VBR MPEG video encoding for ATM networks with dynamic bandwidth renegotiation
AssigneeNEC USA, Inc.
InventorsGopalakrishnan Ramamurthy, Dipankar Raychaudhuri, Daniel Jorge Reininger
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Abstract
A system for variable bit-rate video coding in which encoding bandwidth as characterized by a usage parameter control (UPC) parameters is renegotiated between a video encoder and an asynchronous transfer mode network in order to maintain quality-of-service and save bandwidth. The coding system includes adjusting the video source quantization in a manner for controlling the occupancy level of a buffer while new UPC parameters are requested from an ATM network.
Claims8
A system for VBR video coding in which encoding bandwidth is renegotiated during a call comprising:
- VBR video encoder for generating compressed bit-stream video from input video and for providing frame-size information;
- quantizer controller for selecting a quantization value (Q) based on a target video coding specification and providing the value Q to said VBR video encoder and to a UPC monitor;
- UPC monitor for receiving the value Q, target video coding specifications and frame size information and calculating desired UPC (usage parameter control) parameters;
- and
- control processor for comparing the quantization value Q of a frame with a target quantization (Q.sub.target) and requesting renegotiation of the desired UPC parameters received from the UPC monitor when the values of Q and Q.sub.target are different for a predetermined quantity of frames.
A method of VBR video coding in which encoding bandwidth is renegotiated during a call comprising the steps of:
- generating compressed bit-stream video from input video;
- selecting a quantization value (Q) based on a target video coding specification;
- calculating desired UPC parameters responsive to the quantization value;
- comparing the quantization value Q of a frame and a target quantization value (Q.sub.target);
- and
- sending the desired UPC parameters to a call admission control for renegotiating UPC values when the value Q and value Q.sub.target differ for a predetermined quantity of frames.
Dependencies are inferred from the claim text.