Webcam resolution in VLC (and elsewhere)

[Celejar <celejar@gmail.com>]

Hi,

I'm puzzled by VLC's handling of my webcam. When I open it using
default settings, either via the GUI or CLI ('vlc v4l2://'), it opens
(according to 'Tools / Media Information / Codec') in 848x480. The
camera supports HD, however, and I can get that by 'vlc
v4l2://:width=1280:height=720' (or by making up random higher numbers
for width and height).

1) Why does VLC default to the lower resolution? Incidentally, I see
that Cheese also opens the camera by default at a lower resolution -
but a different one: 960x540. Why? Is this to save space when recording?

2) VLC's GUI doesn't seem to offer any way to set the resolution.
I see all kind of references on the internet to knobs to turn to set
resolution, but none of them seem available in my VLC when using a v4l2
camera. Why?

VLC's documentation is often terrible, and in this case, it says:

"For Video4Linux devices, you can set the name of the video and audio
devices using the "Video device name" and "Audio device name" text
inputs. The "Advanced options..." button allows you to select some
further settings useful in some rare cases, such as the chroma of the
input (the way colors are encoded) and the size of the input buffer."

https://wiki.videolan.org/Documentation:Open_Media/#Play_from_an_acquisition_card

So does this mean what I think it means? The standard settings don't
have a resolution knob, and neither do the advanced ones (which should
only be necessary "in some rare cases" anyway)?

Here's VLC's v4l2 module's (CLI) documentation:

https://wiki.videolan.org/Documentation:Modules/v4l2/

So there's no way to just tell VLC to use the highest resolution, and
the user has to somehow figure out that he has to first discover the
offered resolutions via something like lsusb or Cheese [0], and then enter
them manually via the 'width' and 'height' parameters?!

Who designed this thing's UIs? At least Cheese offers a relatively
straightforward way of setting the resolution.

[0] https://askubuntu.com/questions/214977/how-can-i-find-out-the-supported-webcam-resolutions

Celejar