Hi Ronni,
like I said, it has to do with interpolation. I'm working on a chapter for the Pd FLOSS Manual about soundfiles now, but here is the short version... math gurus on the list please correct me if I am wrong since this will likely end up in that chapter!
When you play back the samples in the array at the same rate that they were recorded, then Pd doesn't have a lot of work to do since it just reads back the values. However, when you play them back at a different rate, for example by reading a 44.1K sample at 48K, then Pd often has to interpolate (i.e. guess the "missing" values in between the samples) in order to create the audio. That is what the "4" in [tabread4~] means: 4 point interpolation which uses the 4 nearest values to calculate any value which might fall in between two samples.
Super-geek explanation by Miller here: http://www-crca.ucsd.edu/~msp/techniques/v0.11/book-html/node31.html
Here is the part where I know the answer but not the explanation, however... but the larger the soundfile you load into an array, the lower the quality of the interpolation. Can someone fill *me* in on this so I can write intelligently about it in the FLOSS Manual?
Best, Derek
On 11/24/10 2:57 AM, ronni montoya wrote:
hi derek , can you explain me why does sound qualit goes own as file size goes up? Is that something particular in pd?