Update to ffmpeg5

[brad-richardson]

Description

Attempt at moving at least Windows to ffmpeg5, most of these changes were pulled from #50. I additionally updated all the CBS headers to the latest from the ffmpeg5 branch.

Notes:

• After my changes, I couldn't get curl to link without the #define CURL_STATICLIB, not sure why that became a problem but found that solution here: https://stackoverflow.com/questions/54587853/c-curl-undefined-reference-to-imp-curl-easy-init-codeblocks
• I'm out of my element here, so unsure how to verify I'm actually running ffmpeg5 and not encountering a weird link to ffmpeg4 somewhere
• Tested on Win11 with an Intel Arc A750, so no hardware encode

TODO:

• Test Linux
• Test hardware encode
• Merge with changes from Bump ffmpeg from 4.4 to latest #402 ?

Issues Fixed or Closed

• Resolves FFMPEG dependency update #44

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)
• Documentation update (changes to documentation)
• Repository update (changes to repository files)

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

[CLAassistant]

All committers have signed the CLA.

[ReenigneArcher]

Thanks for submitting this PR!

In addition the specific line comments, I have a few more.

1. Can we add the cbs stuff as a submodule? Seems weird if the files are just copied and pasted into here.
2. The #402 PR you mentioned is just moving to ffmpeg5 for the AUR package. It's not ready to use and I don't really have time to play with it much. Ideally, all the ffmpeg5 updates could be moved to your PR. Macports build is already using ffmpeg5 I believe.
3. I'm not 100% sure if the version in our ffmpeg-prebuilt repo is ffmpeg5 or not, but I'd bet it is due to the published date.
4. ffmpeg-prebuilt should probably have some attention given to it, to:

• Have a more consistent workflow/build process.
• Ensure the Linux version is sufficient for Sunshine needs.
• Actually use the Linux version.
• Add a macOS version, and use it as well.

5. Can we statically link ffmpeg (and maybe all dependencies)? Users are going to have a tough time with a linux distro that doesn't include ffmpeg5 if we don't.

[ReenigneArcher]

I'm confused why this is needed since your changes don't affect that. I guess it's an isolated build issue? But if it improves the build I'm okay with keeping it.

[psyke83]

This define is probably necessary, but as of the merging of #216, it's already added via cmake through ${CURL_STATIC_CFLAGS}: https://github.com/LizardByte/Sunshine/blob/nightly/CMakeLists.txt#L94

This should therefore be unnecessary on latest nightly.

[ReenigneArcher]

By the way, I was also investigating moving ffmpeg (and potentially other dependency) building over to this repo (https://github.com/LizardByte/build-deps).

See here: https://github.com/LizardByte/build-deps/blob/master/.github/workflows/build-ffmpeg.yml (just Linux so far, and don't know if it has everything required for Sunshine).

If you're on our discord server, we can discuss some things there a little easier. https://app.lizardbyte.dev/discord

[brad-richardson]

Closing in favor of #509