CD Basics

 CD Audio










Premastering title graphic

CD & DVD Premastering 

Premastering processes depend on the format, eg CD audio, CD-ROM, DVD-Video, DVD-Audio etc

Before replication can begin the data content of the disc (whether CD or DVD) must be premastered.  This involves taking the source data (as computer files for CD-ROM and DVD discs) and creating a disc image on a suitable tape or disc format.

CD Audio Premastering

CD Audio is the only format where the data (ie audio in this case) is not stored on the disc as data files.  The audio data will normally be provided with the correct sampling frequency (ie 44.1 kHz) and quantisation (16 bits per channel).  Audio premastering therefore usually starts with digital audio (eg on U-matic, DAT or CD-R) and includes the following operations:

  • PQ encoding (adding Table of Contents data with track start times)
  • Editing and Compilation, which is made easy with modern PC based editors.  Audio can be input from various sources including CD, DAT or U-matic, stored on hard disk, edited and written to Exabyte or CD-R. Editing includes compilations, sample rate conversion, cross fades, equalisation, dynamic range compression etc.
  • Sample rate conversion, eg from 48kHz (eg on some DATs) to the 44.1kHz needed for CD.

CD-ROM Premastering

CD-ROM titles can include games, multimedia titles and computer databases and these will need to be created using specific software tools and will include software development and authoring processes.  The end result will usually be a CD-R containing the complete application (or multiple CD-Rs if the application will not fit on one disc), which is used for glass mastering, without any further premastering operations.  In some cases a separate premastering process may be needed and this depends on the final format.  Examples of premastering processes are:

  • Formatting to ISO 9660, HFS or hybrid formats to play on both Windows and Mac platforms from individual files on tape, CD or hard disk.  With the widespread use of CD-Recorders this is becoming increasingly rare as a separate premastering process.
  • Video CD formatting which is normally part of the authoring process.
  • CD EXTRA formatting using the Blue Book multisession format with mode 2 sectors and, optionally, with hybrid format for PC/Macintosh.  This will often involve combining the audio and data sessions ready for glass mastering.
  • CD Graphics and CD TEXT formatting including R to W subcode data.

DVD-Video Premastering

DVD-Video Premastering is usually a complex process, which involves video and audio compression, graphics editing, authoring and testing. The finished application data must be formatted according to the appropriate DVD specification and transferred to DLT (digital linear tape) for glass mastering.  

DVD-5 discs can alternatively be mastered from a DVD-R disc unless the application needs copy protection. DVD-10 discs can also be mastered from two DVD-Rs discs in the same way. DVD-9 discs can be mastered only from DLT.

Where copy protection is required, for DVD-Video or DVD-Audio, certain steps need to be taken during premastering. For CSS (DVD-Video) the CSS flags must be set and the VTS's to be protected must be marked. This is normally easy to carry out using the premastering tools available. 

DVD-Audio Premastering

DVD-Audio premastering is similar to DVD-Video, using similar authoring and premastering tools.  The audio must be prepared as PCM data at the appropriate sampling frequency (eg 96kHz) and quantisation (eg 24 bits) in up to 5 channels (for surround sound).  This audio is then converted to MLP, together with a stereo downmix if required.  Authoring will add optional still images, menus, subpictures and video.

DVD-Audio titles can use CPPM copy protection and the premastering tool must add two dummy files (DVDAUDIO.MKB and DVDAUDIO.BUP) which will, after glass mastering, contain the Media Key Block (MKB) data for that disc.

The result of premastering will normally be an image file plus DDP file and control data stored on a DLT tape.  But DVD-R (both authoring and general use) may be used for a DVD-5 if there is no copy protection or region coding required.

DVD-ROM Premastering

DVD-ROM premastering is similar to CD-ROM premastering with the following differences:

  • DVD-ROM discs are much larger so the data needs to be written to DVD-R or DLT for mastering.
  • DVD-ROMs that require a DVD-9 (dual layer disc) must be premastered and the data written to two DLTs, one for each layer.  Two DVD-Rs are not suitable because the two layers must be a single volume with one file system instead of two.  The final disc will be formatted as a parallel track path disc (unlike DVD-Videos which are usually opposite track path) with the file system data on layer 0.
In this page:
CD Audio Premastering
CD-ROM Premastering
DVD-Video Premastering
DVD-Audio Premastering
DVD-ROM Premastering

Copyright 2001-2003 CalProd.  All Rights Reserved