Add CI for Windows

Author: mthrok

.github/workflows/_build_windows.yml

@@ -56,3 +56,53 @@ jobs:
           packaging/vc_env_helper.bat            ^
             bash                                 ^
               .github/scripts/check_package.sh
+
+  unit-test:
+    if: "${{ inputs.run-test == 'true' }}"
+    name: "test ffmpeg"
+    needs: ["build"]
+    strategy:
+      fail-fast: false
+      matrix:
+        ffmpeg-version: ["4.4.2", "5.1", "6.1", "7.1", "8.0"]
+    runs-on:  "${{ inputs.os }}"
+    defaults:
+      run:
+        shell: bash -el {0}
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          persist-credentials: false
+
+      - uses: actions/download-artifact@v4
+        with:
+          name: "${{ env.ARTIFACT }}"
+          path: package
+
+      - uses: conda-incubator/setup-miniconda@v3
+        with:
+          python-version: ${{ inputs.python-version }}
+          conda-remove-defaults: "true"
+
+      - name: Unit test
+        run: |
+          if [[ "${{ inputs.free-threaded }}" == 'ft' ]]; then
+            conda install -q -c conda-forge python-freethreading
+          fi
+
+          # Install SPDL
+          pip install $(find package -name '*.whl' -depth -maxdepth 1)
+
+          # Install PyTorch and others
+          if [[ "${{ inputs.free-threaded }}" == 'ft' ]]; then
+            pip install torch numpy pytest
+          else
+            pip install torch numpy numba pytest
+          fi
+
+          # Install FFmpeg
+          conda install -q -c conda-forge "ffmpeg==${{ matrix.ffmpeg-version }}"
+
+          pytest -v \
+              tests/spdl_unittest/io/ \
+              tests/spdl_unittest/dataloader/

tests/spdl_unittest/io/audio_encoding_test.py

@@ -6,6 +6,8 @@
 
 # pyre-unsafe
 
+import os
+import sys
 from tempfile import NamedTemporaryFile
 
 import numpy as np
@@ -200,8 +202,18 @@ def test_encode_audio_integer_planar(sample_fmt):
         np.testing.assert_array_equal(hyp.T, ref)
 
 
+# On Windows GHA CI, the default mp3 encoder is `mp3_mf`, which does not
+# support s16p. `libmp3lame` seems to be not available.
+_WIN_CI = sys.platform == "win32" and "GITHUB_ACTIONS" in os.environ
+
+
 @pytest.mark.parametrize(
-    "ext,sample_fmt", [(".mp3", "s16p"), (".flac", "s16"), (".aac", "fltp")]
+    "ext,sample_fmt",
+    [
+        (".mp3", "s16" if _WIN_CI else "s16p"),
+        (".flac", "s16"),
+        (".aac", "fltp"),
+    ],
 )
 def test_encode_audio_smoke_test(ext, sample_fmt):
     """Can save audio data in commoly used format."""
@@ -234,10 +246,6 @@ def test_encode_audio_smoke_test(ext, sample_fmt):
                 sample_fmt=sample_fmt,
                 sample_rate=sample_rate,
             ),
-            # on Windows, the default might be mp3_mf, which
-            # does not support planar format.
-            # So we specify lame
-            encoder="libmp3lame" if ext == ".mp3" else None,
         )
 
         frame_size = encoder.frame_size or 1024