Why so many 640 res encodes?

[kikker]

Why does it seem to be almost the standard in the community to encode with a horizontal resolution of 640 instead of maintaining a DVD's 720 resolution? Is it an issue of marginal benefits for the increased size of the file?

[BigDid]

Why does it seem to be almost the standard in the community to encode with a horizontal resolution of 640 instead of maintaining a DVD's 720 resolution? Is it an issue of marginal benefits for the increased size of the file?
Hi,

In the old :) times of ESS SAP like the very popular but very limited Philips DVP 642 (2 or 3 years ago), it had problems with QPEL, custom CQM AND more than 640 width resolution, see a test here: http://home.wi.rr.com/ntngod/dvp642_vs_dvp5140/

There is also the ongoing challenge between high resolution/low DRF vs low resolution high DRF partisans (High DRF quality means low numbers)

Autogk is more mid resolution mid DRF unless enough filesize and in this case it will be a mid to high resolution/high DRF. For some movies with low compressibility going from 640 to 720 width (and from soft to sharp matrix) would need x1,5 to x2 more filesize!

Did

[VintageGold]

I was wondering this same thing. I mean, it seems like it would make more sense, with increasing size in hard drives, and more up to date technology, that there would be a shift in this trend toward wider widths on AVI's, especially if you consider wide screen HD sets are becoming more and more prevalent. Why not preserve the width of the movie as much as possible?

[b9AcE]

For me, it has to do with the cropping.
In order to not encode any extra black pixels around the video it has to be cropped.
When there is cropping you have to resize, so that the aspect ratio error gets minimized.
Since (almost) all movies need to get at least some cropping, they also need downsizing (upsizing is not a good idea).
Downsizing from the original 720 often happens to get to 640 before reaching a (to me) acceptable aspect ratio error.