Fix resampler for ffmpeg 6

To get ffmpeg 6 to work, we need to set AVFrame.channels. This does not exist in FFmpeg 7, and worse yet, Cython's compile time is terrible. 
To get the builds working for both 6 and 7, we implement our own comptime in scripts/comptime.

.github/workflows/smoke.yml

@@ -142,6 +142,7 @@ jobs:
         . $CONDA/etc/profile.d/conda.sh
         conda activate pyav
         python scripts\\fetch-vendor.py --config-file scripts\\ffmpeg-${{ matrix.config.ffmpeg }}.json $CONDA_PREFIX\\Library
+        python scripts\\comptime.py  ${{ matrix.config.ffmpeg }}
         python setup.py build_ext --inplace --ffmpeg-dir=$CONDA_PREFIX\\Library
 
     - name: Test

Makefile

@@ -1,5 +1,5 @@
 LDFLAGS ?= ""
-CFLAGS ?= "-O0"
+CFLAGS ?= "-O0 -Wno-incompatible-function-pointer-types"
 
 PYAV_PYTHON ?= python
 PYAV_PIP ?= pip

av/audio/frame.pyx

@@ -47,6 +47,7 @@ cdef class AudioFrame(Frame):
         self.ptr.nb_samples = nb_samples
         self.ptr.format = <int>format
         self.ptr.ch_layout = layout
+        # [FFMPEG6] self.ptr.channels = layout.nb_channels  # ffmpeg 6 only
 
         # Sometimes this is called twice. Oh well.
         self._init_user_attributes()

include/libavcodec/avcodec.pxd

@@ -378,6 +378,8 @@ cdef extern from "libavcodec/avcodec.h" nogil:
 
         int nb_samples  # Audio samples
         int sample_rate  # Audio Sample rate
+        # [FFMPEG6] int channels
+
         AVChannelLayout ch_layout
 
         int64_t pts

scripts/build

@@ -21,4 +21,5 @@ which ffmpeg || exit 2
 ffmpeg -version || exit 3
 echo
 
+"$PYAV_PYTHON" scripts/comptime.py
 "$PYAV_PYTHON" setup.py config build_ext --inplace || exit 1

scripts/comptime.py

@@ -0,0 +1,30 @@
+import os
+import sys
+
+def replace_in_file(file_path):
+    try:
+        with open(file_path, "r", encoding="utf-8") as file:
+            content = file.read()
+
+        modified_content = content.replace("# [FFMPEG6] ", "")
+
+        with open(file_path, "w") as file:
+            file.write(modified_content)
+    except UnicodeDecodeError:
+        pass
+
+
+def process_directory(directory):
+    for root, dirs, files in os.walk(directory):
+        for file in files:
+            file_path = os.path.join(root, file)
+            replace_in_file(file_path)
+
+if sys.platform == "win32":
+    is_6 = sys.argv[1].startswith("6")
+else:
+    is_6 = os.environ.get("PYAV_LIBRARY").startswith("ffmpeg-6")
+
+if is_6:
+    process_directory("av")
+    process_directory("include")

tests/test_audioresampler.py

@@ -68,53 +68,54 @@ def test_matching_passthrough(self):
         oframes = resampler.resample(None)
         self.assertEqual(len(oframes), 0)
 
-    # TODO: Fails on ffmpeg 6
-    # def test_pts_assertion_same_rate(self):
-    #     av.logging.set_level(av.logging.VERBOSE)
-    #     resampler = AudioResampler("s16", "mono")
-
-    #     # resample one frame
-    #     iframe = AudioFrame("s16", "stereo", 1024)
-    #     iframe.sample_rate = 48000
-    #     iframe.time_base = "1/48000"
-    #     iframe.pts = 0
-
-    #     oframes = resampler.resample(iframe)
-    #     self.assertEqual(len(oframes), 1)
-
-    #     oframe = oframes[0]
-    #     self.assertEqual(oframe.pts, 0)
-    #     self.assertEqual(oframe.time_base, iframe.time_base)
-    #     self.assertEqual(oframe.sample_rate, iframe.sample_rate)
-    #     self.assertEqual(oframe.samples, iframe.samples)
-
-    #     # resample another frame
-    #     iframe.pts = 1024
-
-    #     oframes = resampler.resample(iframe)
-    #     self.assertEqual(len(oframes), 1)
-
-    #     oframe = oframes[0]
-    #     self.assertEqual(oframe.pts, 1024)
-    #     self.assertEqual(oframe.time_base, iframe.time_base)
-    #     self.assertEqual(oframe.sample_rate, iframe.sample_rate)
-    #     self.assertEqual(oframe.samples, iframe.samples)
-
-    #     # resample another frame with a pts gap, do not raise exception
-    #     iframe.pts = 9999
-    #     oframes = resampler.resample(iframe)
-    #     self.assertEqual(len(oframes), 1)
-
-    #     oframe = oframes[0]
-    #     self.assertEqual(oframe.pts, 9999)
-    #     self.assertEqual(oframe.time_base, iframe.time_base)
-    #     self.assertEqual(oframe.sample_rate, iframe.sample_rate)
-    #     self.assertEqual(oframe.samples, iframe.samples)
-
-    #     # flush
-    #     oframes = resampler.resample(None)
-    #     self.assertEqual(len(oframes), 0)
-    #     av.logging.set_level(None)
+    def test_pts_assertion_same_rate(self):
+        import av
+
+        av.logging.set_level(av.logging.VERBOSE)
+        resampler = AudioResampler("s16", "mono")
+
+        # resample one frame
+        iframe = AudioFrame("s16", "stereo", 1024)
+        iframe.sample_rate = 48000
+        iframe.time_base = Fraction(1, 48000)
+        iframe.pts = 0
+
+        oframes = resampler.resample(iframe)
+        self.assertEqual(len(oframes), 1)
+
+        oframe = oframes[0]
+        self.assertEqual(oframe.pts, 0)
+        self.assertEqual(oframe.time_base, iframe.time_base)
+        self.assertEqual(oframe.sample_rate, iframe.sample_rate)
+        self.assertEqual(oframe.samples, iframe.samples)
+
+        # resample another frame
+        iframe.pts = 1024
+
+        oframes = resampler.resample(iframe)
+        self.assertEqual(len(oframes), 1)
+
+        oframe = oframes[0]
+        self.assertEqual(oframe.pts, 1024)
+        self.assertEqual(oframe.time_base, iframe.time_base)
+        self.assertEqual(oframe.sample_rate, iframe.sample_rate)
+        self.assertEqual(oframe.samples, iframe.samples)
+
+        # resample another frame with a pts gap, do not raise exception
+        iframe.pts = 9999
+        oframes = resampler.resample(iframe)
+        self.assertEqual(len(oframes), 1)
+
+        oframe = oframes[0]
+        self.assertEqual(oframe.pts, 9999)
+        self.assertEqual(oframe.time_base, iframe.time_base)
+        self.assertEqual(oframe.sample_rate, iframe.sample_rate)
+        self.assertEqual(oframe.samples, iframe.samples)
+
+        # flush
+        oframes = resampler.resample(None)
+        self.assertEqual(len(oframes), 0)
+        av.logging.set_level(None)
 
     def test_pts_assertion_new_rate_up(self):
         resampler = AudioResampler("s16", "mono", 44100)