Hi, i just stumbled over a strange behavior in canvases with overlapped blocks without resampling (e.g. set with [block~ 1024 2]). In such canvases e.g. [osc~ 440] delivers a cosine wave with an actual frequency of 220 Hz, because of the double overlap. This is because dsp signal vectors carry the wrong sample rate (sp[0]-
s_sr = 88200 instead of 44100).
[samplerate~] correctly reports 44100 because it uses a different method of retrieving the sample rate.
I consider that a bug and would file a bug report, but since this must have been present for a long time and must surely have been discovered by other people as well it might also be a feature.... any ideas?
gr~~~
Thomas Grill wrote:
Hi, I consider that a bug and would file a bug report, but since this must have been present for a long time and must surely have been discovered by other people as well it might also be a feature.... any ideas?
my personal explanation for this was always, that the "samplerate" really means "datarate"; since you get the double amount of samples in the same time, the doubled samplerate is somewhat understandable (though unexpected).
i think there is even a feature request to have samplerate & overlap (and resampling factor) exposed in the t_signal structure. in old versions of Pd there was only samplerate, but i think this has changed recently (iirc)
fgmadsr IOhannes
Am 28.06.2008 um 11:50 schrieb IOhannes m zmölnig:
Thomas Grill wrote:
Hi, I consider that a bug and would file a bug report, but since this must have been present for a long time and must surely have been discovered by other people as well it might also be a feature.... any ideas?
my personal explanation for this was always, that the "samplerate" really means "datarate"; since you get the double amount of samples in the same time, the doubled samplerate is somewhat understandable (though unexpected).
while it is understandable from a developer's perspective it's certainly a bug from the user's point of view, no? (given that sample- rate-sensitive objects behave wrong) For osc~ it's possible to correct the frequency by using the reblocking parameters, but that not the case for more complicated objects. I'll file a bug report....
gr~~~
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IOhannes m zmölnig -
Thomas Grill