Add CI job that builds non-GPL ffmpeg libraries from source #4

	# Taken and adapted from torchaudio.
	# Ref: https://github.com/pytorch/audio/blob/main/.github/workflows/ffmpeg.yml
	# This job is not directly related to regular CI pipeline.
	# It is intended to create FFmpeg binaries that we upload on S3,
	# which then will be used during all the build process in CI or local.
	#
	# This job does not include the uploading part.
	# Upload needs to be done manually, and it should be done only once
	# par new major release of FFmepg.
	name: Build non-GPL FFmpeg from source

	on:
	workflow_dispatch:
	schedule:
	- cron: '0 0 * * 0' # on sunday
	pull_request: # TODO REMOVE!! This is just for testing.


	defaults:
	run:
	shell: bash -l -eo pipefail {0}

	jobs:
	LGPL-Linux-x86_64:
	runs-on: ubuntu-latest
	strategy:
	fail-fast: false
	matrix:
	ffmpeg-version: ["4.4.4", "5.1.4", "6.1.1", "7.0.1"]
	steps:
	- name: Check out repo
	uses: actions/checkout@v3
	- name: Build FFmpeg
	run: \|
	export FFMPEG_VERSION="${{ matrix.ffmpeg-version }}"
	export FFMPEG_ROOT="${PWD}/ffmpeg"

	.github/scripts/build_ffmpeg.sh

	tar -czf ffmpeg.tar.gz ffmpeg/include ffmpeg/lib

	mkdir -p artifact_dir
	mv ffmpeg.tar.gz artifact_dir/ffmpeg_${FFMPEG_VERSION}.tar.gz"
	- uses: actions/upload-artifact@v4
	with:
	name: "ffmpeg_${{ matrix.ffmpeg-version }}_linux_x86_64"
	path: artifact_dir

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