[MPlayer-users] Re: mencoder/crop => image distortion

[Jonathan Rogers]

D Richard Felker III wrote:
> Or more likely they's just stupid. DVD is limited in bitrate, and you
> will reduce quality by encoding worthless junk...

That's right, if someone does it a different way than you would 
have, they must be stupid.

DVD movies have borders that vary from zero to tens of pixels. 
They vary in size from about 4.5 GB to 7.5 for a 1.5 to 2.5 hour 
movie. Newer ones are usually smaller in data size. There is also 
a significant range of quality of DVD movie transfer and 
encodings. The movies which have noticeable noise from the MPEG 
encoding are older movies, but I've seen no significant 
relationship between those three variables (borders, data size, 
and quality).

To me, this suggests that there is such a huge number of bits 
available on a DVD that no special effort is needed to get good 
quality with modern MPEG-2 encoders. The people who do the 
encoding simply don't have to waste all the time we do cropping, 
resizing, and tweaking to get the best results. Maybe they just 
have better things to do with their time.

Jonathan Rogers