Abstract: A method and device for producing and delivering constant quality digital video bitstreams over channels of any bit-rate and variability are provided. The method and device may be applicable to any standardized video coding system, but preferably within the MPEG-4 standard. For constant capacity networks, the method and the device re-distribute the coded bits in a constant-quality variable bit-rate bitstream to construct a constant bit-rate bitstream. For variable capacity networks, the method and the device achieve constant quality as described by a metric that incorporate both spatial and temporal visual quality. The method and the device incorporate user, network, and channel parameters in controlling the bit-rate while encoding video material.

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.

Abstract: The present invention provides a method (200, 400, 500, 600), device (300, 400, 500, 600, 700) and digital camera (800) for error control of a wavelet-based image codec, wherein wavelet coefficients are encoded using entropy coding. The method includes: A) utilizing, in a decoder, control information and a plurality of resynchronization markers inserted at arbitrary positions in a wavelet-based image bitstream wherein the control information provides decoding information for decoding at least a forward sequence of wavelet coefficients; and B) detecting errors in an image bitstream and limiting propagation of errors in a decoded image utilizing the control information and the plurality of resynchronization markers.

Abstract: The present invention provides a method (200, 400) and device (500) for, within a variable or fixed block size video compression scheme, providing optimal bit allocation among at least three critical types of data: segmentation, motion vectors and prediction error, or DFD. Since the amount of information represented by one bit for a particular type of data is not equivalent to the information represented by one bit for some other data type, this consideration is taken into account to efficiently encode the video sequence. Thus, a computationally efficient method is provided for optimally encoding a given frame of a video sequence wherein, for a given bit budget the proposed encoding scheme leads to the smallest possible distortion and vice versa, for a given distortion, the proposed encoding scheme leads to the smallest possible rate.

Abstract: The present invention provides a method (200) and device (300) for error control of a video compressed sequence in which error protection for both random and burst channel errors is provided. The error control syntax (100) applies a fixed length packet synchronization system to variable length coded compressed video data, which provides the capability to limit error propagation within the decoded video bit stream. The fixed length packet control information provides information to decode compressed video data in both forward and reverse directions to allow for the recovery of correctly decoded video data within a decoded frame after long bursts of channel errors while reducing the overhead for error control. The error control method also provides video error detection which may be used for error concealment.

Abstract: A method (100, 200), device (300) and microprocessor (400) are provided for selectively compressing video frames of a motion compensated prediction-based video codec based on a predetermined set of compression techniques. An energy estimate of the current displaced frame difference, DFD, is used to compute a ratio between the estimate and a historical mean of energy estimates. The ratio is iteratively compared to a predetermined set of thresholds which are associated with the predetermined set of compression techniques. The comparisons are used to choose a technique based on the thresholds, and a technique is selected to be used for encoding the current DFD.

Abstract: The present invention provides a method (100, 200) and a device (300, 400, 600) for containing and concealing errors which occur in a transmitted video bitstream. Utilizing a plurality of predetermined scanning patterns, particular macroblocks are chosen per frame to have their intensity information encoded and transmitted. This approach provides an efficient method to limit the degradation to the visual quality of a video sequence decoded from a bitstream corrupted by an extended error burst. Concealment of areas within a video sequence that are affected by short error bursts and/or random errors is achieved by estimating the corresponding lost macroblock information from the remaining uncorrupted macroblocks. That is, for each lost macroblock a prediction of the intensity information is generated through the use of a motion vector from a neighboring uncorrupted macroblock.