Add support for modern libcamera Raspberry Pi camera stack

[scul81]

Hi,

I am using the latest version Raspbian (2022-04-04) and the latest version of Motioneye (0.42.1)

My infrared nightvision camera is connected to the internal Raspberry Pi camera port.
When I run libcamera-hello I can see that the camera is working
The devices are connected under Unicam /dev/media1 and ISP /dev/media0
The stream is 1296x972-YUV420
When I load Motioneye I cannot seem to add the camera in any way possible. I have tried all 20 or so devices in the list and none of them work.

[MichaIng]

The cameras I deal with are shown as /dev/video*. Can you check whether they are listed here:

v4l2-ctl --list-devices

It may be related to RPi MMAL camera detection with legacy camera stack vs modern camera stack. Currently we use vcgencmd get_camera to detect the RPi camera module, and I'm not sure whether this works when using KMS + modern camera driver stack with V4L2 and libcamera. I guess you have camera_auto_detect=1 and dtoverlay=vc4-kms-v3d in your /boot/config.txt?

[scul81]

Hi the output of that command gives

bcm2835-codec-decode (platform:bcm2835-codec):
	/dev/video10
	/dev/video11
	/dev/video12
	/dev/video18
	/dev/video31
	/dev/media3

bcm2835-isp (platform:bcm2835-isp):
	/dev/video13
	/dev/video14
	/dev/video15
	/dev/video16
	/dev/video20
	/dev/video21
	/dev/video22
	/dev/video23
	/dev/media0
	/dev/media2

unicam (platform:fe801000.csi):
	/dev/video0
	/dev/media1

vcgencmd get_camera
supported=0 detected=0, libcamera interfaces=0

and yes those commands are in the /boot/config.txt

[scul81]

I have done some more reading, this thread is helpful.
https://forums.raspberrypi.com/viewtopic.php?t=325259

The output of "libcamera-hello --list-cameras" equals
[1:19:22.870166766] [1172]  INFO Camera camera_manager.cpp:293 libcamera v0.0.0+3424-e68e0f1e
[1:19:22.897339457] [1174] ERROR CameraSensor camera_sensor.cpp:551 'ov5647 10-0036': Camera sensor does not support test pattern modes.
[1:19:22.929102130] [1174]  INFO RPI raspberrypi.cpp:1317 Registered camera /base/soc/i2c0mux/i2c@1/ov5647@36 to Unicam device /dev/media1 and ISP device /dev/media0
Available cameras
-----------------
0 : ov5647 [2592x1944] (/base/soc/i2c0mux/i2c@1/ov5647@36)
    Modes: 'SGBRG10_CSI2P' : 640x480 1296x972 1920x1080 2592x1944

[MichaIng]

I'm not sure how such infrared camera is commonly provided. E.g. based on v4l2-ctl --list-devices output it seems like /dev/media1 can also be obtained from /dev/video0, but /dev/media0 is associated with a larger number of /dev/video* devices, so not sure if/how this may work.

However, you added it as MMAL camera, right? In this case vcgencmd get_camera is used, and this only works with the legacy camera stack where the output needs to start with supported=1 detected=1. Since you have the modern camera stack enabled (which is perfectly fine, in general, the default on modern RPi OS), this isn't recognised. For this we need to implement libcamera utilities support. I hence adjusted this issue to reflect it being a feature request for supporting libcamera MMAL cameras.

But it would be interesting to know whether the cameras an be accessed via V4L2. It should show the large list of devices from your v4l2-ctl --list-devices output. Probably you can try whether any of those is working, probably even /dev/media0 and /dev/media1?

... https://www.raspberrypi.com/documentation/accessories/camera.html#v4l2-drivers

Actually to me it seems like MMAL is generally the legacy driver, V4L2 the one used with libcamera. Probably the libcamera- utilities are not necessary at all. The question is whether motion is able to catch the camera stream with modern stack, e.g.: #1857

Related issue on motion project: Motion-Project/motion#1434
Seems like currently motion is not able to handle the modern RPi camera stack. Solution would be to either switch to legacy stack, or providing the stream with other software, like mjpg-streamer, then adding it as local network camera.

[scul81]

I have not added it as an MMAL camera, as that does not work.

The interface produces an error, the camera box remains black and you can click the OK button a million times but it will never proceed.

Under V4L2 you get the following options:

I have tried adding every single one of them but none of them work.

When I select unicam I get video0, also doesn't work.

I have tried switching the camera back by enabling "legacy camera support" in raspi-config and the V4L2 output then becomes different, but the issue remains that none of the cameras selected work.

[MichaIng]

Ah right, makes sense that it doesn't work as MMAL with modern camera stack. I'm wondering why the cameras are spread across so many /dev devices. CLI can only access one at a time, confusing. Sadly I have no DSI (?) camera module to test whether this is expected, or special for your ISP camera.

After you switched to legacy camera stack, could you retry adding it as MMAL? Respectively does it show "supported" then in:

vcgencmd get_camera

?

[scul81]

I have now switched the configuration back to legacy stack. Under the MMAL selection the problem remains the same. The block remains blank and you can click OK but it never proceeds.

Under V4L2 I have more options.

I will try them out and update this post.
UPDATE. I tried all of them and none work.

The result of the command is:
supported=1 detected=1, libcamera interfaces=0

The result of "v4l2-ctl --list-devices" is:

None of them work in motioneye. ;(
By the way this is the camera:
https://www.aliexpress.com/item/1005001586246249.html

[MichaIng]

Looks like we should add the device path to the camera name, for such cases where multiple devices have the same name, or one camera provides multiple devices for whatever reason.

If vcgencmd get_camera now reports supported=1 detected=1, libcamera interfaces=0, you should see the camera(s) in the MMAL list, isn't it? ... ah

Under the MMAL selection the problem remains the same. The block remains blank and you can click OK but it never proceeds.

This is unexpected. We check for MMAL cameras via if support.startswith('supported=1 detected=1'):, which should be true as of your output 🤔. Can you verify in shell:

[[ $(vcgencmd get_camera) == 'supported=1 detected=1'* ]] && echo 'Yes it does!' || echo 'It does NOT!'

[scul81]

Well

Camera detected with that command

No camera detected in motioneye