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
Try doing the video processing in one instance of PD with the audio processing in another instance of pd and pass messages between the two instances with netsend. Assuming you're on a dual-core machine, I think this will cause each instance to occupy a different CPU and fix your jumpy sound. This worked for me on Windows.
On Nov 13, 2011, at 7:17 PM, Ricardo Fabbri rfabbri@gmail.com 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 GEM-dev@iem.at http://lists.puredata.info/listinfo/gem-dev
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 GEM-dev@iem.at 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
On Windows, when on dual or more cores, you could also try to (additionally) set the affinity of a process to a certain core. So one pd instance has affinity with one or two or four cores, and another with one or two or four other cores. This can be done in task manager, processes, right click, set affinity. I am unsure if and how this could be done on Linux.
Bye, menno
On Mon, Nov 14, 2011 at 4:32 AM, Hans-Christoph Steiner hans@at.or.at 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 GEM-dev@iem.at 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
GEM-dev mailing list GEM-dev@iem.at http://lists.puredata.info/listinfo/gem-dev
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 hans@at.or.at 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 GEM-dev@iem.at 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
there is also the pd~ approach which i like for various reasons. examples here: http://www.uni-weimar.de/medien/wiki/Audiovideo
http://www.uni-weimar.de/medien/wiki/Audiovideo
Am 14.11.2011 um 15:39 schrieb Ricardo Fabbri:
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 hans@at.or.at 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
-
Hans-Christoph Steiner -
Joe Newlin -
Max -
Menno van der Woude -
Ricardo Fabbri