Build armv7

.github/workflows/build-ffmpeg.yml

@@ -93,7 +93,7 @@ jobs:
       - name: Install packages for macOS
         if: runner.os == 'macOS'
         run: |
-          brew unlink gettext libidn2 libpng libtiff libunistring libx11 libxau libxcb libxdmcp little-cms2 unbound
+          brew unlink gettext libidn2 libpng libtiff libunistring libx11 libxcb libxdmcp
           if [ "${{ matrix.os }}" = "macos-15-intel" ]; then
             brew install nasm
           fi
@@ -128,13 +128,15 @@ jobs:
 
   cross-build:
     needs: fan
-    runs-on: ubuntu-24.04
+    # armv7l is cross-compiled from an aarch64 host with the arm-linux-gnueabihf
+    # toolchain; the other arches cross-compile from x86_64.
+    runs-on: ${{ matrix.arch == 'armv7l' && 'ubuntu-24.04-arm' || 'ubuntu-24.04' }}
     strategy:
       fail-fast: false
       matrix:
         build: [ "manylinux_", "musllinux_" ]
         # arch: [ "loongarch64", "ppc64le", "riscv64", "s390x" ]
-        arch: [ "ppc64le", "riscv64" ]
+        arch: [ "armv7l", "ppc64le", "riscv64" ]
     steps:
       - uses: actions/checkout@v6
       - uses: actions/setup-python@v6

README.rst

@@ -7,7 +7,7 @@ users to easily install PyAV without perform error-prone compilations.
 
 The builds are provided for several platforms:
 
-- Linux (x86_64, aarch64, ppc64le, riscv64)
+- Linux (x86_64, aarch64, armv7l, ppc64le, riscv64)
 - macOS (x86_64, arm64)
 - Windows (x86_64, aarch64)
 
@@ -24,8 +24,8 @@ Currently FFmpeg 8.1.1 is built with the following packages enabled for all plat
 - png 1.6.58
 - webp 1.6.0
 - opencore-amr 0.1.6
-- x264 32c3b801191522961102d4bea292cdb61068d0dd
-- x265 4.2
+- x264 32c3b801191522961102d4bea292cdb61068d0dd (except armv7l)
+- x265 4.2 (except armv7l)
 
 The following additional packages are also enabled on Linux:
 

scripts/build-ffmpeg.py

@@ -86,7 +86,8 @@ def main():
     dest_dir = os.path.abspath(args.destination)
 
     machine = platform.machine().lower()
-    is_arm = machine in {"arm64", "aarch64"}
+    is_arm32 = machine in {"armv7l", "armv8l", "arm"}
+    is_arm = machine in {"arm64", "aarch64"} or is_arm32
     is_riscv = machine in {"riscv64"}
 
     use_alsa = plat == "Linux"
@@ -158,10 +159,14 @@ def main():
         "--enable-libwebp",
         "--enable-libxcb" if plat == "Linux" else "--disable-libxcb",
         "--enable-zlib",
-        "--enable-libx264",
-        "--enable-libx265",
     ]
 
+    # x264/x265 are skipped on 32-bit ARM (armv7)
+    if not is_arm32:
+        ffmpeg_package.build_arguments.extend(
+            ["--enable-libx264", "--enable-libx265"]
+        )
+
     if use_cuda:
         ffmpeg_package.build_arguments.extend(["--enable-nvenc", "--enable-nvdec"])
 
@@ -181,11 +186,13 @@ def main():
         )
 
     if plat == "Linux" and "RUNNER_ARCH" in os.environ:
+        # FFmpeg expects "arm" for 32-bit ARM, not the uname "armv7l".
+        ff_arch = "arm" if is_arm32 else machine
         ffmpeg_package.build_arguments.extend(
             [
                 "--enable-cross-compile",
                 "--target-os=linux",
-                "--arch=" + machine,
+                "--arch=" + ff_arch,
                 "--cc=/opt/clang/bin/clang",
                 "--cxx=/opt/clang/bin/clang++",
             ]
@@ -220,7 +227,11 @@ def main():
 
     if use_gnutls:
         packages += gnutls_group
-    packages += codec_group
+    if is_arm32:
+        # x264/x265 are not built on 32-bit ARM (armv7)
+        packages += [p for p in codec_group if p.name not in {"x264", "x265"}]
+    else:
+        packages += codec_group
     packages += [ffmpeg_package]
 
     # Disable runtime CPU detection for opus on Windows ARM64

scripts/install-static-clang.sh

@@ -51,7 +51,7 @@ esac
 case "${AUDITWHEEL_POLICY}-${AUDITWHEEL_ARCH}" in
 	*-riscv64) M_ARCH="-march=rv64gc";;
 	*-x86_64) M_ARCH="-march=x86-64";;
-	*-armv7l) M_ARCH="-march=armv7a";;
+	*-armv7l) M_ARCH="-march=armv7-a -mfpu=neon-vfpv3 -mfloat-abi=hard";;
 	manylinux*-i686) M_ARCH="-march=k8 -mtune=generic";;  # same as gcc manylinux2014 / manylinux_2_28
 	musllinux*-i686) M_ARCH="-march=pentium-m -mtune=generic";;  # same as gcc musllinux_1_2
 esac