Error starting camera: size in main stream should be (width, height) and OSError: [Errno 12] Cannot allocate memory

[olliraa]

I got around the type error (fixed in 3.5.4), but now when starting the server I get "Inernl error 500" in browaser and console shows this:

 File "/usr/lib/python3/dist-packages/picamera2/picamera2.py", line 588, in sensor_modes
    self.configure(temp_config)
  File "/usr/lib/python3/dist-packages/picamera2/picamera2.py", line 1210, in configure
    self.configure_("preview" if camera_config is None else camera_config)
  File "/usr/lib/python3/dist-packages/picamera2/picamera2.py", line 1182, in configure_
    self.allocator.allocate(libcamera_config, camera_config.get("use_case"))
  File "/usr/lib/python3/dist-packages/picamera2/allocators/dmaallocator.py", line 43, in allocate
    fd = self.dmaHeap.alloc(f"picamera2-{i}", stream_config.frame_size)
         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3/dist-packages/picamera2/dma_heap.py", line 98, in alloc
    ret = fcntl.ioctl(self.__dmaHeapHandle.get(), DMA_HEAP_IOCTL_ALLOC, alloc)
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
OSError: [Errno 12] Cannot allocate memory
[2025-07-07 13:09:10,752] ERROR in camera_pi: Thread 2530173952: CameraController.requestStart - Error starting camera: size in main stream should be (width, height)
[2025-07-07 13:09:10,778] ERROR in camera_pi: Thread 2530173952: CameraController.requestStart - Error starting camera: size in main stream should be (width, height)
[2025-07-07 13:09:12,861] ERROR in camera_pi: Thread 2530173952: CameraController.requestStart - Error starting camera: size in main stream should be (width, height)
[2025-07-07 13:09:12,866] ERROR in camera_pi: Thread 2530173952: CameraController.requestCameraForConfig - camera could not be started

If I refresh the browser I I can login, but preview (naturally) dos not work etc. Running on Zero w and latest Dietpi, is there some trick to get around this error?

[signag]

It seems that the system cannot allocate sufficient memory required by Picamera2.
You might try setting lower buffer count or Stream Size in the Config screen, but i doubt that this would be satisfactory.

I have no experience with Dietpi. Probably, memory management is specific.

You may have a look at chapter Checking Contiguous Memory (CMA) which has been written to handle memory issues occurring with Docker.
You could check the available CMA memory and try increasing it, if necessary.
.... if you need to stay with Dietpi for some reason.

I am running a Pi Zero W with the official full Bullseye OS from Imager:

RaspiCamSrv works fine on that system.

On a Pi Zero 2 W, I am even running raspiCamSrv on full Bookworm.
Also there, RaspiCamSrv works fine, even with OpenCV, numpy and matplotlib for histograms and extended motion detection.