| 摘要 |
<p>A signal processing apparatus generating, from left-channel and right-channel stereo signals (SL,SR), a centre-channel signal (SC). The stereo signals (SL,SR) are split into different frequency bands by two identical filter banks (1L,1R). Within each frequency band, the phase difference between the stereo signals is determined by a phase difference detector (204). For each frequency band, a gain is calculated by gain generator (205) as a function of the phase difference. The gain is set to 0 for phase differences of ±180° and to 1 for phase differences of 0°. This gain is applied by a multiplier (203) to the average (201,202) of the stereo signals within each frequency band. The resulting outputs of all frequency bands are synthesised by a signal synthesiser (13) to form the resulting centre-channel signal (SC).</p> |
