Capturing framebuffer from LCD

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1

All –

I was wondering if anyone knows how to capture a framebuffer to an image file. I’ve been able to do the following:

cp /dev/fb0 framebuffer.dump (on BB-xm target)

fbgrab -i -w 640 -h 480 -b 32 -f framebuffer.dump fb.png (on host)

I’ve tried lots of variations (16, 24, 32 bits/pixel and –i or no –i ) and it all results in a distorted image.

John

2

John Weber wrote:

All �

I was wondering if anyone knows how to capture a framebuffer to an image file. I�ve been able to do the following:

cp /dev/fb0 framebuffer.dump (on BB-xm target)

fbgrab -i -w 640 -h 480 -b 32 -f framebuffer.dump fb.png (on host)

I�ve tried lots of variations (16, 24, 32 bits/pixel and �i or no �i ) and it all results in a distorted image.

fbset should be able to tell you the current frame buffer resolution.

Also, width might not be enough, there could be a stride involved that is > width.

If the image that you see looks remotely like your content, but is distorted, I would
play with increasing width until it looks good.

3

Thanks Vladimir. In the end, I think it was the 32-bit pixel from the
omapfb that was messing it up. Looks like the pixel is organized RGB where R
is in bits 23 - 16, G is in bits 15-8, and B is in bits 7-0.

I was able to open the raw file in Gimp and exchange the colors that way. I
don't need to do this much, so this works for now.

John