[mythtv] firestick 4k lock up with interlaced playback

John Pilkington johnpilk222 at gmail.com
Thu Dec 20 17:32:17 UTC 2018

On 18/12/2018 15:29, David Engel wrote:
> On Tue, Dec 18, 2018 at 09:56:40AM -0500, Peter Bennett wrote:
>> I have had a report of mediacodec playback locking up with interlaced h264
>> on a firestick 4k. I have been using the fire stick for a lot of playback of
>> progressive h264 without problems. It seems that interlaced content may be
>> what is causing the issue.
> FWIW, I let mine run for ~35 minutes on h.264/1080i this weekend as a
> test.  No issues found.  I can try to let it run longer this evening
> if it would help.
> David

Mine had an update on Friday, too.  With MediaCodec decoding it still 
reliably locks up at the end of the station ident on the recording (BBC 
FOUR HD, DVB-T2, Feb 2016) from which I took the clip posted earlier. 
After what seems a long time it quits  with 'Video frame buffering 
failed too many times.'

With standard decoding nothing seems wrong and the playback quality is 
excellent.  I have looked at adb log output in both cases but see 
nothing that seems unusual at the position where things lock up.


ISTR that mythtranscode used to have problems when subsidiary streams 
would suddenly start up or close.  That could perhaps be what is 
happening here.  In the sample I posted there was no obvious event in 
the main streams that coincided with the failure, but it was close to 
the end of the programme. The one I mentioned above was at the start of 
the content.  Stream analyses around the fail points might be useful; at 
present I don't know the easiest way to do that and I can't record from 
the HD channels.



is a longer file cut from a recording made this year.  It plays in 
mythfrontend on the firestick with the Standard decoder but sticks at 
'Please wait' with MediaCodec.  It plays with my nVidia card too.

And it plays with the android-for-firestick VLC, with differences in the 
picture for the various acceleration options.

Here are ffprobe results for the two clips.Sometime next year, when I've 
finished reading ffprobe --help, I might be able to look at different 
testpoints.  I'm posting only grepped results, and without the 
multicoloured error preamble.

  mythffprobe -hide_banner -v error -show_streams -show_format -of json 
firestick_test_h264.ts | grep field

             "field_order": "progressive",

  mythffprobe -hide_banner -v error -show_streams -show_format -of json 
firestick_itvHD.ts | grep field

             "field_order": "tt",


John P

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