QSV hardware encoding

[brad-richardson]

Description

Initial support for Intel Quick Sync Video. This will use the libmfx/mediasdk route for now as FFmpeg 5.1 does not have oneVPL.

This is mostly copied from the work done on #77 plus a few of the mentioned fixes as best as I could interpret them.

Currently using a test build of the ffmpeg libraries from LizardByte/build-deps#56 (third-party/test/ffmpeg-windows-x86_64)

TODO:

• Get it working 🙃
• Update docs
• Web changes

Issues Fixed or Closed

• Resolves Is it not possible to host through Intel igpu on Windows? #436

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