[mythtv] Fwd: MythTV Kernel HW GL Deinterlacer

[Peter Bennett]

-------- Forwarded Message --------
Subject: 	MythTV Kernel HW GL Deinterlacer
Date: 	Thu, 29 Nov 2018 16:36:38 -0600
From: 	David Engel <david at istwok.net>
To: 	Peter Bennett <pb.mythtv at gmail.com>, Mark Spieth 
<mark at digivation.com.au>



FYI, I tried but failed to figure out the OpenGL, kernel deinterlacer
issue. I decided to reach out to Mark Kendall. He originally wrote
the code in question but left the project several years ago under very
acrimonious circumstances. He replied and also offered some
additoinal comments about the current state of openglvideo.cpp. Here
is that email discussion so far. Feel free to jump in.

David

-- 
David Engel
david at istwok.net

David

Thank you for copying us on that. I have done very little OpenGL, and I 
also tried to understand the MythTV OpenGL code, but largely failed. 
There are multiple layers to it. The way the OpenGL code gets modified 
by the C++ code makes it more difficult for me to figure it out.

My current dilemma is that the OpenGL is too slow for some devices. On 
the fire stick (non-4K), it decodes fast enough, but in rendering at 
1080 30fps it drops 50% of frames or more. Perhaps if all of the 
optional OpenGL processing was removed and it just had to display the 
textures it would work at full speed. I believe there is a lot of OpenGL 
code for things like format change, color adjustment that may be slowing 
it down.

I also need to figure out how to move the image directly from the 
decoder to the display without going through memory for mediacodec, 
vaapi2 and cuda. This may be key to displaying 4K video at 50 fps.

4K video has the option of 10bit which enhances the number of colors and 
is not supported by MythTV OpenGL. The 10bit images are currently 
translated down to YUV before being displayed. This needs to be fixed. 
Hopefully if the images moved directly from decoder to texture this 
would be handled.

Peter
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From: David Engel <david at istwok.net>
Subject: MythTV Kernel HW GL Deinterlacer
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From: Mark Kendall <mark.kendall at gmail.com>
Subject: Re: MythTV Kernel HW GL Deinterlacer
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From: David Engel <david at istwok.net>
Subject: Re: MythTV Kernel HW GL Deinterlacer
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