diff options
Diffstat (limited to 'applause.lua')
| -rw-r--r-- | applause.lua | 40 |
1 files changed, 17 insertions, 23 deletions
diff --git a/applause.lua b/applause.lua index 25bb534..4e87d74 100644 --- a/applause.lua +++ b/applause.lua @@ -2121,8 +2121,6 @@ function HPFStream:gtick() b2 = -(1.0 - sqrt2C + C2) * a0 end - local sample = tick() - local y0 = sample + b1*y1 + b2*y2 local result = a0 * (y0 - 2*y1 + y2) @@ -2141,14 +2139,10 @@ end -- to the passband width BPFStream = DeriveClass(MuxableStream) --- Trailing non-stream arguments -BPFStream.sig_last_stream = 2 - function BPFStream:muxableCtor(stream, freq, quality) self.stream = stream self.freq_stream = freq - -- FIXME: Does this make sense to be a stream? - self.quality = quality + self.quality_stream = quality end function BPFStream:gtick() @@ -2165,22 +2159,26 @@ function BPFStream:gtick() local tick = self.stream:gtick() local freq_tick = self.freq_stream:gtick() - local cur_freq = nil + local quality_tick = self.quality_stream:gtick() + local cur_freq, cur_quality return function() local sample = tick() local freq = freq_tick() + local quality = quality_tick() - if sample == nil or freq == nil then + if sample == nil or freq == nil or quality == nil then -- don't filter if we run out of frequency samples return sample - elseif freq ~= cur_freq then + elseif freq ~= cur_freq or quality ~= cur_quality then -- calculate filter coefficients -- avoid recalculation for constant frequencies + -- and quality factors cur_freq = freq + cur_quality = quality local pfreq = cur_freq * radians_per_sample - local pbw = 1 / self.quality*pfreq*0.5 + local pbw = 1 / cur_quality*pfreq*0.5 local C = 1/tan(pbw) local D = 2*cos(pfreq); @@ -2190,8 +2188,6 @@ function BPFStream:gtick() b2 = (1 - C)*a0 end - local sample = tick() - local y0 = sample + b1*y1 + b2*y2 local result = a0 * (y0 - y2) @@ -2210,14 +2206,10 @@ end -- to the passband width BRFStream = DeriveClass(MuxableStream) --- Trailing non-stream arguments -BRFStream.sig_last_stream = 2 - function BRFStream:muxableCtor(stream, freq, quality) self.stream = stream self.freq_stream = freq - -- FIXME: Does this make sense to be a stream? - self.quality = quality + self.quality_stream = quality end function BRFStream:gtick() @@ -2234,23 +2226,27 @@ function BRFStream:gtick() local tick = self.stream:gtick() local freq_tick = self.freq_stream:gtick() - local cur_freq = nil + local quality_tick = self.quality_stream:gtick() + local cur_freq, cur_quality -- NOTE: Very similar to BPFStream.gtick() return function() local sample = tick() local freq = freq_tick() + local quality = quality_tick() - if sample == nil or freq == nil then + if sample == nil or freq == nil or quality == nil then -- don't filter if we run out of frequency samples return sample elseif freq ~= cur_freq then -- calculate filter coefficients -- avoid recalculation for constant frequencies + -- and quality factors cur_freq = freq + cur_quality = quality local pfreq = cur_freq * radians_per_sample - local pbw = 1 / self.quality*pfreq*0.5 + local pbw = 1 / cur_quality*pfreq*0.5 local C = tan(pbw) local D = 2*cos(pfreq); @@ -2260,8 +2256,6 @@ function BRFStream:gtick() b2 = (1 - C)*a0 end - local sample = tick() - local y0 = sample - b1*y1 - b2*y2 local result = a0 * (y0 + y2) + b1*y1 |