cpu load of webcam read out with omap3/beagleboard
Hi,
I have beagleboard with the OMAP3530 processor and I want to read a usb webcam out. But I only get usable results at 160x120 resolution.
I set the pixelformat to "V4L2_PIX_FMT_RGB24" and the resolution to 160x120. With these settings I get 30fps at 4% cpu load. But when I set the resolution to 320x240 or 640x480 the cpu load is at 98% and I get only 17 or 4fps. Also I get at 640x480 errors like "libv4lconvert: Error decompressing JPEG: fill_nbits error: need 9 more bits".
Is this a normal behavior or is there a way to fix this? I think the problem is the conversion from MJPEG to RGB, because when I set the pixelformat to MJPEG the cpu load is <1%. But I need RGB data for image processing.
I hope someone can help me.
Regards, Joern
Nobody has an idea? I think this cpu load isn't normal, becuase everywhere you can read, that the bealgeboard is very fast and it has 500MHz...
Regards, Joern
----- Original Message ----- From: "Rath" <[email protected]>
To: "Linux-Media" <[email protected]>
Sent: Sunday, October 18, 2009 12:43 PM
Subject: cpu load of webcam read out with omap3/beagleboard
Quoted 15 lines
Hi,
I have beagleboard with the OMAP3530 processor and I want to read a usb webcam out. But I only get usable results at 160x120 resolution.
I set the pixelformat to "V4L2_PIX_FMT_RGB24" and the resolution to 160x120. With these settings I get 30fps at 4% cpu load. But when I set the resolution to 320x240 or 640x480 the cpu load is at 98% and I get only 17 or 4fps. Also I get at 640x480 errors like "libv4lconvert: Error decompressing JPEG:fill_nbitserror: need 9 more bits".Is this a normal behavior or is there a way to fix this? I think the problem is the conversion from MJPEG to RGB, because when I set the pixelformat to MJPEG the cpu load is <1%. But I need RGB data for image processing.
I hope someone can help me.
Regards, Joern
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Quoted 32 lines
-----Original Message-----
From: rath [mailto:[email protected]]
Sent: Friday, October 23, 2009 7:58 PM
To: [email protected]
Cc: Hiremath, Vaibhav
Subject: Re: cpu load of webcam read out with omap3/beagleboardNobody has an idea? I think this cpu load isn't normal, becuase everywhere
you can read, that the bealgeboard is very fast and it has 500MHz...Regards, Joern
----- Original Message -----
From: "Rath" <[email protected]>
To: "Linux-Media" <[email protected]>
Sent: Sunday, October 18, 2009 12:43 PM
Subject: cpu load of webcam read out with omap3/beagleboardQuoted 3 lines
Hi,
I have beagleboard with the OMAP3530 processor and I want to read
a usb
Quoted 2 lines
webcam out. But I only get usable results at 160x120 resolution. I set the pixelformat to "
V4L2_PIX_FMT_RGB24" and the resolutionto
Quoted 1 line
160x120. With these settings I get 30fps at 4% cpu load. But when
I set
Quoted 1 line
the resolution to 320x240 or 640x480 the cpu load is at 98% and I
get only
Quoted 9 lines
Quoted 1 line
17 or 4fps. Also I get at 640x480 errors like "libv4lconvert:
Error
Quoted 3 lines
decompressing JPEG:
fill_nbitserror: need 9 more bits".Is this a normal behavior or is there a way to fix this? I
think the
Quoted 1 line
problem is the conversion from MJPEG to RGB, because when I set
the
Quoted 1 line
pixelformat to MJPEG the cpu load is <1%.
[Hiremath, Vaibhav] This itself clarifies that the conversion is proving to be costly here, since with MJPEG you are getting <1% CPU consumption. I have never used/came across such use-case/scenario, so it is really difficult to comment on this.
Thanks,
Vaibhav
Quoted 14 lines
But I need RGB data
for imageQuoted 7 lines
processing.
I hope someone can help me.
Regards, Joern
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To unsubscribe from this list: send the line "unsubscribe linux-media" in
Quoted 3 lines
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html