Varying frame rate
Hello,
I am writing an application that capture video/pictures from a webcam.
My program is built on moinejf.free.fr/*svv*.*c*
which again is built on v4l2spec.bytesex.org/v4l2spec/*capture*.*c*
OS is linux 2.6.29.6-217.2.3.fc11.x86_64
Webcam is "Logitech Quickcam Pro for Notebooks" (046d:0991)
My obeservation is : Depending on what my camera focus on, the framerate varies from 5 to 15 fps. I have tried several times, same result.
Why is that. How can I avoid this ?
Best regards
Håvard Holm
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Quoted 6 lines · Haavard Holm
Hello,
I am writing an application that capture video/pictures from a webcam.
My program is built on moinejf.free.fr/*svv*.*c*
which again is built on v4l2spec.bytesex.org/v4l2spec/*capture*.*c*
Quoted 7 lines
OS is linux 2.6.29.6-217.2.3.fc11.x86_64
Webcam is "Logitech Quickcam Pro for Notebooks" (046d:0991)My obeservation is : Depending on what my camera focus on, the framerate varies from 5 to 15 fps. I have tried several times, same result.
Why is that. How can I avoid this ?
I have observed similar issues with uvc camera on my aspire one (low frame rate while the illumination is low)
Probably this is a hardware issue, and maybe there is a control to turn this off.
Best regards,
Maxim Levitsky
Quoted 9 lines
Best regards
Håvard Holm
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Quoted 1 line · On Sun, 16 Aug 2009 03:43:52 +0300 Maxim Levitsky <[email protected]>…
On Sat, 2009-08-15 at 23:48 +0200, Haavard Holm wrote:
[snip]
Quoted 3 lines
Quoted 3 lines
My obeservation is : Depending on what my camera focus on, the framerate varies from 5 to 15 fps. I have tried several times, same result.
[snip]
Quoted 5 lines
I have observed similar issues with uvc camera on my aspire one (low frame rate while the illumination is low)
Probably this is a hardware issue, and maybe there is a control to turn this off.
Hello,
The frame rate depends on the exposure time. If auto exposure is set, you may have such a behaviour.
Best regards.
Signature · 7 lines
Ken ar c'hentañ | ** Breizh ha Linux atav! ** Jef | http://moinejf.free.fr/ -- video4linux-list mailing list Unsubscribe mailto:[email protected]?subject=unsubscribe https://www.redhat.com/mailman/listinfo/video4linux-list
Quoted 12 lines · Jean-Francois Moine
Quoted 1 line · On Sun, 16 Aug 2009 03:43:52 +0300 Maxim Levitsky <[email protected]>…
On Sat, 2009-08-15 at 23:48 +0200, Haavard Holm wrote:
[snip]Quoted 3 lines
Quoted 3 lines
My obeservation is : Depending on what my camera focus on, the framerate varies from 5 to 15 fps. I have tried several times, same result.
[snip]Quoted 3 lines
I have observed similar issues with uvc camera on my aspire one (low frame rate while the illumination is low)
Quoted 7 lines
Quoted 2 lines
Probably this is a hardware issue, and maybe there is a control to turn this off.
Hello,
The frame rate depends on the exposure time. If auto exposure is set, you may have such a behaviour.
Exactly, that is what I was trying to say, but didn't...
Best regards,
Maxim Levitsky
Quoted 3 lines
Best regards.
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Quoted 17 lines · Jean-Francois Moine
Quoted 2 lines · On Sun, 16 Aug 2009 03:43:52 +0300 Maxim Levitsky<[email protected]>…
On Sat, 2009-08-15 at 23:48 +0200, Haavard Holm wrote:
[snip]Quoted 4 lines
Quoted 4 lines
My obeservation is : Depending on what my camera focus on, the framerate varies from 5 to 15 fps. I have tried several times, same result.
[snip]Quoted 3 lines
I have observed similar issues with uvc camera on my aspire one (low frame rate while the illumination is low)
Quoted 8 lines
Quoted 3 lines
Probably this is a hardware issue, and maybe there is a control to turn this off.
Hello,
The frame rate depends on the exposure time. If auto exposure is set, you may have such a behaviour.
From a c-program - how do I turn off auto exposure ?
Best
Håvard Holm
Quoted 3 lines
Best regards.
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On Sun, 16 Aug 2009 10:35:56 +0200
Haavard Holm <[email protected]> wrote:
[snip]
Quoted 5 lines
Quoted 3 lines
The frame rate depends on the exposure time. If auto exposure is set, you may have such a behaviour.
From a c-program - how do I turn off auto exposure ?
You may do it by the VIDIOC_S_CTRL ioctl (look at v4l2-apps/util/v4l2-ctl.cpp in the LinuxTv mercurial main repository)
Otherwise, by program, I know about v4l2ucp or vlc (1.0.x).
Best regards.
Signature · 7 lines
Ken ar c'hentañ | ** Breizh ha Linux atav! ** Jef | http://moinejf.free.fr/ -- video4linux-list mailing list Unsubscribe mailto:[email protected]?subject=unsubscribe https://www.redhat.com/mailman/listinfo/video4linux-list
Hi, I want to know what is the new procedure or
email adress for the new V4L newsletter?
________________________________________
De : [email protected] [[email protected]] de la part de Jean-Francois Moine [[email protected]] Date d'envoi : 16 août 2009 05:09
À : [email protected]
Objet : Re: Varying frame rate
On Sun, 16 Aug 2009 10:35:56 +0200
Haavard Holm <[email protected]> wrote:
[snip]
Quoted 5 lines
Quoted 3 lines
The frame rate depends on the exposure time. If auto exposure is set, you may have such a behaviour.
From a c-program - how do I turn off auto exposure ?
You may do it by the VIDIOC_S_CTRL ioctl (look at v4l2-apps/util/v4l2-ctl.cpp in the LinuxTv mercurial main repository)
Otherwise, by program, I know about v4l2ucp or vlc (1.0.x).
Best regards.
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Ken ar c'hentañ | ** Breizh ha Linux atav! **
Jef | http://moinejf.free.fr/
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