Uncompressed or Compressed DVD rip?

[DMN1981]

Hi All,

I have recently started to build my media setup up at home, and starting the process of ripping my DVD collection. So I have done quite a bit of research, I understand containers, codecs, bitrates etc etc..

However I can't seem to find the answer to a question I have, which will help me decide how to rip my collection.

I am ripping my collection to ISO so I can keep an exact 1:1 replicate copy, if I decide to just keep the main movie later, I can just convert the ISO.

Now I know that by the very nature of compression, you do lose quality. So my question is:

Will I get better quality from an uncompressed DVD rip, or a straight compressed rip of a DVD? Now the file size between the two can be between 2-3Gb difference, so whilst I'm not worried about the storage needed at this stage, the less storage I use the better in the long run.

That leads me to another question, if there is a difference in quality in an uncompressed and a compressed DVD rip, is it noticeable?

Thanks guys!

DMN1981

[DB83]

Well you have already answered your question although, despite your 'research', you do not understand the concepts.

Firstly, there is no such thing as an un-compressed dvd rip. A 1:1 iso is compressed simply because the original content of your dvd is compressed.

Your idea of creating a compressed 'rip' is simply to take that compressed source and compress it even more. The mere act of compression, as you state, will lose you quality because information is thrown away by the compression.

Will you notice it ? That will depend on 1. The codec you employ and 2. The bit-rate you choose. A 'compressed rip', just to use your own term, that looks the same quality as the original is an optical illusion and has no real bearing on actual quality.

[Kerry56]

An uncompressed copy of your dvd will be the best quality you can achieve. If you want the entire movie, not just the main movie, this is especially true, since you would have to compress using mpeg2 to get a smaller size and retain menus and extras. I'd suggest using DVDRebuilder to re-encode it if you want the entire movie in a compressed form, as this program will give the best results.

Backing up to another format, and using only the main movie, you can save much more space, and can still make an excellent copy. H264 in an mkv or mp4 file can be done at half the size of the original, possibly even smaller. You will lose some video quality, this is true, and if you examine the copy frame by frame, you may be able to spot some of these areas of deterioration. But using Vidcoder or Handbrake in a two pass encode, or a CRF 18 encode, your copy will generally be hard to pick out from the original when actually playing the movie.

[DMN1981]

Hi,

Thanks for your replies, sorry maybe I didn't explain it very well.

I am using DVDFab (trial) and DVDShrink to make 1:1 ISO rips of my DVDs (in full, including menus, extras etc). For example, in DVDFab you can select Full Disc and then DVD5 or DVD9. DVD9 being circa 7Gb and DVD5 being circa 4-5Gb.

Therefore, would the DVD9 setting provide a better quality rip? Does that make sense?

In DVDShrink, if I leave compression to Auto, the ISOs are the same as the DVD itself, circa 4Gb, if I set to no compression, it increases to the full circa 7Gb.

I'm keen to keep the menus etc, so again from what I understand, this can only be achieved through ISO 1:1 rips, and not via converting to MP4 or MKVs, correct?

I guess ultimately, you can't get better quality than a true 1:1 ISO rip end of?

Cheers!

DMN1981

[DB83]

No. You can not retain menus if you convert

A 1:1 copy is just that. If your dvd is 7 gig then your 'un-compressed rip' is also 7 gig.

If your rip, from the same dvd, is 4 gig it is not a 1:1 copy, although all all the content is still there. You have compressed it and, yes, you have lost quality because you have lowered the bitrate.

If your dvd is 7 gig then, yes, the DVD9 setting is giving you better quality. That stands to reason. Actually, 'better' is not the right word. 'Best' is a more appropiate word.

What you can not do is take a 7 gig dvd and make a 8.5 gig dvd from it. Well not from the software you are using. And even if you did then you would not get better quality than if you left it at 7 gig.

[DMN1981]

Hi mate,

Yep that makes sense, and as I thought. Thanks for clarifying....

Out of interest, would the uncompressed DVD rip be noticeably different? If not, then I don't see the point, and I'll leave DVDShrink set to Auto and DVDFab set to DVD5.

Again out of interest, and it's probably a stupid question! . When you watch a DVD on a standard DVD player, is the quality you're watching, the smaller compressed or larger uncompressed image?

Cheers

DMN1981

[Kerry56]

If you have the room, make uncompressed copies. This can be done to an ISO or as files. The size of the movie will be the same as what it is on the disc.

If you want the menus, and you want smaller sizes, decrypt the movie and rip it uncompressed to the hard drive. Then use DVDRebuilder to make a complete copy (menus, main movie and extras all included) and it will output in a size meant to fit onto a single layer dvd. That is approximately, 4.3gb. The output from DVDRebuilder will be better overall than compressed output from DVDFab or DVDShrink, especially with movies that require more compression to hit this size. There is a free version of DVDRebuilder, but it does not include decryption in itself, so you must rip first.

Converting to other formats you will lose the menus.

Edit: And to answer your last post...it is possible to tell the difference between the original and output that is compressed, depending on the amount of compression needed and the type of compression applied. Shrink and Fab work ok for movies that don't need much compression. They are transcoders. DVDRebuilder uses HCenc to re-encode the movie.

[DB83]

It's impossible to answer. Some dvds will be better than others simply because the original material is better. Only your eyes can tell.

It is a stupid question You see what you have created. That 4 gig dvd not does magically appear as the 7 gig original.

[DMN1981]

If you have the room, make uncompressed copies. This can be done to an ISO or as files. The size of the movie will be the same as what it is on the disc.

If you want the menus, and you want smaller sizes, decrypt the movie and rip it uncompressed to the hard drive. Then use DVDRebuilder to make a complete copy (menus, main movie and extras all included) and it will output in a size meant to fit onto a single layer dvd. That is approximately, 4.3gb. The output from DVDRebuilder will be better overall than compressed output from DVDFab or DVDShrink, especially with movies that require more compression to hit this size. There is a free version of DVDRebuilder, but it does not include decryption in itself, so you must rip first.

Converting to other formats you will lose the menus.

Awesome thanks Kerry, I'll try DVDRebuilder... However I'm not too worry about storage to be honest, as discs for NAS are pretty cheap now. Might be a different story when I start ripping Blu-Rays!

[hello_hello]

Out of interest, would the uncompressed DVD rip be noticeably different? If not, then I don't see the point, and I'll leave DVDShrink set to Auto and DVDFab set to DVD5.

Again out of interest, and it's probably a stupid question! . When you watch a DVD on a standard DVD player, is the quality you're watching, the smaller compressed or larger uncompressed image?

I think maybe you're still confusing the terminology a little. If you use a program such as DVDShrink to make an exact copy of a DVD (either ripping it to multiple files or as a single ISO file etc) then it'll be a copy of the original. No re-encoding.
The "smaller compressed image" you refer to is a re-compressed version of the original, so the quality may be lower. It can still be saved to an ISO file but if DVDShrink is "shrinking" then it's re-encoding.
If you go into DVDShrink's settings, you'll see one labelled something like "target output size". You can set it to whatever you like. It's set to DVD5 by default (4GB or single layer blank DVD size). When the size of the files on the disc exceeds that target size, DVDShrink will re-encode the video to "shrink it". If you change it to DVD9 (7GB or dual layer blank DVD size) then it won't try to re-encode until the total file size exceeds 7GB. Or you can manually specify any size you like. You can of course over-ride the "auto compression" setting once DVDShrink has opened the DVD, but changing the target output size in DVDShrink's options means you won't need to.

If DVDFab has some sort of output size option (ie DVD5) then no doubt it works the same way. If the total file size is under the set output size the video will be copied. If it's greater then it'll be re-encoded to "shrink" it.

Depending on how fast your CPU is, you'll probably notice a speed difference according to whether DVDFab/DVDShrink is just ripping the DVD or whether it's ripping and re-encoding it (shrinking it).

I use DVDShrink for ripping by opening the disc directly, but because it's not been updated for a long time it can't handle some of the newer copy protections. For those discs I run AnyDVD (not free) in the background to do the decrypting. If all you're wanting to do is rip the entire disc to ISO (or the usual DVD files) without re-encoding anything, then AnyDVD and DVDFab (I assume) can do that too.

For the record, an ISO file is kind of like a zip file for disc images. Ripping to ISO itself has no bearing on whether the video was re-encoded as it was ripped. You can extract the contents of ISO files using many compression programs (WinRAR, TugZip, Ultimate Zip etc). The main difference between an ISO and something like a zip file is ISO contains the information required to burn the files to a new disc using the same structure as the original.

So while the video on the DVD is compressed, in DVDShrink terminology if it's not compressing then you're copying everything as-is (ripping only). If DVDShrink is compressing then it's re-compressing (re-encoding) the video.

[jagabo]

The quality drop from a 7 GB ISO to 4 GB ISO will almost always be noticeable. Unless you're watching on a 13" TV from 10 feet away.

[johns0]

7gb dvd compressed to 4gb with dvdshrink and watching on a 37" and higher hdtv will show you just how bad it looks compared to the uncompressed dvd.

[DMN1981]

Hi Hello_Hello,

Thanks for the indepth explanation (far more useful some other comments! ).

Yes all makes sense.

Thanks

DMN1981

[jagabo]

Note that DvdShrink doesn't really re-encode to compress a rip, it re-quantizes. That is much faster than re-encoding but doesn't deliver as good quality. If you have to shrink by more than about 10 percent you're usually better off (quality wise) re-encoding. But if I'm reencoding a movie I'd rather use x264 in an MKV container. That gives a smaller file and better quality than reencoding to MPEG 2. I don't need the original menus. I would rather navigate to my NAS, select a file, and have it play.

[Hoser Rob]

I'd rip (as mentioned, this does not involve compressing or re encoding) to a VIDEO_TS folder rather than a .iso. It's a lot easier to find a software player that can play a VIDEO_TS.

For inexperienced users I really think a straight rip is a better option, even though it involves more $$$ spent on HD storage. But video encoding isn't simple, and it's time consuming.

[hello_hello]

Note that DvdShrink doesn't really re-encode to compress a rip, it re-quantizes. That is much faster than re-encoding but doesn't deliver as good quality. If you have to shrink by more than about 10 percent you're usually better off (quality wise) re-encoding.

The only time I've used DVDShrink to "shrink" a DVD is if I've had to burn it to a DVD5 disc for some reason, which is very rare. Mostly I just rip and convert (xvid for quite a while, now x264) so I've never investigated DVDShrink's "better quality" options. "Deep analysis" and "adaptive error compensation". The former uses 2 pass encoding. Do they make much difference and is the video still re-compressed the same way?

[redwudz]

If all you want is a exact copy of the decrypted DVD in ISO format, you don't need DVDShrink for anything. It just seems a unnecessary extra step. It can be useful for removing some 'junk' on a DVD file, such as the warnings and extras, but then you wouldn't have an 'exact' copy.


Personally, I wouldn't convert to a ISO either as you are limiting your playback programs. Not that many programs can play an ISO file. If you just rip the DVD to a VIDEO_TS and AUDIO_TS file, then you still have an exact copy. The downside with this is the enclosing folder would need the name of the DVD, while a ISO (Still a container/folder) can be named directly with the DVD name. I use VLC for ISO file playback, and also for VIDEO_TS folder playback. Even when it's in a surrounding titled folder it plays back the same as an ISO.


And if a reason for ISO is easy conversion back to a DVD disc, ImgBurn can burn a DVD disc from either a ISO or a VIDEO_TS folder.