Crankshaft black screen

[Ramortada]

Hello,

When connecting a USB webcam with crankshaft, I get a black screen whenever I switch to the camera.

The device supports MJPG pixel format, I don't know if this is the cause. I have similar results with this issue. https://github.com/meekys/cam_overlay/issues/10

I would very much appreciate any help

[meekys]

@Ramortada Just a couple of questions.

• Which branch are you using? MJPG is only available in the cpp branch
• After stopping (Ctrl+C or killing the process), what is logged in the terminal?

[Ramortada]

I don't know what you mean by cpp branch. I am using an FPV RCA camera connected to usb with this device : https://fr.aliexpress.com/item/1005004107556241.html?spm=a2g0o.cart.0.0.3f9e378dy4kvvB&mp=1&gatewayAdapt=glo2fra

I get a video signal on my laptop. Could be the same as issue #25 ?

I won't have access to my setup until next week, I can try any commands Im sorry

[meekys]

@Ramortada Without seeing the console output, I can't really say why it might not be working. Once I see them, hopefully we can figure out what's causing the black screen.

Did you compile cam_overlay yourself, or are you using it as part of crankshaft?

[Ramortada]

Thank you this is very nice of you. What do you mean by seeing the console output? And I am using cam_overlay with crankshaft

[Ramortada]

Hello, so I have the output when I use crankshaft rearcam show : Opened device ' /dev/video0' ; Dimensions : 640 x 480 Pixel Format : MJPG ; Cannot open 'shader-MJPG.frag' : 2, No such file or directory

I get the same result if the cam is connected and not connected. I also tried to remove the dtoverlay=vc4-fkms-v3d command from config.txt but I had the same output.

If I add dtoverlay=vc4-fkms-v3d in confid.txt below [all] like Maxwime suggested in issue #28, I now get this : `Opened device ' /dev/video0' ; Dimensions : 640 x 480 Pixel Format : MJPG ;

• failed to add service - already in use?`

If you need the v4l2 output, I have a picture. If you have any idea how I could fix this, I'm all in.

[meekys]

Ok, thanks for the logs.

This is an issue with crankshaft, as they'll need to update to the cpp branch, which should support MJPG

Unfortunately, as there are breaking changes, this hasn't happened yet

[Ramortada]

Thanks. Is there a way to do what I'm trying to do with a custom script on crankshaft?

[meekys]

I'm not sure, sorry. I'm not familiar enough with how it's been integrated into crankshaft

The best I can suggest is looking at stage3/03-crankshaft-base/files/opt/crankshaft/service_gpiotrigger.sh, as that looks like it starts the process.

You'd need to compile the cpp branch of cam_overlay, as well as integrating it into crankshaft in that script (presumably)

[Ramortada]

I appreciate it, I will start from there

[Geekyadz]

Hi @Ramortada

Did you have any joy with this?

I'm kinda in the same boat, certainly in the sense of I'm getting:

Crankshaft Management Tool v2.4.0 is executing command...

Show rearcam...

Done. pi@CRANKSHAFT-NG:~ $ Opened device '/dev/video0' Dimensions: 1920 x 1080 Pixel Format: MJPG

• failed to add service - already in use?

Any suggestions on how to resolve this issue?