Build FFmpeg for musllinux in addition to manylinux

Author: jlaine

.github/workflows/build-ffmpeg.yml

@@ -68,7 +68,6 @@ jobs:
           CIBW_BUILD: cp311-*
           CIBW_REPAIR_WHEEL_COMMAND_LINUX: LD_LIBRARY_PATH=/tmp/vendor/lib:$LD_LIBRARY_PATH auditwheel repair -w {dest_dir} {wheel}
           CIBW_REPAIR_WHEEL_COMMAND_WINDOWS: delvewheel repair --add-path C:\cibw\vendor\bin -w {dest_dir} {wheel}
-          CIBW_SKIP: "*musllinux*"
           CIBW_TEST_COMMAND: python -c "import dummy"
         run: |
           pip install cibuildwheel delvewheel

scripts/build-ffmpeg.py

@@ -10,6 +10,7 @@
 from cibuildpkg import Builder, Package, When, fetch, get_platform, log_group, run
 
 plat = platform.system()
+is_musllinux = plat == "Linux" and platform.libc_ver()[0] != "glibc"
 
 
 def calculate_sha256(filename: str) -> str:
@@ -211,6 +212,8 @@ def calculate_sha256(filename: str) -> str:
     Package(
         name="x264",
         source_url="https://code.videolan.org/videolan/x264/-/archive/master/x264-master.tar.bz2",
+        # assembly contains textrels which are not supported by musl
+        build_arguments=["--disable-asm"] if is_musllinux else [],
         # parallel build runs out of memory on Windows
         build_parallel=plat != "Windows",
         when=When.community_only,

scripts/cibuildpkg.py

@@ -25,7 +25,10 @@ def get_platform() -> str:
     system = platform.system()
     machine = platform.machine()
     if system == "Linux":
-        return f"manylinux_{machine}"
+        if platform.libc_ver()[0] == "glibc":
+            return f"manylinux_{machine}"
+        else:
+            return f"musllinux_{machine}"
     elif system == "Darwin":
         return f"macosx_{machine}"
     elif system == "Windows":
@@ -310,7 +313,10 @@ def _build_with_cmake(self, package: Package, for_builder: bool) -> None:
             cmake_args.append("-DCMAKE_INSTALL_NAME_DIR=" + os.path.join(prefix, "lib"))
 
         if package.name == "srt" and platform.system() == "Linux":
-            run(["yum", "-y", "install", "openssl-devel"])
+            if platform.libc_ver()[0] == "glibc":
+                run(["yum", "-y", "install", "openssl-devel"])
+            else:
+                run(["apk", "add", "openssl-dev"])
 
         # build package
         os.makedirs(package_build_path, exist_ok=True)