Efficient binary coding scheme for multimedia content descriptions

A computer-readable storage medium having executable instructions to cause a computer to perform a method comprising:

• determining a context node from a plurality of context nodes in a content description, the plurality of context nodes corresponding to description schemes for a particular multimedia content described by an instance document, wherein the plurality of context nodes are represented in the encoded instance document as a plurality of data structures;
• obtaining a schema associated with the context node, the schema defining required attributes, optional attributes, required elements, and optional elements for the context node, with the optional attributes and optional elements having an order;
• creating a required attributes section containing a value for each required attribute for the context node;
• creating an optional attributes section containing a value for each optional attribute for the context node that appears in the content description;
• creating a required elements section containing a value for each required element for the context node;
• creating an optional elements section containing a value for each optional element for the context node that appears in the content description;
• and
• generating the encoded instance document comprising the attributes and elements sections defined by the schema for each of the plurality of context nodes and a context-node reset code specifying an address for a next context node in the content description for each context node except a last context node, wherein the encoded instance document is a compressed representation of the instance document.

A 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
• determine a context node from a plurality of context nodes in a content description, the plurality of context nodes corresponding to description schemes for a particular multimedia content described by an instance document, wherein the plurality of context nodes are represented in the encoded instance document as a plurality of data structures,
• obtain a schema associated with the context node, the schema defining required attributes, optional attributes, required elements, and optional elements for the context node, with the optional attributes and optional elements having an order,
• create a required attributes section containing a value for each required attribute for the context node,
• create an optional attributes section containing a value for each optional attribute for the context node that appears in the content description,
• create a required elements section containing a value for each required element for the context node,
• create an optional elements section containing a value for each optional element for the context node that appears in the content description, and
• generate the encoded instance document comprising the attributes and elements sections defined by the schema for each of the plurality of context nodes and a context-node reset code specifying an address for a next context node in the content description for each context node except a last context node, wherein the encoded instance document is a compressed representation of the instance document.

A computerized method for decoding an encoded instance document representing a content description, the method comprising:

• obtaining a schema associated with a context node in the instance document, the context node being one of a plurality of context nodes corresponding to description schemes for a particular multimedia content described by the instance document, the schema defining required attributes, optional attributes, required elements, and optional elements for the context node, with the optional attributes and optional elements having an order, wherein the plurality of context nodes are represented in the encoded instance document as a plurality of data structures, and wherein the encoded instance document is a compressed representation of the instance document comprising the attributes and elements sections defined by the schema for each of the plurality of context nodes and a context-node reset code specifying an address for a next context node in the content description for each context node except a last context node;
• extracting a value for each required attribute from a required attributes section when present in the encoded instance document;
• extracting a value for each optional attribute that appears in the content description from an optional attributes section when present in the encoded instance document;
• extracting a value for each required element from a required elements section when present in the encoded instance document;
• extracting a value for each optional element that appears in the content description from an optional elements section when present in the encoded instance document, and
• generating the instance document from the values extracted from the compressed representation of the instance document.

A computer-readable storage medium having executable instructions to cause a computer to perform a method comprising:

• obtaining a schema associated with a context node in an instance document, the context node corresponding to a description scheme for a particular multimedia content described by an instance document, the schema defining required attributes, optional attributes, required elements, and optional elements for the context node, with the optional attributes and optional elements having an order, wherein the plurality of context nodes are represented in the encoded instance document as a plurality of data structures, and wherein the encoded instance document is a compressed representation of the instance document comprising the attributes and elements sections defined by the schema for each of the plurality of context nodes and a context-node reset code specifying an address for a next context node in the content description for each context node except a last context node;
• extracting a value for each required attribute from a required attributes section when present in the encoded instance document;
• extracting a value for each optional attribute that appears in the content description from an optional attributes section when present in the encoded instance document;
• extracting a value for each required element from a required elements section when present in the encoded instance document;
• extracting a value for each optional element that appears in the content description from an optional elements section when present in the encoded instance document;
• and
• generating the instance document from the values extracted from the compressed representation of the instance document.

A system comprising;

• a processor coupled to a bus;
• a memory coupled to the processor through the bus;
• and
• a decode process for an encoded instance document representing a content description, the decode process executed by the processor from the memory to cause the processor to
• obtain a schema associated with a context node in the instance document, the context node being one of a plurality of context nodes corresponding to description scheme for a particular multimedia content described by an instance document, the schema defining required attributes, optional attributes, required elements, and optional elements for the context node, with the optional attributes and optional elements having an order, wherein the plurality of context nodes are represented in the encoded instance document as a plurality of data structures, and wherein the encoded instance document is a compressed representation of the instance document comprising the attributes and elements sections defined by the schema for each of the plurality of context nodes and a context-node reset code specifying an address for a next context node in the content description for each context node except a last context node,
• extract a value for each required attribute from a required attributes section when present in the encoded instance document,
• extract a value for each optional attribute that appears in the content description from an optional attributes section when present in the encoded instance document,
• extract a value for each required element from a required elements section when present in the encoded instance document,
• extract a value for each optional element that appears in the content description from an optional elements section when present in the encoded instance document;
• and
• generate the instance document from the values extracted from the compressed representation of the instance document.