[MEncoder-users] Green boxes on non-computer DVD player

[Eli Billauer]

Hello,

I'm using mencoder to author an MPEG2 DVD (together with dvdauthor). 
Playing the DVD disc on a Hitachi DVD/Video player, I get groups of 
scattered green boxes in sporadic flashes, in particular when the scene 
shifts quickly (when the frame changes completely, and also when small 
regions change). This artifact tends to happen more in the bottom half 
of the viewed frame. On a normal movie, this happens every 30 seconds or 
so. Mplayer plays the same MPEG stream perfectly.

Other than this, a complete 90-minutes movies plays perfectly both with 
mplayer and the Hitachi machine.

The green box patterns are exactly repeatable between two discs burned 
from the same ISO image (same patterns on the same frames).

I've tried this on home-compiled Mencoder-1.0rc1-3.2.2 under x86-linux 
as well as precompiled binary for Windows (MEncoder 1.0pre8-3.4.2), 
yielding seemingly the same behaviour.

The command line used:
mencoder -oac lavc -ovc lavc -of mpeg -mpegopts format=dvd -vf 
scale=720:400,expand=720:576,harddup -srate 48000 -af 
lavcresample=48000,volume=-12 -lavcopts 
vcodec=mpeg2video:vrc_buf_size=1835:vrc_maxrate=9800:vbitrate=9000:keyint=15:acodec=ac3:abitrate=192:aspect=4/3 
-ofps 25 -o "$out.mpg" "in.avi"

It should be noted, that the real bitrate turned out to be around 
3000kbit/sec (as verified by the output file's size).

I also tried vrc_buf_size=1835:vrc_maxrate=9800:vbitrate=5000 as well as 
vrc_buf_size=300:vrc_maxrate=3000:vbitrate=1500. The former yielded more 
or less the same file size, the second a smaller file, but both suffered 
from the same green box issue.

I also used dvdunauthor to reclaim the VOBs from the DVD itself (to take 
the blame off dvdauthor). The VOB played perfectly with mplayer. I've 
also used dvdauthor with MPEGs from a difference source (video sampler) 
and that worked perfectly. So it looks like dvdauthor is not to blame.

I will gladly try to tweak some other elements, in order to help 
catching the lion in the desert. Personally, I've run out of ideas of 
what to play with.

Suggestions are mostly welcome. Even tools to check an MPEG stream's 
behaviour. Anything.

Thanks in advance,
    Eli

P.S. It appears like this problem was reported before, but was not 
solved, at least not in public:
http://lists.mplayerhq.hu/pipermail/mencoder-users/2006-July/003745.html

There are two apparently related bug reports,
http://sourceforge.net/tracker/index.php?func=detail&aid=887416&group_id=16082&atid=116082 

and 
http://sourceforge.net/tracker/index.php?func=detail&aid=978964&group_id=16082&atid=116082 


-- 
Web: http://www.billauer.co.il