Bound AudioFrame.planes by the number of planes

CHANGELOG.rst

@@ -51,6 +51,7 @@ Fixes:
 - ``FilterContext.link_to`` raises ``ValueError`` when linking filters from different graphs instead of aborting the process.
 - Filters added or linked after ``Graph.configure()`` are now configured on the next push or pull instead of segfaulting.
 - ``SubtitleCodecContext.decode(None)`` flushes the decoder instead of raising ``RuntimeError``, so delayed decoders such as EIA-608 closed captions return their final subtitle.
+- ``AudioFrame.planes`` no longer counts one plane too many for 8-channel planar audio (e.g. ``fltp`` with ``7.1``), which made ``planes``, ``to_ndarray()``, and ``from_ndarray()`` raise ``ValueError``, and no longer reads past the end of ``extended_data`` for more channels. By :gh-user:`ChandraChaan` in (:pr:`2502`).
 
 v19.0.2
 -------

av/audio/frame.py

@@ -148,8 +148,9 @@ def planes(self):
 
         :type: tuple
         """
+        nb_planes: cython.int = self.layout.nb_channels if self.format.is_planar else 1
         plane_count: cython.int = 0
-        while self.ptr.extended_data[plane_count]:
+        while plane_count < nb_planes and self.ptr.extended_data[plane_count]:
             plane_count += 1
 
         return tuple([AudioPlane(self, i) for i in range(plane_count)])

tests/test_audioframe.py

@@ -45,6 +45,17 @@ def test_manual_fltp_stereo_constructor() -> None:
     assert frame.samples == 160
 
 
+def test_manual_fltp_7_1_constructor() -> None:
+    # With 8 planes, extended_data points at the frame's data[8] array, which
+    # is not NULL-terminated: the next field is linesize[0].
+    frame = AudioFrame(format="fltp", layout="7.1", samples=160)
+    assert len(frame.planes) == 8
+
+    array = np.arange(8 * 160, dtype="f4").reshape(8, 160)
+    frame = AudioFrame.from_ndarray(array, format="fltp", layout="7.1")
+    assertNdarraysEqual(frame.to_ndarray(), array)
+
+
 def test_manual_s16_mono_constructor() -> None:
     frame = AudioFrame(format="s16", layout="mono", samples=160)
     assert frame.format.name == "s16"