Try setting arch to x86_64

Author: WyattBlue

.github/workflows/build-ffmpeg.yml

@@ -33,7 +33,7 @@ jobs:
             arch: x86_64
             shell: bash
           - os: windows-latest
-            arch: AMD64
+            arch: x86_64
             shell: 'msys2 {0}'
             msys_prefix: mingw-w64-x86_64
             msys_system: MINGW64
@@ -69,7 +69,7 @@ jobs:
           path-type: inherit
       - name: Build FFmpeg
         env:
-          CIBW_ARCHS: ${{ matrix.arch }}
+          CIBW_ARCHS: ${{ matrix.msys_prefix && 'AMD64' || matrix.arch }}
           CIBW_BEFORE_BUILD: python scripts/build-ffmpeg.py /tmp/vendor --community
           CIBW_BEFORE_BUILD_WINDOWS: python scripts\build-ffmpeg.py C:\cibw\vendor --community
           CIBW_BUILD: cp311-*

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) 
+- Linux (x86_64, aarch64)
 - macOS (x86_64, arm64)
 - Windows (x86_64)