DVD vs AVI format

[lordmeatball]

OK, so I'm filling up my hard drive with my DVD collection and I need more space. Can anyone tell me another format I could use which takes up less space but still has decent quality? I thought maybe I could use AVI. It has to be compatible with the media extenders.

Sorry for the n00b question.

Thanks.

[jcesare]

AVI takes up more space then MPEG. Its use case is digital video editing where it is then transcoded to mpeg for DVD buring.

[lordmeatball]

So ripping straight from DVD produces decent quality at 5 gig, would MPEG produce similar quality using less space?

[ke6guj]

Ripping straight from DVD is .vob, which is basically mpeg2, IIRC. So space usage would be the same. What jcesare meant was that uncompressed AVI is very large, but most people use XVID or Divx compression on the .avi to make a good quality file in the 800-1500meg size range from a standard dvd.

There are even newer, better compression utilities that create .mp4 files that could even be in the 500meg range. Nero Recode is one that you may want to look at.

[evilpenguin]

We're getting some terms confused here.

The video on DVD's is MPEG-2 video stored in an MPEG container. What people are talking about when they "rip" DVD's into AVI is they're taking that MPEG-2 video and translating it into another video format with better compressibility (xvid,divx,h.264) etc. and putting that into an AVI container. I recommend taking a trip over to www.doom9.org and looking in the guides sections for more details. It should get you straightened out over the terminology as well give you various options for saving space with your personal DVD's.

[stanger89]

Originally Posted by lordmeatball

OK, so I'm filling up my hard drive with my DVD collection and I need more space. Can anyone tell me another format I could use which takes up less space but still has decent quality? I thought maybe I could use AVI. It has to be compatible with the media extenders.

Sorry for the n00b question.

Thanks.

There is no definitive answer to that, it all depends on how you define "decent". Many people are happy with ~1GB rips in either MPEG-4 (ie DivX/XviD) or MPEG-4 AVC (H.264, eg "x264", Nero Digital AVC. etc).

Some people are OK with ~2GB rips. Personally, the only time I find quality even close to acceptable is once you exceed about 1/2 the size of the original (ie 2.5-3GB), and IMO at that range, the nominal space savings isn't worth the drastically increased effort.

Also, the Extender only natively supports MPEG-2, so if you convert to another format, Sage will have to transcode it back to MPEG-2 for the Extender to play.

[jprine01]

Go pretty much go by the doom9 guide for dvds to xvid (robot4rip scripts the ripping process, gordiansknot scripts the encoding)
I usually test the compression on each movie before i encode because I am quality freak. The Xvid (MPEG4) version of my dvds are generally 1.5-2.2GB and I keep the original 6 channel audio tracks.

The quality on those is almost the same as the original DVD.

[lobosrul]

I've found nero re-encode AVC to be the simplest and quickest way to encode DVD's. It far outstrips DIVX and even XVID quality wise, but isnt quite up to par with some open source x264 encoders (just way easier to use).

You can easily choose which titles you want to encode from the DVD, crop and resize them, and select up to two audio tracks, in 5.1 or stereo if you choose.

I like to encode DVD's at their full anamorphic resolution (720x480), or crop 2.35:1 video down to 720x360 (aprx). If you encode at anamorphic you must use a player than can stretch it back out again (Sage can).

At about 1.65mbps on AVC Cinema, encodes look just as good as the DVD to me. Thats about 4 to 1 compression of the video. Plus your compressing audio, and stripping out menu's and extras. So, on average, I'd estimate, your actually compressing at around 6 to 1.

[jprine01]

DVD are not at all the same bitrate as one another.
One 2 hour movie can be 3.5GB on the DVD, another 2 hour movie can be 7.5GB on the DVD.

The movie "trains plains and automobiles" the dvd is 3.5GB 6:1 compression would be 500megs or so!? I can't see that being dvd quality.
Even my simpsons episodes are 150MB and thats 20minutes with 2 channel audio.

I find the stock soundtracks are compressed enough, a full length movie with 5.1 channel audio is about 300MB worth of audio in its stock DVD format (ac3)..
If you comapare that to the typical Music MP3's on your system, your average Mp3 is 1MB per 1Minute..
120minutes x 2.5 times as many audio tracks.. 300MB

[lobosrul]

Originally Posted by jprine01

DVD are not at all the same bitrate as one another.
One 2 hour movie can be 3.5GB on the DVD, another 2 hour movie can be 7.5GB on the DVD.

The movie "trains plains and automobiles" the dvd is 3.5GB 6:1 compression would be 500megs or so!? I can't see that being dvd quality.
Even my simpsons episodes are 150MB and thats 20minutes with 2 channel audio.

No not evey DVD is exactly the same, but most newer movie DVD's are 720x480 anamorphic at about 5.5mbps. Older DVD's were sometimes made to fit into a single density disc.

I'd like to know what 2 hour movie you have that takes up 7.5 GB. Maybe a sony superbit DVD? Or there are a ton of special features.

Animated, especially something like The Simpsons, can be much more heavily compressed than live action.

Originally Posted by jprine01

I find the stock soundtracks are compressed enough, a full length movie with 5.1 channel audio is about 300MB worth of audio in its stock DVD format (ac3)..
If you comapare that to the typical Music MP3's on your system, your average Mp3 is 1MB per 1Minute..
120minutes x 2.5 times as many audio tracks.. 300MB

Mp3 audio compression, well sucks. But Nero automatically encodes the audio with AAC. I increase the bitrate to 192kbps. I have a decent 5.1 setup in my living room, and I cannot tell the difference between it and AC3, although I've never tried to.

IMHO if your trying to encode a movie to about 1200MB taking up 300MB of that with audio is a bit excessive.

[jprine01]

I'm curious how big your audio files are before spliced in with the video. 192kbps should be good!

Like I was saying before my movies are 1.5-2.2gb with the 300mb audio, i do a test encode to see how much the movie can be compressed before encode and set it to keep all the detail. If that turns out to be much over 2gb i will sacrafice some quality, all movies are different for me.

[lobosrul]

Most 5.1 AC3 tracks are 384kbps, and occasionaly 448. So encoding the audio at 192kbps, will simply save half.

For a two hour movie 192kbps would be 192/8 * 7200 / 1024 = 169MB.

[bialio]

I struggled through all of these issues recently. Here's what I landed on:

I use a free tool that lets you "reauthor" the disc onto your hard drive, selecting only the tracks that you want. So I select the main title and the main sound track only.

Convert to DivX : AutoGK (http://www.autogk.me.uk/) This lets you convert your ripped DVD to a single .avi file. This has a few options, I select the 80% quality, and fix the width the be the same as it is on DVD (720), encoding to DivX.

DivX 6.X doesn't work well with AutoGK - so I have DivX 5.2 installed on my machine.

So I end up with DivX encoded .avi files, ranging from 1.5 -> 2.2 GB in size. I don't see any hit in the quality.

btl.