DVD disc Characteristics

[LiCal]

I was examining a Concert commerical DVD and surprised to learn that it has about 28 files with a total of 7.4 GB in size.

1. How to check/determine whether this disc is a double-layer type (did not see any logo for such on this disc among ntsc, dolby etc) ?

2. If not a DL disc, how is possible to squeeze that much volume, almost double the DVD capacity, onto a standard -R disc?

3. Then when I am authoring next DVD, how do I calculate/determine the max data/files to burn onto a DVD?

[Shocker Milwaukee]

If it's more than 4.7 GB in size, it's dual-layer.

You can squeeze more size by lowering bitrate or dropping resolution to Half-D1.

There are bitrate calculators available to help with authoring.

[Noahtuck]

I was examining a Concert commerical DVD and surprised to learn that it has about 28 files with a total of 7.4 GB in size.

1. How to check/determine whether this disc is a double-layer type (did not see any logo for such) ?

You answered your own question.
Just the fact that it is 7.4g say's its a DL disc.
But you can use DvdInfo which will tell you its a DL disc.

2. If not a DL disc, how is possible to squeeze that much volume, almost double the DVD capacity, onto a standard -R disc?

It's not possible to have 7.4g on a disc that is not DL, thats like asking how you can put 4 gallons of water in a one gallon jug 8) you can compress the 7.4g down to fit onto a dvdr with many programs.

3. Then when I am authoring next DVD, how do I calculate/determine the max data/files to burn onto a DVD?

https://www.videohelp.com/tools?tool=VideoHelp_Bitrate_calculator

Edit:Shocker Milwaukee hit the short answer while i was typing all this :P

[128commands]

Exactly. Commercial dvd's are very often DVD-9. Single sided, dual layer discs. These have been replicated and not duplicated. So basically glassmasters were cut from two DLTs that were sent to the rep house. The info is stamped onto the disc unlike when burning discs.

When you go to replication you usually will have to have a min of 500-2000+ units ran off but the figure varies from rep house to rep house.

We can now burn DVD+R DL (double layer) media and DVD-R DL (dual layer) media. These are not DVD-9 so do not carry the DVD-VIDEO disc logo. You will not see a ±R logo on commercial dvd's cause replicated discs are not recordable media.

So we can burn 4.7 billion bytes (4.37GB) or 8.54 billion bytes (7.95 GB) to blank media or go to replication and have DVD-5, DVD-9, DVD-10, DVD-18 and so on.

There is also Authoring media when it comes to -R and you can also find double sided -R as well...

The pro's of replication are that you're aiming to have 100% compatibility, can add copy protection and large runs become more and more cost effective... DLT (Digital Linear Tape) is pretty much the standard for submission but these days there are more and more options. Loads of authors use dvd-r but Plant Direct type features are becoming more and more accepted also.

FWIW, DLT drives use a SCSI interface and you can find used DLT4000-8000's quite cheap...

commands[128]

[128commands]

Also, on most of the commercial packaging you'll see it say:

DUAL LAYER FORMAT. Layer transition may trigger a slight pause.

That will of course give it away too... and the pause is cause the laser has to refocus from LAYER_0 to LAYER_1 before carrying on...

commands[128]

[LiCal]

Thanks for the info. DVDinfo confirms that it is a DL disc.