Dynamic data rate adjustment to maintain throughput of a time varying signal

A method of sustaining communication of a time varying signal over a bus, the method comprising the steps of:

• (a) requesting data representing the time varying signal at a requested quality level;
• (b) receiving the data representing the time varying signal;
• (c) determining a data delivery rate at which the data was received;
• (d) adjusting the requested quality level to an adjusted quality level according to a comparison of the data delivery rate to an expected delivery rate, the adjusted quality level requiring a different number of bits of data per unit time to represent the time varying signal;
• and
• (e) requesting additional data at the adjusted quality level.

A method of transferring motion video from a video source over a bus of a computer system, the method comprising the steps of:

• (a) selecting a digital representation for the motion video, the digital representation defining a requested number of frames per second and a requested number of bits per frame;
• (b) requesting video data from the video source, the video data having a requested bandwidth and format defined by the digital representation;
• (c) receiving a plurality of frames during a first interval;
• (d) evaluating whether the requested number of frames per second was transmitted during the first interval;
• (e) adjusting the requested bandwidth by selecting a different digital representation which alters a quality level of the digital representation based on a comparison of the plurality of frames received during the first interval to the requested number of frames per second.

A system which performs processing of a time varying signal, the system comprising:

• a processor;
• a controller coupled to the processor by a processor bus;
• a source of digital values representing a time varying signal, the source being coupled to the controller;
• a main memory coupled to the processor and the controller, the main memory containing therein:
• a data request routine for requesting digital values representing the time varying signal at a selected quality level;
• a data receipt routine;
• a plurality of data items received by the data receipt routine;
• a value corresponding to a data item count for the plurality of data items;
• an adjustment routine for comparing the value to an expected value determined by the selected quality level and for adjusting the selected quality level so that each data item is represented by a different number of digital values if the data item count does not match the expected value.

An article comprising a machine readable medium containing a program which, when executed by a machine performs:

• (a) transferring a first number of data elements representing a time varying signal by a requested digital representation during a first time period;
• (b) determining an allocated bandwidth value representing a data transfer rate achieved in transferring the first number of data elements;
• and
• (c) adjusting the requested digital representation according to a comparison of the allocated bandwidth value to an expected bandwidth value so that a different number of data elements per unit of time represent the time varying signal.