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Better Quality: SD DVD uncompressed or Compressed Blu-ray?

M

mattchu09

macrumors newbie
Original poster
Jan 14, 2009
8
0
I just recently purchased a 1 terabyte Seagate external hard drive so that I can begin the process of ripping my physical DVD library into digital and I had a question about quality. I have read extensively about quality and compression settings using handbrake for converting DVD's to mp4, but I had a question I couldn't find an answer to.

Would I be better off doing lower compression through handbrake on a standard DVD, which would result in a 3-4 GB mp4, or would I be better off with a Blu-ray HD source compressed to about the same file size of 3-4 GB? The reason I ask is because most of the Blu-ray DVD's I have "found" on the internet in 720p are in the 3-4GB range and from my understanding a pure 720p rip should be much larger (around 8 gigs depending on the length). These files which I have "found" have obviously then been compressed therefore should have lost some of the quality in the process.

So I pose the question, am I better off using these compressed Blu-ray rips, or very lightly compressed SD DVD rips? Thanks for your help guys.
 
I have a mix of different stuff, but after doing 600GB worth of my own DVD's I have started to do them all again!!!

I was using 2500KBPS on video + AAC + AC3
But now I've started using CRF on 59% and they're coming out looking great, and taking up a LOT less space which is great as I've been buying drives like no tomorrow.
I’ve recoded about 30 720P movies and most of them turn out looking extremely close to the source, and look excellent on the TV.
Me personally most movies I would go with DVD as the source and keep the file size down, then for certain movies that would you really like or big action movies etc, you’ll get a nice gain having then in HD.
Play about with handbrake on different sources and different settings, see what works for you.
 
You can't look at filesize as a measure of quality. Some hollywood films compressed using h264 at quality 62% are pretty mich identical to the DVD at 1.5gb in size.

So using less compression won't make it any higher quality, just wasteful.

Bear in mind that the original DVD is compressed using MPEG2 compression, which is not a good compression algorithm. So when transcoding you are simply swapping compression algorithms and getting a smaller filesize for the same quality.

The HD video was already using a good compression algorithm, therefore any reduction in file size from the original means lower quality, ignoring that some of the lower file size may be due to discarding audio tracks.

I would stick with the SD, the quality will be higher most of the time.

Cheers, Ed
 
That is what my line of thinking had been originally. A lot the Blu-ray rips you find on the world wide web end up being file sizes which are much smaller a true no compression, Blu-ray rip, which means they have been shrunk and therefore lost quality.

The decision I have to make when building my digital library is the fact that I don't have the equipment to rip and encode Blu-Ray myself (No External Drive, or PS3) so my only choice would be to "get" them from other sources (sources which have obviously been compressed). My other choice is obvious, which is to take the standard DVD's I own and keep high quality versions of them in my library.

For me it really isn't a question of the file size but the end quality. Sounds like I am better of ripping my current SD DVD's with very little compression versus "getting" compressed 720p rips from alternate sources. Does that sound about right?
 
Depends on the film and how much time is taken to do the encode. An SD encode in plain MP4 640 wide (iPod high quality) single pass at 2.5Mbs looks very good and takes very little time to encode. I've lately been using the command line version of handbrake on my AMD64 single core Sempron Linux box and it rips and encodes a full DVD of a 2 hour movie in about 30 mins. This produces a reasonable file size and the quality is good enough to run on my HD projection without it looking too hideous.

However, I have also "found" HD rips from Blu-ray on the internet where they have been encoded using two pass H264 and the files are similar in size, if not smaller, than my typical SD DVD rip. Some of these have been pretty poor quality and artefacts have made it clear that it is over compressed but others have looked stunning and definitely better than a SD DVD rip. Basically, for H264 two-pass 720p (actually, 533p for a 2.35:1 movie) you need about 1GB per hour of film minimum and it will look better than an SD rip. But the encoding time needed unless you have something really beefy is going make for much longer encodes.
 
Pick one: smooth DVD rips, or crisp 720p

It's been my experience that DVDs come out smoother (at the expense of resolution), and 720p rips come out crisper (at the expense of compression artifacts in broad areas of color). In my opinion, films with a lot of CGI (e.g. Transformers) look better in compressed 720p, and most others look just fine as DVD rips, where a crisp, highly detailed picture is not as paramount to the viewing experience.
 
Of course I would take a 6GB Blu-ray rip over SD DVD rip of the same size, but what I am concerned about is these files on the internet that you can "get" that are very highly compressed blu-ray.

Example:

Which would be better? A standard DVD rip of The Dark Knight at basically full size, barely any encoding (I am assuming around 6GB) or one I have "found" on the web that is a .mkv file, 720p Blu-ray rip that is 2.05GB. Is the compressed Blu-ray file still going to be a better video quality than the standard DVD?
 
mattchu09 said:
Of course I would take a 6GB Blu-ray rip over SD DVD rip of the same size, but what I am concerned about is these files on the internet that you can "get" that are very highly compressed blu-ray.

Example:

Which would be better? A standard DVD rip of The Dark Knight at basically full size, barely any encoding (I am assuming around 6GB) or one I have "found" on the web that is a .mkv file, 720p Blu-ray rip that is 2.05GB. Is the compressed Blu-ray file still going to be a better video quality than the standard DVD?
Click to expand...

Best bet is to try it out for yourself. Personally, any 720p rip I've 'found' has been in between 4-8gbs. I'll run it through VisualHub and cut it down to about 3gbs (give or take a gb) and even then I still prefer the the bluray rip. My example is The Matrix. I have it ripped at 2500kbps from my DVD. Then I got a 720p .mkv and used visualhub to cut it down to 4gbs. That was WAY better. I tried re-ripping The Matrix DVD at a really high bitrate and have a huge file (5-6gb... huge for a standard dvd rip I mean) and I still preferred the compressed and recompressed bluray rip.
 
define "better"

mattchu09 said:
Of course I would take a 6GB Blu-ray rip over SD DVD rip of the same size, but what I am concerned about is these files on the internet that you can "get" that are very highly compressed blu-ray.

Example:

Which would be better? A standard DVD rip of The Dark Knight at basically full size, barely any encoding (I am assuming around 6GB) or one I have "found" on the web that is a .mkv file, 720p Blu-ray rip that is 2.05GB. Is the compressed Blu-ray file still going to be a better video quality than the standard DVD?
Click to expand...

again, it all depends on where your priorities are... to me, the 720p file at just over 2 gigs for a 2 1/2 hour movie will look like a$$ compared to the same movie as a 6 gig, low compression, high-bitrate DVD rip. If your only priority is resolution/detail, then go with the super-compressed Blu-ray rips, but prepare yourself for a bunch of compression artifacts in large areas of color.

As I hinted at in my previous post, only you can be the judge, depending on what you like most in your picture quality, be it fine detail at the expense of some blockiness, or an overall very smooth picture at the expense of diminished detail. As others have said, bump the 720p file up to a more reasonable file size, and it will win hands down. But if your "found" mkv file of The Dark Knight truly is only 2.05 gigs, that doesn't sound like a file I'd enjoy watching, even before compressing it a second time.
 
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