Your acceptable compression rate

[Slowburn]

After ripping a DVD to just the movie, the compression rate was about 67%. How low do you let it go before trying to burn to 2 disks?

[redwudz]

This is not advanced and has been asked many, many times. Do a forum search. I can tell you in general that you will see some amount of quality degradation at 67%, assuming you are asking about Shrink. If so, 80% is about as low as I would go, even with Deep analysis. Moving you.

EDIT: And I should of said my <80% is with backing up the main movie only. But maybe I'm particular.

[dfluke]

Don't worry so much about the compression. I don't want to say its meaningless, as far as quality goes, but you can't get much meaning out of it. The "compression" in Shrink is more about memory size and the time it will take to Shrink, not about quality.

The problem is you don't know how much compression was needed to get the movie on to the DVD. A 1 hr movie with plenty of action (or scene changes) may actually be a larger movie (originally in terms of file size) then a 3 hr movie with no action (or scene changes.) So compressing a 3hr movie 50% may look better then compressing a 1hr movie 80%. (OK, this may be an exaggeration but hopefully you get the point.)

So since you don't know how much compression the studio used to get it on the DVD, its hard to say how much more compression is acceptable.

So my advice is to just backup the movie only since this is what you will most likely will be watching over and over again. Unless you are an extra person, then just backup the extras only.

P.S. I bet this will stir up even more controversy about this subject.

[edDV]

...

P.S. I bet this will stir up even more controversy about this subject.

It comes down to personal tolerance of compression artifacts. Paris, Texas looks good until you have seen Paris France. But some may still choose to move back to Paris, Texas for economic or personal reasons.

[manono]

Hi-

The problem is you don't know how much compression was needed to get the movie on to the DVD.

But it's easy enough to find out by checking the average quant. I thought your post was one of the more common sensical I've seen on the subject, and not controversial at all. Only the ignorant can take issue with your main point.

The maximum amount of compression you can and should use in Shrink is meaningless, unless you find out how much "overhead" there is for further compression. As you said, 50% may be fine for some movies, and 80% too much for others.

It also depends on what the backer-upper plans to watch his transcoded DVDs on. It may look fine on his 27" CRT TV, but after he upgrades to a 50" HDTV, it may look like crap. And as edDV said, it also depends on your tolerance for compression artifacts. Some people just don't care. All they care about is how long it takes. Me, I've never used Shrink, as I prefer true encoders.

[Super Warrior]

After ripping a DVD to just the movie, the compression rate was about 67%. How low do you let it go before trying to burn to 2 disks?

Is that Full-disc?

If so did you remove all excess trailors, ads, and or needless extras you don't want, as well as downsize the extras that you are keeping first? Also removing the ending credits usually results in about 170MB-200MBs saved. Yes 200MBs extra can make a difference. Can also downsize menus too. Less compression required, the more quality available for the movie.

As for me, eh i don't go by compression rate in % but rather in time. A SL-DVD can hold up to 3 hours of excellent quality video. Anymore than that and you're entering the SVCD/VHS levels, and probabley should look to getting rid of some extras for less compression space or splitting to two discs.

[lordsmurf]

Read this:
https://forum.videohelp.com/viewtopic.php?p=1510051#1510051

[ROF]

Compression does not effect me anymore since dual layer discs are now quite cheap. In answer to your question though anything below 90% looks horrible. Plus if I have to throw away more than 10% of the data why am I bothering to back it up anyways?

[NiteLite]

After ripping a DVD to just the movie, the compression rate was about 67%. How low do you let it go before trying to burn to 2 disks?

Compression is subjective.
Dual layer disc prices are subjective.
Nothing below 90%, 80%, 70% is subjective.
They mean nothing to you.
Is your TV large, medium, small? SD or HD? Those factors may make a difference.
Suggestion: Try it at 67% and see if you are happy.

Many think they can tell minute (exceptionally small) differences in audio/video until a true double blind is done.
Then they try to compress their embarressment as much as possible.
NL

[jman98]

Compression is subjective.
Dual layer disc prices are subjective.
Nothing below 90%, 80%, 70% is subjective.
They mean nothing to you.
Is your TV large, medium, small? SD or HD? Those factors may make a difference.
Suggestion: Try it at 67% and see if you are happy.

Many think they can tell minute (exceptionally small) differences in audio/video until a true double blind is done.
Then they try to compress their embarressment as much as possible.
NL

You are so right! Unfortunately, a rather large number of people here who do contribute positively to the forum aren't honest enough to admit that this is all subjunctive. I recently used DVD Shrink and compressed a DVD down to about 67% or so. It was a film with very little fast action. It looked really good on my 27 inch SD TV. Will it still look as good later on an HD TV? Don't know. I don't have an HD TV yet. However I was certainly satisfied with what DVD Shrink did and I'm certainly not a novice and I wouldn't say that compression artifacts don't bother me at all.

[ROF]

Compression is subjective.
Dual layer disc prices are subjective.
Nothing below 90%, 80%, 70% is subjective.
They mean nothing to you.
Is your TV large, medium, small? SD or HD? Those factors may make a difference.
Suggestion: Try it at 67% and see if you are happy.

Many think they can tell minute (exceptionally small) differences in audio/video until a true double blind is done.
Then they try to compress their embarressment as much as possible.
NL

You are so right! Unfortunately, a rather large number of people here who do contribute positively to the forum aren't honest enough to admit that this is all subjunctive. . . . . I don't have an HD TV yet. However I was certainly satisfied with what DVD Shrink did and I'm certainly not a novice and I wouldn't say that compression artifacts don't bother me at all.

I would guess just about everyone here is offering an opinion on what they see as being the threshold they will not cross. As edDV says, "It comes down to personal tolerance of compression artifacts." Of course, not having a modern television set will certainly make it appear that everything is OK til you view your compressed 20% data thrown away film on something beyond the blurry sets of yesteryear.

[greymalkin]

I had to shrink to about 55-60% on a project to fit on dual layer. Watched it on my parents 55" HDTV and although the difference was noticeable, there were no noticeable macroblocks or anything else "horrible" about it. On my 27" you'd be hard pressed to see a difference. Saying anything under 90% is horrible is just stupid.

[ROF]

Saying anything under 90% is horrible is just stupid.

Really? Considering 99.9% of my burning involves data or video that i want to archive or backup I would say that throwing away 10% or more defeats the purpose. Why would I bother archiving something when I do not care if 10% or more is just thrown into the trash?

[lordsmurf]

Saying anything under 90% is horrible is just stupid.

Really? Considering 99.9% of my burning involves data or video that i want to archive or backup I would say that throwing away 10% or more defeats the purpose. Why would I bother archiving something when I do not care if 10% or more is just thrown into the trash?

I have to agree with greymalkin. ROF, your argument lacks perspective.

If the video is 50% in excess, then shaving 10% or even 40% from that should have no ill effects visually. If you do not know the source, you are not qualified to give % numbers.

[Cornucopia]

ROF, don't confuse the issue. This is about backing up Video titles, not archiving data.

Of course, for archiving data, you need 100%. If it's too big, you span discs.

Personally, I don't like losing much more, because the way I see it, the movie is already extremely compressed (~30--200:1) and there's only so much entropy left.
You would probably put me in the "never less than 80%" camp.

Scott

[tgm4883]

110% If I don't think a scene is good enough quality I break out the video camera and reshoot it myself

[ROF]

ROF, don't confuse the issue. This is about backing up Video titles, not archiving data.

So 10% or more of a video is so unimportant that you require making a backup of unimportant video? That makes no sense. The reason you back something up is because it is important to you. If it is only 90% or less important to you why bother?

[lordsmurf]

ROF, don't confuse the issue. This is about backing up Video titles, not archiving data.

So 10% or more of a video is so unimportant that you require making a backup of unimportant video? That makes no sense. The reason you back something up is because it is important to you. If it is only 90% or less important to you why bother?

It's becoming quite clear you just want to argue.

Everything has been explained already. But let's try again....

Would you back up the same file 3 times on the same disc, if it were data? No.

So why would you back up excessive video data in the same manner? Indeed, some of it may be extra that can be skipped for the backup. This is where the % number comes in, and why you have to know about the source. Just because something is there does not mean it's valuable and needed. Figuring out just how much is excessive was the entire point of this post. And the answer depends on the source, blind % numbers are worthless.

[ROF]

Figuring out just how much is excessive was the entire point of this post. And the answer depends on the source, only a moron will blindly give out % numbers.

The original poster provided a percentage. That percentage was 67%. So 1/3 of the video is in excess? Show me any video that is recorded with a third of the video or audio being excessive?

The moron here is the person who can not accept other peoples opinions based on the original post of what is excessive(percentage wise) without calling names.

Edit: Nice edit BTW, too bad you got caught!

[tgm4883]

Show me any video that is recorded with a third of the video or audio being excessive?

Matrix Reloaded
Matrix Revolutions
Star Wars Episode 1

[ROF]

Show me any video that is recorded with a third of the video or audio being excessive?

Matrix Reloaded
Matrix Revolutions
Star Wars Episode 1

None of which is excessive and looks all rather horrible when compressed down to 67% it's normal size. Do a test yourself. Compress Matrix reloaded to 67% it's size.

[tgm4883]

Show me any video that is recorded with a third of the video or audio being excessive?

Matrix Reloaded
Matrix Revolutions
Star Wars Episode 1

None of which is excessive and looks all rather horrible when compressed down to 67% it's normal size. Do a test yourself. Compress Matrix reloaded to 67% it's size.

Apparently you didn't get the joke. I was referring to some of the content of those movies. You could definently cut 1/3 of the matrix reloaded and end up with the same movie.

[lordsmurf]

Show me any video that is recorded with a third of the video or audio being excessive?

Matrix Reloaded
Matrix Revolutions
Star Wars Episode 1

None of which is excessive and looks all rather horrible when compressed down to 67% it's normal size. Do a test yourself. Compress Matrix reloaded to 67% it's size.

You must be using some really shitty transcoder.
DVD Shrink with deep analysis and max smooth AEC, image is fine.

[ROF]

Show me any video that is recorded with a third of the video or audio being excessive?

Matrix Reloaded
Matrix Revolutions
Star Wars Episode 1

None of which is excessive and looks all rather horrible when compressed down to 67% it's normal size. Do a test yourself. Compress Matrix reloaded to 67% it's size.

You must be using some really shitty transcoder.
DVD Shrink with deep analysis and max smooth AEC, image is fine.

In your eyes, maybe, yet I highly doubt it. But I believe a wise person once said this is all subjective. In any case I own all three movies, why on earth would I destroy them by removing 1/3 of the content or waste media doing so?

[kush]

Perhaps I missed something, but the OP didn't state what he used to arrive @ the 67% level? I'd assume it's DVD Shrink though, and barring clarification on that end, I'd say the op should look @ DVDRebuilder with either CCE Basic @ $60, or HCenc or something for the freeware encoders.

Back when Shrink was more popular, ie: when DVDRB was still in early beta or before, I'd do anywhere from 65-80ish% depending on the source.. But, I pretty much use DVDRB for *all* rips these days, since RB is pretty much fool proof, and altough sometimes imperceptable to the naked eye - it's definately better than any of the transcoders (DVD Shrink/CloneDVD etc) out there, due to actually encoding the 'shrinked' frames. Besides my PC is a dual core S939 system, and it's on pretty much 24/7 anyway, so encoding times are a non-issue for me in that respect.

Then again all that long story for short subject stuff is moot (as others alluded to previous), if you are considering going w/ a hi-def TV anytime soon.. Any artifacts in transcoded stuff will be that much more amplified on an upconverted SD DVD when played back on an HDTV (read: I'd go for DVD-RB regardless of encode time for this fact alone, unless you plan to replace all your SD discs with HDDVD/BR down the line)..And although I still find DL discs to be too expensive for day-day use, you can easily find good DL discs (read: Verbatims) for well under $1/disc if you look around the deal sites and/or wait for the good sales @ the online or B&M stores..

[Slowburn]

Thanks for all the info. Yes, I did use DVDShrink to try ripping a disk, in this case it was Terminator. Still a bit of a noob about this stuff, but did notice the 67% compression rate I originally mentioned and was curious why it was at that rate.
I did a successful burn and it looked great. Out of curiosity, I checked the properties of the burned disk and it was full, so DVDShrink created that size to completely fill the disk.
It looks good on my 36" TV anyway.
Thanks for all your help guys.

Slowburn

[fritzi93]

DVDShrink reduces down DCT data, it's essentially error-correction. The less movement in the video, the more DCT can be reduced without visible degradation. Call it "excess" data. Some folks think that a transcode at a couple percent can actually be better than a re-encode. In theory, anyway, how you'd tell is beyond me. We're talking "visible" difference here.

My own preference (for viewing on a 32" HDTV) is DVDRB beyond a few percent, but that's JMHO.

Slowburn, you might find this interesting:

http://forum.doom9.org/showthread.php?&threadid=63587

[ClaudiuS01]

In my opinion you are not keeping focus! The original question was about wich percentage would be tolerable to watch when shrinking a DVD to DVDR using DVDShrink.

You can't give one clear answer to that, since DVD9's are all different in size and quality measured in amount of data sent per timeunit (mbps). Furthermore this mediastream consists of both video- and audio- as well as subpicturestreams.

If your question is related to the videoquality alone you can gain some "quality" by removing unwanted features first. Audiostreams in foreign languages fx. If you have both DTS and AC3 5.1 audiostreams you can remove the DTS, and so on.

But important is that the final quality is related "only" to the amount of data sent per timeunit.