Mapping a GPU resource for CPU read immediately after GPU write creates
a large stall on the graphics thread. Use a small circular buffer, and
read the oldest frame instead.
Removing the first call to `video_output_stop` prevents the `data_mutex`
field in `struct video_output` from being destroyed while still in use.
The `render_preview_source` function will call `video_output_lock_frame`
upon that mutex and encounter a NULL pointer exception.
Co-authored-by: Paul Hindt <paulh@aja.com>
This leads to a crash when the output is stopped, either by clicking the
stop button or when exiting OBS studio.
This crash is:
- intermittent in release builds
- reliable for me in debug builds
It is held by an `OBSData`, which, if not null, will automatically
call `obs_data_release()` on scope exit.
Code submissions have continually suffered from formatting
inconsistencies that constantly have to be addressed. Using
clang-format simplifies this by making code formatting more consistent,
and allows automation of the code formatting so that maintainers can
focus more on the code itself instead of code formatting.
