media-playback: Fix possible crash if frame width or height is zero

[RytoEX]

Description

If a frame has a width or height of zero, this value will make it into libobs/media-io/video-frame.c:video_frame_init and cause linesizes or heights to be zero, which will result in a bmalloc(0) call and OBS will crash.

Instead of letting the call stack get that far, check the frame width and height here at the source, log an error, and return early if the frame width or height are zero.

Motivation and Context

https://obsproject.com/logs/3ApOqPpoBR2XcHqO
2025-03-30 23-01-46-1.txt

See also:

• win-dshow: Fix possible crash if frame width or height is zero #11861

How Has This Been Tested?

Tested locally by forcing width or height to zero to see if OBS crashes or not.

I have not been able to spontaneously reproduce this crash otherwise.

Types of changes

• Bug fix (non-breaking change which fixes an issue)

Checklist:

• My code has been run through clang-format.
• I have read the contributing document.
• My code is not on the master branch.
• The code has been tested.
• All commit messages are properly formatted and commits squashed where appropriate.
• I have included updates to all appropriate documentation.