Apparatus and computer-implemented process for providing real-time multimedia data transport in a distributed computing system

A network interface for directing video and audio data from a computer network to output devices, comprising:

• means for associating a video output device having a memory with a first channel having a direct memory access engine;
• means for associating an audio output device having a memory with a second channel having a direct memory access engine;
• means for receiving data packets from a computer network into a buffer, wherein each data packet includes header information and data, including an indication of one of the first and second channels;
• and
• means for transferring the data in each data packet directly from the buffer to the memory of the output device corresponding to the indication of the first and second channels using the direct memory access engine of the channel, thereby bypassing copying of the data by the operating system to system level memory.

A network interface for directing video and audio data from a computer network to output devices, comprising:

• a first channel having a direct memory access engine for accessing memory in a video output device;
• a second channel having a direct memory access engine for accessing memory in an audio output device;
• a buffer for receiving data packets from a computer network, wherein each data packet includes header information and data, including an indication of one of the first and second channels;
• and
• a controller for transferring the data in each data packet directly from the buffer to the memory of the output device corresponding to the indication of the first and second channels using the direct memory access engine of the channel, thereby bypassing copying of the data by an operating system to a system level memory.

A process for controlling flow of data over a computer network from a server to a client, comprising:

• sending a request to a server indicating a channel at the client, a file to be accessed and an amount of data to be read from the file;
• sending a message to a server authorizing data to be transferred from the file in an amount less than an amount of space available in a buffer on the network interface;
• receiving data packets from the server and storing the data packets into the buffer, wherein each data packet includes an indication of the channel at the client;
• processing the received data to provide the received data from the buffer to a device associated with the indicated channel;
• and
• repeating steps of sending the message, receiving data packets and processing the received data until the amount of data to be read from the file is received.

An apparatus for controlling flow of data over a computer network from a server to a client, comprising:

• means for sending a request to a server indicating a channel at the client, a file to be accessed and a desired amount of data to be read from the file;
• means for sending a message to a server authorizing data to be transferred from the file in an amount less than an amount of space available in a buffer on the network interface;
• means for receiving data packets from the server and storing the data packets into the buffer, wherein each data packet includes an indication of the channel at the client;
• means for processing the received data to provide the received data from the buffer to a device associated with the indicated channel;
• and
• wherein the means for sending the message, means for receiving data packets and means for processing the received data cooperate to cause the desired amount of data to be received from the file.

A network interface for controlling flow of data over a computer network from a server to one or more channels at a client, comprising:

• a buffer for receiving and storing data packets from the server, wherein each data packet includes an indication of one of the channels at the client;
• a controller that sends a request to a server indicating one of the channels at the client, a file to be accessed and a desired amount of data to be read from the file and that controls flow of transfer of the desired amount of data by sending a sequence of messages to a server authorizing data to be transferred from the file in an amount less than an amount of space available in the buffer on the network interface;
• and
• means for processing the received data to provide the received data from the buffer to a device associated with the indicated channel.

A process for controlling flow of data over a computer network from a server to a client, comprising:

• receiving a request from the client indicating a channel at the client, a file to be accessed and a desired amount of data to be read from the file;
• retrieving data from the file to be accessed and storing the data in a buffer;
• receiving a message from the client authorizing an amount of data to be transferred from the file;
• sending data packets to the client, wherein each data packet includes an indication of the channel at the client and data read from the buffer;
• and
• repeating steps of receiving the message and sending data packets until the amount of data to be read from the file is received.

An apparatus for controlling flow of data over a computer network from a server to a client, comprising:

• means for receiving a request from the client indicating a channel at the client, a file to be accessed and a desired amount of data to be read from the file;
• means for retrieving data from the file to be accessed and storing the data in a buffer;
• means for receiving a message from the client authorizing an amount of data to be transferred from the file;
• means for sending data packets to the client, wherein each data packet includes an indication of the channel at the client and data read from the buffer;
• and
• wherein the means for receiving the message and sending data packets cooperate to transfer to the client the desired amount of data.

A process for transferring media data for a plurality of streams from a server over a computer network to a client during synchronized playback of the media data, wherein the client has one or more output devices for playing back each stream, and wherein each stream has a buffer for storing media data before playback, the process comprising:

• determining an amount of data in the buffer for the output device for each stream;
• selecting one of the streams, wherein the selected stream has the least amount of data in the buffer for the output device for the stream, and selecting a desired amount of data to be read for the stream;
• for the selected stream, issuing one or more requests for data from the server over the computer network until the desired amount of data to be read is received from the server;
• processing the data received from the server to provide the received data from the computer network to the buffer for the output device associated with the selected stream for playback by the output device;
• and
• repeating steps of determining, selecting, issuing and processing during synchronized playback of the media data of the plurality of streams.

A system for transferring media data for a plurality of streams from a server over a computer network to a client during synchronized playback of the media data, wherein the client has one or more output devices for playing back each stream, and wherein each stream has a buffer for storing media data before playback, the process comprising:

• means for determining an amount of data in the buffer for the output device for each stream;
• means for selecting one of the streams, wherein the selected stream has the least amount of data in the buffer for the output device for the stream, and selecting a desired amount of data to be read for the stream;
• means for issuing one or more requests for data from the server over the computer network for the selected stream until the desired amount of data to be read is received from the server;
• means for processing the data received from the server to provide the received data from the computer network to the buffer for the output device associated with the selected stream for playback by the output device;
• and
• wherein the means for determining, selecting, issuing and processing cooperate during synchronized playback of the media data of the plurality of streams.