| 摘要 |
A system allows greater dynamic range in fixed-width sample representations of waveforms. Known properties of the waveform are used to determine an unlikely, or impossible, data condition to be used as an exception condition. In a preferred embodiment that is directed to processing of audio waveforms, a first large value transitioning to a second large value of different sign is used to indicate an exception condition. Samples following the exception condition are assumed to be shifted by a predetermined amount so that their representation within the allowable dynamic range of the word results in an extended dynamic range. In a preferred embodiment, pre-processing of a waveform is used to create exception conditions and to perform “peak packing” to shift portions of the waveform that would otherwise become clipped, so that the waveform peaks reside in a shifted position within the digital representation. Analogously, playback processing serves to detect the exception conditions and to restore the peaks of the waveform back to their original status for, e.g., audible digital-to-analog playback, high-resolution processing, etc.
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