Compressing my DVD backups?

ImpossibleDuck

Hi, I'm planning on backing up my DVD collection to my hard drive, so that I can make a new copy if any disc stops working or whatever. Some of these DVD's have up to 2GB of data on them and I was wondering if there is anyway of compressing the file size by a considerable amount so that they don't take up as much space on my hard drive. I've tried 7Zip and WinRAR but both have about a 98% compression ratio, which is so high that it's not even worth doing. Is there anyway to significantly reduce the file size for now and be able to un-compress (de-compress?) the files later if I want to make another hard copy.

Can anyone shed some light on the situation?

mp22

Convert them to mp4's

ImpossibleDuck

mp22 wrote: »

Convert them to mp4's

How much difference will this make? Just a rough number off the top of your head. 2GB to what?

Thanks

mp22

2 gb should be able to go 7 to 800 mb

Agent67

Sorry for jumping in, but what software are you using to copy the dvds and i am having trouble with the copy process as in the film is split into three or four parts. thanks

Voodu Child

What kind of DVDs are they? Commerical DVDs (ie movies) use MPEG-2 and most are about 4-6GB......are you sure yours are only 2GB?

ImpossibleDuck

mp22 wrote: »

2 gb should be able to go 7 to 800 mb

That would be brilliant!

Agent67 wrote: »

Sorry for jumping in, but what software are you using to copy the dvds and i am having trouble with the copy process as in the film is split into three or four parts. thanks

I'm using DVD Shrink. Great program.

Voodu Child wrote: »

What kind of DVDs are they? Commerical DVDs (ie movies) use MPEG-2 and most are about 4-6GB......are you sure yours are only 2GB?

Yeah movies. I decided to use my longest one as an example -- Apocalypse Now Redux (about 200mins or 3 and a half hours) -- and it was 1.9GB and about 25MB of other stuff (subtitles, menus etc.)

Voodu Child

ImpossibleDuck wrote: »

Yeah movies. I decided to use my longest one as an example -- Apocalypse Now Redux (about 200mins or 3 and a half hours) -- and it was 1.9GB and about 25MB of other stuff (subtitles, menus etc.)

I have Apocalypse Now Redux on DVD, and the disc is nearly 8GB. The feature film and one English audio track is 6.8GB

Where are you getting your figures from? Windows explorer? Have you already ripped it to your HDD? If it genuinely is 1.9GB it means you've already compressed it during the ripping stage, do you know what codec you used?

ImpossibleDuck

Voodu Child wrote: »

I have Apocalypse Now Redux on DVD, and the disc is nearly 8GB. The feature film and one English audio track is 6.8GB

Where are you getting your figures from? Windows explorer? Have you already ripped it to your HDD? If it genuinely is 1.9GB it means you've already compressed it during the ripping stage, do you know what codec you used?

It's a single layer DVD, it can't be 8GB! It is ripped to my hard drive already using a non-compression ripping software and according to both the software and explorer, it's 1.9GB.

thenightrider

ImpossibleDuck wrote: »

It's a single layer DVD, it can't be 8GB! It is ripped to my hard drive already using a non-compression ripping software and according to both the software and explorer, it's 1.9GB.

How do you know it is a single layer dvd ? Do you know what a duel layer dvd is ? All my dvd's are in around 6GB + if i rip them i can get them down to about 700 mb

Voodu Child

ImpossibleDuck wrote: »

It's a single layer DVD, it can't be 8GB! It is ripped to my hard drive already using a non-compression ripping software and according to both the software and explorer, it's 1.9GB.

It's definitely not 1.9GB on the disc, typically the feature movie itself is 4-6GB and you have menus, special features etc padding out the rest of the disc.

So if it is only 1.9GB on your HDD, then it has been compressed during the ripping stage (DVDshrink can do this) or maybe you're looking at something else.

First I would re-rip it, because for any video conversion you always want to go back to the original source in order to get the best results. Check your settings to make sure it is not compressed during the ripping stage.

Second I would decide just how much quality you want to preserve. The only perfect backup is to leave the full rip as is. However by converting from MPEG-2 to H.264, you can achieve something that looks almost the same at approx 1/2 to 1/4 the size. The smaller you go, the worse it will look, and everybody has a different eye for detail.

I suggest Handbrake to re-encode it - try the normal preset, it'll give you H.264 video in a MP4 container. Most of the default settings should be fine, ask about any settings you're not sure of.

The ratefactor (RF) determines the quality - smaller is better, but obviously higher quality will result a larger file. Do a couple of encodes using a RF of say 20, 18 and 16 and then look at the results. Then narrow it down using RF values in between those ones (or even smaller/larger if that's what you want). You have to decide yourself what kind of quality you are trying to preserve.

Don't forget to consider the audio - do you want to preserve the exact audio track off the disc? Or are you happy to encode it down to something like AAC or MP3?

ImpossibleDuck

Voodu Child wrote: »

It's definitely not 1.9GB on the disc, typically the feature movie itself is 4-6GB and you have menus, special features etc padding out the rest of the disc.

So if it is only 1.9GB on your HDD, then it has been compressed during the ripping stage (DVDshrink can do this) or maybe you're looking at something else.

I was reading an article on the subject that mentioned the two routes you can go down when ripping. Getting software that compresses(DVD shrink) and getting software that doesn't. I wanted to preserve the quality so I decided to go for the non-compression method. I ripped it and there you have it 1.9GB.

I used DVD Fab HD decrypter as I was told this doesn't compress and you won't lose quality. I'm almost sure it's single layer but I could be wrong, don't think I am, but could be. I didn't use any settings to compromise the quality as it took about 4-6 hours to rip which I assumed was making sure it was high quality given the time taken.

Voodu Child

Ripping happens basically as fast as your optical drive allows, maybe 10 minutes for a DVD on an average computer/laptop.

So if it took you 6hours it was also re-encoding at the same time. It means you have already compressed it. Personally I wouldn't compress it further using this source - for the best quality always go back to the original.

DVDFab will compress it if you tell it to. Aside from the basic ripping, it's got various conversion modes for iPods etc. You must have used one of those.

So I would go back and re-rip, making sure to use the basic DVDCopy option and 100% quality. Go for 'full disc' if you want all the menus and special features, or else use the 'main movie' option if you just want the movie (and you can discard audio commentaries or foreign language tracks). If it's taking any longer than 10-15 minutes it is probably doing more than just ripping.

ImpossibleDuck

Voodu Child wrote: »

So I would go back and re-rip, making sure to use the basic DVDCopy option

Are you sure about this? Last time I used the DVD Rip option. Logical decision imo, but am I supposed to use DVD Copy? It looks like it will output the data on the \ Drive? This seems odd to me? However it is showing 7000MB

Voodu Child

ImpossibleDuck wrote: »

Are you sure about this? Last time I used the DVD Rip option. Logical decision imo, but am I supposed to use DVD Copy? It looks like it will output the data on the \ Drive? This seems odd to me? However it is showing 7000MB

Yes.
You can choose wherever you want to put it, if you have space on the D drive then put it there if you want.
7GB sounds about right.

ImpossibleDuck

Voodu Child wrote: »

Yes.
You can choose wherever you want to put it, if you have space on the D drive then put it there if you want.
7GB sounds about right.

I might sound like a total idiot here but is the D drive not the disk itself?

Voodu Child

ImpossibleDuck wrote: »

I might sound like a total idiot here but is the D drive not the disk itself?

I don't know, its your computer and not mine

If the D drive is your optical then yeah, don't put it there Just change the path to somewhere on your HDD.

ImpossibleDuck

Voodu Child wrote: »

I don't know, its your computer and not mine

If the D drive is your optical then yeah, don't put it there Just change the path to somewhere on your HDD.

Oh right sorry, I see now Got a bit confused there. I assumed DVD Copy was an option for making copies of the DVD's i.e. copying the movie from one disk to another

Thanks anyway and I'll let you know how it turns out

ImpossibleDuck

Ok I have it on my hard drive now as 7.57GB which seems right

But my original question still remains, is there anyway of storing it away using as little space as possible (without losing any quality) until such time as I would need it? If I use compression software will it reduce the quality?
Like, can I can compress it to an unusable state and then when I need it, restore it back to it's original size and quality.

I don't mind if it's not easily accessible as I might not need it for quite a while.

Is there any software that offers better compression ratios than 95%+

Voodu Child

ImpossibleDuck wrote: »

But my original question still remains, is there anyway of storing it away using as little space as possible (without losing any quality) until such time as I would need it?

No. All popular consumer video codecs are lossy, they compress video by throwing away detail.

Going from MPEG-2 to H.264, with good settings you can get something that looks almost the same but is much smaller. Like I said, play around with the rate factor (RF) and then go and compare your encodes to the original DVD.

Personally, something like 2-3GB sounds fine for compressing a DVD with the full AC3 track. I wouldn't try and achieve 700MB because it's not even close to a legit 'backup' - if your disc was lost damaged, you'd go back to your 700MB encode and realise it was full of blocking/banding and had no grain retention.

ImpossibleDuck

Mmm I just did a rough estimation there and I'm guessing I'm looking at at least 200GB to back up without compressing.

Not sure what I'm going to do, thanks anyway VooduChild