diff options
Diffstat (limited to 'src/devices/sound/flt_biquad.cpp')
-rw-r--r-- | src/devices/sound/flt_biquad.cpp | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/src/devices/sound/flt_biquad.cpp b/src/devices/sound/flt_biquad.cpp index de6bfe63462..e56c355ac95 100644 --- a/src/devices/sound/flt_biquad.cpp +++ b/src/devices/sound/flt_biquad.cpp @@ -527,6 +527,7 @@ void filter_biquad_device::recalc() break; // For highpass and friends, block the entire signal. case biquad_type::HIGHPASS1P: + case biquad_type::HIGHPASS1P1Z: case biquad_type::HIGHPASS: case biquad_type::BANDPASS: case biquad_type::PEAK: @@ -563,6 +564,13 @@ void filter_biquad_device::recalc() m_a1 = -m_a1; m_b1 = m_b2 = m_a2 = 0.0; break; + case biquad_type::HIGHPASS1P1Z: + normal = 1.0 / (K + 1.0); + m_b0 = normal; + m_b1 = -normal; + m_a1 = (K - 1.0) * normal; + m_b2 = m_a2 = 0.0; + break; case biquad_type::LOWPASS: m_b0 = Ksquared * normal; m_b1 = 2.0 * m_b0; |