DIGITAL AUDIO PROCESSING SYSTEM COMPATIBLE WITH DVD-VIDEO STANDARD

摘要

PROBLEM TO BE SOLVED: To obtain a high-quality digital audio data by subtracting digital audio data obtained by decimatingly filtering, upsampling and interpolating filtering first digital audio data from the first digital audio data and encoding residual data to make the first digital audio data compatible with a DVD video standard. SOLUTION: Digital audio data whose sampling frequency is 192 kHz and whose number of quantization bits is 24 bits are decimated with the rate of 2:1 by a decimation filter 11 to be data whose sampling frequency is 96 KHz and the data obtained by interpolatingly filtering the decimated data with an interpolation ratio reverse to the decimation rate in an interpolation filter 13 are subtracted from the input digital audio data delayed by a prescribed time in a delay unit 12 by using a subtractor 14 and the obtained residual data are losslessly encoded. A recording part 16 records the data from the decimation filter 11 in the recording area of a DVD and also records the encoded residual data in another area and at the time of reproduction, the part adds the residual data to the audio data.