diff options
Diffstat (limited to 'libs/ardour/kmeterdsp.cc')
| -rw-r--r-- | libs/ardour/kmeterdsp.cc | 39 |
1 files changed, 15 insertions, 24 deletions
diff --git a/libs/ardour/kmeterdsp.cc b/libs/ardour/kmeterdsp.cc index afd0f71719..181378cf76 100644 --- a/libs/ardour/kmeterdsp.cc +++ b/libs/ardour/kmeterdsp.cc @@ -1,6 +1,6 @@ /* Copyright (C) 2008-2011 Fons Adriaensen <fons@linuxaudio.org> - Adopted for Ardour 2013 by Robin Gareus <robin@gareus.org> + Adopted for Ardour 2013 by Robin Gareus <robin@gareus.org> This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by @@ -17,12 +17,13 @@ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ - #include <math.h> -#include "kmeterdsp.h" +#include "ardour/kmeterdsp.h" + float Kmeterdsp::_omega; + Kmeterdsp::Kmeterdsp (void) : _z1 (0), _z2 (0), @@ -36,6 +37,10 @@ Kmeterdsp::~Kmeterdsp (void) { } +void Kmeterdsp::init (int fsamp) +{ + _omega = 9.72f / fsamp; // ballistic filter coefficient +} void Kmeterdsp::process (float *p, int n) { @@ -44,45 +49,37 @@ void Kmeterdsp::process (float *p, int n) // p : pointer to sample buffer // n : number of samples to process - float s, t, z1, z2; + float s, z1, z2; // Get filter state. z1 = _z1; z2 = _z2; - // Process n samples. Find digital peak value for this - // period and perform filtering. The second filter is - // evaluated only every 4th sample - this is just an - // optimisation. - t = 0; + // Perform filtering. The second filter is evaluated + // only every 4th sample - this is just an optimisation. n /= 4; // Loop is unrolled by 4. while (n--) { s = *p++; s *= s; - if (t < s) t = s; // Update digital peak. z1 += _omega * (s - z1); // Update first filter. s = *p++; s *= s; - if (t < s) t = s; // Update digital peak. z1 += _omega * (s - z1); // Update first filter. s = *p++; s *= s; - if (t < s) t = s; // Update digital peak. z1 += _omega * (s - z1); // Update first filter. s = *p++; s *= s; - if (t < s) t = s; // Update digital peak. z1 += _omega * (s - z1); // Update first filter. z2 += 4 * _omega * (z1 - z2); // Update second filter. } - t = sqrtf (t); // Save filter state. The added constants avoid denormals. _z1 = z1 + 1e-20f; _z2 = z2 + 1e-20f; - s = sqrtf (2 * z2); + s = sqrtf (2.0f * z2); if (_flag) // Display thread has read the rms value. { @@ -96,7 +93,6 @@ void Kmeterdsp::process (float *p, int n) } } - /* Returns highest _rms value since last call */ float Kmeterdsp::read () { @@ -105,15 +101,10 @@ float Kmeterdsp::read () return rv; } -void Kmeterdsp::init (int fsamp) -{ - _omega = 9.72f / fsamp; // ballistic filter coefficient -} - void Kmeterdsp::reset () { - _z1 = _z2 = _rms = 0.0; - _flag=false; + _z1 = _z2 = _rms = .0f; + _flag = false; } -/* vi:set ts=8 sts=8 sw=8: */ +/* vi:set ts=8 sts=8 sw=4: */ |