Abstract: A sound source playback unit plays back sound data from a sound source and outputs a playback signal. An amplification unit amplifies the playback signal and outputs the playback signal as an output signal converted to sound in a speaker. A fault detection unit including a first conversion circuit compares the playback signal to a predetermined first threshold, converts a waveform of the playback signal, and outputs the converted waveform as a converted playback signal. A second conversion circuit compares the output signal to a predetermined second threshold, converts a waveform of the output signal, and outputs the converted waveform as a converted output signal. A comparison circuit compares the converted playback signal to the converted output signal, and a determination circuit determines an output of the comparison circuit. Based on the determination, the fault detection unit detects a fault in the amplification unit.

Abstract: A video player provides a video signal to a display device. A selection unit outputs a first signal of an interlaced format or outputting a second signal of a progressive format according to a state of a selection signal. A frequency generator outputs a first frequency or a second frequency according to the state of the selection signal. An adjuster executes a first operation with the signal output from the selection unit for generating a process signal according to the frequency output from the frequency generator. A processor executes a second operation with the process signal for generating the video signal.

Abstract: A signal receiving apparatus includes a frequency converting circuit, a computing circuit, and a control circuit. The frequency converting circuit is for converting a RF signal to respectively generate a first converted signal and a second converted signal according to a first converting frequency and a second converting frequency. The computing circuit is for computing signal quality parameters of the first converted signal and the second converted signal. The control circuit is for outputting a control signal according to the signal quality parameters of the first converted signal and the second converted signal, wherein the control signal corresponds to the converting frequency of the frequency converting circuit.