Add subtitle feed filter, overlay filter and producer. #1056

	name: build-test-linux-on-push

	on: [push, pull_request]

	jobs:
	python:
	runs-on: ubuntu-latest
	strategy:
	matrix:
	python-version: ['3.7', '3.8', '3.9', '3.10', '3.11']
	steps:
	- uses: actions/checkout@v2

	- name: Set up Python ${{ matrix.python-version }}
	uses: actions/setup-python@v2
	with:
	python-version: ${{ matrix.python-version }}

	- name: Install dependencies
	run: \|
	python -m pip install --upgrade pip
	pip install flake8

	- name: Lint with flake8
	run: \|
	# stop the build if there are Python syntax errors or undefined names
	flake8 . --count --select=E901,E999,F821,F822,F823 --show-source --statistics

	build-cmake:
	runs-on: ubuntu-22.04
	steps:
	- uses: actions/checkout@v2

	- name: Build C/C++ with CMake
	env:
	DEBIAN_FRONTEND: noninteractive
	run: \|
	sudo sed -i '/^#\sdeb-src /s/^#//' "/etc/apt/sources.list"
	sudo apt-get -qq update
	sudo apt-get -yqq build-dep mlt
	sudo apt-get -yqq install cmake ninja-build kwalify
	cmake -D CMAKE_BUILD_TYPE=Debug -D BUILD_TESTING=ON -D SWIG_PYTHON=ON -S . -B build -G Ninja
	cmake --build build
	sudo cmake --install build

	- name: Run tests
	env:
	DEBIAN_FRONTEND: noninteractive
	LD_LIBRARY_PATH: /usr/local/lib
	run: \|
	sudo locale-gen de_DE.UTF-8
	cd build && ctest --output-on-failure

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