Signal processing apparatus, signal processing method, and program

A signal processing method comprising steps of, by a signal processing apparatus:

• acquiring a PCM signal and a DSD signal;
• upsampling the PCM signal to a sampling frequency of the DSD signal;
• removing a high-frequency component of the DSD signal;
• analyzing a correlation between the DSD signal from which a high-frequency component has been removed and the PCM signal after upsampling, and detecting a delay amount;
• and
• adjusting timing of the DSD signal and the PCM signal after upsampling by using the detected delay amount, and crossfading the DSD signal and the PCM signal after upsampling.

A program for causing a computer to function as:

• an acquisition unit that acquires a PCM signal and a DSD signal;
• a PCM upsampling unit that upsamples the PCM signal to a sampling frequency of the DSD signal;
• a DSD filter that removes a high-frequency component of the DSD signal;
• a delay amount detection unit that analyzes a correlation between the DSD signal from which a high-frequency component has been removed and the PCM signal after upsampling, and detects a delay amount;
• and
• a crossfade unit that adjusts timing of the DSD signal and the PCM signal after upsampling by using the detected delay amount and crossfades the DSD signal and the PCM signal after upsampling.