Bi-directional video compression for real-time video streams during transport in a packet switched network

A data processing system comprising:

• a processor;
• a memory coupled to the processor;
• a network interface device coupled to the memory;
• a coder/decoder coupled to the memory;
• a utility which when executed on the processor enables the data processing system to perform the functions of:
• detecting a real-time flow containing multiple frames;
• receiving a sequence of frames from the real-time flow, wherein the real-time flow is received and re-transmitted as a stream of data packets;
• retrieving one or more of (a) a differentiated services code point packet classification, (b) a quality of service class identifier and (c) a real-time transport protocol content-type parameter, from one or more packet headers of received data packets;
• determining whether the real-time flow is a real-time transport protocol video flow based on one or more of the differentiated services code point packet classification, the quality of service class identifier and the real-time transport protocol content-type parameter;
• retrieving stored differentiated services code point parameter values corresponding to the real-time flow, comprising parameter values for frame size, optimal end-to-end delay and optimal end-to-end jitter;
• obtaining a value of an expected one way end-to-end delay from a source of the real-time flow to a target of the real-time flow, wherein the value is retrieved from a real-time transport control protocol report;
• calculating an estimated end-to-end delay to the target based on an actual delay from the source to a receiving node and an estimated remaining transport delay from the receiving node to the target;
• evaluating a processing opportunity delay by comparing the estimated end-to-end delay to the target with the value for optimal end-to-end delay for the real-time flow;
• initiating bi-directional compression of one or more frames of the real-time flow based on one or more of (a) the processing opportunity delay, (b) the estimated remaining transport delay to the target, (c) a complexity ratio that is obtained from a ratio of the intra-coded frame rate and the predicted frame rate, and (d) an overall frame rate;
• and
• when the real-time flow is re-compressed, forwarding the real-time flow with inserted bi-predictive frames to a target.

A network server comprising:

• a processor;
• a computer readable medium coupled to the processor;
• and
• program code on the computer readable medium that when executed by the processor provides the functionality of:
• detecting a real-time flow containing multiple frames;
• receiving a sequence of frames from the real-time video flow, wherein the video flow is received and re-transmitted as a stream of data packets;
• retrieving one or more of (a) a differentiated services code point packet classification, (b) a quality of service class identifier and (c) a real-time transport protocol content-type parameter, from one or more packet headers of received data packets;
• and
• determining whether the real-time flow is an real-time transport protocol video flow based on one or more of the differentiated services code point packet classification, the quality of service class identifier and the real-time transport protocol content-type parameter;
• retrieving stored differentiated services code point parameter values corresponding to the real-time flow, comprising parameter values for frame size, optimal end-to-end delay and optimal end-to-end jitter;
• obtaining a value of an expected one way end-to-end delay from a source of the real-time flow to a target of the real-time flow, wherein the value is retrieved from a real-time transport control protocol report;
• calculating an estimated end-to-end delay to the target based on an actual delay from the source to a receiving node and an estimated remaining transport delay from the receiving node to the target;
• evaluating a processing opportunity delay by comparing the estimated end-to-end delay to the target with the value for optimal end-to-end delay for the real-time flow;
• initiating bi-directional compression of one or more frames of the real-time flow based on one or more of (a) the processing opportunity delay, (b) the estimated remaining transport delay to the target, (c) a complexity ratio that is obtained from a ratio of the intra-coded frame rate and the predicted frame rate, and (d) an overall frame rate and
• when the real-time flow is re-compressed, forwarding the real-time flow with inserted bi-predictive frames to a target.