fails test test_reformat_pixel_format_align on PowerPC arches: ALTIVEC: Color Space RGB24

Created by: jonassmedegaard

Debian build fails testsuite on hardware architecture ppc64el:

=================================== FAILURES ===================================
___________ TestVideoFrameReformat.test_reformat_pixel_format_align ____________

self = <tests.test_videoframe.TestVideoFrameReformat testMethod=test_reformat_pixel_format_align>

    def test_reformat_pixel_format_align(self):
        height = 480
        for width in range(2, 258, 2):
            frame_yuv = VideoFrame(width, height, 'yuv420p')
            for plane in frame_yuv.planes:
                plane.update(b'\xff' * plane.buffer_size)
    
            expected_rgb = numpy.zeros(shape=(height, width, 3), dtype=numpy.uint8)
            expected_rgb[:, :, 0] = 255
            expected_rgb[:, :, 1] = 124
            expected_rgb[:, :, 2] = 255
    
            frame_rgb = frame_yuv.reformat(format='rgb24')
            array_rgb = frame_rgb.to_ndarray()
            self.assertEqual(array_rgb.shape, (height, width, 3))
>           self.assertTrue((array_rgb == expected_rgb).all())
E           AssertionError: False is not true

tests/test_videoframe.py:335: AssertionError
------------------------------ Captured log call -------------------------------
WARNING  libav.swscaler:test_videoframe.py:332 No accelerated colorspace conversion found from yuv420p to rgb24.
WARNING  libav.swscaler:test_videoframe.py:332 No accelerated colorspace conversion found from yuv420p to rgb24.
 (repeated 6 more times)
WARNING  libav.swscaler:test_videoframe.py:332 ALTIVEC: Color Space RGB24
=========================== short test summary info ============================
FAILED tests/test_videoframe.py::TestVideoFrameReformat::test_reformat_pixel_format_align
=========== 1 failed, 112 passed, 8 skipped, 43 deselected in 1.20s ============

Full build log: https://buildd.debian.org/status/fetch.php?pkg=python-av&arch=ppc64el&ver=8.0.3-1&stamp=1629295226&raw=0