Linux UDF Application Level Toolkit for Block Addressable WORM Edition

Overview

This special edition of the UDF Application Level Toolkit is designed for use with block addressable media, such as MO WORM (write once) and UDO WORM (write once) discs from Sony, Plasmon and other manufacturers. It can also provide WORM emulation on standard re-writable block addressable devices such as hard disk drives and removable hard disk drive based systems such as the RDX-1000 product line marketed by Dell Computer.

This edition includes all of the functionality of the standard UDF Application Level Toolkit, plus the block addressable WORM support in a single toolkit.

Here is how the software components of the toolkit integrate with Linux:

Linux Application Level Developer Toolkit Block Addressabele WORM Edition (I)

The Block Addressable WORM Edition of the UDF Application Level Toolkit is designed to quickly and easily integrate formatting, reading and writing in OSTA compliant UDF within your proprietary application. In addition to the media support provided by the standard Application Level Toolkit, this version supports block addressable WORM media using the UDF specification writing method referred to in the OSTA UDF specification as the "4096" writing option.

The Toolkit consists of the read/write UDF file system with built in support for standard and "4096" operations, a formatting module in module format, documentation, sample code, and a development license.

The software is written in C++ with a plain C "wrapper". The file system supports all published UDF versions, including 1.02, 1.5, 2.0, 2.0.1, 2.5 and 2.6 for a wide variety of storage devices.

The formatting module is designed for easy integration into your application, so there is a single interface for all functions designed by you.

The file system supports packet writing, session writing and direct block writing methods, depending on the media type and the UDF version selected.

In addition to supporting DVD-R, DVD+R, DVD-RW, DVD+RW, DVD-RAM, BD-R, BD-RE, re-writable MO, re-writable UDO-1 & UDO-2 and a variety of block addressable devices (including most hard disk drives and USB flash memory devices), this version adds support for MO, UDO-1 & UDO-2 WORM media.

Block Addressable WORM Writing vs. Session WORM Writing in UDF

With block addressable WORM media, when a file is written to the disc, the UDF file system writes each block of data directly to the disc in a number of write operations. At the end of each write operation it adds a separate file and directory block called an Information Control Block (ICB) that references the location of the written file extent. Each ICB includes an unwritten section for future linking to subsequent ICB's.

Write operations continue until the entire file is written to the disc. Each time another ICB is added to reference each new file extent and a reference pointer is written to the previous ICB to link the ICB's into a chain. This facilitates keeping track of every version of every file written to the disk.

Files deleted by an application running in Linux can be marked deleted but will remain on the disc and can be accessed by an application if the developer desires to provide access.

Block Addressable WORM Writing (B)

VAT Based Session Writing for Sequential Recording Media in UDF

When writing to sequential recording media such as DVD-R or BD-R, the toolkit uses the OSTA UDF "session writing" method that requires creation of a virtual session "image file" on the system's hard disk that includes file and directory metadata, and then writes the combined file data and directory data in a single sequential writing session to the disc as a second step. Depending on the device and application requirement, each writing session may be finished by adding a session directory table known as a " VAT" . Multiple writing sessions may be peformed to the same disc, in which case the last VAT includes pointers to previous VAT's for access to all files written to the disc.

VAT Based Session Writing (C)

The selection of a writing method should be based primarily on the device and media type specified for your application to support. This edition of the Toolkit provides support for both within the same file system.

OSTA Compliant

The UDF format created by the software is 100% OSTA UDF compliant, which ensures readability on any OSTA UDF compliant system. ( "OSTA " stands for the Optical Storage Technology Association, the organization that publishes and maintains the UDF specification.)

For more information on UDF specification, contact OSTA at: www.osta.org.

System Requirements

Intel or AMD based PC's running Linux kernel v2.6.21 or later.

API

To obtain a copy of the Toolkit API, please contact us at support@softarch.com

Qualification

If you need further information about qualification, please click here.