[mythtv-users] mythtranscode in V31

[David King]

On 4/4/20 2:41 PM, James Abernathy wrote:
> I guess a detected commercial list is different from a cut list???? 

True, they are indeed two separate things.  The "mythutil --gencutlist
..." command-line utility can be used to automatically generate a
cutlist from the commercial marks.  But this would require a custom
transcoding script, and since you're still going to manually edit the
file to adjust the location of the cuts anyway, mythutil probably isn't
an answer for you.

I have a custom script that I use to do sort of the same thing that you
are doing, except that my ultimate target is to put the cleaned up
recording into a TV Series/Season folder in the Videos part of MythTV,
not to have it replace the original recording file.  One of the things I
learned when doing this is that the cuts made by running "mythtranscode
--honorcutlist" outputing into a file aren't precise.  These cuts are
made at keyframe boundaries.  So, when you're editing your recording, if
you're putting your cut points on individual frames that are in between
the keyframes, this level of precision is going to be lost when these
recordings are transcoded.  The way to make precise frame-level cuts is
to use the "mythtranscode --cleancut" option.  The problem with that
option is that it requires that the output be directed into FIFO pipes,
one for the audio and one for video.  Something else has to be running
at the other end of those pipes, ffmpeg for example, reading the data
from the pipes and encoding it into a video file.  Once again, this
means writing your own script.

If you decide to go that route:

Here's a template for a custom transcoding script:
https://www.mythtv.org/wiki/Transcode_wrap

Here's the script that I use to transcode a recording into a video
file.  It has lots of extraneous stuff in it that you might not care
about, but it does show how I did the mythtranscode
--cleancut->pipes->ffmpeg->file thing that I described above:
https://github.com/dlk3/recording2video

David King
dave at daveking dot com