[mythtv-users] [OT] ProjectX user guide

Michael T. Dean mtdean at thirdcontact.com
Tue Nov 22 14:29:20 EST 2005

Steve Adeff wrote:

>project X is PERFECT for what your looking for. It is *meticulous* in keeping 
>video and audio output time synced.
Audio and video stay (mostly) in sync at the expense of clicks and pops 
in the audio (when audio was either deleted or inserted to maintain the 
sync).  The new mpeg2cut being integrated into SVN's mythtranscode, on 
the other hand, inserts video frames to keep the sync (but Geoffrey is 
still working on a plan for the missing audio corrections).  Since video 
never pops, this should be much less distracting.

Note, also, that I say mostly in sync because I have found that I get 
sections of recordings lasting between 5 and 30 seconds where A/V sync 
is off by as much as about 0.5 seconds.  Depending on (you and) your 
recording, you may not even notice this (if no mouths are shown or no 
dialog is in progress, it's not noticeable, and since it happens at 
"random" places throughout the stream, it's a matter of luck--which is 
bound to run out after you edit enough recordings).

Also, A/V sync can be off by quite a bit before people are likely to 
notice it; however, once a person has noticed a sync offset within a 
video, that person is much more likely to notice other instances of sync 
offset.  Basically, the threshold at which a person notices the offset 
is initially high, but once he/she has identified an offset, the 
threshold plummets--allowing the viewer to easily identify offsets far 
below the initial threshold.


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