Re: [PATCH] usbvision: remove (broken) image format conversion

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



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
--
To unsubscribe from this list: send the line "unsubscribe linux-media" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html


[Index of Archives]     [Linux Input]     [Video for Linux]     [Gstreamer Embedded]     [Mplayer Users]     [Linux USB Devel]     [Linux Audio Users]     [Linux Kernel]     [Linux SCSI]     [Yosemite Backpacking]
  Powered by Linux