Method and apparatus for testing copy protected compact discs

Abstract

A method and associated apparatus for identifying, to manufacturing test equipment, copy protection information contained on a compact disc (CD). The method includes adding data in standardized industry formats to unused sectors of a CD and providing the capability to test equipment to read the data. The added data is unreadable and ignored by conventional compact disc readers and compact disc drives. The added data is defined by manufacturers and users of copy protection techniques. Additional copy protection verification can be accomplished by using specialized verification tools.

What is claimed is:  
     
         1 . A method of marking a compact disc comprising the acts of: 
 providing a copy protection scheme;    identifying a portion of the compact disc not containing program material;    applying copy protection data related to the copy protection scheme to the identified portion of the compact disc, whereby the copy protection data is readable by compliant test equipment.    
     
     
         2 . The method of  claim 1 , wherein the copy protection data is not readable by compact disc readers.  
     
     
         3 . The method of  claim 1 , wherein a lead-in area of the compact disc is provided, and the copy protection data is applied in the lead-in area.  
     
     
         4 . The method of  claim 1 , wherein a Q-channel of the compact disc is provided, and the copy protection data is in the Q-channel.  
     
     
         5 . The method of  claim 1 , wherein the copy protection data is in 1 to 30 sectors of every 100 sectors of the compact disc.  
     
     
         6 . The method of  claim 1 , wherein the copy protection data is in a 20 to 200 bit word.  
     
     
         7 . The method of  claim 6 , wherein the word comprises in sequence: 
 sync bits;    control bits;    address bits;    identification bits;    user bits; and    cyclic redundancy code bits.    
     
     
         8 . The method of  claim 1 , where the compact disc is one of a CD master, CD stamper, or production CD.  
     
     
         9 . The method of  claim 1 , wherein the copy protection data identifies a particular copy protection scheme.  
     
     
         10 . The method of  claim 9 , wherein the copy protection data identifies a particular supplier of the copy protection scheme.  
     
     
         11 . The method of  claim 7 , wherein the cyclic redundancy code bits are readable only by a compliant reader.  
     
     
         12 . The method of  claim 7 , wherein the cyclic redundancy code bits include a first and a second cyclic redundancy code.  
     
     
         13 . The method of  claim 12 , wherein the first cyclic redundancy code is identifiable by test equipment, and the second cyclic redundancy code is translated by the test equipment.  
     
     
         14 . A compact disc comprising of: 
 program material;    copy protection data, and    data identifying the copy protection data, whereby a compliant test apparatus reads the data identifying the copy protection data.    
     
     
         15 . The compact disc of  claim 14  wherein the copy protection data is in the lead-in area of the compact disc.  
     
     
         16 . The compact disc of  claim 15  wherein the copy protection data is in the Q-Channel portion of the compact disc.  
     
     
         17 . A compact disc test apparatus comprising: 
 a demodulator that receives signals from a compact disc under test wherein the compact disc contains copy protection data and identification data identify the copy protection, the demodulator outputting an EFM signal;    an EFM demodulator coupled to receive the EFM signal and processes the EFM signal into subcode data, the subcode data containing the copy protection data and identification data; and    a subcode processor coupled to the EFM demodulator that receives and reads the subcode data.    
     
     
         18 . The compact disc test apparatus of  claim 17  further comprising: 
 a test equipment interface to the subcode processor, whereby the test equipment interface outputs copy protection information to an operator.  
 
     
     
         19 . The compact disc test apparatus of  claim 17  wherein the subcode data comprises of a first CRC contained in a sector of the compact disc, wherein the first CRC is validated by the test apparatus, wherein a valid first CRC outputs information of the sector of the compact disc containing the CRC.  
     
     
         20 . The compact disc test apparatus of  claim 18  wherein the subcode data comprises of: 
 a first CRC contained in a sector of the compact disc, wherein the first CRC is validated by the test apparatus, wherein a valid first CRC outputs information of the sector of the compact disc containing the CRC.  
 
     
     
         21 . The compact disc test apparatus of  claim 19  wherein the subcode data further comprises: 
 a second CRC contained in the sector of the compact disc, wherein the test apparatus finding an invalid first CRC, validates the second CRC, wherein a valid second CRC allows the test equipment to decode and output the copy protection data.  
 
     
     
         22 . The compact disc test apparatus of  claim 20  wherein the subcode data further comprises: 
 a second CRC contained in the sector of the compact disc, wherein the test apparatus finding an invalid first CRC, validates the second CRC, wherein a valid second CRC allows the test equipment to decode and output the copy protection data.