Hi all,
I am trying to bring up Caspa on Overo FE. I built an image with required V4L utils (such as media-ctl, yavta) using poky. I am able to boot it up with no issues. mt9v032 module is up and running. Also, I can capture frames in Bayer format (SGRBG10 752x480) with following pipeline configuration:
media-ctl -l '"mt9v032 3-005c":0->"OMAP3 ISP CCDC":0[1]'; 
media-ctl -l '"OMAP3 ISP CCDC":1->"OMAP3 ISP CCDC output":0[1]'; 
media-ctl -f '"mt9v032 3-005c":0[SGRBG10 752x480]';
media-ctl -f '"OMAP3 ISP CCDC":1[SGRBG10 752x480]';

to capture:
yavta -p -f SGRBG10 -s 752x480 -n 4 --capture=1 --skip 0 $(media-ctl -e "OMAP3 ISP CCDC output") --file=img.bin  # It works well.

I want to get ISP to do bayer to YUV conversion so that I can convert YUV frames to RGB for further processing. In order to do so, I tried following ISP pipeline configuration:
media-ctl -v -l '"mt9v032 3-005c->"OMAP3 ISP CCDC":0[1]'
media-ctl -v -l '"OMAP3 ISP CCDC":2->"OMAP3 ISP preview":0[1]'
media-ctl -v -l '"OMAP3 ISP preview":1->"OMAP3 ISP preview output":0[1]'
media-ctl -v -f '"mt9v032 3-005":0 [SGRBG10 752x480]'
media-ctl -v -f '"OMAP3 ISP CCDC":2 [SGRBG10 752x480]'
media-ctl -v -f '"OMAP3 ISP preview":1 [YUYV 752x480]'

When I try to capture a frame with following yavta command, It asks me to press any key to start capturing. Then I trigger capturing but it prints 'Unable to start streaming: Invalid argument (22)' and fails.
yavta -p -f YUYV -s 752x480 -n 4 --capture=1 --skip 0 /dev/video4 --file=img.bin  # It fails. /dev/video4 is pointing to ISP preview output.

Am I missing something either in pipeline configuration or capturing command? 

Do you have any feedback to my Caspa usage strategy for image processing?
My strategy:
1 - First employ ISP for Bayer to YUV conversion
2 - Get YUV output from ISP pipeline 
3 - Convert it to RGB.

Does this strategy make sense? Is it possible to convert Bayer to RGB (bypassing YUV stage) without any significant loss?