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| author | Robin Haberkorn <robin.haberkorn@googlemail.com> | 2015-04-20 14:58:19 +0200 |
|---|---|---|
| committer | Robin Haberkorn <robin.haberkorn@googlemail.com> | 2015-04-20 14:58:19 +0200 |
| commit | 1174032a180acd0a01615dc52eaf3e6e2f295e3b (patch) | |
| tree | 5c42f0ad56ba9c012ea4f77bf27d3b0b69d72923 | |
| parent | cb29ed5d19e37cb94c02eabf6e6110ac0649e565 (diff) | |
| download | applause2-1174032a180acd0a01615dc52eaf3e6e2f295e3b.tar.gz | |
filters: handle input streams shorter than the frequency stream
| -rw-r--r-- | applause.lua | 42 |
1 files changed, 24 insertions, 18 deletions
diff --git a/applause.lua b/applause.lua index 8abdd1a..c4a27d8 100644 --- a/applause.lua +++ b/applause.lua @@ -739,13 +739,15 @@ function LPFStream:tick() local cur_freq = nil return function() - -- calculate filter coefficients - -- avoid recalculation for constant frequencies + local sample = tick() local freq = freq_tick() - if freq == nil then + + if sample == nil or freq == nil then -- don't filter if we run out of frequency samples - return tick() + return sample elseif freq ~= cur_freq then + -- calculate filter coefficients + -- avoid recalculation for constant frequencies cur_freq = freq local pfreq = cur_freq * radians_per_sample * 0.5 @@ -759,8 +761,6 @@ function LPFStream:tick() b2 = -(1.0 - sqrt2C + C2) * a0 end - local sample = tick() - local y0 = sample + b1*y1 + b2*y2 local result = a0 * (y0 + 2*y1 + y2) @@ -796,13 +796,15 @@ function HPFStream:tick() -- Can we factor out the similarity without sacrificing -- too much performance? return function() - -- calculate filter coefficients - -- avoid recalculation for constant frequencies + local sample = tick() local freq = freq_tick() - if freq == nil then + + if sample == nil or freq == nil then -- don't filter if we run out of frequency samples - return tick() + return sample elseif freq ~= cur_freq then + -- calculate filter coefficients + -- avoid recalculation for constant frequencies cur_freq = freq local pfreq = cur_freq * radians_per_sample * 0.5 @@ -854,13 +856,15 @@ function BPFStream:tick() local cur_freq = nil return function() - -- calculate filter coefficients - -- avoid recalculation for constant frequencies + local sample = tick() local freq = freq_tick() - if freq == nil then + + if sample == nil or freq == nil then -- don't filter if we run out of frequency samples - return tick() + return sample elseif freq ~= cur_freq then + -- calculate filter coefficients + -- avoid recalculation for constant frequencies cur_freq = freq local pfreq = cur_freq * radians_per_sample @@ -913,13 +917,15 @@ function BRFStream:tick() -- NOTE: Very similar to BPFStream.tick() return function() - -- calculate filter coefficients - -- avoid recalculation for constant frequencies + local sample = tick() local freq = freq_tick() - if freq == nil then + + if sample == nil or freq == nil then -- don't filter if we run out of frequency samples - return tick() + return sample elseif freq ~= cur_freq then + -- calculate filter coefficients + -- avoid recalculation for constant frequencies cur_freq = freq local pfreq = cur_freq * radians_per_sample |