copy_perform assumes the data is 4-byte aligned so might save a test or two compared to memcopy() - but I really don't know. I never benchmarked the two against each other :)
M On Fri, Jan 11, 2013 at 09:36:41PM +0100, katja wrote: > Hi Miller, > > Thanks for the solution. The routines are in place so copying the > right channel input to output should do it. Is there any reason to > prefer copy_perform() over memcpy()? I'm trying to make the most > efficient reverb for RPi & Co. > > Katja > > > > On Fri, Jan 11, 2013 at 7:57 PM, Miller Puckette <m...@ucsd.edu> wrote: > > Hi Katja - > > > > There's one example of this in sigfft_dspx() - a complex FFT that 'natively' > > works on 2 signals in-place but has to deal with various cases in which > > buffers get re-used. It's ugly but the basic idea is first to get the > > inputs copied to the outputs (unless they're already there in the correct > > order in which case nothing needs to be done) and then run the in-place > > algorithm. > > > > If the algo only works out-of-place (i.e. you need 4 distinct buffers, 2 > > in and 2 out) the only way out is (at least conditionally) allocate > > temporary > > copies of the inputs before writing to any outputs. > > > > I may be able to add an optional way tilde objects can request that output > > buffers be distinct from input ones sometime in the future - but this is a > > couple of steps away for me right now :) > > > > M > > > > On Fri, Jan 11, 2013 at 03:32:09PM +0100, katja wrote: > >> Hello, > >> > >> I'm working on a Pd class with stereo channels (reverb), and the > >> routine happens to be most efficient when iterating over the samples > >> per channel, instead of left and right together in the perform loop. > >> However, when doing two while loops in one object, one for left and > >> one for right, the right channel samples get overwritten because of > >> sample-wise in-place computation. Is this an inescapable truth? I > >> mean, I could write a left channel class and a right channel class > >> (actually did that to verify that it works), but it's inconvenient to > >> use. What could be an efficient way to get them in one object? > >> > >> Thanks, > >> Katja > >> > >> _______________________________________________ > >> Pd-list@iem.at mailing list > >> UNSUBSCRIBE and account-management -> > >> http://lists.puredata.info/listinfo/pd-list > > _______________________________________________ > Pd-list@iem.at mailing list > UNSUBSCRIBE and account-management -> > http://lists.puredata.info/listinfo/pd-list _______________________________________________ Pd-list@iem.at mailing list UNSUBSCRIBE and account-management -> http://lists.puredata.info/listinfo/pd-list