Bandwidth efficient communication of user data in digital television data stream

Abstract

A method and apparatus are provided for communicating VBI user information for digital television. A syntax is provided which allows the transport of closed captions, non-realtime video, sampled video and AMOL. Non-realtime video can be used to transport various types of data, such as a vertical interval test signal (VITS) through the system at full resolution. The provision in the syntax of a count for each type of VBI user information enables the adjustment of a digital television data stream to accommodate variable amounts and types of such information without space being reserved in advance. The provision of a priority number in the syntax enables decoders to discard VBI user information priorities which are not supported by the particular decoder.

We claim:  
     
       1. A bandwidth efficient method for communicating variable amounts of a plurality of different types of user information in a digital television data stream, comprising the steps of: 
       extracting user information from portions of input video data that correspond to vertical blanking intervals (VBIs) of successive video frames;  
       providing a first identifier for each type of the extracted user information, each of said first identifiers specifying a count of the user information associated with the identifier;  
       inserting said first identifiers and the associated user information into a video syntax for said digital television data stream such that each type of said user information can be identified by a relative position of said first identifiers in the video syntax; and  
       communicating said data stream including said first identifiers and associated user information to a receiver;  
       wherein said first identifiers enable the adjustment of said data stream to accommodate variable amounts of different types of user information without space being reserved for specific amounts and type of user information in advance.  
     
     
       2. A method in accordance with  claim 1  comprising the further steps of: 
       providing a second identifier for each type of the extracted user information; and  
       inserting said second identifiers into the video syntax;  
       said second identifiers designating a priority of the particular type of user information specified by said first identifiers;  
       wherein said priority corresponds to a hardware capability level for processing the particular type of user information.  
     
     
       3. A method in accordance with  claim 2  wherein said first and second identifiers precede the user information associated therewith in said video syntax, with each second identifier following a counterpart first identifier. 
     
     
       4. A method in accordance with  claim 1  wherein the extracted user information comprises non-realtime video data, said method comprising the further step of: 
       providing second and third identifiers for said non-realtime video data, said second identifiers designating a sequence number and said third identifiers designating segment numbers for portions of said non-realtime video data.  
     
     
       5. A method in accordance with  claim 1  wherein the extracted user information comprises AMOL data, said method comprising the further step of: 
       providing second identifiers to designate whether the AMOL data is null data represented in an abbreviated form.  
     
     
       6. A method in accordance with  claim 5  comprising the further step of: 
       providing third identifiers to designate parity values for said AMOL data.  
     
     
       7. A method in accordance with  claim 1  wherein the extracted user information inserted into said video syntax comprises at least one of closed caption data, non-realtime video data, sampled video data, and AMOL data. 
     
     
       8. A method in accordance with  claim 1  wherein said video syntax is assembled to provide a first identifier specifying a count for closed caption data, followed by a first identifier specifying a count for non-realtime video data, followed by a first identifier specifying a count for sampled video data, followed by a first identifier specifying a count for AMOL data. 
     
     
       9. A method in accordance with  claim 1  wherein said video syntax is assembled to provide a first identifier specifying a count for closed caption data, a first identifier specifying a count for non-realtime video data, a first identifier specifying a count for sampled video data, and a first identifier specifying a count for AMOL data. 
     
     
       10. A method for decoding user information communicated in accordance with the method of  claim 7  comprising the steps of: 
       receiving said digital television data stream at a decoder and detecting said first identifiers therein; and  
       processing said closed caption data when the first identifier specifying said count of closed caption data indicates the presence of such data.  
     
     
       11. A method for decoding user information communicated in accordance with the method of  claim 7  comprising the steps of: 
       receiving said digital television data stream at a decoder and detecting said first identifiers therein; and  
       processing said non-realtime video data when the first identifier specifying said count of non-realtime video data indicates the presence of such data.  
     
     
       12. A method for decoding user information communicated in accordance with the method of  claim 7  comprising the steps of: 
       receiving said digital television data stream at a decoder and detecting said first identifiers therein; and  
       processing said sampled video data when the first identifier specifying said count of sampled video data indicates the presence of such data.  
     
     
       13. A method for decoding user information communicated in accordance with the method of  claim 7  comprising the steps of: 
       receiving said digital television data stream at a decoder and detecting said first identifiers therein; and  
       processing said AMOL data when the first identifier specifying said count of AMOL data indicates the presence of such data.  
     
     
       14. A method in accordance with  claim 7  wherein: 
       prior to communicating said digital television data stream to said receiver, second identifiers are provided in said video syntax, said second identifiers designating a priority of the particular type of user information specified by said first identifiers;  
       wherein said priority corresponds to a hardware capability level for processing the particular type of user information.  
     
     
       15. A method in accordance with  claim 14  wherein the decoding of said user information comprises the further steps of: 
       detecting said second identifiers in the received data stream; and  
       inhibiting the processing of particular user information if the priority thereof identified by the corresponding second identifier is not a priority supported by the decoder.  
     
     
       16. A method in accordance with  claim 8  comprising the further steps of: 
       providing second identifiers for the extracted user information, said second identifiers designating a priority of the particular type of user information specified by said first identifiers;  
       wherein said priority corresponds to a hardware capability level for processing the particular type of user information;  
       providing third and fourth identifiers for said non-realtime video data, said third identifiers designating a sequence number and said fourth identifiers designating segment numbers for said non-realtime video portions; and  
       providing fifth and sixth identifiers for said AMOL data, said fifth identifiers designating whether the AMOL data is null data represented in an abbreviated form and said sixth identifiers designated parity values for said AMOL data.  
     
     
       17. Receiver apparatus for decoding user information contained in digital television signals, comprising: 
       means for detecting information from a video syntax carried by a video blanking portion of a received digital television signal by identifying at least one of:  
       (a) a count of closed caption data which is associated with the information according to a relative position of the count in the video syntax; and  
       (b) a count of non-realtime video data which is associated with the information according to a relative position of the count in the video syntax;  
       means responsive to said detecting means for processing said closed caption data when said count of closed caption data indicates the presence of such data in said vertical blanking portion; and  
       means responsive to said detecting means for processing said non-realtime video data when said count of non-realtime video data indicates the presence of such data in said vertical blanking portion.  
     
     
       18. Receiver apparatus in accordance with  claim 17  further comprising: 
       means for detecting information in said video syntax identifying at least one of a count of sampled video data and a count of AMOL data;  
       means responsive to said detecting means for processing said sampled video data when said count of sampled video data indicates the presence of such data in said vertical blanking portion; and  
       means responsive to said detecting means for processing said AMOL data when said count of AMOL data indicates the presence of such data in said vertical blanking portion.  
     
     
       19. Receiver apparatus in accordance with  claim 17  wherein each of said processing means comprise: 
       means for detecting information identifying a priority of the received data;  
       said priority corresponding to a hardware capability level for processing the user information; and  
       means responsive to said means for detecting information identifying said priority for inhibiting the processing of the data if said identified priority is not supported by the receiver apparatus.  
     
     
       20. Receiver apparatus in accordance with  claim 17  wherein said received digital television signal has an MPEG format. 
     
     
       21. Apparatus for communicating user information in a bandwidth efficient manner in a digital television data stream, comprising: 
       means for extracting user information from portions of digital video data that correspond to vertical blanking intervals of successive video frames;  
       means for quantifying at least one particular type of user information extracted by said extracting means and associating a first identifier therewith, said first identifier specifying a count of the particular type of user information following the identifier; and  
       means for combining the extracted user information including the first identifiers associated therewith with active video portions of said digital video data to form said digital television data stream such that each type of said user information can be identified by a relative position of said first identifiers in the data stream;  
       wherein said first identifiers enable the adjustment of said data stream to accommodate variable amounts and types of user information without space being reserved for said user information in advance.  
     
     
       22. Apparatus in accordance with  claim 21  further comprising: 
       means for associating second identifiers with the extracted user information, said second identifiers designating a priority of the particular type of user information specified by said first identifiers; wherein:  
       said priority corresponds to a hardware capability level for processing the user information.  
     
     
       23. Apparatus in accordance with  claim 22  wherein each of said second identifiers is inserted into said data stream following a counterpart first identifier. 
     
     
       24. Apparatus in accordance with  claim 21  wherein said means for quantifying and associating provides a first identifier specifying a count for closed caption data and a first identifier specifying a count for non-realtime video data. 
     
     
       25. Apparatus in accordance with  claim 24  wherein said means for quantifying and associating further provides a first identifier specifying a count for sampled video data and a first identifier specifying a count for AMOL data. 
     
     
       26. A bandwidth efficient method for processing an input video signal carrying user information to provide a corresponding digital output television signal with compressed pictures for transmission to a receiver, comprising the steps of: 
       ( a )  extracting at least a first type of user information from the vertical blanking intervals  ( VBIs )  of at least one picture of the input video signal that is used to produce one of the compressed pictures;    
       ( b )  counting a number of constructs of the extracted first type of user information that are to be provided in the corresponding compressed picture;    
       ( c )  responsive to said step  ( b ) , providing a count syntax element for a video syntax for said output television signal that designates the number of the constructs for the corresponding compressed picture;    
       ( d )  compressing an active video portion of the input video signal to provide the compressed pictures;    
       ( e )  providing the constructs in the video syntax after the associated count syntax element for the corresponding compressed picture such that the constructs are correlated with the associated first type of user information based on a position of the constructs in the video syntax; and    
       ( f )  combining the compressed pictures with the corresponding video syntax to provide the output television signal; wherein:    
       
         the count syntax element allows the corresponding constructs to be carried in the video syntax without requiring space to be reserved in advance for a specific number of constructs per compressed picture. 
       
     
     
       27. The method of  claim 26 , wherein: 
       
         the count syntax element is variable to designate a variable number of constructs in different compressed pictures. 
       
     
     
       28. The method of  claim 26 , wherein: 
       
         each of the constructs comprises at least one byte. 
       
     
     
       29. The method of  claim 26 , wherein: 
       
         each of the constructs comprises at least one closed caption character. 
       
     
     
       30. The method of  claim 26 , wherein: 
       
         the count syntax element designates when a zero number of constructs are provided in the corresponding compressed picture. 
       
     
     
       31. A bandwidth efficient apparatus for processing an input video signal carrying user information to provide a corresponding digital output television signal with compressed pictures for transmission to a receiver, comprising: 
         means for extracting at least a first type of user information for the vertical blanking intervals  ( VBIs )  of at least one picture of the input video signal that is used to produce one of the compressed pictures;    
       
         means for counting a number of constructs of the extracted first type of user information that are to be provided in the corresponding compressed picture;  
       
       
         means, responsive to said counting means, for providing a count syntax element for a video syntax for said output television signal that designates the number of the constructs for the corresponding compressed picture;  
       
       
         means for compressing an active video portion of the input video signal to provide the compressed pictures;  
       
       
         means for providing the constructs in the video syntax after the associated count syntax element for the corresponding compressed picture such that the constructs are correlated with the associated first type of user information based on a position of the constructs in the video syntax; and  
       
       
         means for combining the compressed pictures with the corresponding video syntax to provide the output television signal; wherein:  
       
       
         the count syntax element allows the corresponding constructs to be carried in the video syntax without requiring space to be reserved in advance for a specific number of constructs per compressed picture. 
       
     
     
       32. The apparatus of  claim 31 , wherein: 
       
         the count syntax element is variable to designate a variable number of constructs in different compressed pictures. 
       
     
     
       33. The apparatus of  claim 31 , wherein: 
       
         each of the constructs comprises at least one byte. 
       
     
     
       34. The apparatus of  claim 31 , wherein: 
       
         each of the constructs comprises at least one closed caption character. 
       
     
     
       35. The apparatus of  claim 31 , wherein: 
       
         the count syntax element designates when a zero number of constructs are provided in the corresponding compressed picture. 
       
     
     
       36. A method for decoding user information carried in a received digital television signal, comprising the steps of: 
       ( a )  detecting a count syntax element for at least a first type of user information from a video syntax in at least one video blanking portion of a compressed picture in the received digital television signal;    
       ( b )  determining a number of constructs of the first type of user information for the corresponding compressed picture in accordance with the detected count syntax element;    
       
         wherein the constructs are provided in the video syntax after the associated count syntax element for the corresponding compressed picture;  
       
       ( c )  recovering the constructs from the video syntax in response to said step  ( b ) ; and    
       ( d )  correlating the constructs with the first type of user information based on a position of the constructs in the video syntax; wherein:    
       
         the count syntax element allows the corresponding constructs to be carried in the video syntax without requiring space to be reserved in advance for a specific number of constructs per compressed picture. 
       
     
     
       37. The method of  claim 36 , wherein: 
       
         the count syntax element is variable to designate a variable number of constructs in different compressed pictures. 
       
     
     
       38. The method of  claim 36 , wherein: 
       
         each of the constructs comprises at least one byte. 
       
     
     
       39. The method of  claim 36 , wherein: 
       
         each of the constructs comprises at least one closed caption character. 
       
     
     
       40. The method of  claim 36 , wherein: 
       
         the count syntax element designates when a zero number of constructs are provided in the corresponding compressed picture. 
       
     
     
       41. An apparatus for decoding user information carried in a received digital television signal, comprising: 
       
         means for detecting a count syntax element for at least a first type of user information from a video syntax in at least one video blanking portion of a compressed picture in the received digital television signal;  
       
       
         means for determining a number of constructs of the first type of user information for the corresponding compressed picture in accordance with the detected count syntax element;  
       
       
         wherein the constructs are provided in the video syntax after the associated count syntax element for the corresponding compressed picture;  
       
       
         means, responsive to said determining means, for recovering the constructs from the video syntax; and  
       
       
         means for correlating the constructs with the first type of user information based on a position of the constructs in the video syntax; wherein:  
       
       
         the count syntax element allows the corresponding constructs to be carried in the video syntax without requiring space to be reserved in advance for a specific number of constructs per compressed picture. 
       
     
     
       42. The apparatus of  claim 41 , wherein: 
       
         the count syntax element is variable to designate a variable number of constructs in different pictures. 
       
     
     
       43. The apparatus of  claim 41 , wherein: 
       
         each of the constructs comprises at least one byte. 
       
     
     
       44. The apparatus of  claim 41 , wherein: 
       
         each of the constructs comprises at least one closed caption character. 
       
     
     
       45. The apparatus of  claim 41 , wherein: 
       
         the count syntax element designates when a zero number of constructs are provided in the corresponding compressed picture. 
       
     
     
       46. A bandwidth efficient digital television signal, comprising: 
       
         at least one compressed picture carrying a video syntax with a count syntax element and associated constructs of at least a first type of user information; wherein:  
       
       
         the count syntax element designates a number of the constructs for the corresponding compressed picture;  
       
         the first type of user information is extracted from vertical blanking intervals  ( VBIs )  of pictures of an input video signal;    
       
         the count is obtained by counting a number of the constructs of the extracted first type of user information for the corresponding compressed picture;  
       
       
         the constructs are provided in the video syntax after the associated count syntax element for the corresponding compressed picture such that the constructs are correlated with the associated first type of user information based on a position of the constructs in the video syntax; and  
       
       
         the count syntax element allows the corresponding constructs to be carried in the video syntax without requiring space to be reserved in advance for a specific number of constructs per compressed picture.