Add support for RGBA capture for Windows software encoding

[cgutman]

Description

This PR adds support for RGBA capture for software encoding on Windows. Previously, DWM had to convert RGBA desktop surfaces to BGRA for our capture code, which causes additional load on the system and reduces performance.

I pulled in the changes from @psyke83 's old PR #522 for handling RGB surfaces in video.cpp with modifications to work with the current code.

Screenshot

Issues Fixed or Closed

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Dependency update (updates to dependencies)
• Documentation update (changes to documentation)
• Repository update (changes to repository files, e.g. .github/...)

Checklist

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have added or updated the in code docstring/documentation-blocks for new or existing methods/components

Branch Updates

LizardByte requires that branches be up-to-date before merging. This means that after any PR is merged, this branch
must be updated before it can be merged. You must also
Allow edits from maintainers.

• I want maintainers to keep my branch updated

[cgutman]

Looks like the color conversion isn't correct on this one when in RGBA capture mode

[ns6089]

Looks like the color conversion isn't correct on this one when in RGBA capture mode

How incorrect are we talking here, tolerable or intolerable level? Or it's just a matter of changing our color conversion shaders.

[cgutman]

How incorrect are we talking here, tolerable or intolerable level? Or it's just a matter of changing our color conversion shaders.

Noticable, which is too much. This codepath isn't actually using shaders. It's using sws_scale() for software color conversion and scaling.

I think I know how to fix it, but I want to also change the way we use swscale to take advantage of the new threaded swscale support in FFmpeg. Color conversion is the currently by far the biggest bottleneck for software encoding, since it's a single thread operating individually on every pixel in an entire frame.

[LizardByte-bot]

This PR is stale because it has been open for 90 days with no activity. Comment or remove the stale label, otherwise this will be closed in 10 days.

[LizardByte-bot]

This PR was closed because it has been stalled for 10 days with no activity.