Method for encoding digital audio signals and apparatus thereof

A method for encoding a digital audio signal comprising the steps of:

• mapping a digital audio signal into a plurality of sub-bands and outputting the mapped sub-band signals;
• allocating a number of bits to the mapped sub-band signal of each sub-band according to human psychoacoustic properties, on the basis of the mapped sub-band signals;
• compensating said each mapped sub-band signal by receiving a transmitted previous quantized error considering band weight, quantizing the compensated sub-band signal according to said allocated bit number, and transferring the current quantized error to a next quantization of an adjacent frequency component of the same sub-band considering band weight;
• and
• forming a transmit bit stream in frame units from said quantized data.

An apparatus for encoding a digital audio signal comprising:

• a mapping unit for mapping a digital audio signal into a plurality of sub-bands and outputting the mapped sub-band signals;
• a bit number allocating unit for allocating a number of bits to the sub-band signal of each band according to human psychoacoustic properties, on the basis of said mapped sub-band signals;
• a quantizing unit for compensating said each sub-band signal by receiving a transmitted previous quantized error, quantizing the compensated sub-band signal according to said allocated bit number, and transferring the current quantized error to a next quantization of an adjacent frequency component of the same sub-band;
• and
• frame packing means for forming a transmit bit stream in frame units from the quantized data.