OK, I tested your patch and on my side, i get a solid red square. No flicker. ++
Jack Le 24/10/2017 à 18:33, Jack a écrit : > Hello, > > Le 24/10/2017 à 11:24, Peter P. a écrit : >> * cyrille henry <c...@chnry.net> [2017-10-24 13:32]: >>> >>> >>> Le 24/10/2017 à 13:18, Peter P. a écrit : >>>> Hi list, >>>> >>>> I am trying to convert an audio signal to pixel data using pix_sig2pix~ >>>> and then back to audio data using pix_pix2sig~ without further >>>> manipulations. Please see attached patch. >>>> >>>> I do scale the audio signal from -1 to 1 to lie in a range compliant >>>> to pixel data, which I assume to be 0 to 1. >>>> >>>> Not having connected an input to the subpatch, this signal will hence be >>>> 0.5 and will display in the red color channel. >>>> >>>> Converting that red channel back to audio signals and doing the opposite >>>> scaling operation, I am getting a 51dB constant signal at the output >>>> even without having attached a signal to the input of pix_sig2pix~. >>>> Checking with a snapshot~ object indicates a constant signal of 0.003921 >>>> >>>> I assume this to be due to limited resolution numbers in the pixel data >>>> and wonder what their resolution is? >>> >>> 8 bits / channels >>> >>> so resolution is 1/256 = 0.0039... >>> >>> You can code MSB in Red, and LSB in green is you want 16 bits... >>> >>>> >>>> Then I texture the pixel data onto a rectangle. This rectangle >>>> does flicker and flip diagonally from time to time and I wonder if it is >>>> an error on my machine only and where it could come from. >>> >>> I don't see any flicker in your patch. (linux / intel GPU) >> >> Thank you Cyrille for this helpful information! >> >> Jack, I am on Debian GNU/Linux with an onboard Intel graphics controller >> (i915 variant). > > OK, i guessed you were on nvidia because if you are not sync to vblank, > you often get a line diagonaly separating two pictures. It is called > "screen tearing". > I didn't test your patch yet... > ++ > > Jack > > >> >> P >> >> _______________________________________________ >> Pd-list@lists.iem.at mailing list >> UNSUBSCRIBE and account-management -> >> https://lists.puredata.info/listinfo/pd-list >> > > > _______________________________________________ > Pd-list@lists.iem.at mailing list > UNSUBSCRIBE and account-management -> > https://lists.puredata.info/listinfo/pd-list > _______________________________________________ Pd-list@lists.iem.at mailing list UNSUBSCRIBE and account-management -> https://lists.puredata.info/listinfo/pd-list