Messages in this thread | | | Date | Tue, 26 Apr 2011 13:54:53 +0200 | From | Hans de Goede <> | Subject | Re: [PATCH] usbvision: remove (broken) image format conversion |
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Hi,
On 04/26/2011 10:30 AM, Ondrej Zary wrote: > On Tuesday 26 April 2011, you wrote: >> On Monday, April 25, 2011 23:23:17 Ondrej Zary wrote: >>> The YVU420 and YUV422P formats are broken and cause kernel panic on use. >>> (YVU420 does not work and sometimes causes "unable to handle paging >>> request" panic, YUV422P always causes "NULL pointer dereference"). >>> >>> As V4L2 spec says that drivers shouldn't do any in-kernel image format >>> conversion, remove it completely (except YUYV). >> >> What really should happen is that the conversion is moved to libv4lconvert. >> I've never had the time to tackle that, but it would improve this driver a >> lot. > > Depending on isoc_mode module parameter, the device uses different image > formats: YUV 4:2:2 interleaved, YUV 4:2:0 planar or compressed format. > > Maybe the parameter should go away and these three formats exposed to > userspace?
That sounds right,
> Hopefully the non-compressed formats could be used directly > without any conversion. But the compressed format (with new V4L2_PIX_FMT_ > assigned?) should be preferred (as it provides much higher frame rates). The > code moved into libv4lconvert would decompress the format and convert into > something standard (YUV420?).
Correct.
> >> Would you perhaps be interested in doing that work? > > I can try it. But the hardware isn't mine so my time is limited. >
If you could give it a shot that would be great. I've some hardware to test this with (although I've never actually tested that hardware), so I can hopefully pick things up if you cannot finish things before you need to return the hardware.
Thanks & Regards,
Hans
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