AviSynth AVI resizing for creating a SVCD

[aldaco12]

Hi. I'm experiencing this strange fact, and I would like to know if usuallly happens with AVI (maybe because they are already non-interlaced. This does not happen with D2V files!).

Let's supose I have a 610 x 344 AVI movie.

I load it with this script:

AviSource("movie.avi")
LanczosResize(448,344)
AddBorders(16,116,16,116)
AddAudio()
ConvertToYUY2()

so the final image will be (448+16+16,344+116+116) = (480,576) PAL SVCD
using the whole 344 Y pixels of the AVI (adding black border to have a PAL compliant video) and taking into account the 16+16=32 pixels lost by my TV screen (no black border is seen).

What I observed is that I always keep , when I resize in this way, the aspect ratio even if I didn't take into account the aspect ratio existing in the original AVI. This is very useful, because in this way, I keep all Y AVI resolution and almost all AVI X resulution (losing only a few X pixels , the ones exceeding 448) losing almost nothing, because the command LanczosResize is very good.

My question is: why does, this, seem to happen always, on AVIs?

[stephanV]

That is just pure luck...

[aldaco12]

No, I disagree! I made a large number of SVCDs using many types of AVI : 720x384, 720x756, 576x320, 608x344 and I always had aspect ratio kept perfectly, encoding them with CCE and this simple script:

AviSource(Movie.avi)
LanczosResize(448,Y)
AddBorders(16,b,16,b)
AddAudio()
ConvertToYUY2()

with b = (576-Y)/2 .

I cannot believe it is simple luck, There's no rule I can find, to link the type of AVI I converted succesfully!

[Didée]

If you process an avi that has anamorphic content, your method definetly fails.

[aldaco12]

So it seems a feature of the input AVI only.
For instance , I noticed, if I load a DVD using a D2V, I necessary need to put 16:9 pixels (e.g. 640x360) or I don't get anything from CCE. I though that it is due to the fact that you have interlaced video, only.
But...what are those 'problematic' features, how can I detect them in my AVI and how can I correct them?