Provided is a modulation circuit that can correct an output state in real time and reliably modulate an input signal to output the modulated signal. The signal modulation circuit includes a subtractor, an integrator, a chopper circuit, a frequency divider, and a D-type flip-flop. A delay circuit of a sigma delta modulation circuit is not provided to a feedback circuit, and a signal is delayed and quantized in the D-type flip-flop. The chopper circuit inserts a zero level at timing synchronized with a clock signal, so that pulse density modulation is performed.

The present technology relates to a signal processing apparatus, a signal processing method, and a program that make it possible to cope with an output of a PCM signal using one DSD signal. A distribution apparatus includes an extraction section that, in a case where a PCM signal having a predetermined sampling frequency is generated from a DSD signal, extracts a predetermined number of samples from the DSD signal around samples at a predetermined interval determined by the predetermined sampling frequency, and a filtering section that generates the PCM signal having the predetermined sampling frequency by filtering the extracted predetermined number of samples. The present technology is applicable to, for example, a distribution apparatus, etc., that distributes the PCM signal to a client apparatus.

The present technology relates to a signal processing apparatus, a signal processing method, and a program that make it possible to cope with an output of a PCM signal using one DSD signal. A distribution apparatus includes an extraction section that, in a case where a PCM signal having a predetermined sampling frequency is generated from a DSD signal, extracts a predetermined number of samples from the DSD signal around samples at a predetermined interval determined by the predetermined sampling frequency, and a filtering section that generates the PCM signal having the predetermined sampling frequency by filtering the extracted predetermined number of samples. The present technology is applicable to, for example, a distribution apparatus, etc., that distributes the PCM signal to a client apparatus.

There is provided a signal processing device including a signal coincidence detection portion which detects samples, in which values based on a number of times of appearance of bits coincide with each other over a plurality of samples within a pre-set period, between a first modulated signal obtained by delaying an input signal obtained by modulation and a second modulated signal obtained by subjecting the input signal to the modulation again, a signal changeover portion which switches between the first modulated signal and the second modulated signal for outputting, and a switching control portion which controls the switching between the first modulated signal and the second modulated signal by the signal changeover portion in the samples in which the values based on the number of times of the appearance coincide with each other obtained by the signal coincidence detection portion.