[MPlayer-users] mencoder mpeg2->divx audio delay question

[Steven M. Schultz]

Hi!

	Something odd happened when using mencoder to convert a mpeg-2 movie
	this morning. 

	The movie is ftp://movie0.archive.org/pub/movies/mpeg2/19150.mpg

	MPlayer works fine with the original file - A/V sync is perfect.

	After creating the .avi with:

----------
#!/bin/sh

rm -f frameno.avi lavc_stats.txt

mencoder 19150.mpg -oac mp3lame -lameopts vbr=3:br=128:q=4 \
	-ovc frameno -o frameno.avi

mencoder 19150.mpg -oac copy -lameopts vbr=3:br=128:q=4 \
	-ovc lavc -lavcopts \
	vcodec=mpeg4:vbitrate=2500:vhq:vmax_b_frames=4:keyint=150:vpass=1 \
	-o 19150.avi

mencoder 19150.mpg -oac copy -lameopts vbr=3:br=128:q=4 \
	-ovc lavc -lavcopts \
	vcodec=mpeg4:vbitrate=2500:vhq:vmax_b_frames=4:keyint=150:vpass=2 \
	-o 19150.avi

# then use "mplayer -aspect 4:3 19150.avi" to play it back
---------

	the A/V sync is ~-300ms off.  Using "mplayer -delay -0.300 19150.avi"
	(or using the '-' key 3 times) results in correct playback of the 
	divx movie.

	Mencoder has the '-audio-delay' option but that does not accept
	negative values.

	Where is the 300ms gap being introduced I wonder?   MPlayer works
	fine but encoding somehow introduced a delay.

	Steven Schultz
	sms at 2bsd.com