[mythtv-users] mythtranscode in V31

[Jim Abernathy]

On 4/5/20 12:25 AM, David King wrote:
> 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
>
Thanks for reconfirming this.  For production work I use manual editing 
the detected commercials to build and save a cutlist. I don't use the 
built-in transcode because I have no idea what it does or how to control 
it. I created a mythtv backend job called SendTVtoNAS using a shell 
script that I found on Mythtv Forum. It does something similar to what 
you do except only uses --honorcutlist. It leaves the original file 
alone and puts the edited and compressed file (m4v) on my NAS in 
TV-Show-season-episode order. That script is a combination of 
mythtranscode and handbrake.

I was more or less testing v31 mythtranscode to see if it's working for 
RPi4. Since I can't get it working on an x86_64 system. I guess I should 
not worry about using it anyway.

 From what I've found mythtranscode is only useful as a console command 
or custom script/job and the transcode jobs in mythtv are not useful as 
setup by default.

Thanks again,

Jim A