Description

This article is from the CD-Recordable FAQ, by Andy McFadden (fadden@fadden.com) with numerous contributions by others.

6-3-1] What's UDF?

(2003/12/21)

UDF is an acronym for the humbly-named "Universal Disk Format". It's a
specification for a filesystem intended for use on write-once and
rewritable media. It's currently being used for DVD and some of the
CD-R/CD-RW packet writing software (e.g. Roxio DirectCD).

There have been four important releases of the specification:

- 1.02: first release; primarily useful for read-only media like DVD-ROM.

- 1.5: includes defect management, useful for CD-R and CD-RW.

- 2.0: adds support for Stream Files, Access Control Lists, and
power calibration.

- 2.01: adds support for Real Time Files.

- 2.5: adds Metadata Partition.

MacOS 8.1 and Win98 support UDF v1.02. Windows XP supports 1.02, 1.5,
and 2.01. To read UDF-format packet-written CD-R and CD-RW discs, you
need UDF v1.5 support. Roxio has made free UDF 1.5 drivers available for
Mac and Windows on their web site (check there for a list of supported
CD-ROM drives). Also, if you insert a disc formatted with DirectCD v3.0
or later into a Windows machine without a UDF reader, you will be offered
the opportunity to install one.

Download free UDF 1.5 drivers for MacOS and Win95/Win98/WinNT4 from
http://www.roxio.com/en/support/udfwin/index.html
http://www.roxio.com/en/support/udfmac/udfmacreadme.html

(The Windows driver appears to have moved; look at the bottom of
http://www.roxio.com/en/support/roxio_support/ecdc/ecdc_software_updatesv4.jhtml.)

The technical specifications for the UDF filesystem can be found at
http://www.osta.org/specs/index.htm.

UDF is based on the ISO/IEC 13346 standard, now ECMA-167, available from
http://www.ecma-international.org/publications/standards/ECMA-167.htm.

You can find Linux source code under development at
http://trylinux.com/projects/udf/.

Philips has made UDF verification software available (source and binaries) at
http://www.extra.research.philips.com/udf/.

Continue to:

• prev: 6-3] What is packet writing (a/k/a DLA - Drive Letter Access)?
• Index
• next: 6-3-2] Do I want to do packet writing?