[mythtv-users] Master on Raspbian Buster - 1280i 25Hz on a 50Hz display

[John]

mythfrontend version: master [v31-Pre-1485-g234f34b06d]
1280i 25Hz on a 50Hz display
The frontend seems to  be reading the display refresh rate incorrectly 
on Raspbian Boxer.
xrandr shows the refresh rate correctly as preferred 60 Hz and currently 
50Hz

xrandr
Screen 0: minimum 320 x 200, current 1920 x 1080, maximum 7680 x 7680
HDMI-1 connected primary 1920x1080+0+0 (normal left inverted right x 
axis y axis) 160mm x 90mm
    1920x1080     60.00 +  60.00    50.00*   59.94 30.00    25.00    
24.00    29.97    23.98
    1600x1200     60.00
    1680x1050     59.88
    1280x1024     75.02    60.02
    1440x900      74.98    59.90
    1280x960      60.00
    1280x800      59.91
    1152x864      75.00
    1280x720      60.00    60.00    50.00    50.00 59.94
    1024x768      75.03    70.07    60.00
    832x624       74.55
    800x600       72.19    75.00    60.32    56.25
    720x576       50.00    50.00
    720x480       60.00    60.00    59.94    59.94
    640x480       75.00    72.81    66.67    60.00 59.94
    720x400       70.08

mythfrontend reports the video mode as
  Display: Desktop video mode: 1920x1080 60.000 Hz

VDP: decoder<->render support: ffmpeg      null opengl opengl-yv12
VDP: decoder<->render support: v4l2        opengl-hw
VDP: decoder<->render support: v4l2-dec    null opengl opengl-yv12
VDP: decoder<->render support: mmal-dec    null opengl opengl-yv12
VDP: Ignoring profile 216 (decoder mmal is not available)
VDP: Ignoring profile 215 (decoder vdpau is not available)
Bonjour: Service registration complete: name 'MythTV on pi4' type 
'_airplay._tcp.' domain: 'local.'
Display: Available modes:
1920x1080    60.00    60.00    59.94    50.00    30.00 29.97    25.00    
24.00    23.98
1680x1050    59.88
1600x1200    60.00
1440x900    74.98    59.90
1280x1024    75.02    60.02
1280x960    60.00
1280x800    59.91
1280x720    60.00    60.00    59.94    50.00    50.00
1152x864    75.00
1024x768    75.03    70.07    60.00
832x624    74.55
800x600    75.00    72.19    60.32    56.25
720x576    50.00    50.00
720x480    60.00    60.00    59.94    59.94
720x400    70.08
640x480    75.00    72.81    66.67    60.00    59.94

and then selects FPS as 24.75
28.992390 I  AFD: Selected FPS: 24.75 (Avg:24.75 Mult:1 Codec:0 
Container:90000 Estimated:25)