#6 Soft scale

[Gaspard Petit]

From an email I received:

I have a few questions or suggestions related to
the aspect ratios of
DVDs:

AFAIK all PAL DVDs come with a resolution of 720
x 576 pixels which is
an
aspect ratio of 4:3. If the movies is encoded with
an aspect ratio of
16:9
it's simply stretched horizontally, creating
rectangular pixels on
screen.
The output resolution is then exactly 1024 x 576
pixels (16:9).

I found that QuickTime is also able to do the same
stretching with any
movie. So you could simply convert a DVD pixel by
pixel into a QT movie
keeping the resolution of 720 x 576 pixels and then
set the playback
size
to 1024 x 576 to get the correct aspect ratio back.
For widescreen you
just keep the width and crop the height, but let's
keep it simple here
first.

That's in QuickTime Player under Movie -> Get
Movie Properties, Video
Track -> Size. When you click on "Adjust" some red
controllers appear
inside the Player window that allow you to stretch
(and sheer) the
movie
to any dimensions.
So you can get the properties to say

Normal: 720 x 576 pixels
Current: 1024 x 576 pixels

Using this QT feature you can retain the DVD
aspect ratio without
adding
pixels to the QT movie's resolution.
Now I've done some tests and I found that using
QT to do the scaling
for
the aspect ratio at playback time

- creates considerably smaller files
- yields a much better playback rate
- produces better quality

So how can I do this in MediaPipe: Keep the pixels
as they are and then
just add the scaling info to the QT header?
So far I could only get it to create movies with
square pixels, so
adding
to the resolution. Or is this already inplemented
and I simply didn't
get
it... 8-)
--
TIA,
Norbert