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

[Giacomo Comes]

On Tue, Nov 28, 2006 at 05:45:59PM +0200, Eli Billauer wrote:
> Giacomo Comes wrote:
> 
> >mencoder -endpos $ENDPOS -oac lavc -ovc lavc -of mpeg -mpegopts
> >format=xvcd -vf scale=480:400,expand=480:576,harddup -srate 44100 -af
> >lavcresample=44100 -lavcopts
> >vcodec=mpeg2video:mbd=2:keyint=15:vrc_buf_size=917:vrc_minrate=600:vbitrate=2500:
> >vrc_maxrate=2500:acodec=mp2:abitrate=224
> >-ofps 25 -o "$2_nostrict_svcd.mpg" "$1"
> >
> >vcdimager -t vcd2 (mpg file)
> >
> OK, that worked. My DVD player was fooled to recognize the disc as VCD, 
> and was then force-fed with MPEG2 in SVCD style. Nothing I would do for 
> real life purposes, but since you're curious to know about our green 
> boxes...
> 
> >My guess now is that vstrict=0 is necessary for MPEG2 video, therefore Eli 
> >should
> >be able to see the green block if he does not use vstrict=0 with the SVCD 
> >with header trick.
> > 
> >
> And so it was: Green boxes appeared in the (fake) SVCD for which no 
> vstrict option was given. I'm under the impression that they were more 
> rare on the SVCD disc compared with plain DVD. It took some effort to 
> catch them. It seems to me that it has to do with the fact that the 
> boxes always appear in the lower part of the image, and that the SVCD 
> format's image is smaller.
> 
> But frankly, with the prices of DVD blank discs today, I see no reason 
> to use SVCD nor VCD anymore. So with this experiment coming to its 
> successful end, and a solution for the original problem handy, I think 
> it's time to leave the green boxes in peace. ;)

Agreed. Thanks anyway for the time you have spent.

Giacomo

> 
> I've been asking myself why there's a divertion from the strict standard 
> at all. Even as an option, there's always a chance that someone will 
> unawaringly turn the obscure option into default, making people all over 
> the world bang their heads trying to understand what went wrong. Is the 
> possible improvement in bitrate and/or image quality really worth it?
> 
>    Eli