[LAD] FLTK vs GTKmm

[Steve Harris]

On 11 Aug 2009, at 08:04, Jens M Andreasen wrote:

>
> On Tue, 2009-08-11 at 07:45 +0100, Steve Harris wrote:
>> O
>> If that's what the CUDA interface to the outside world looks like  
>> then
>> wouldn't it be better to expose it as a JACK App, which loads CUDA-
>> specific plugins onto the graphics card?
>>
>> I don't see why you'd want to embed it in the jack daemon.
>>
>
> It is the scatter/gathering of data that is killing. I need to have  
> one
> and only one transfer on the PCIe line for each period to be  
> efficient,
> preferably in the 10 - 20KB range or more.  The jack model of one
> channel, one buffer does not fit very well here.

It's not ideal, but assembling all the jack buffers into one big one  
is not going to be that much load on the CPU.

> Potentially It should also be possible to stream from harddisk via DMA
> directly to the device without bothering the CPU at all. That OIOH  
> hand
> would work for prerecorded material with say ardour, since you can  
> look
> ahead as many bytes as you like.

Yeah, I think that would have to be app specific.

Another tack would be to provide a library that could execute LV2  
plugins (with CUDA versions of the code in the bundle). It would  
presumably need a daemon or such, but would be more generally useful  
than a hacked jackd.

> Doing live performances requres another approach though.
>
> Do you believe it would be very difficult to implement? I do
> unfortunately not have the required knowledege of jackd internals to
> judge wether or not.

Not difficult, just not what anyone really wants. The whole point of  
jack is that it lets you combine bits of software in different ways,  
this would take that away to some extent.

- Steve