Thanks for the replies. problems solved by using 2 Pd instances, one for video, the other for audio, communicating via OSC on the same machine (or even different machines). The machine also had to have a better CPU as doing this on a slower dualcore laptop only fixed the audio, while the video got very slow.
best, On Monday, November 14, 2011, Hans-Christoph Steiner <[email protected]> wrote: > > I think generally, for gem + audio patches, people run two instances of Pd, one for Gem and the other for the audio. The audio instance has realtime priority, and the Gem one does not. > > .hc > > On Nov 13, 2011, at 10:17 PM, Ricardo Fabbri wrote: > >> Hi, >> >> I am building instalations/instruments which control sounds >> through the webcam, using a color detector that I submitted to this >> list a couple of days ago. Things work well, and I am just facing real >> time/delay issues now. >> When I try to generate sound with any pix >> processing, I am getting jumps in the sound (like on/off sounds at >> about 5-20Hz). Turning off any pix processing, the sound is then back >> to normal, even if I show the raw video from the camera on a gemwin. >> By pix processing I mean anything with even only 1 pass through the >> image on the CPU. I am using a ps3eye camera, which makes things >> better as it has a high framerate, but I still get interruptions in >> the sound. >> >> Why is this lag in the sound? The image with the output of the pix >> processing doesn't seem to be moving any slower with or without sound. >> >> What are your experiences in trying to get gem pix processing, video, >> and DSP to work in real time? My application is interactive, so that I >> really need the sound to be as smooth as possible. Here are some >> factors I will investigate, let me know if they make any sense to you: >> >> - It could be just too much data, even a single pass on each pixel >> could be causing delays/jumps. I could downsample the image prior to >> any pix processing >> - The kernel is too slow in processing the video stream; I tried '-rt' >> with no success >> - Perhaps there is a problem in Pd sound scheduling vs pix processing >> - Perhaps its just the CPU. In fact, I used OSC to do the video on one >> machine, send the parameters to a second machine which then processes >> the audio there. This effectively solved the problem. Question is, is >> this due to CPU or to another factor? >> >> I would really appreciate hearing ideas from you, as I am new to this. >> Best, >> Ricardo Fabbri >> -- >> Linux registered user #175401 >> www.lems.brown.edu/~rfabbri >> labmacambira.sf.net >> >> _______________________________________________ >> GEM-dev mailing list >> [email protected] >> http://lists.puredata.info/listinfo/gem-dev > > > > ---------------------------------------------------------------------------- > > Computer science is no more related to the computer than astronomy is related to the telescope. -Edsger Dykstra > > > -- Ricardo Fabbri -- Linux registered user #175401 www.lems.brown.edu/~rfabbri labmacambira.sf.net
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