[mythtv-users] Lossless Transcoding problems - Is it solvable or are there other options ?

[John Finlay]

On 10/10/2013 5:31 AM, Chris Gaskell wrote:
> I've just moved from 0.24 to 0.26 and am finding the same issues as 
> others have found with lossless transcodes.  I'm using mythtranscode 
> to cut commercials and the end of the preceding programme. I had no 
> problem in 0.24 so this is pretty frustrating.
>
> Using 0.26.0 lossless transcodes failed completely. After reading 
> previous comments I updated to 0.26.1 and found lossless transcodes 
> worked, but I lose the first few seconds of audio and according to the 
> playback info, it thought my 45 minute programme lasted 26+ hrs! 
> Furthermore, playback crashes if I try to skip forwards. I've not 
> tried it yet but I believe vlc and handbrake also don't work properly 
> with these files so it's all a bit unsatisfactory.
>
> From other threads, it seems the problems I'm seeing are a known 
> issue.  Is there any way to fix it, or can anyone recommend another 
> way of lossless commercial removal?  I'm no whizz from a terminal so 
> would like a fix that I can use from inside mythtv - maybe a user job 
> that calls ffmpeg ?
>
> Can anyone give some advice to get better results ?
>
I think that 0.27 lossless cut transcoding may work better for playback 
in mythtv than 0.26 transcoding but I still get a few missing seconds of 
sound at the beginning though seeking seems to bring the sound back. But 
when using the transcoded file as input to mythffmpeg, avconv, vlc or 
handbrake I do not get good results. In the best case the reported 
duration is wrong sometimes wildly wrong (e.g. 27h for a 30m video) and 
in the worst case handbrake and ffmpeg seem to hang until I kill the 
process. The response that I got from Mike Dean could be interpreted to 
mean that no developer is actively looking into the post-processing 
problems so I am also looking for an alternative. I have been using 0.27 
mythffmpeg to cut commercials with some success as long as I cut on 
keyframes only but the cuts are not accurate which my be a limitation of 
mythffmpeg or the mythtv editing process. At least the resulting files 
can be post-processed by avconv, ffmpeg and handbrake.

John