Professional Studio made DVD capacity

DADSGETNDOWN · Post by **DADSGETNDOWN** » Thu Apr 20, 2006 5:55 pm

Hello, not exactly sure what to call it, but when we buy a DVD movie etc from a store they can be 2-3 or hours long, digital surround etc, commentary, extras, cut sceenes, bloopers, GREAT QUALITY, ALL that on a SINGLE dvd, and have been for a good few years now, help me understand why we can hardly get 1 single hour of camcorder, video and sound, on to a single dvd, what's the trick ? where do we take it? how many millions does it cost?. 1 hour of video and sound could easily take up 13 GB ? phewee even dual layer can't do that. IS movie Factory or media studio any different? or some other product maybe able to do this....

TubaDad · Post by **TubaDad** » Thu Apr 20, 2006 6:08 pm

One of the biggest issues is problably that you are writing to 4.7Gb DVDs, while the studios are using the dual layer 9Gb DVDs, that doubles the capacity right out of the gate. The other thing is the video bit rate.

As a general starting point:
8000bits = 60 minutes on a 4.7Gb DVD
6000bits = 90 minutes
4000bits = 120 minutes

Double that when burning dual layer DVDs.

Search on the forum and you will find links to bit rate calculators to do this more accurately for you.

sjj1805 · Post by **sjj1805** » Thu Apr 20, 2006 6:13 pm

Commercial DVD's are not burned in a DVD burner like ours, they are pressed. They are a greater size than the blank DVD disks we buy.

The one's we buy come in two sizes.
Normal which confusingly says 4.7 then only lets you put 4.3 on the disc
(Even I have problems remembering why and I would have to look it up again)
Dual Layer which is approx 9GB.

We are currently on the brink of a new format which will see blank DVD discs holding as much as 25GB of data. Currently their is a battle going on between Blue Ray and High Definition discs, sort of like the betamax -v- VHS thing several years ago.

VideoStudio 10 is ready for both formats.

TubaDad · Post by **TubaDad** » Thu Apr 20, 2006 6:42 pm

Steve, Yesterday I was reading about a four layer 100Gb Blue-ray disc in our future.

I can't imagine filling one of those, but then we would never need more that 64k of RAM on the Commodore PC either. Maybe I'm showing my age there.

sjj1805 · Post by **sjj1805** » Thu Apr 20, 2006 6:45 pm

I wouldn't be surprised if in the future we dont even use discs.
We will probably use cartridges - no moving parts!

DVDDoug · Post by **DVDDoug** » Thu Apr 20, 2006 8:58 pm

The other "trick" is Dolby AC3 sound. An AC3 soundtrack (even a sourround sound track) takes-up very little disc space.

You can easily put 3 hours of high-quality video and AC3 audio on a dual-layer DVD.

Another thing you can do is use a lower bitrate for the "extras" and alternate soundtracks. This doesn't give you more total playing time, but it puts the quality where it's most important. (I've noticed that some DVDs with "alternate angles" have lower quality for those optional shots.)

1 hour of video and sound could easily take up 13 GB ?

That's the DV format, from your digital camcorder. The video on a DVD is much more compressed with MPEG-2 format. MPEG is "lossy" compression, so the quality is not quite as good as the original, but it's also "smart" compression... It tries to throw-away the least-important data.

Post by **lancecarr** » Thu Apr 20, 2006 11:36 pm

An additional consideration regarding commercial DVDs is the encoding. While we fool around at the bottom of the tank with our "two pass" encoding, the commercial production houses are converting to MPEG using up to twenty passes before their software does the conversion. That's how they get away with a 4000bps DVD yet have fantastic quality.

macks64 · Post by **macks64** » Sun Apr 23, 2006 12:47 pm

I think the 4.3GB vs 4.7GB may be simply related to the definition of a Gigabyte (however, I am only guessing). Sometimes you see this issue with the advertised capacity of normal disk drives. Technically, a Gigabyte should be 1024x1024x1024 bytes. However, sometimes a Gigabyte is used to describe one billion bytes. If you take 4.7 billion and divide it by 1024x1024x1024, you get (surprise, surprise): 4.38 genuine Gigabytes.