Abstract: Integrated circuit provides single-pass, real-time digital image encoding by digital signal processor for variable bit rate (VBR) control to improve decoded output quality. Possible peak bit rate range for multiple groups of pictures (GOP) and averaged bit rate limit encoded signal bit rate. Possible bit rate range constraint sets upper/lower range, which is pre-specified or dynamically adapted for current and future GOPs. Signal processor calculates perceptual weighting variable at macroblock level for multiple GOPs, nominal quantization parameters for multiple GOPs, quantization parameter associated at picture level, effective bit rate for each GOP, bit allocation for each picture, and total bit allocation for multiple GOPs. Variable rate signal is recordable in DVD or camcorder device.

Abstract: A digital signal processor encodes video signals per MPEG standard to achieve multi-stage, low-complexity motion estimation for interframe video coding. A dual-stage motion prediction module processes a compressed bitstream through pixel-averaging, and then applies a Sum-Of-Absolute-Difference (SOAD) function to the bitstream. A minimum motion vector signal is thereby generated over a search range initially for rough determination, then to provide a more refined estimation, the SOAD function is re-applied to the surrounding 16.times.16 blocks, preferably by full and half-pel vertical and horizontal offsets.

Abstract: A preprocessing method and circuit is utilized to convert a video sequence between a high resolution interlaced format used when the video sequence is read out of a storage medium and a low resolution progressive format suitable for compression encoding at a low bit rate. In accordance with the inventive format conversion preprocessing algorithm, the video sequence in the high resolution interlaced format is first processed by a linear filter with a diamond-shaped passband in y-t space. The output of the linear filter is processed by a non-linear filter and the resulting signal is then decimated to produce the video signal in the low resolution progressive format. The inventive preprocessing algorithm serves to eliminate aliasing, noise, and jerkiness of motion from the sequence in the low resolution progressive format.