provide full-fledged example for ESP camera

[rursprung]

Motivations

while the HAL provides a cam module and a minimalistic example of how to acquire raw images through that there's no example how to go from there to having processed images (JPG, YUV, etc.)

Solution

provide an example (probably in esp-hal-community) on how to use cam to acquire an image and process it from there (common use-cases include grabbing images and offering them via HTTP or storing them to an SD card), similar to what esp32-camera has in the README (but that's C code).

Alternatives

n/a

Additional context

see also this conversation on matrix

[Dominaezzz]

Just to clarify, the existing example already does JPEGs. You're just asking for an MJPEG server and a save to SD card example.

[rursprung]

note: in this issue i mentioned the lcd_cam::cam module but i was personally interested in the i2s camera support (not yet merged, see #3219). probably examples should be provided for both.

in the best case scenario instead of a simple example a proper rust-native version of esp32-camera would be provided which abstracts over the different types of cameras supported by different esp chips & boards

[Dominaezzz]

https://github.com/Dominaezzz/esp32-mjpeg

[rursprung]

i've now created a similar example for the ESP32-CAM board (based on the original ESP32 and #3219): https://github.com/rursprung/esp32-cam-test/