[mythtv] OpenGL Performance problems - specific commit that causes the problem

Peter Bennett pb.mythtv at gmail.com
Thu Jan 3 21:11:18 UTC 2019


I ran a bisect. Before the below commit, UYVY playback on Fire Stick 4K 
30fps was perfect. After this commit it can only play 5 or 10 fps. Note 
that after this commit the color also went wrong, color was later fixed 
but the 5-10 fps limitation remained consistent after this commit.

commit 43b64d5c1fdb08f1334ac18fafdfa7245a23dcfa
Author: Mark Kendall <mark.kendall at gmail.com>
Date:   Tue Dec 18 08:54:40 2018 +0000

     OpenGLVideo: Remove custom UYVY packing code

      - opengl video now defaults to regular UYVY input textures.
      - this fixes the interlaced chroma upsampling bug and works around
     precision issues on some OpenGLES implementations.
      - this avoids the extra filter stage required for the old code but 
     use a larger texture in video memory
      - FFmpeg conversion is avoided (as it does not handle interlaced
     chroma) so we use our own packing code. This is MMX assisted where
      - TODO add NEON SIMD support to packing code


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