Layer Jump Recording (LJR) is a writing method used for
DVD-R DL (Dual Layer).
Overview
LJR permits recording the disc per increments called session (see
Optical disc authoring
Optical disc authoring, including DVD and Blu-ray Disc authoring, is the process of assembling source material—video, audio or other data—into the proper logical volume format to then be recorded ("burned") onto an optical disc ( ...
), a.k.a. multi-session. It also permits a faster closing of the disc by saving extraneous padding when the amount of recorded data does not fill-up the disc. It overcomes these limitations of Sequential Recording (SR), the writing method usually applied to write-once optical media.
The layer jump is a switch (jump) between the layer closer to the laser head (referred as L0) to the farther layer (referred as L1), or vice versa. Jumping layers is already necessary for reading multiple layer optical media (so far market released products are limited to two layers despite some research prototypes having up to eight layers), as well as for recording them with Sequential Recording. However the layer jump during the recording occurs only once, at the position called Middle Area, during a Sequential Recording, while it may occur multiple times with Layer Jump Recording.
Two different Layer Jump methods are defined: Manual Layer Jump and Regular Layer Jump. The first require the
software
Software is a set of computer programs and associated software documentation, documentation and data (computing), data. This is in contrast to Computer hardware, hardware, from which the system is built and which actually performs the work.
...
to specify to the hardware each jump point from layer zero to layer one (the jump from layer one to layer zero occurring always at the symmetric jump point). The latter requires the software to specify to the hardware only once the jumping interval size.
This technology was championed by
Pioneer Corporation
commonly referred to as Pioneer, is a Japanese multinational corporation based in Tokyo, that specializes in digital entertainment products. The company was founded by Nozomu Matsumoto in January 1, 1938 in Tokyo as a radio and speaker repair ...
, optical device manufacturer among other things, and introduced to the market in 2005. The physical part of the technology was first specified within
DVD Forum, and then a matching device command set was introduced to the Mt Fuji specification (which eventually was replicated within the
MMC specification). Later the Layer Jump Recording impacted the
UDF file system specification.
Unlike most recording methods, Layer Jump Recording was not unanimously adopted by optical driver manufacturers. The limited backward compatibility with legacy optical devices, complexity of device
firmware
In computing, firmware is a specific class of computer software that provides the low-level control for a device's specific hardware. Firmware, such as the BIOS of a personal computer, may contain basic functions of a device, and may provide ...
implementation, need of significant software update for support and the slightly awkward writing sequencing, slowed down the adoption. In 2006, drives supporting the Layer Jump Recording methods were released by Pioneer itself,
Plextor,
BenQ,
Lite-On
Lite-On (also known as LiteOn and LiteON) is a Taiwanese company that primarily manufactures consumer electronics, including LEDs, semiconductors, computer chassis, monitors, motherboards, optical disc drives, and other electronic components. ...
, and
Sony
, commonly stylized as SONY, is a Japanese multinational conglomerate corporation headquartered in Minato, Tokyo, Japan. As a major technology company, it operates as one of the world's largest manufacturers of consumer and professional ...
. The technology was also supported by optical drive chipsets from key manufacturer MediaTek.
The technology is supported by multiple recording software, but also not unanimously supported.
Nero
Nero Claudius Caesar Augustus Germanicus ( ; born Lucius Domitius Ahenobarbus; 15 December AD 37 – 9 June AD 68), was the fifth Roman emperor and final emperor of the Julio-Claudian dynasty, reigning from AD 54 unt ...
,
Sonic/Roxio,
CyberLink and
Ulead Systems claim support for Layer Jump Recording in their software.
External links
*
tp://ftp.avc-pioneer.com/Mtfuji_8/Spec/FUJI8R100.zip Mt Fuji Commands for Multimedia Devices Version 8, 5.18.1.1 Three Recording Modes for DVD-R DL discby the SFF Committee
Nero - First To Support Layer-Jump Recording (LJR) of dual-layer DVD-R mediaCyberLink Partners with MediaTek to Deliver DVD-R Dual Layer Recording
{{DEFAULTSORT:Layer Jump Recording (Ljr)
SCSI
DVD