From becee15370a6b6b73fdcb9316af8a1c9ebeeff09 Mon Sep 17 00:00:00 2001 From: Robin Gareus Date: Tue, 30 Jul 2013 20:22:31 +0200 Subject: [PATCH] RMS meter: remove unused peak-detection --- libs/ardour/kmeterdsp.cc | 16 ++++------------ 1 file changed, 4 insertions(+), 12 deletions(-) diff --git a/libs/ardour/kmeterdsp.cc b/libs/ardour/kmeterdsp.cc index d4460f94cb..181378cf76 100644 --- a/libs/ardour/kmeterdsp.cc +++ b/libs/ardour/kmeterdsp.cc @@ -49,45 +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. {