lossless compression?

[Scheme138]

is their a lossless compression i can backup my DVDs onto my hard drive? I use DVD Shrink with the highest compression but it loses a lot of quality. I would like it to be as compressed as possible since they will all stay on my hard drive but i want to keep the quality.

with series DVDs i was dvd shrinking with the highest compression, and then converting to xvid so i could have a whole series in 1 folder instead of multiple discs worth of vob files.

I think i need a better system. Any suggestions?

[HardwareGeek]

AFAIK, there's no such thing as lossless compression of a dvd. As you know, lossless means that it loses nothing. But in compressing, it has to throw out some data, even if the data is not very important.

The only lossless compression of a single-layer disc would be 4.7GB rip to 4.7GB, which isn't really compression.

[DarkNite]

Lossless compression takes A LOT of space. I have several terabytes of storage space, and I still only use lossless for temporary intermediate files.

The best you could possibly hope for (in my experience) is a 15:1 compression ratio. So you'd take 1/15th of the space a raw YV12 file would (which depends mostly on the resolution used), but that is still larger than a DVD5 for the usual 90 minute movie.

You could use H264 (x264, Recode, or whatever you choose) at about half the bitrate of the movie (3Mbps range) and not have to worry about any quality loss aside from some of the film grain going bye bye.

Check out the MPEG-4 AVC section for discussions concerning Nero's Recode, Doom9's MeGUI, Stax's Staxrip and other great tools.

[kotrtim]

http://www.compression.ru/video/codec_comparison/lossless_codecs_en.html

not a good idea.....lossless compression is really space hungry.
I would suggest H264 if you want smallest size/ best quality possible...

[Scheme138]

well i had heard that consumer DVDs are unneccesarily inflated to the 9gb size just to make it harder for backing it up. or at least more inconvienant. And that the real size was significantly smaller at the same quality. I thought there was a way to compress it back down without losing quality.

But regardless....i tried looking into H264 since it was recomended twice. I didnt see much. Since im posting in the n00b forum, a friendly app like dvd shrink would be great but im not sure if it exists. How do i go about compressing to H264 and what format does it compress to? can i still play it with my standard media or dvd player?

[Teegedeck]

DVD video is MPEG-2 which is already a lossy form of compression and you cannot compress that again without loosing anything. But the perceivable loss will be minimal if you use a codec that is more powerful than MPEG-2. What your friend probably meant was that most DVDs could easily have been compressed to a smaller filesize to start with, even with MPEG-2, if just the studio had wanted to.

No, there is no application that requires as little brain and time as DVD-Shrink. If you want to use anything besides that you'll have to get used to the thought of thinking now and then and waiting a day for the encode to complete. ;)

But MeGUI is as easy as x264 compression can be. Look for it in the MPEG-4 AVC subforum. Ah, MPEG-4 AVC is what x264 compresses to.

And no, that doesn't play on any standalone player (yet).

[Bodysurf]

is their a lossless compression i can backup my DVDs onto my hard drive?
Yes -- rip the DVD to the hard drive as an ISO image file.

This ISO image file will not be compressed relative to the original DVD, and will maintain its full original quality.

I use DVD Shrink with the highest compression but it loses a lot of quality. I would like it to be as compressed as possible since they will all stay on my hard drive but i want to keep the quality.
Any compression will cause a quality loss. YOU just have to decide how much quality you are willing to tolerate.

with series DVDs i was dvd shrinking with the highest compression, and then converting to xvid so i could have a whole series in 1 folder instead of multiple discs worth of vob files.

I think i need a better system. Any suggestions?
Don't "shrink" (transcode) prior to converting to XviD. You are incurring two quality loss steps by doing that. Go directly from the source DVD files to XviD. I find using a compression quality level of "3" results in little quality loss.

Of course, I am assuming these are all non-copyrighted or legally entitled to backup DVD-Videos we are talking about here. Why? Because, unless you state otherwise, I choose to give you the benefit of the doubt and presume innocence rather than guilt.

[snherbst]

I guess this has been discussed before. But DVD Shrink dosn't give out the same quality as eg. DVD Rebuilder.

http://forum.doom9.org/showthread.php?t=103356