QVideoFrame allocation is broken for pixel format YUV422P. The U & V planes only have quarter width, but they should have half width. See attached test code.

I think the commit that broke this is https://github.com/qt/qtmultimedia/commit/0a6a1883b6dde64b195a564a0c02a949d7718b25

See line 116: https://github.com/qt/qtmultimedia/commit/0a6a1883b6dde64b195a564a0c02a949d7718b25#diff-d317360aabc354bbc245ce504feb2ae70ced4592d8a7d4ee465e50bef15973deL116

where the computation of the total bytes required changes from 2*s.width()*s.height(), which is correct, to stride * ((height * 3 / 2 + 1) & ~1), which is too small and effectively halves the space left for the U & V planes. Line size is then computed based on (total size - y plane size). So I think it's sufficient to fix this computation of the total size.

Test output:

-------------------------------------------------------------------------------
QVideoFrame.plane_sizes
-------------------------------------------------------------------------------
utils-qt/tests/qvideoframe.cpp:44
...............................................................................

utils-qt/tests/qvideoframe.cpp:70: FAILED:
  CHECK( av_plane_linesize == qt_plane_linesize )
with expansion:
  640 (0x280) == 320 (0x140)
with messages:
  av_pix_fmt=yuv422p
  qt_pix_fmt=YUV422P
  width=1280, height=720
  plane=1

utils-qt/tests/qvideoframe.cpp:81: FAILED:
  CHECK( av_plane_size == qt_plane_size )
with expansion:
  460800 (0x70800) == 230400 (0x38400)
with messages:
  av_pix_fmt=yuv422p
  qt_pix_fmt=YUV422P
  width=1280, height=720
  plane=1

utils-qt/tests/qvideoframe.cpp:70: FAILED:
  CHECK( av_plane_linesize == qt_plane_linesize )
with expansion:
  640 (0x280) == 320 (0x140)
with messages:
  av_pix_fmt=yuv422p
  qt_pix_fmt=YUV422P
  width=1280, height=720
  plane=2

utils-qt/tests/qvideoframe.cpp:81: FAILED:
  CHECK( av_plane_size == qt_plane_size )
with expansion:
  460800 (0x70800) == 230400 (0x38400)
with messages:
  av_pix_fmt=yuv422p
  qt_pix_fmt=YUV422P
  width=1280, height=720
  plane=2

===============================================================================
test cases:   1 |   0 passed | 1 failed
assertions: 168 | 164 passed | 4 failed