[mythtv-commits] Ticket #13054: Video Playback vertical offset when using UseVideoModes=1 for JudderFree support

[MythTV]

#13054: Video Playback vertical offset when using UseVideoModes=1 for JudderFree
support
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 Reporter:  support@…                |          Owner:  pbennett
     Type:  Bug Report - General     |         Status:  infoneeded_new
 Priority:  minor                    |      Milestone:  unknown
Component:  MythTV - Video Playback  |        Version:  0.28.1
 Severity:  medium                   |     Resolution:
 Keywords:                           |  Ticket locked:  0
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Comment (by chrisw@…):

 Replying to [comment:26 pbennett]:
 > You have a screen size of 1920x1080 and a video of 1280x720. You set the
 video mode to 1920x1080 which is the same size as the GUI mode.

 Correct.  I really only want the mode change to match screen rate to video
 rate with the GPU hardware scaling

 > I just now tried exactly the same thing with MythTV master version and I
 see no black bar.
 > The video is full screen.
 >
 > The changes I had originally made were to address the case where the
 resolution was changed.
 > However in your case the resolution did not change.

 Correct.  Here is a version with a resolution change  (same input video)

 * VAAPI Normal
 * Settings > Appearance > Separate video modes for GUI and TV playback
 checked
 * Video output set to 1280x720 (i.e. matching the test video size and
 different to the GUI size)
 * Video playback is offset

 The debug output in SetupOpenGL() shows an adjustment.
 {{{
 Sep  2 12:21:57 mythtv mythfrontend[4341]: I CoreContext
 videoout_opengl.cpp:489 (CreatePainter) VidOutGL: Using main UI painter
 Sep  2 12:21:57 mythtv mythfrontend[4341]: I CoreContext
 videoout_opengl.cpp:384 (SetupOpenGL) VidOutGL: Before adjustment
 Sep  2 12:21:57 mythtv mythfrontend[4341]: I CoreContext
 videoout_opengl.cpp:387 (SetupOpenGL) VidOutGL: mainSize[w=1920 h=1080]
 Sep  2 12:21:57 mythtv mythfrontend[4341]: I CoreContext
 videoout_opengl.cpp:392 (SetupOpenGL) VidOutGL: dvr[l=0 t=0 w=1280 h=720]
 Sep  2 12:21:57 mythtv mythfrontend[4341]: I CoreContext
 videoout_opengl.cpp:409 (SetupOpenGL) VidOutGL: After adjustment
 Sep  2 12:21:57 mythtv mythfrontend[4341]: I CoreContext
 videoout_opengl.cpp:412 (SetupOpenGL) VidOutGL: mainSize[w=1920 h=1080]
 Sep  2 12:21:57 mythtv mythfrontend[4341]: I CoreContext
 videoout_opengl.cpp:417 (SetupOpenGL) VidOutGL: dvr[l=0 t=-360 w=1920
 h=1080]
 }}}

 > The image cannot be sitting on the bottom edge of the screen, some of it
 must be cut off,
 > because at 1280x720 it is the same shape and size as the screen, or am I
 missing something here?

 Agreed.  The 1280x720 should scale by 1.5 to exactly 1920x1080.  The
 video, while offset, is not distorted. You're not missing something, I
 was.

 > If I can recreate the problem I expect I could fix it, but nothing I do
 creates this effect.
 >
 > If you change to use OpenGL playback profile, with standard decoding
 instead of VAAPI, does anything change?

 Changing only 'VAAPI Normal' to 'OpenGL Normal' gives me the same result.
 This removes the hardware decoding but not OpenGL from play I guess.

 > I assume if you disable the separate modes for video and GUI that the
 problem goes away?

 Correct.
 * VAAPI Normal
 * Settings > Appearance > Separate video modes for GUI and TV playback
 UNCHECKED
 * Video playback is correctly positioned (full screen in this case).

 I also tried this in case we have two similar options being used in
 different places:
 * 'VAAPI Normal'
 * Settings > Appearance > !Theme/Screen Settings > Use GUI size for TV
 playback UNCHECKED
 * Settings > Appearance > Separate video modes for GUI and TV playback
 CHECKED
 * Video playback is offset

 > Could there be a broken OpenGL implementation? Perhaps some versions of
 OpenGL handle resolution changes differently?

 I guess it is possible but I see this on Intel and earlier reports have
 seen it on NVidia. It could be a breakage in Qt5 OpenGL but you might
 expect that to be universally broken. Several different Qt versions have
 been reported in this thread.

 I will try:
 * the master git branch
 * more recent Mesa and other components
 (https://01.org/linuxgraphics/downloads/2017q2-intel-graphics-stack-
 recipe)

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Ticket URL: <https://code.mythtv.org/trac/ticket/13054#comment:27>
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