[mythtv-users] transcoding using mencoder

[Craig Longman]

Jason Radford wrote:

>On Mon, 16 Jun 2003 22:27:54 -0400
>Craig Longman <craigl at begeek.com> wrote:
>  
>
>>Jason Radford wrote:
>>    
>>
>>>After fixing that and running the script it does re-encode them, but
>>>the video/audio is out of sync, which I tested on 3 different *.nuv
>>>recordings (mpeg4 ftp'ed from my myth box).
>>>
>>>      
>>>
>>how far out of sync?  about 1/3-1/2 a second, or further?
>>    
>>
>Yes, I'd say 1/2 a second or less, but you can tell the video is ahead
>of the audio.
>
>ideas?
>
i think so.  the mpeg-2 files i've been encoding, and other people have 
reported similar problems with mpeg-4 i think, seem to put the audio 
10-12 frames after the relevant video frame (as in codec frame).  this 
means that if you don't pay attention to the timestamp, you will get 
audio 10-12 frames too soon, 1/3-1/2 a second.

i had thought that mythmkmovie handled this by fudging in some black 
frames when processing cutlists, but maybe there's a problem with that. 
 i've fixed up ReencodeFile() to resync the audio and video more 
closely, as well as handle some other audio problems when actual 
conversion is taking place, but need to clean it up a bit and deal with 
non-conversion cases before submitting it.  

this might be same problem here, it sounds suspicious.

cheers,

    CraigL->Thx();