[mythtv-users] [Bulk] lossless cut question

[glen]

On 05/16/2013 06:06 PM, Doug Vaughan wrote:
> On 13-05-16 07:40 PM, glen wrote:
>> i am trying to use the scripts for hdpvr recordings only. on each 
>> occassion the resulting mkv loses audio sync gradually. on a 42 
>> minute show, it is off -300ms everytime by the end.
>>
>> if i look up the cutpoints in mythconverge, and manually calculate 
>> the timecodes and use the mkvmerge gui, and use 'split in parts based 
>> on timecodes', the resulting mkv is alway in sync. are there any 
>> changes i can make to the script to get the same result from the 
>> script ?
>>
>> thanks for any help.
>>
>> using latest mkvmerge, on mythbuntu (precises) and 0.25 fixes.
> Glen,
>     Although I use 0.26 fixes I do remember that the majority of v0.25 
> hdpvr recordings had a time sync issue of 300-340ms. Back then Iwas 
> manually cutting commercials with Avidemux2.5xand had to use mkvgui to 
> correct the sync issue. I never experienced majoraudio sync drift 
> issues as you described.
>
> My own experience with Lossless_cut and hdpvr 0.26 recordings over the 
> last severalmonths has been that some cut recordings have aconsistent 
> audio sync issue of 150ms (audio needs to be delayed). It is 
> infrequent but happens. I correct the cut video with mkvgui to apply 
> an audio delay.
>
> The only gradual audio drift I've noticed was with cut recordings 
> longer than 2hrs where the original recording duration was 3hrs+. 
> Therefore many cuts are required to pare it down to ~2hrs.The drift 
> was slight enough that it was tolarable. There is a special mkvmerge 
> command line variable you can use to compensate for gradual drift but 
> Inever tired is myself. From what I remember it is only meantfor 
> slight drift over a long time not forwhat you describe.
>
> I certainly cannot guarantee that upgrading to MythTV v0.26 fixes will 
> resolve this issue but that version includes a number of 
> improvements/fixes related to h264 encoded videos.
>
> Sorry I do not have any other suggestions at this time. My testing of 
> Lossless_Cut with MythTV v0.25 did not reveal this issue but I was 
> using hdpvr recordings that were originally made by MythTV v0.26as I 
> have a limited test environment. Maybe that accounts for the 
> dependencies.
>
> Doug

thanks for your time and efforts. for now i will just manually use the 
mkverge gtk entering in the timecodes, but when i do upgrade to 0.26 i 
will check again. i don't need to do it very often; just on a few tv 
series i retain and later use handbrake to get them to mp4 for 
compatibility to roku's (via plex) and other devices. thanks again,

> _______________________________________________
> mythtv-users mailing list
> mythtv-users at mythtv.org
> http://www.mythtv.org/mailman/listinfo/mythtv-users