From owner-freebsd-multimedia  Mon Oct 28 11:22:43 2002
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Date: Mon, 28 Oct 2002 20:22:30 +0100
From: Steve O'Hara-Smith <steve@sohara.org>
To: Carl Makin <carl@stagecraft.cx>
Cc: freebsd-multimedia@FreeBSD.ORG
Subject: Re: FreeBSD 4.7R: no sound when recording with ffmpeg?
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On Mon, 28 Oct 2002 23:21:32 +1100
Carl Makin <carl@stagecraft.cx> wrote:

CM> I have a Celeron 600 and the above ffmpeg parms give me excellent
CM> video with only the occasional jerkyness,

	At what resolution ? I'm impressed if a Celeron 600 can keep
up with full resolution (720x576 for PAL).

CM> however the audio goes out
CM> of sync *very* quickly.  After 120 seconds of recording the sound is
CM> obviously wrong.  How do you keep the audio in sync?

	Erm, well, erm, it just stays in sync for me. Is the sound
slippage related to the jerkiness (I'm thinking that the video is
skipping occasional frames but the audio is complete which is what I'd
expect to happen if frame encoding overuns from time to time).

CM> Any hints?

	Not unless I can figure out a way to detect a missed frame
sync interrupt (that bit is easy enough) and sort out the resultant
mess, which would be a neat trick.

<time passed here>

	Hmm, I have an idea which seems to work. Could you try building
the port with files/grab_bsdbktr.c replaced by the one now on
ftp.sohara.org in /pub and let me know if it is any better for you.

-- 
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