[LAD] CV data protocol in apps.

Simon Jenkins sjenkins at blueyonder.co.uk
Fri Feb 19 14:15:13 UTC 2010


On 19 Feb 2010, at 13:47, Fons Adriaensen wrote:

> On Fri, Feb 19, 2010 at 04:20:19PM +0300, alex stone wrote:
> 
>> The use case i'm thinking of is a crescendo or decrescendo using gain
>> in a continuous stream of data. Will 1/16 reduce the......
>> "smoothness"?
> 
> No, the DSP code has to perform smoothing anyway, no matter
> what the source of the control data is. Does your GUI fader
> provide smooth audio rate updates ? Of course not, you'd be
> lucky if it updates 25 times per second.
> 

If the receiving application is going to smooth the data back up to audio rate anyway then what's the point? If the sender has already got audio-rate data then this is a big *lose* efficiency wise, with the sender spending cycles decimating a buffer that's going to be upsampled as soon as it arrives. Even if the sender hasn't got audio-rate data, it might as well do the smoothing itself rather than push the cost into *all* the apps that receive the data.

"control rate" optimisations make more sense when you're NOT going to smooth the data, eg when you don't want to update your filter parameters every sample. In this case (as I just said in another post) the receiver can skip down an audio buffer at control rate jumps with no help from anybody.

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.linuxaudio.org/pipermail/linux-audio-dev/attachments/20100219/547d2fba/attachment.html>


More information about the Linux-audio-dev mailing list