[MPlayer-users] Re: can -vop scale increase the size?

[Rémi Guyomarch]

On Mon, Apr 22, 2002 at 02:41:34PM -0700, Steven M. Schultz wrote:
> [Automatic answer: RTFM (read DOCS, FAQ), also read DOCS/bugreports.html]
> Hi -
> 
> 	Can the scaling (with "-vop scale=") increase the size?   I have a 16:9
> 	DVD (NTSC with 720x480 data) that I tried converted to Divx4 using the 
> 	command:
> 
>   mencoder -dvd 1 -vop scale=854:480 -sws 2 -ovc lavc \
> 	-lavcopts vcodec=mpeg4:vhq -o title1.avi
> 
> 	the movie playback window is the right size but the movie is corrupted,
> 	slanted to the right, with diagnonal lines, and so on.    The '854'
> 	is what MPlayer scales to when playing the DVD 
> 
> 	If I maintain the 16:9 aspect ratio with the command:
> 
> 	mencoder -dvd 1 -vop scale=720:405 -sws 2 -ovc lavc \
> 		-lavcopts vcodec=mpeg4:vhq -o title1.avi
> 
> 	then the avi file plays back correctly.   The problem would seem to
> 	be scaling the width to a larger value (from 720 to 854).

I bet if you play the resulting file like that :

	mplayer -vop expand 864:-1 -vo xv title1.avi
or	mplayer -vo x11 title1.avi
or	mplayer -vo sdl title1.avi

it will play just fine.

The problem is that some XV drivers want a 8-byte aligned width or
an even stronger aligned width. At least it's true on my Radeon
VE. Even if SDL use XV for the final output, it seems to workaround
this problem.

So the fix would be to add a few pixels to the width during encoding
to let it be aligned on a 8-byte boundary or something like that. You
won't notice a few pixel wider. Or you can use "-vop expand" during
playback.

-- 
Rémi