Mulitple updates to content descriptions using a single command

Abstract

Updates to a content description represented as a tree are contained in a series of fragment update units. Each fragment update unit includes an update command and a navigation path, and may include a fragment payload depending on the update command. The update command is applied to a set of nodes in the tree that are selected using the navigation path. The fragment payload may contain a fragment, a fragment reference, or an attribute. The update command may be an add, delete or replace command. More than one fragment payload may be present in the fragment update unit, with each fragment payload applied to a different one of the nodes from the set selected by the navigation path.

1 . A computerized method of updating a multimedia content description represented as a description tree, the method comprising:
 selecting, by an encoder, an update command to update a set of nodes in the description tree;   formatting a fragment payload if required by the update command;   
     calculating a navigation path that selects the set of nodes, wherein the navigation path is a content-based address that selects a set of nodes based on their content; and 
     creating the fragment update unit from the navigation path, the update command, and the fragment payload if required. 
   
   
       2 . The computerized method of  claim 1 , wherein formatting a fragment payload comprises including an attribute identification tag when an attribute is to be updated. 
   
   
       3 . The computerized method of  claim 1 , wherein the fragment payload is not required when a fragment is to be deleted. 
   
   
       4 . The computerized method of  claim 1 , wherein the content-based address is expressed as an XML XPath location path when the multimedia content description is coded in XML (extensible markup language). 
   
   
       5 . The computerized method of  claim 1  further comprising formatting a plurality of fragment payloads. 
   
   
       6 . The computerized method of  claim 1 , wherein the fragment payload is selected from the group consisting of a fragment, a fragment reference, and an attribute. 
   
   
       7 . The computerized method of  claim 1 , wherein the update command is selected from the group consisting of add, delete, and replace commands. 
   
   
       8 . The computerized method of  claim 1  further comprising:
 sending the fragment update unit as part of an access unit.   
   
   
       9 . A computer-readable storage medium having executable instructions to cause a computer to execute a method comprising:
 selecting an update command to update a set of nodes in a tree representing a multimedia content description;   formatting a fragment payload if required by the update command;   
     calculating a navigation path that selects the set of nodes, wherein the navigation path is a content-based address that selects a set of nodes based on their content; and 
     creating the fragment update unit from the navigation path, the update command, and the fragment payload if required. 
   
   
       10 . The computer-readable storage medium of  claim 9 , wherein formatting a fragment payload comprises including an attribute identification tag when an attribute is to be updated. 
   
   
       11 . The computer-readable storage medium of  claim 9 , wherein the fragment payload is not required when a fragment is to be deleted. 
   
   
       12 . The computer-readable storage medium of  claim 9 , wherein the content-based address is expressed as an XML XPath location path when the multimedia content description is coded in XML (extensible markup language). 
   
   
       13 . The computer-readable storage medium of  claim 9 , wherein the method further comprises formatting a plurality of fragment payloads. 
   
   
       14 . The computer-readable storage medium of  claim 9 , wherein the fragment payload is selected from the group consisting of a fragment, a fragment reference, and an attribute. 
   
   
       15 . The computer-readable storage medium of  claim 9 , wherein the update command is selected from the group consisting of add, delete, and replace commands. 
   
   
       16 . The computer-readable storage medium of  claim 9 , wherein the method further comprises:
 sending the fragment update unit as part of an access unit.   
   
   
       17 . A system for updating a multimedia content description represented as a description tree, the system comprising:
 a processor coupled to a bus;   a memory coupled to the processor through the bus; and   an encode process executed by the processor from the memory to cause the processor
 to select an update command to update a set of nodes in the tree, 
 to format a fragment payload if required by the update command, 
 to calculate a navigation path that selects the set of nodes, wherein the navigation path is a content-based address that selects a set of nodes based on their content, and 
 to create the fragment update unit from the navigation path, the update command, and the fragment payload if required. 
   
   
   
       18 . The system of  claim 17 , wherein the encode process further causes the processor to include an attribute identification tag when an attribute is to be updated to format a fragment payload. 
   
   
       19 . The system of  claim 17 , wherein the fragment payload is not required when a fragment is to be deleted. 
   
   
       20 . The system of  claim 17 , wherein the encode process further causes the processor to format a plurality of fragment payloads. 
   
   
       21 . The system of  claim 17 , wherein the fragment payload is selected from the group consisting of a fragment, a fragment reference, and an attribute. 
   
   
       22 . The system of  claim 17 , wherein the update command is selected from the group consisting of add, delete, and replace commands. 
   
   
       23 . The system of  claim 17 , wherein the system further comprises a communications interface coupled to the processor through the bus and further coupled to a communications medium and the encode process further causes the processor to send the fragment update unit as part of an access unit through the communications interface.