> the actual limit of the delay line is the buffersize minus the windows size
actually, I made some tests and it is the (buffersize - windows size + one block 0f 64 samples). But anyway, this limitation is what I perceived, but I fail to see why any such limitation should happen. If the delay is "x" long, we should be able to read from "x" behind in time... if not, there's a bug in it. That's how I see it, and why I marked this issue as a potential bug. >From the [vd~] help file, it says "The delay time is always at least one sample *and at most the length of the delay line (specified by the delwrite~)*" So if we can't read it at most from the specified delay line, there's a bug! > since the delay line is only written for every block and you want to read > the last N samples from the delay line, [vd~] simply clips to the > maximum reading index. Again, I fail to see a reason here. If such a limitation happens, maybe the object could be coded in a way that it allows an extra something to make it possible a total length read out. But I thought that maybe the order forcing of delay objects could be something to take into consideration. Well, I did the order forcing and many such tests, but nothing really changed! I have then the latest version attached. I'm copying miller here and also sending to the list. I'll also post this as a bug report. cheers 2015-09-21 16:45 GMT-03:00 Christof Ressi <[email protected]>: > Hey, as I suspected, you are simply hitting the limit of the delay line. > You can test this on your own with the patch I've sent you. Note that the > actual limit of the delay line is the buffersize minus the windows size, > since the delay line is only written for every block and you want to read > the last N samples from the delay line. [vd~] simply clips to the maximum > reading index. Note that there isn't any phase difference anymore between > the two windows after both have exceeded the limit. > > Cheers > > *Gesendet:* Montag, 21. September 2015 um 19:53 Uhr > *Von:* "Alexandre Torres Porres" <[email protected]> > *An:* "Christof Ressi" <[email protected]>, "[email protected]" < > [email protected]> > *Betreff:* Re: Re: PVoc patch "bug"? > I've simplified the patch a lot so many things can be discarded. > > The window size shouldn't affect anything as the reading point in the > delay line is fixed. Now I don't have [vline~] or anything, just a steady > signal fed to [vd~], when we get close to the end of the delay line it just > gets ruined, and that's all that there is to it. There's no flaw in the > patch, nothing I didn't think of. It's really something very mysterious or > perhaps a bug. > > The patch is now simpler and also vanilla compatible. I tried it in the > new Pd Vanilla 0.46-7 and I got the same weird behaviour. > > Check attachment please > > cheers > > 2015-09-21 14:12 GMT-03:00 Christof Ressi <[email protected]>: >> >> Well, I just think you're hitting the limit of the delay line. Your >> window size is 2048 samples, so inside the subpatch that's 2048/(44,1*4) = >> 11,6 ms. But one window is one hop size (2,9 ms) behind, therefore 11,6 ms >> + 2,9 ms = 14,5 ms and 1000 ms - 14,5 ms = 985,5 ms --> that's pretty much >> the limit you were experiencing. Hope that helps. >> >> Cheers >> *Gesendet:* Montag, 21. September 2015 um 18:27 Uhr >> *Von:* "Alexandre Torres Porres" <[email protected]> >> *An:* "Christof Ressi" <[email protected]>, "[email protected]" < >> [email protected]> >> *Betreff:* Re: PVoc patch "bug"? >> my patch has a little issue, I'm saying the delay line is 60000 ms (this >> is for the wrapping objects) when it's only 4000, but that is not a problem >> for what I'm asking here as the wrapping doesn't influence anything. It's >> just something weird that happens even without the wrapping. >> >> I wonder what's the principle you'd have for not using cyclone :) >> >> 2015-09-21 12:32 GMT-03:00 Christof Ressi <[email protected]>: >>> >>> Hey, >>> >>> the first thing I noticed: your [delwrite~] is at 4000 ms, but [s >>> $0-buff_size] is still fed with 60000 ms... Is this on purpose? >>> The second thing: Even if you got the range for [pong~] right, my guess >>> is that this will create a sudden jump from the end of the delay line to >>> the beginning. You'd need some kind of enveloping to mask the >>> discontinuity. Maybe this won't be noticeable if you pass the 'problematic' >>> area quickly, but might sound terrible if you stay there. In your case, >>> however, it seems that the delay line is simply clipped since you've sent a >>> wrong value to [pong~]. >>> This is just some remote diagnostics, though, since I don't use any >>> cyclone objects as a matter of principle :-D. >>> >>> Cheers >>> >>> PS: I didn't put this on the list on purpose, because it's only about a >>> specific patch and not something more general. >>> >>> >>> *Gesendet:* Montag, 21. September 2015 um 06:48 Uhr >>> *Von:* "Alexandre Torres Porres" <[email protected]> >>> *An:* "[email protected]" <[email protected]>, "Christof Ressi" < >>> [email protected]> >>> *Betreff:* PVoc patch "bug"? >>> Hi there, still struggling with my circular buffer Phase Vocoder, now >>> I've found an issue that has no apparent reason. >>> >>> Check the attached patch please >>> >>> the speed is 100% and pitcnh shift is "0", so the signal from vline~ >>> stands still in one particular point in the buffer (read from [vd~]). >>> >>> buffer size is 4000 ms, into the PVoc subpatch is supposed to be "1000" >>> for it does oversampling with the overlap of 4 (we've discussed this >>> before). Anyway, I'm using sampstoms~ and mstosamps~ to convert in a way >>> that works for the patch. >>> >>> The point is, when getting close to the end of the delay line, things >>> get ruined for no reason! The end of the buffer is 1000 ms, not 4000 ms as >>> pointed above. You can check my patch and see how that goes. >>> >>> If the reading point is at somewhere just after the buffer size less a >>> window size plus a hop size (around 985 ms) things get bad. >>> >>> I can't find a reason for that in a million years. Please help >>> >>> thanks >>> >>
Delay-limit-issue.pd
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