Method and device for control and compatible delivery of digitally compressed visual data in a heterogeneous communication network

Abstract

A method and apparatus automatically manipulates a digitally compressed video bitstream such that the result is compatible with different bandwidth and error resilience requirements at a receiving point in a heterogeneous communication network. The method and device provide for analysis of bitstream header information to determine its relevant coding syntax parameters. Feedback from the receiving point on the network is then used to identify error robustness requirements for an intermediate bitstream. The bitstream is then manipulated by an error robustness regulator to achieve error protection in the network. The bitrate requirements of the network establish a selection of relevant and irrelevant bits from the bitstream The present method and device include identification of irrelevant and low priority video bits; intentional introduction of packet losses to reduce bitrate while maintaining visual quality; use of replacement tags for irrelevant and low priority components of the bitstream for compatible decoding by a wide array of decoders; and insertion of resynchronization tags and translation of predictively coded video packet bits for the improvement of error resilience.