Abstract: A method and apparatus for ensuring that MIDI data stored in the subcode channel area of a compact disc is synchronized with the main channel audio of the compact disc. Synchronization problems have been created when transferring audio on a tape from an audio studio to a PCM 1630 tape which is to be used as a compact disc master resulting in a squashing or stretching of the audio data with respect to the MIDI data. One reason this can occur is because F-1 tape records and plays back at 29.97 frames per second while PCM 1630 tape records and plays back at 30 frames per second. The result is that even if the MIDI data and main channel audio data begin in sync, they lose sync during transfers and may drift apart linearly over time as well as be offset with respect to each other. The present invention corrects such synchronization problems by playback simulation, MIDI data/Main channel audio sync measurement and MIDI data adjustment.

Abstract: A system and method for use as an authoring system for the development of CD-ROM products containing interleaved digitized audio and graphic images and other information which may be read and displayed or played under control of a computer. The graphic images and other computer information are stored in a file on the CD-ROM such that when the CD-ROM is accessed by a user, the graphic images and other computer information are displayed and made available to the user synchronously with the playing of the audio information. Combinations of several streams of audio and graphic/computer information can be interleaved into the same file. The system enables an editor to combine various audio files in synchronization with multiple graphic images into a single file which can then be stored on a CD-ROM. Other computer information can also be interleaved with the graphics and audio to allow for control over the playback at runtime.

Abstract: An apparatus and method for encoding data in a text format such as ASCII or EBCDIC on a laser disc or compact disc without affecting the digitized sound by utilizing what is known as the subcode channel of the laser disc or compact disc. By storing text data in the subcode channel region as described herein, it is possible to create subtitles for movies in a number of languages such that the language in which the subtitles appear is user selectable. In this manner, it is possible to create laser discs having subtitle information in, for example, ten languages thereby avoiding the necessity of creating ten separate laser discs, each having a different language used for subtitling.