Erik,

> Thats about right. The A-D and D-A converters probably use sigma-delta
> technology so that would add about 30-60 samples delay at each
> conversion 
> stage. Thats a total of 60-120 samples delay just in the converter.
> 

This is very good to know - I had no idea that the latency for the converters
could be so high.  Do you have any good sources for information about the
latency of converters?

> If you're using a buffer length of 192 samples, you must remember that
> you need a minimum of 2 buffers; one for the input and one for the
> output.
> 

Well, this is fragment based io so the read/write is 64 samples.  Your right
that the capture will add at least 1 fragment, I think, which would make the
total delay 4 - 6 fragments (256 - 384 samples).  The number of capture
fragments used depends on when the app gets woken up by poll(2).

Thanks a lot for you comments,

Karl

> (30 to 60) + 192 + 192 + (30 to 60) = 444 to 504
> 
> 
> Hope this helps,
> Erik
> -- 
> +----------------------------------------------------------+
>   Erik de Castro Lopo  [EMAIL PROTECTED] (Yes its valid)
> +----------------------------------------------------------+
> Percussive Maintenance: The fine art of whacking the c**p out 
> of an electronic device to get it to work again.
> 


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