OMAP-L138 LCDK vvpif_mmap_loopback Error in opening capture device for channel 0

Ilya Kravchuk

Other Parts Discussed in Thread: OMAP-L138, OMAPL138

I'm trying to capture video, from analog cam, connected through composite in on my OMAP-L138 LCDK board via example application vpif_mmap_loopback.
But, when I'm executing this application(./vpif_mmap_loopback -m 1 -p 0) one of following errors appears. It's strange, that application cancels in different places.
How can I fix this problem?

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root@omapl138-lcdk:~/vpif/omap# ./vpif_mmap_loopback -m 1 -p 0
standard.name = NTSC
standard.name = NTSC-M
standard.name = NTSC-M-JP
standard.name = NTSC-M-KR
standard.name = PAL
Found standard support in the driver
Error in opening capture device for channel 0
root@omapl138-lcdk:~/vpif/omap# ./vpif_mmap_loopback -m 1 -p 0
VIDIOC_S_INPUT
: Invalid argument
Error in opening capture device for channel 0

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over 9 years ago

0 Titusrathinaraj Stalin over 9 years ago

TI__Guru** 116100 points

I'm not sure what could be the problem, this information is also not sufficient and its some debug effort.
Please check where the code get stucks or getting an error.
Enable the debug prints in video and vpif_mmap_loopback.c file.
root@omapl138-lcdk:~/vpif/omap# echo 8 > /proc/sys/kernel/printk
root@omapl138-lcdk:~/vpif/omap# ./vpif_mmap_loopback -m 1 -p 0

I think, this vpif mmap loopback code is for OMAPL138 LogicPD EVM, we may need to modify it for LCDK board, but not sure.

0 Ilya Kravchuk over 9 years ago in reply to Titusrathinaraj Stalin

Expert 1520 points

I've set debug prints in vpif_capture.c and tvp514x.c. After executing vpif_mmap_loopback -m 1 - p, vpif_capture.c failed on function
ret = v4l2_subdev_call(vpif_obj.sd[sd_index], video, s_routing, input, output, 0), when driver tries to set input handler in vpif_s_input function.
What may be cause of this problem?

0 Titusrathinaraj Stalin over 9 years ago in reply to Ilya Kravchuk

TI__Guru** 116100 points

Can you please make sure that you don't have the problem mentioned in this wiki page ?
processors.wiki.ti.com/.../Arago_build_recipe_for_OMAPL1

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OMAP-L138 LCDK vvpif_mmap_loopback Error in opening capture device for channel 0