| 摘要 |
PURPOSE:To evade unnatural impression of sound and to obtain a multiple-speed reproduced sound of a high quality by prohibiting the decoding processing for codes with a long recording interval and making use of only the output of one head in case of the multiple-speed recording of a PCM audio signal that is recorded on an inclined track on a magnetic tape by a rotary head. CONSTITUTION:The locus of a head on a track at the time of double speed reproduction is shown in the figure. An A represents a track recorded by a head AH, and a B shows a track recorded by a head BH. Since the data are reproduced from dispersed tracks, the interleaving pair relation between the data reproduced by the head AH and that reproduced by the head BH in the one turn of a cylinder, collapses. This means that the even-number sample of L-channel and the odd-number sample of R-channel in a frame (n) and the odd-number sample of L-channel and the even-number sample of R-channel in frame n+1 are reproduced, hence sounds in different fields are mixed and outputted. Therefore, only one of the heads is made in a reproducing state, and the decoding processing for a code with a long recording interval is prohibited.
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