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RMS meter: remove unused peak-detection

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This commit is contained in:
Robin Gareus 2013-07-30 20:22:31 +02:00
parent 362976a2fd
commit ab7842edfd
1 changed files with 4 additions and 12 deletions
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16
libs/ardour/kmeterdsp.cc
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@ -49,45 +49,37 @@ void Kmeterdsp::process (float *p, int n)
// p : pointer to sample buffer // p : pointer to sample buffer
// n : number of samples to process // n : number of samples to process
float s, t, z1, z2; float s, z1, z2;
// Get filter state. // Get filter state.
z1 = _z1; z1 = _z1;
z2 = _z2; z2 = _z2;
// Process n samples. Find digital peak value for this // Perform filtering. The second filter is evaluated
// period and perform filtering. The second filter is // only every 4th sample - this is just an optimisation.
// evaluated only every 4th sample - this is just an
// optimisation.
t = 0;
n /= 4; // Loop is unrolled by 4. n /= 4; // Loop is unrolled by 4.
while (n--) while (n--)
{ {
s = *p++; s = *p++;
s *= s; s *= s;
if (t < s) t = s; // Update digital peak.
z1 += _omega * (s - z1); // Update first filter. z1 += _omega * (s - z1); // Update first filter.
s = *p++; s = *p++;
s *= s; s *= s;
if (t < s) t = s; // Update digital peak.
z1 += _omega * (s - z1); // Update first filter. z1 += _omega * (s - z1); // Update first filter.
s = *p++; s = *p++;
s *= s; s *= s;
if (t < s) t = s; // Update digital peak.
z1 += _omega * (s - z1); // Update first filter. z1 += _omega * (s - z1); // Update first filter.
s = *p++; s = *p++;
s *= s; s *= s;
if (t < s) t = s; // Update digital peak.
z1 += _omega * (s - z1); // Update first filter. z1 += _omega * (s - z1); // Update first filter.
z2 += 4 * _omega * (z1 - z2); // Update second filter. z2 += 4 * _omega * (z1 - z2); // Update second filter.
} }
t = sqrtf (t);
// Save filter state. The added constants avoid denormals. // Save filter state. The added constants avoid denormals.
_z1 = z1 + 1e-20f; _z1 = z1 + 1e-20f;
_z2 = z2 + 1e-20f; _z2 = z2 + 1e-20f;
s = sqrtf (2 * z2); s = sqrtf (2.0f * z2);
if (_flag) // Display thread has read the rms value. if (_flag) // Display thread has read the rms value.
{ {