Arducam 64MP HAT black images with libcamera on Raspberry Pi

Raspberry Pi Cameras
1

I’m using the 64MP Autofocus Quad-Camera Kit for Raspberry Pi (#B0402). I need to capture 64MP images without native AWB correction, but libcamera-still keeps producing totally black images. The command I’ve been running is:

libcamera-still --width 80000 --height 40000 --gain 1 --awbgins 1,1 -o test.jpg --shutter 10000000 --immediate

I need the full 64M output, but everything comes out black. Has anyone run into this?

2

Let’s narrow it down. First, 80000x40000 is not a valid sensor resolution for this module—the 64MP sensor is 9152x6944, so that may already be part of the problem. Can you try removing --immediate and see if the image is still black? Also post your libcamera version and how the camera is registered (dmesg or libcamera-hello output).

3

Tried a few things:

  • At smaller resolutions, the first 1-2 captures are fine, then later ones go totally black again.
  • –width and --height seem to be ignored.
  • With --immediate the captured data is always black. Without --immediate, the data looks correct.
  • After re-installing libcamera, the first capture works, but every capture after that fails.
  • When a capture succeeds, I see v4l2-related info in the log. When it fails, there is no v4l2 log at all.
4

Thanks, that’s useful. Can you share your exact environment? Sensor model string, libcamera version, and the device nodes the camera is registered to would help.

5

Sensor is arducam_64mp. libcamera is v0.0.0+4186-d1dc0373. The camera is registered at /base/soc/i2c0mux/i2c@1/arducam_64mp@1a, connected to Unicam /dev/media3 and ISP /dev/media0. The highest sensor format reported is 9152x6944-SBGGR10. Also note 8000x4000 would be 32M, not 64M.

6

We tested a 64MP HAT here and reproduced an exposure problem. We also tested the 1-to-4 HAT configuration; I’ve sent you the test report in a private message. If the 1-to-4 result is acceptable for your setup, it can be used as an alternative.

7

So is the black frame caused by the HAT exposure issue? I still need to capture raw without AWB at the highest resolution—what should I use?

8

That’s part of it. The full picture is:

  • Your original resolution --width 80000 --height 40000 is wrong; the module max is 9152x6944 (64MP).
  • Using --immediate captures before exposure/AWB has settled, so frames can be completely black. Without --immediate the data is correct.
  • At full 9152x6944 raw, capture fails with V4L2 buffer allocation errors, which points to a Raspberry Pi hardware/memory limitation.

We reproduced it with:

libcamera-raw -o test.raw --gain 1 --awbgains 1,1 --rawfull --shutter 10000000

[1:07:46.040470684] [1855] INFO Camera camera_manager.cpp:299 libcamera v0.0.0+4186-d1dc0373
[1:07:46.043940695] [1856] WARN CameraSensorProperties camera_sensor_properties.cpp:205 No static properties available for ‘arducam_64mp’
[1:07:46.044024232] [1856] WARN CameraSensorProperties camera_sensor_properties.cpp:207 Please consider updating the camera sensor properties database
[1:07:46.095324954] [1856] WARN RPI raspberrypi.cpp:1308 Mismatch between Unicam and CamHelper for embedded data usage!
[1:07:46.096390526] [1856] INFO RPI raspberrypi.cpp:1425 Registered camera /base/soc/i2c0mux/i2c@1/arducam_64mp@1a to Unicam device /dev/media3 and ISP device /dev/media0
[1:07:46.097391635] [1855] INFO Camera camera.cpp:1028 configuring streams: (0) 640x480-YUV420 (1) 9152x6944-SBGGR10_CSI2P
[1:07:46.097703264] [1856] INFO RPI raspberrypi.cpp:805 Sensor: /base/soc/i2c0mux/i2c@1/arducam_64mp@1a - Selected sensor format: 9152x6944-SBGGR10_1X10 - Selected unicam format: 9152x6944-pBAA
[1:07:46.304545522] [1856] ERROR V4L2 v4l2_videodevice.cpp:1241 /dev/video0[12:cap]: Unable to request 1 buffers: Cannot allocate memory
[1:07:46.304607170] [1856] ERROR RPI raspberrypi.cpp:1069 Failed to allocate buffers
ERROR: *** failed to start camera ***

9

That matches what I saw—when it fails there’s no v4l2 log, which I guess means it dies at buffer allocation. So what do I do now?

10

For now, the workaround is:

  1. Use libcamera-raw instead of libcamera-still for raw capture with native AWB correction disabled.
  2. Avoid --immediate.
  3. Full 64MP raw (9152x6944) cannot be allocated on this Pi due to the V4L2 memory limitation, so use a reduced raw size such as:

libcamera-raw -o test.raw --gain 1 --awbgins 1,1 --rawfull --shutter 10000000 --width 8000 --height 4000

  1. Please run the firmware-version script from GitHub - edward-ardu/tools: Some small programs to help detect errors · GitHub and send me the output privately.
  2. Install the latest libcamera following libcamera and rpicam-apps - Arducam Wiki
  3. See the 64MP FAQ: How to use arducam_64mp & arducam_64mp FAQ - #2 by Edward

Also note the 64MP HAT itself has the exposure issue we reproduced, and the 1-to-4 HAT is the alternative we tested (report in private message).