Patent ID: 6501798
Filing Date: 2002-12-31
Classification: H04N

Abstract:
In a video encoder comprising motions estimation means (22) providing a predicted block for each predefined block based upon estimating the motion between said predefined block of a current image and the corresponding block in a previous image, transform means (16) for transforming a prediction error resulting from the difference between said predicted block and said predefined block into the frequency domain, and quantizing means (20) for quantizing coefficients of the prediction error in the frequency domain and providing the quantized coefficients to a video multiplex coding unit (30), wherein said quantized coefficients are de-quantized (24) and inverse transformed (26) to give back said prediction error and add it to said predicted block whereby the result is provided to said motion estimation means in order to get a new current predicted block;a device comprising means for generating from one video sequence, multiple video bitstreams of different bit-rates and corresponding to different quality levels, said device further comprising: means for building a hierarchical H.263 bitstream including at least one and up to four substreams each corresponding to one different quality level generated from said video sequence, a CPM bit of the H.263 bitstream being set to 1, a PSBI 2 bit field being set to the number of different quality level substreams stored, a first Group Of Block comprising a 2 bit field GSBI being set to the first quality level bitstream, the corresponding Macroblock layer comprising MVD, MVD2, MVD3, MVD4, MVDB bit fields storing motion information generated from said video sequence for said first quality level bitstream, following Group Of Blocks comprising a 2 bit field GSBI being set to the value corresponding to the range of the following quality level bitstreams wherein the corresponding Macroblock layer MVD, MVD2, MVD3, MVD4, MVDB bit fields do not store motion information.