[mythtv-users] mythtranscode crashes on a .ts HD file
John Pilkington
johnpilk222 at gmail.com
Mon Jan 14 13:04:54 UTC 2019
On 14/01/2019 12:03, Stefan Davids wrote:
> On 14-01-2019 10:43, UB40D wrote:
>> On Sun, 13 Jan 2019 at 17:45, Stefan Davids <mythtv at stefan.davids.uk.net>
>> wrote:
>>
>>>
>>> To use mythtranscode on h264 with a cutlist you need to use it in fifo
>>> mode to output raw video which can then be transcoded by ffmpeg or
>>> similar reading from the fifos. Or generate the cutlist via mythutil
>>> and just use ffmpeg directly to cut out those bits and concatenate it
>>> together.
>>>
>>
>> Groan.
>
> It's not too hard when the script is written since it lends itself to
> automation...
>
>>> If you're familar with perl there's an example I use here at
>>> http://git.netscum.org.uk/stefan/h264_fifo/src/master/transcode_perl or
>>> there are many other examples in shell script or python around (at least
>>> two on the mythtv website).
>>>
>>
>> Thank you. I am not familiar with Perl and would understand more from a
>> shell or Python script. Which ones do you mean? I've done a bit of
>> searching of the website and there's a hodgepodge of scripts at
>> https://www.mythtv.org/wiki/Transcode_Video, none of which says clearly
>> whether it works for HD.
>
> the ones I was thinking of are:
>
> https://www.mythtv.org/wiki/H264_commercial_remover_and_remuxer
>
> which uses a shell script to chop up the file via ffmpeg. That
> should be completely lossless but putting the bits back together
> possibly isn't. Also
>
> https://www.mythtv.org/wiki/Example_Script_using_mythtranscode_in_fifodir_mode
>
>
> shows mythtranscode working in fifo mode. I remembered it as python
> but it's ruby apparently....
>
> I'm happier with perl so I reworked those as examples into something
> I use.
>
>>> It seems almost impossible to get the cutting exactly right though for
>>> h264 though.
>>
>> Pity. If it has to be such a faff I may give up on doing it on Linux and
>> may resort to Premiere, for the few things I really need to export for
>> work.
>
> I think there has been Linux video editing software recommended for this
> sort of thing before but I've never used it, can't remember what it's
> called
> and don't know if it's any better. I think you need to potentially remux
> to move keyframes around to get cutting perfect with h264 which I've never
> worked out if ffmpeg will do.
>
> Usually I end up doing the cut close to where it should be with my script
> and then edit the new file again in mythtv to remove what remained.
> I'm sure there are better workflows though!
>
> Stefan
I hadn't seen the script from the mythtv forum, and maybe that will work
for you. Last year I tried vidcutter, which has its own editor/viewer,
but it was unable to handle the non-AV streams in my DVB-T2 recordings.
Things may have changed since then.
John P
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