Digital signal processing method

A digital signal processing method comprising the steps of:

• (a) composing, from digital video data, a plurality of first encoded video data and a plurality of second encoded video data, wherein a number of the first encoded video data is 2×N (“N” being an even number), and the second encoded video data is 2×N;
• (b) dividing, each of N/2×K channels (“K” being a natural number) of high quality quantized by M bits (“M” being a natural number) into audio data of upper L (“L” being a natural number) bits from most significant bit and audio data of lower M-L bits from least significant bit, wherein “L” is a quantized bits of standard audio data, and “M” is larger than “L” and no larger than twice of “L” (that is, L<M≦2×L);
• (c) forming a plurality of first basic data and a plurality of second basic data,
• wherein a number of the first basic data is “N”, N/2 data of the first basic data have respective K channels high quality audio data of upper L bits multiplexed together with each of N/2 data of the first encoded video data, and remaining N/2 data of the first basic data have respective K channels L bits standard audio data multiplexed together with each of remaining N/2 data of the first encoded video data, and,
• wherein number of the second basic data is “N”, N/2 data of the second basic data have respective K channels audio data of audio data of lower M-L bits multiplexed together with each of N/2 data of the second encoded video data, and remaining N/2 data of the second basic data have respective K channels L bits standard audio data multiplexed together with each of remaining N/2 data of the second encoded video data, and;
• (d) transmitting said plurality of the first basic data in a first data bus;
• and
• (e) transmitting said plurality of the second basic data in a second data bus.