[LAU] Ardour export question...

[Dale Kazakore Powell]

On 09/03/15 04:58, Fons Adriaensen wrote:
> On Sun, Mar 08, 2015 at 08:34:42PM +0000, alexus / dotcommon wrote:
>
>> (Please excuse if this is a stupid question...)
>>
>> I am learning Ardour doing some practice on my system (Debian
>> stable, RT kernel, RT tuning, MAudio Audiophile 2496 PCI, 3GHz 4core
>> CPU, 8GB RAM, JACK buffer 512). Working with a 3min stereo audio
>> (24bit, 88.1kHz) I have noticed DSP goes to 100% when exporting
>> (WAV)...
>> Is it normal (simply Ardour is using all the available resources
>> during the export) or something is going wrong (and I will have
>> glithces/pops in the output file)?
> It's perfectly normal. Export puts Jack in 'freewheeling' mode
> which means that it doesn't sync to the soundcard but starts
> a new cycle as soon as the previous one has ended (the sound
> card output gets 'silence' for output meanwhile, and input is
> discarded). So things will run 'as fast as possible' which
> means CPU load will go up to 100%.
>
> Ciao,
>
But what if you want to listen to audio from a different application 
connected to Jack while exporting? Surely it should just disconnect from 
Jack (although this could possible cause routing issues on reconnecting 
once finished) and run as fast as possible using max CPU cycles.

Actually I know I have personally exported files after normalising while 
listening to different music connected through Jack so your description 
seems a little strange to me... Does Ardour export with external sources 
(eg jack connected soft synths) so only the internal audio? If the 
former then it should always be done real time (maybe the source comes 
from the real world, not the digital realm) if the latter then there is 
no real to involve Jack, or anything related to the audio interface side 
of things at all!

Dale.