[mythtv-users] Alternatives to lossless transcode

Mark Perkins perkins1724 at hotmail.com
Tue Nov 19 04:32:27 UTC 2013


>On 14/11/2013 08:57, Paul Gardiner wrote: 
>> On 14/11/2013 05:57, mark wrote: 
>>> I've gone back and re-looked at a few segments to try and see if there 
>>> is audio out of sync (using --fifodir) - to be honest if there is it is 
>>> very very slight. The ProjectX cut file audio probably leads the video 
>>> by as much as the --fifodir audio lags the video, it is very very 
>>> slight. Probably less of a difference than what is introduced by the 
>>> transmission path and electronic processing circuits of the various 
>>> connected sound system devices. 
>> 
>> mythtranscode in --fifodir mode performs cutting carefully dropping or 
>> inserting frames to ensure the sync between the data in the two fifos 
>> is continuously maintained, so I believe that any lack of sync you are 
>> seeing has to be either a problem with the source or with 
>> mythtranscode's interpretation of the source. The outputting algorithms 
>> should in theory produce perfect results (to within a frame period). 
> 
>Oh, another thought: what are you using to play back the transcoded 
>files and seeing them slightly out of sync? 
>
>P.

Using Windows Media Player. Sorry for delayed response - had some account
problems.
Is there a program which can be used for mp4 files that shows both video
frame with audio waveform so I can pick a spot (ie a door closing) and see
the audio spike at the same time? I've used VideoReDo previously but it
doesn't support mp4. Otherwise it's up to my eyes to judge and that's not
necessarily a good thing.



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