From 1fadfdf60bb2c02086c2c9689ea44c73bed41571 Mon Sep 17 00:00:00 2001
From: Carl Hetherington <cth@carlh.net>
Date: Tue, 26 Feb 2013 08:15:51 +0000
Subject: Pretty dumb smoothing.

---
 src/lib/analyse_audio_job.cc |  3 +--
 src/lib/audio_analysis.cc    | 28 ++++++++++++++++++++++++++++
 src/lib/audio_analysis.h     |  2 ++
 3 files changed, 31 insertions(+), 2 deletions(-)

(limited to 'src/lib')

diff --git a/src/lib/analyse_audio_job.cc b/src/lib/analyse_audio_job.cc
index 588e9fc3d..bcabb6c91 100644
--- a/src/lib/analyse_audio_job.cc
+++ b/src/lib/analyse_audio_job.cc
@@ -95,8 +95,7 @@ AnalyseAudioJob::audio (shared_ptr<AudioBuffers> b)
 			_current[j][AudioPoint::PEAK] = max (_current[j][AudioPoint::PEAK], fabsf (s));
 
 			if ((_done % _samples_per_point) == 0) {
-				_current[j][AudioPoint::RMS] = 20 * log10 (sqrt (_current[j][AudioPoint::RMS] / _samples_per_point));
-				_current[j][AudioPoint::PEAK] = 20 * log10 (_current[j][AudioPoint::PEAK]);
+				_current[j][AudioPoint::RMS] = sqrt (_current[j][AudioPoint::RMS] / _samples_per_point);
 				_analysis->add_point (j, _current[j]);
 				
 				_current[j] = AudioPoint ();
diff --git a/src/lib/audio_analysis.cc b/src/lib/audio_analysis.cc
index b29ed1707..0cf08c5bd 100644
--- a/src/lib/audio_analysis.cc
+++ b/src/lib/audio_analysis.cc
@@ -31,6 +31,8 @@ using std::ofstream;
 using std::ifstream;
 using std::vector;
 using std::cout;
+using std::max;
+using std::list;
 
 AudioPoint::AudioPoint ()
 {
@@ -121,3 +123,29 @@ AudioAnalysis::write (string filename)
 	f.close ();
 	boost::filesystem::rename (tmp, filename);
 }
+
+float
+AudioAnalysis::smooth (list<float> const & data, AudioPoint::Type t)
+{
+	float val;
+
+	switch (t) {
+	case AudioPoint::PEAK:
+		/* XXX: fall-off, or something...? */
+		val = -200;
+		for (list<float>::const_iterator i = data.begin(); i != data.end(); ++i) {
+			val = max (val, *i);
+		}
+		return val;
+	case AudioPoint::RMS:
+		val = 0;
+		for (list<float>::const_iterator i = data.begin(); i != data.end(); ++i) {
+			val += pow (*i, 2);
+		}
+		return sqrt (val / data.size());
+	default:
+		assert (false);
+	}
+
+	return 0;
+}
diff --git a/src/lib/audio_analysis.h b/src/lib/audio_analysis.h
index c2d8db876..a8cfbdeca 100644
--- a/src/lib/audio_analysis.h
+++ b/src/lib/audio_analysis.h
@@ -22,6 +22,7 @@
 
 #include <iostream>
 #include <vector>
+#include <list>
 
 class AudioPoint
 {
@@ -59,6 +60,7 @@ public:
 
 	void write (std::string);
 
+	static float smooth (std::list<float> const &, AudioPoint::Type);
 
 private:
 	std::vector<std::vector<AudioPoint> > _data;
-- 
cgit v1.2.3