DVD-intro

DVD-tech

DVD-faq

DVD formats

DVD rec

The DVD technical specifications are contained in five books A to E published by the DVD Forum.

Book	Name	Physical	File System	Appli- cation	Ver
A	DVD-ROM	Read-only	ISO 9660 + UDF	undefined	1.01
B	DVD-Video	Read-only	UDF	MPEG-2 video	1.1
C	DVD-Audio	Read-only	UDF	high quality audio	1.2
D	DVD-R	Write once	UDF	not defined	2.0
E	DVD-RAM & DVD-RW	Re-writable	UDF	not defined	2.0

Physical Parameters

The table below summarizes the physical parameters of DVD and compares them with those of CD and CD-ROM.

DVD Sector Structure

The data on a DVD disc are organized as sectors of 2048 bytes plus 12 bytes of header data. 

 

Header			User Data
ID	IED	CPR_MAI
12 bytes			2048 bytes
DVD Sector Structure

The header contains the following information:

 

Field	Bytes	Content
ID	4	Sector type, data type, layer number and sector number
IED	2	ID error correction code
CPR_MAI	6	Copy protection and region code (for DVD-Video)

Blocks of 16 sectors are error protected using RSPC  (Reed Solomon Product Code), which is block oriented and is more suitable for re-writable discs (with packet writing) than CIRC which does not use a block format. The PI and PO data are parity bytes calculated horizontally and vertically over the data bytes.

In addition DVD uses an 8 to 16 modulation scheme giving pit lengths of 3 to 14 (minimum to maximum length) compared with CD's 3 to 11 with EFM modulation.

Burst Cutting Area

The Burst Cutting Area (BCA) is an annular area within the disc hub where a bar code can be written for additional information such as serial numbers. The BCA can be written during mastering and will be common for all discs from that master or, more usually, will be written using a YAG laser to 'cut' the barcode into the aluminum reflective layer of the finished disc.

The data stored in the BCA can be from 12 bytes to 188 bytes in steps of 16 bytes. The Divx format used BCA to uniquely identify every disc. BCA can be used as a unique, tamper-proof means of identifying individual discs.