[MPlayer-users] hi avi,mpg,divx,dat file size reduction

[Jack]

Upendra L. Gandhi wrote:

>HI all
>today only I have joined mailing list ..:)
>
>I need some help to reduce the size of my video files like even if sound
>intensity lowers to 1/2  or also if resolution to 1/2 than previous is ok
>how do i use mencoder for this ?
>
>reducing volume but not degrading would help i think.
>
>thank u
>upendra
>Mplyer ROCKS
>  
>

That depends on a lot of things.  If the original files are staticy, 
(vhs rips/tv capture/cheap camera) just running it through -vf denoise3d 
can shrink it a bunch.  If there's black bars on the top and bottom of 
the image, cropping those off can help.  Use -cropdetect ... a lot of 
times there's a 2 or 3 pixel wide black bar on the edge - you can't see 
it, but it steals bits.  If the video or audio is encoded with an old or 
inefficient codec, reincode it to mpeg4/Ogg/Mp3. A lot of the time, you 
can shave a lot off an old or just poorly encoded file without losing 
quality or resolution.

If I had some files that I wanted to make smaller, I'd do something like 
this:

mencoder old-big-file.avi -vf denoise3d,scale=480:320 -oac mp3lame 
-lameopts q=4:mode=1 -ovc lavc -lavcopts vhq:v4mv:trell:vqscale=3 -o 
new-small-file.avi

The online documentation is full of encoding tips... so are the 
manpages.  Try different filters, resolutions, and audio codecs (vorbis 
is very good).  Play with it - you have nothing to lose but CPU time.

-lt