| 摘要 |
Apparatus and method for automatically and non-invasively detecting and recording random and/or intermittent errors made during play by digital disc players without supervision, without need for invasive player component testing or disassembly, and without need for analyzing complex waveforms, or use of high level processors.Intermittent errors are found in an actual playback audio signal derived from the output of a digital disc player. A test digital disc prerecorded with a test tone comprising an expected audio signal is played, while an analyzer reads the actual playback audio signal produced, and detects deviations of the actual playback audio signal from the expected audio signal.To detect deviations of the actual playback audio signal from the expected audio signal, the analyzer can comprise an amplitude detection circuit, a phase detection circuit, and a noise detention circuit, each optionally generating character signals that simplify processing.Embodiments allow intermittent error detection for players giving only digital output, through a frame decoder and D-A converter to derive, from the actual playback digital signal, the actual playback audio signal needed.Low required processing power, and the separation and detection of noise are enhanced or facilitated by use of low frequency test tones.
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