Best resolution and Aspect ratio for DVD-rip choices?

[Garak128]

I always see people making DVD-rips at different resolutions and aspect ratio's. Mostly incorrect ones too. Even most programs don't even support correct resolutions..Like Fairuse. Why is this?

For best quality, youd want to maintain the resolution exactly and just encode it with a good codec like xvid at a decent bitrate.
Ofcourse you can't do this with DVD because mpeg2 stores aspect ratio values, but avi won't do that.

Plus most dvd movies are 720x480 resized to 16:9 and then letterboxed to 2.35:1 to maintain the same aspect ratio as theaters. Ofcourse that means it won't fit correctly on any TV, even widescreens, but oh well.

So what I do is maintain the width and resize/crop the height. For 2.35:1 movies that is 480 resized to 16:9 (400 pixels) then cropped to 2.35:1 (bout 306, but codec limits you to 304 or 300). Or in reverse, crop to 720x360, then resized to 720x304 as Gknot seems to do.

So you get a 720x304, top quality rip.

But now many rip programs don't even support that? They limit you to 640 width and all the width option did not even work with 2.35:1! (640x272)

Is it somehow better to use 640? Higher res always looks better to me..

Or is it better to maintain the height, and resized the width upwards?, which I believe DVD-players do. Which is like 1129x480 for 2.35:1, guess it would require a higher bitrate, but maybe produce a higher quality rip too.

I think that i right for 4:3 videos, because resizing the height would stretch it. But you could drop the width to 640, and maintain 480 height for the correct aspect ratio.

[flaninacupboard]

dvd rips (in the form od Divx or Xvid) are generally 640xwhatever because less pixels means less information to encode, means a lower bitrate can be used. and as you correctly point out a 4:3 dvd resized to 640x480 is correct to view on a 1:1 display such as a monitor. except pal dvd's which start life at 720x576, these need resizing to 768x576 for correct viewing at 4:3 or 1024x576 for 16:9.

whether you reduce 720 to 640 or not, a bigger loss is resizing 480 to 360, the even bigger loss is using a format like Divx. and at the end of it all that's your limiting factor. the mpeg4 codecs work by basically reducing optical resolution when the codec thinks it should. if the bitrate is low enough you'll end up with an image made of blocks totalling 200x100, regardless of if you started at 720 or 640.

yes, there's a lot of people out there who do a bad job of turning DVD to Divx, but so what? the original DVD is still sat on a shelf in wal mart.

[Garak128]

I just find it strange that most programs do not even support correct aspect ratios at full resolution.

Obviously mpeg4 codecs limit you the most, but adding in resizing to the mess just makes the quality that much worse.

[flaninacupboard]

i don't find it that strange, if you backup a DVD to MPEG format you can specify the right aspect ratio, if you back it up to a hacked super compressed mpeg 4 format you're stuck with 1:1.
solution, do your own backups instead of relying on other people!

[daniel T]

I suggest to use full dvd resolution, so only do some deinterlacing.
of cource that uses much more coding time but quality is better the more pixels you have. with a spezified filesize/bitrate the codec "downsizes" or blurs the image if needed - so you have full resolution in slow mowing scenes and about half resolution in fast movin ones.
i' ve testet so much. i got a 2 h ,16:9 movie with 700kb/s and 128kbmp3 (means to fit a 700 MB disc) in full resulution and it' quality in the moving scenes is ok.

[Suntan]

If you plan for playback from a computer then just crop the black borders and encode to Xvid at the original resolution. Then you can adjust the AR to whatever you want during playback (Zoomplayer).

Standalones are a different matter.

-Suntan