Abstract: A copy-protected compact disc includes, within a single session, a table of contents (TOC) and a Video CD index (VI). Each track (T) is prefaced by unrecoverable data (UD) at a track start position (ATOC) indicated by the table of contents (TOC). However, the Video CD index (VI) indicates the actual position (AP) of the tracks. DVD players use the Video CD index (VI) to locate the tracks, while the CD-ROM drives use the table of contents (TOC) and read the unrecoverable data (UD), which prevents them from reading the subsequent track (T). The unrecoverable data (UD) may be prefaced by data pointers (DP) which cause the CD-ROM drive to load a player program in response to the error condition. The player program can be used to play the tracks (T), but restricts copying. Subchannel data (P; DX) causes audio CD players to ignore the Video CD index (VI) and the unrecoverable data (UD), and to play the tracks (T) at their actual start positions (AP).

Abstract: A copy-protected compact disc includes, within a single session, a table of contents (TOC) and a Video CD index (VI). Each track (T) is prefaced by unrecoverable data (UD) at a track start position (ATOC) indicated by the table of contents (TOC). However, the Video CD index (VI) indicates the actual position (AP) of the tracks. DVD players use the Video CD index (VI) to locate the tracks, while the CD-ROM drives use the table of contents (TOC) and read the unrecoverable data (UD), which prevents them from reading the subsequent track (T). The unrecoverable data (UD) may be prefaced by data pointers (DP) which cause the CD-ROM drive to load a player program in response to the error condition. The player program can be used to play the tracks (T), but restricts copying. Subchannel data (P; DX) causes audio CD players to ignore the Video CD index (VI) and the unrecoverable data (UD), and to play the tracks (T) at their actual start positions (AP).

Abstract: A copy-protected compact disc includes, within a single session, a table of contents (TOC) and a Video CD index (VI). Each track (T) is prefaced by unrecoverable data (UD) at a track start position (ATOC) indicated by the table of contents (TOC). However, the Video CD index (VI) indicates the actual position (AP) of the tracks. DVD players use the Video CD index (VI) to locate the tracks, while CD-ROM drives use the table of contents (TOC) and read the unrecoverable data (UD), which prevents them from reading the subsequent track (T). The unrecoverable data (UD) may be prefaced by data pointers (DP) which cause the CD-ROM drive to load a player program in response to the error condition. The player program can be used to play the tracks (T), but restricts copying. Subchannel data (P; DX) causes audio CD players to ignore the Video CD index (VI) and the unrecoverable data (UD), and to play the tracks (T) at their actual start positions (AP).

Abstract: A data payload PD is recorded on a compact disc in a format including a lead-in indicating a track start address ATOC and a subchannel P which changes state at a payload start address AP, subsequent to the track start address ATOC. Data ED recorded at the track start address ATOC includes unrecoverable data. Where the data payload PD is an audio track, an audio-only player begins to search sequentially from the track start address ATOC until the subchannel changes state, and reproduces the audio track from that point. A data player, on the other hand, begins to reproduce data from the track start address ATOC. When the unrecoverable data is read, the read operation is aborted, as it appears that the data has been corrupted. This operation cannot be easily circumvented, because it is not normally acceptable to ignore corrupt CD-ROM data.