[kenelbow]

Follow up: Turning the transcoding completely off on my HDHR Plus seems to make the Live TV function of 13.1 much more stable. It doesn't seem to crash at all and channel changes are much faster and reliable (no a/v sync issues or buffering messages like I see with H.264). The video playback performance seems to be fine too -- this is surprising since the Fire TV claims to not have hardware support for the MPEG2.

Another curious observation: looking at the Codec Info data during playback shows the CPU usage about equal between H.264 (using "stf-h264" decoder) and MPEG2 playback (using "stf-mpeg2"). It seems that they are both using about 1/2 of CPU cores 0 and 1 -- and nothing on 1 and 2. I would have expected the H.264 stream to decoded in hardware and to use much less CPU than MPEG2.

For the record, if I turn MediaCodec on (and libstagefright off), everything seems to go to hell: lots of crashes, CPU usage goes way up (3 cores going pretty strong), and the "drop" frame counter goes crazy. The decoder changes to "ff-h264" and "ff-mpeg2" in that case.

Interesting. I have a similar setup and LiveTV (and recordings) have not been great. MythTV 0.27 on Ubuntu server 14.04 and HDHomeRun Plus results in the video lagging behind the audio, some times the video freezes completely while the audio continues. I also get complete crashes on occasion. This only happens on FireTV running XBMC on Windows or Linux is fine. So what settings do you use for acceleration? MediaCodec off and libstagefright on?

Yes, MediaCodec off, libstagefright on. You should be able to verify the codec being used in playback with the 'o' key (http://wiki.xbmc.org/?title=Codecinfo). I think if you see "stf-mpeg2" as the video codec, you know it's stagefright. Changing channels improved drastically with no transcoding on the HDHR Plus. It changes just as fast and smooth as Dish Network does for me now. Perhaps H.264 is harder to decode at first or more sensitive to weaker OTA signals -- which may explain its poorer behavior in some cases?

I also have audio passthrough enabled for Dolby Digital -- not sure if that mitigates the audio/video lag in some way.

I would be curious to know if you see a jump in reliability by turning transcoding off on your HDHR Plus. Part of the complication with that is network bandwidth: I've got my AFTV using ethernet and not WiFi. Not sure how WiFi can handle ~2MB/s that MPEG2 can generate.

I'll give your settings a shot. To be honest channel changing hasn't been that bad for me. Though my signals are relatively strong thanks to my roof mounted antenna. One question though. When disabling transcoding, does that mean you can no longer enable deinterlacing for 1080i ATSC channels? That my get annoying for me, but I will at least try it out. It would be better to have interlaced video than to have video that gets horribly out of sync or having XBMC crash completely. I will try it out tonight after work and report back.