[LAD] handling data streams: file vs callback

Patrick Shirkey pshirkey at boosthardware.com
Sun Aug 5 10:12:52 UTC 2007

Dirk Jagdmann wrote:
> Hello Patrick,
>> I'm trying to jackify xwax. Xwax is a linux based emulator for Rane 
>> serato and Final scratch.
>> I have successfully adapted the code from jackEQ to allow xwax to 
>> register and connect several JACK i/o's.
>> However the original system uses file descriptors for handling the 
>> data (oss/alsa) internally and this is not instantly compatible with 
>> the JACK callback system. At least it's not obvious to me how to link the 
> I don't know xwax, but since it currently has oss and alsa output I 
> guess it is using a "blocking IO" model instead of the "callback" model 
> of jack. Restructuring the logic from blocking to callbacks can be 
> complicated. I you want to have a first result have a look at
> http://bio2jack.sourceforge.net/ which should fill your gap.


Thanks for your suggestion. However I want to get multiple i/o's working 

I'm fairly certain the code doesn't need restructuring. It's more a case 
of how to  connect the internal data stream which is read from disk to 
jack outputs or jack inputs to the internal stream.

I think it would take some of the more advanced programmers on this list 
less than half an hour to fill in the gap. But it's gonna take me a 
couple of weeks of research to get my head around the solution...

Patrick Shirkey - Boost Hardware Ltd.
Http://lau.linuxaudio.org - The Linux Audio Users guide

"Anything your mind can see you can manifest physically, then it will 
become reality" - Macka B

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