P
> 
> you are of course right - i can set a high buffer in jack for any
> recording and to just have the device streaming, but the input mix
> should still be virtually 0 latency. i need someone to smack me in the
> head :)
> 
> on a side note, i have in the past had trouble getting the input mix
> to output anything (i could only get outputs from the pc channels, not
> input mix), but i don't have the ability to test it right now so i
> will assume i was just doing something else silly.

The input mix support for the pro26 might be broken, I still have to 
look into that. Might take some time, might also be fixed fairly soon. 
Can you please try the current branches/libffado-2.0 version to see what 
part of the mixer works and what doesn't?

> 
> porl
> 
> ps. what does the 'mixing/tracking' toggle do? i couldn't notice any
> difference last time i checked.

To be honest: I don't know. It's a control that is present because it's 
also present in the win/mac mixer, but I haven't figured out what 
exactly it does. AFAIK it has something to do with the standalone 
operation of the device. It should be in the manual Focusrite provides.

Greets,

Pieter

> 
> pps. looking forward to getting a chance to test the new low latency
> of ffado! :)
> 
> 2008/9/25 Pieter Palmers <pieterp at joow.be>:
>> porl sheean wrote:
>>> a while ago i purchased a focusrite saffire pro 26io. it has finally
>>> come to a point where it is quite reliably useful as an interface for
>>> jack/ardour (the latency isn't brilliant, but i'm pretty sure that is
>>> the fault of my firewire chipset).
>> I fixed latency for ffado yesterday, and at least one person reports 3x32 as
>> working for him. So if you have a good firewire chipset, you will also be
>> able to achieve this. But maybe wait for beta7.
>>
>>> i found out recently that unfortunately, in order to get teh device
>>> working as a basic 'summing mixer' for live work (i wanted to
>>> essentially use it as a basic 8 in 1 out preamp to send to a small
>>> desk at a venue) it needs to be set in 'streaming mode'. i can get
>>> this working by starting jack and just leaving that running, but i was
>>> wondering if anyone knew of an easier way (maybe one of ffado's
>>> command line utilities? there seem to be a lot in there and i don't
>>> know what half of them do). if not, would it be difficult to write a
>>> small app that basically just 'turns on streaming'? or should i just
>>> keep using jack? (i am hesitant to do this as i have still had a few
>>> issues with dropouts, and as you can imagine at a live performance
>>> this could be a problem).
>> The fact that streaming has to be turned on is a design decision of
>> Focusrite. We can't change that.
>>
>> I don't see why you wouldn't use jack. What's the point in using a separate
>> application that basically does the same? Just run jack with a large period
>> size, and you should be fine. Something along the lines of:
>>
>> jackd -R -d firewire -p2048 -n4
>>
>> should work fine. I've done multi-hour recordings with the pro26 at 3x1024
>> without any problem whatsoever.
>>
>> Greets,
>>
>> Pieter
>>
>> PS: Most of the command line tools in the ffado repository are test or debug
>> tools.
>>
> 




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