Accessing Cameras with the Same Name

[mahyarmirrashed]

Environment:

• Operating system (e.g. Windows, Linux(Debian), Linux(Ubuntu), Mac): Windows 11
• Python version (e.g. 3.7.9, 3.8.5) : 3.8.16
• SDL version (e.g. SDL 2.0.12): 2.26.3
• PyGame version (e.g. 2.0.0.dev10, 1.9.6): 2.1.3
• Relevant hardware (e.g. if reporting a bug about a controller, tell us the brand & name of it): Not necessary.

Current behavior:

I have three web cameras (from the same manufacturer) connected to my USB C dock.

I create a sample program:

>>> import pygame
pygame 2.1.3 (SDL 2.26.3, Python 3.8.16)
Hello from the pygame community. https://www.pygame.org/contribute.html
>>> import pygame.camera
>>> pygame.init()
(5, 0)
>>> pygame.camera.init()
>>> pygame.camera.list_cameras()
['PC Camera', 'PC Camera', 'HP Wide Vision HD Camera', 'PC Camera']

This is annoying. They are all listed as "PC Camera". Therefore, there is no way to access any individual camera, afaik.

Expected behavior:

It would be different if these were named tuples with an option that distinguishes them by their ID.

e.g.

>>> pygame.camera.list_cameras()
[CameraSource(name="PC Camera", uuid=""), etc.]

[mahyarmirrashed]

The best solution here is adding an ability to access the camera objects via index or some other UUID. We could have a dataclass with hidden fields that is then managed by whatever backend. As long as the interface with the user remains consistent, that should be good.

[Starbuck5]

Hi, thank you for opening an issue.

I see this as an API oversight in the camera API.

Here's my solution: make all backends support passing indices.
In type hints format:
Camera(device: int | str, desired_size: Tuple[int, int], format: str)

[Starbuck5]

I opened a super initial PR to try this out (on windows).

If you'd like to test it out, here is the correct wheel for your system I believe:
pygame_ce-2.1.4.dev1-cp38-cp38-win_amd64.zip
Download that, unzip it, and then pip install it.

It should allow you to just pass an index as the device argument.

[oddbookworm]

Quick note:
this problem doesn't actually exist on linux using the default backend because they're reported as ["/dev/video0", "/dev/video1",...]
(of course, there's some linux weirdness where each camera reports as two devices, but that's a separate problem) and I believe MacOS is the same. But yeah, all the backends should behave the same

[pmp-p]

only usb camera will report vendorid, productid and iSerialNumber ( if not cloned because counterfeit item ! )

Firewire cameras or framegrabber connected ones just won't.

As oddbookworm stated the only sane approach is the linux one except that sometime camera may have two modes of operations and one just does not work ( usually the DMA way for USB cameras, and that's why query_image() is not to be relied upon ).

Also you have networked camera which are not supported by this interface and usually stream jpeg images continuously.

The camera interface init is also lacking an async option which can be a problem on browser where a dialog is presented to pick up ONE camera only example.

I think the camera configuration should be a graphical tool separate from pygame core. Pygame should ask for a number of camera inputs, and the tool would allow to connect them and perhaps maintains its own database ( like tools for gamepads and their databases ). And for some case the tool should handle grabbing itself and just feed raw frame to pygame.camera module.

tldr; keep it simple handle ONE camera, or use an extra module to deal with complexity, probably interfaced with opencv.