|
[1.35] Why are the audio and video out of
sync?
There have been numerous reports of "lip sync"
problems, where the audio lags slightly behind the video or sometimes
precedes the video. Perception of a sync problem is highly subjective;
some people are bothered by it while others can't discern it. Problems
have been reported on a variety of players (notably the Pioneer
414 and 717 models, possibly all Pioneer models, some Sony models
including the 500 series and the PS2, some Toshiba models including
the 3109, and some PC decoder cards). Certain discs are also more
problematic (notably Lock, Stock, and Two Smoking Barrels; Lost
In Space; TRON; The Parent Trap; and Austin Powers).
The cause of the sync problem is a complex interaction
of as many as four factors
- Improper sync in audio/video encoding or DVD-Video
formatting.
- Poor sync during film production or editing
(especially post-dubbing or looping).
- Loose sync tolerances in the player.
- Delay in the external decoder/receiver.
Factor 1 or 2 usually must be present in order
for factor 3 or 4 to become apparent. Some discs with severe sync
problems have been reissued after being re-encoded to fix the problem.
In some cases, the sync problem in players can be fixed by pausing
or stopping playback and then restarting, or by turning the player
off, waiting a few seconds, then turning it back on.
A good way to test your player is to simultaneously
listen to the analog and digital outputs (play the digital output
through your stereo and the analog output through your TV). If the
audio echoes or sounds hollow, then the player is delaying the signal
and is thus the main cause of the sync problem.
Unfortunately, there is no simple answer and no
simple fix. More complaints from customers should motivate manufacturers
to take the problem more seriously and correct it in future players
or with firmware upgrades. Pioneer originally stated that altering
the audio-visual synchronization of their players "to compensate
for the software quality would dramatically compromise the picture
performance." Since then Pioneer has fixed the problem on its new
players. If you have an older model, check with Pioneer about an
upgrade.
For many more details, see Michael D's Pioneer Audio Sync
page.
|