20 Dec
2009
20 Dec
'09
1:08 a.m.
On Sat, 19 Dec 2009, David Adler wrote:
Some things I unfortunately don't know:
Does the realtime remapping introduce timing
issues apart from a constant offset fore each note?
How big is the offset?
Does this depend on the app used?
For a typical jack app (like midixlate), you only have
latencies for the hardware ports. (Usually estimated by
SAMPLES_PER_PERIOD * PERIODS_PER_BUFFER / SAMPLE_RATE,
e.g. 1024*2/48000 = 42.7 ms.) I
think you get 2x that figure if you're doing both input and
output -- but it might be 1x.
There's no additional latency for the software
processing.[1] This is the main advertisement for the JACK
API -- it adds *no* additional latency.[2]
Peace,
Gabriel
[1] That is, unless you have a complicated JACK
connection graph, or a processor that
intentionally creates delays.
[2] See http://jackaudio.org/faq "Doesn't use [sic] JACK
add latency?"