[mythtv-users] Low-info picture leads to audio breakup

[Paul Gardiner]

Anyone else seen this: most of the time playback on my FE is
perfect, but every time the picture fades to black, or blooms
to white, the audio stutters. In fact the stutter is just a little
before the fade or bloom is visible on screen. It seem to
be a problem with the image being simple, perhaps with
the bit rate being low. I've also heard of people having trouble
with cartoons, which could be a variant of the same problem,
I guess. All my content is PAL-I SD.

My BE to FE connection is WiFi, but it can't be lack of bandwidth
because normal busy images playback perfectly.

I had a theory, although based on no knowledge of the source. It
could be that somewhere in the path between BE and FE there's
a largish buffer that is passed only when full. When the content
is very simple, and the bit rate very low, it takes a great many
frames to fill the buffer, so the buffer causes a long latency.
If that were the case, then padding unusually small I-frames should
solve the problem.

Interestingly, one of my old DVRs when using an early firmware
release would sometimes get stuck with no picture after a fade
to black.

Paul.