Sun Microsystems, Inc.

Daniel C W Wong

Ema Patki

Amith Yamasani

Jesus David Rivas

A scheme is provided that permits the use of a selectable depacketization module to depacketize data streams. An RTP session manager is responsible for receiving RTP packets from a network and parsing/processing them. A depacketizer module is located using the type of data received on the stream. Thus a specific depacketizer is located at runtime depending on the coding decoding scheme ('codec') used to compress the incoming data stream. A naming convention is followed in order for a specific depacketizer to be located. The depacketizer receives data that has already been parsed and is in a readable form. The depacketizer outputs this data using a well defined interface. This interface has been designed such that it is generic across a number of codecs. The interface passes all relevant information to the decoder where the actual depacketized data stream will be decompressed. The session manager need not know of any codec details since the depacketizer handles all codec specific issues. A default format is described for data that is output by a depacketizer. There is provision for a depacketizer to output data in this pre-defined format. However, there is also a provision for a depacketizer to output data itself in a pre-defined format. This data is provided to a handler that is aware of this format, so that the integration of depacketizers is seamless. Thus, a depacketizer can be made available as long as it implements certain defined interfaces.

Selectable depacketizer architecture

A method and apparatus for providing plug-in media decoders. Embodiments provide a &ldquo;plug-in&rdquo; decoder architecture that allows software decoders to be transparently downloaded, along with media data. User applications are able to support new media types as long as the corresponding plug-in decoder is available with the media data. Persistent storage requirements are decreased because the downloaded decoder is transient, existing in application memory for the duration of execution of the user application. The architecture also supports use of plug-in decoders already installed in the user computer. One embodiment is implemented with object-based class files executed in a virtual machine to form a media application. A media data type is determined from incoming media data, and used to generate a class name for a corresponding codec (coder-decoder) object. A class path vector is searched, including the source location of the incoming media data, to determine the location of the codec class file for the given class name. When the desired codec class file is located, the virtual machine's class loader loads the class file for integration into the media application. If the codec class file is located across the network at the source location of the media data; the class loader downloads the codec class file from the network. Once the class file is loaded into the virtual machine, an instance of the codec class is created within the media application to decode/decompress the media data as appropriate for the media data type.

Method and apparatus for providing plug-in media decoders

Embodiments of the invention make the underlying transport mechanism transparent to the sender and/or receiver. Using embodiments of the invention, it is not necessary for a sender or receiver to interface with the transport mechanism. Messages are received in a single format which eliminates the need for the sender or receiver to accommodate multiple message formats. A socket mechanism implements bi-directional transmissions and acts as a buffer between the sender or receiver and the underlying transport mechanism. The socket mechanism interfaces with a transport delivery mechanism that receives packets from the physical network. The socket forwards messages received from the transport delivery mechanism to a message processor. Further, the socket forwards messages from the message processor to the transport delivery mechanism. The transport deliver mechanism removes a transport header of messages received from and adds a transport header to messages sent to the physical network.

Method and apparatus for network transport independence

A scheme is provided that permits the use of a selectable depacketization module to depacketize data streams. An RTP session manager is responsible for receiving RTP packets from a network and parsing/processing them. A depacketizer module is located using the type of data received on the stream. Thus a specific depacketizer is located at runtime depending on the coding decoding scheme (&ldquo;codec&rdquo;) used to compress the incoming data stream. A naming convention is followed in order for a specific depacketizer to be located. The depacketizer receives data that has already been parsed and is in a readable form. The depacketizer outputs this data using a well defined interface. This interface has been designed such that it is generic across a number of codecs. The interface passes all relevant information to the decoder where the actual depacketized data stream will be decompressed. The session manager need not know of any codec details since the depacketizer handles all codec specific issues. A default format is described for data that is output by a depacketizer. There is provision for a depacketizer to output data in this pre-defined format. However, there is also a provision for a depacketizer to output data itself in a pre-defined format. This data is provided to a handler that is aware of this format, so that the integration of depacketizers is seamless. Thus, a depacketizer can be made available as long as it implements certain defined interfaces.

A method and apparatus for providing plug-in media decoders. Embodiments provide a &ldquo;plug-in&rdquo; decoder architecture that allows software decoders to be transparently downloaded, along with media data. User applications are able to support new media types as long as the corresponding plug-in decoder is available with the media data. Persistent storage requirements are decreased because the downloaded decoder is transient, existing in application memory for the duration of execution of the user application. The architecture also supports use of plug-in decoders already installed in the user computer. One embodiment is implemented with object-based class files executed in a virtual machine to form a media application. A media data type is determined from incoming media data, and used to generate a class name for a corresponding codec (coder-decoder) object. A class path vector is searched, including the source location of the incoming media data, to determine the location of the codec class file for the given class name. When the desired codec class file is located, the virtual machine's class loader loads the class file for integration into the media application. If the codec class file is located across the network at the source location of the media data, the class loader downloads the codec class file from the network. Once the class file is loaded into the virtual machine, an instance of the codec class is created within the media application to decode/decompress the media data as appropriate for the media data type.

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San Jose, CA, United States of America

Daniel C W Wong