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Re: V4L2 Output Format

Hi Dave,

Thanks for the quick reply. I will go ahead and use the YUYV packed format.
When I used the VYUY format, my output image was all green - any reasons you
think this might happen?

I am assuming that nothing is bring written to the image (all 0's in YUV
format) and then when it is converted to RGB that 0 is converted to a green
color value in RGB?


On Fri, Aug 6, 2010 at 11:17 AM, Dave Milici <davemilici@xxxxxxxxxxxxx>wrote:

> On Aug 5, 2010, at 3:46 PM, Vikram Ivatury wrote:
> I am using the .pixfmt = ATMEL_ISI_PIXFMT_CrYCbY and I am wondering what my
> .capture_v4l2_fmt should be. Right now I have my .capture_v4l2_fmt =
> V4L2_PIX_FMT_VYUY but I think it should be V4L2_PIX_FMT_YUYV? Is there a
> difference?
> The difference is in the physical ordering of the Y vs U and V data as to
> which byte comes first (lowest in memory). Some graphics devices are able to
> offer the YUV packed formats with either ordering which is why this would be
> exposed. YUYV ordering is the most commonly used packed format.
> I am looking at Table 3-4 in the Atmel ISI datasheet and there is nothing
> listed under the V4L format for my specific ISI input of CrYCbY. I do not
> want a wrong .capture_v4l2_fmt to lead to a color corruption in the preview
> path. I am using a YUV to RGB conversion in my capture.c program.
> It will be obvious if you chose the wrong pixel format order. The colors
> will be all wrong and super-saturated intensity (like really bright orange).

University of Michigan, Aerospace Engineering
Multi-Disciplinary Design - Space Systems Engineering
M-Cubed Payload Team Lead
Student Space Systems Fabrication Laboratory
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