[mythtv-users] seeking/editing in mythfrontend

Leo Butler leo.butler81 at googlemail.com
Sat Mar 27 11:41:28 UTC 2021

Stephen Worthington <stephen_agent at jsw.gen.nz> writes:

> On Fri, 26 Mar 2021 20:50:26 -0500, you wrote:
>>I transcode my recordings to an x264-encoded video stream in a matroska
>>container. I use ffprobe to update the recordedseek table after
>>transcoding. I have been doing this for a couple years.
>>In both v0.28 and v0.29 (from the mythbuntu ppa), I was able to seek and
>>edit these mkv files without difficulty. In v0.31/fixes from the same
>>ppa, seeking and editing is broken for these transcoded files--it
>>appears that any movement in the video is only by a keyframe. Playback
>>is fine.
>>Seeking and playback in fine in vlc and ffplay, fwiw.
>>This seems like a regression to pre v0.28 behaviour.
>>Has anyone seen similar behaviour? Suggestions on how to workaround the
>>problems? Ideas about what caused the regression?
> Have you tried using the mythcommflag --rebuild option to rebuild the
> seek table using the official method?

Of course. Mythcommflag does not recognize any keyframes for a video
stream in a matroska container:

mythcommflag --chanid=1112 --starttime=20170312041000 --rebuild

MythTV Commercial Flagger, building seek table for:
    Blue Bloods - Family Business
    Rebuild started at Sat. Mar. 27 06:36:53 2021
    Rebuild completed at Sat. Mar. 27 06:38:27 2021

    2021-03-27 06:36:52.126955 C
    mythcommflag version: fixes/31
    [v31.0+fixes.202103051941.6c7c8b0351~ubuntu20.04.1] www.mythtv.org
    2021-03-27 06:36:52.126975 C  Qt version: compile: 5.12.8, runtime:
    No I-frames found, rewinding...
    2021-03-27 06:38:27.387359 E  decoding error End of file


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