Patent ID: 7236521

Claim:
A method of transcoding a digital stream, the method comprising the steps of: decoding a compressed frame of data carried in a first bit stream such that the frame is represented by a first group of sets of run-level pairs defined by a set of quantized levels, which were quantized by a first quantization parameter Q 1 , and an associated set of runs; processing the frame in a domain defined by run and level to generate a second group of sets of run-level pairs representing the frame; decomposing the sets of run-level pairs of the first group of sets of run-level pairs into sets of quantized levels and sets of runs; requantizing in parallel the levels in a given set of quantized levels of the first group using the first quantization parameter Q 1 and a second quantization parameter Q 2 , wherein the values of the requantized levels are smaller than the values of the quantized levels; and encoding the frame using the second group of sets of run-level pairs in a second bit stream, wherein the number of bits of the frame in the second bit stream is less than the number of bits of the frame in the first bit stream.