Quality Comparison between Divx/XVid and DVD-R?

[kelemvor]

I'm looking to make a backup copy of some of my DVDs and I want to keep the best possible quality within the means I have.

I can either use a standard DVDShrink type program to make a backup and burn it to a DVD-R which usually involves at least some compression of the video to get it onto a single layer DVD-R disc...

Or I can rip the movie and use AutoGK or whatever to encode it to Divx/Xvid. If I go this route, I don't want the file to be too big so I can get more on a single hard drive.

It'd seem I can get DVD-Rs for $.40 each on sale. A 160gig hard drive can be gotten for around $40 or so on sale as well. For $40, that's 100 DVDs. So on a 160gig drive to get the same 100 movies, they'd have to be a maximum of 1.5gigs or preferably less.

Now played the DivX files from my PC I'd be limited to S-Video which might be a problem right there whereas on the DVD player I have component. But since it's being compressed anyway, that might not make as big of a difference.

This is NOT on an HD TV, just a plain old 27" CRT.

Any opinions?

Thanks.

[ronnylov]

With DVD-shrink you can reautor to a DVD with movie only and when all the extras are removed you normally don't need that much compression to fit a DVD-R that you would see any difference when backing up with DVD-Shrink.

I think you will loose more quality with divX or XviD at 1.5 GB per movie because you probably need to decrease the resolution a little bit to do that.

There are other options also. If you need to compress much with DVD-Shrink you will loose more quality than using a MPEG2-encoder like HCEnc to compress to DVD-format. I think software like DVD-Rebuilder can do it with better quality than DVD-shrink.

You can compress to x.264 format and get good quality at 1.5 GB per movie (you can probably keep original resolution) but not many standalone players can play it (it can only be watched in the PC).

You may also want to consider that if you intend to restore a DVD disc from your backup then you will loose more quality with avi format because you have to reconvert back to MPEG-2 DVD-format again... But remember that some DVD-players can play avi-files also and then you can put 2 movies per DVD-R and save even more money (compared to put them on hard disk). Of course you can play a DVD-ROM with divx/xvid files or x.264 files in your PC DVD-drive and connect the PC to the TV. So you may not need the new hard drive at all even when going this route.

If you really want the best possible quality then you should backup your DVD's to dual layer discs if they don't fit a single layer and avoid compression at all.

[guns1inger]

If you keep the movies closer to 2 GB then Divx/Xvid will be pretty damn close to your DVD originals, if you encode them well.

Do a couple of tests. Try a constant quality encode - let it run to whatever size it deems necessary - and compare this with a two pass vbr encode.

Most players will play up to 720 width and 2GB in size files.

[ejai]

I back up some of my movies to Divx using a 2 GB size setting and the video is very good, at times indistinguishable from the true DVD original.

[JaceMan]

Even at 1100 - 1400 MB with FairUse Wizard the results are near DVD quality when not viewed back on an HD device.

Sometimes I have to reduct the resolution a tiny bit, but it hasn't seemed to matter to my eyes or the eyes of my wife, friends, and family.

I use FairUse Wizard to put up to 420 (good for 3 or 4 movies) minutes of video on a DVD-R for playback in my Samsung standalone. As long as the Bits/Pixel setting remains higher than .25, 80%+ of people are going to think that your Divx/Xvid encode looks just as good as the DVD you started with. The fact is that on a standard television set, if you know what you're doing, great results can be achieved by sacrificing a "little" resolution which doesn't really hurt you since a standard set can't fully display 720x480 anyway.

[giannid]

I'd buy a dvdplayer that plays Divx (or other mp4's like Xvid). You can usually fit 3 or 4 near DVD quality Xvid films on one DVD-R which will save you space and is much more convenient than watching from your computer using an S-video cable.

I find generally that the quality of 1GB Xvid .avi is usually better than compressing a +6GB film to a 4.7 GB disc.

For widescreen sources, you can get fantastic quality using xvid, 128CBR, and about 10MB per minute, i.e. a 90 minute film = 90 x 10 = 900MB. I'd choose a fixed 720 width for widescreen sources.

For full screen, 10MB/minute may be enough quality for you. For animation it will be enough, however for others you may want a little better quality, something like 12-14MB/minute.

DVD-R backups can be nice for things like music videos, your favorite films, or something with some great menus and extras, especially if you can manage to keep the compression to a minimum. Otherwise, I would opt for Xvid.