Pixelation or Macro Blocking of video from Tivo on Mac playback

When I use cTivo, I have noticed that my PBS transfers, i.e., Vera, from my Roamio Tivo to my Mac (macOS Sierra 10.12.4) are suffering from random picture breakup and macro blocking of the picture. This lasts about 2 seconds and repeats randomly with a mean interval of about 20 to 30 seconds. This macro blocking occurs both on the Mac and also on Apple TV with the iTunes library. I am using the H.264 High Quality format with cTivo version 2.5.1. The other movies transferred from channels...

Pixelation or Macro Blocking of video from Tivo on Mac playback

Pixelation or Macro Blocking of video from Tivo on Mac playback