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Date: Mon, 22 Dec 1997 13:10:21 -0500
From: Randall Hopper <rhh@ct.picker.com>
To: Luigi Rizzo <luigi@labinfo.iet.unipi.it>
Cc: hasty@rah.star-gate.com, multimedia@FreeBSD.ORG
Subject: Re: MPEG audio/video sync & Re: These mtv video pauses are murder
References: <19971222121942.13340@ct.picker.com> <199712221632.RAA02664@labinfo.iet.unipi.it>
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Luigi Rizzo:
 |well my point was that the right (I would even say "the only") approach
 |to get timing info in a video+audio steam is to use the audio sample
 |clock. It makes life easier in the reproduction phase since it is much
 |easier then to keep video in sync.
 |
 |Probably my previous posting was confused enough to obscure the above
 |point.

Oh ok.  Now I see what you mean.  That's a good point.  Rather
than clock to "realtime" and assume that the sound driver is going to
faithfully record (& then play) 44.1KHz samples at "exactly" 44.1Khz.  Clock
to the audio, so if the associated driver happens to record or play a
little slower/faster, the video still stays in sync.

I'll browse around over the holidays and see what I can find out about MPEG
audio/video sync options (the PTS field Pete mentioned, etc.).

Randall