[Performous-commit] Tapio Vierros : Implement microphone pass-through in audio engine.

[Tapio V. <aa...@us...>]

Module: performous
Branch: pass-through
Commit: 36e8ba88cdb79b06903656990bb29a1155d980ff

Author: Tapio Vierros <tap...@gm...>
Date:   Thu Aug 19 17:08:07 2010 +0300

Implement microphone pass-through in audio engine.

* No way to disable it, it even invades menus.
* Requires very low suggestedLatency (so some platforms are probably b0rked).

---

 game/audio.cc            |   13 +++++++++++++
 game/libda/portaudio.hpp |    2 +-
 game/pitch.cc            |   18 ++++++++++++++++++
 game/pitch.hh            |   15 ++++++++++++++-
 4 files changed, 46 insertions(+), 2 deletions(-)

diff --git a/game/audio.cc b/game/audio.cc
index f86e728..a9ae880 100644
--- a/game/audio.cc
+++ b/game/audio.cc
@@ -246,6 +246,7 @@ struct Output {
 	std::auto_ptr<Synth> synth;
 	std::auto_ptr<Music> preloading;
 	boost::ptr_vector<Music> playing, disposing;
+	std::vector<Analyzer*> mics;
 	boost::ptr_map<std::string, Sample> samples;
 	std::vector<Command> commands;
 	volatile bool paused;
@@ -294,6 +295,15 @@ struct Output {
 			}
 			++i;
 		}
+		// Mix in microphones (if pass-through is enabled)
+		// TODO: Create a config var for enable/disable
+		if (mics.size() > 0) {
+			for (float *i = begin; i < end; ++i) *i *= 0.3; // Decrease music volume
+			for (size_t i = 0; i < mics.size(); ++i) {
+				if (mics[i])
+					mics[i]->output(begin, end);  // Do the actual mixing
+			}
+		}
 		// Mix in the samples currently playing
 		{
 			// samples should not be created/destroyed on the fly
@@ -454,6 +464,9 @@ struct Audio::Impl {
 				std::cerr << "Audio device '" << *it << "': " << e.what() << std::endl;
 			}
 		}
+		// Assign mic buffers to the output for pass-through
+		for (size_t i = 0; i < analyzers.size(); ++i)
+			output.mics.push_back(&analyzers[i]);
 	}
 };
 
diff --git a/game/libda/portaudio.hpp b/game/libda/portaudio.hpp
index 4211545..91aa525 100644
--- a/game/libda/portaudio.hpp
+++ b/game/libda/portaudio.hpp
@@ -44,7 +44,7 @@ namespace portaudio {
 		PaStreamParameters params;
 		Params(PaStreamParameters const& init = PaStreamParameters()): params(init) {
 			// Some useful defaults so that things just work
-			channelCount(2).sampleFormat(paFloat32).suggestedLatency(0.05);
+			channelCount(2).sampleFormat(paFloat32).suggestedLatency(0.01);
 		}
 		Params& channelCount(int val) { params.channelCount = val; return *this; }
 		Params& device(PaDeviceIndex val) { params.device = val; return *this; }
diff --git a/game/pitch.cc b/game/pitch.cc
index 773183a..0428bcf 100644
--- a/game/pitch.cc
+++ b/game/pitch.cc
@@ -47,6 +47,24 @@ Analyzer::Analyzer(double rate, std::size_t step):
 	}
 }
 
+void Analyzer::output(float* begin, float* end) {
+	size_t frames = end - begin;
+	if (frames > outbuf.size() * 2) return;
+	size_t i = 0;
+	boost::mutex::scoped_lock l(m_mutex);
+	while (begin != end) {
+		float value = outbuf[i] * 15.0; // Amplify
+		*begin++ += value; // L channel
+		*begin++ += value; // R channel
+		++i;
+	}
+	// Remove used data from the buffer
+	outbuf.erase(outbuf.begin(), outbuf.begin() + frames/2);
+	// If the ouput buffer grows very big, reset it
+	if (outbuf.size() > 5000) outbuf.clear();
+}
+
+
 namespace {
 	bool sqrLT(float a, float b) { return a * a < b * b; }
 
diff --git a/game/pitch.hh b/game/pitch.hh
index 0fa159d..8b50021 100644
--- a/game/pitch.hh
+++ b/game/pitch.hh
@@ -3,8 +3,10 @@
 #include <complex>
 #include <vector>
 #include <list>
+#include <deque>
 #include <algorithm>
 #include <cmath>
+#include <boost/thread.hpp>
 
 /// struct to represent tones
 struct Tone {
@@ -15,7 +17,7 @@ struct Tone {
 	double stabledb; ///< stable decibels
 	double harmonics[MAXHARM]; ///< harmonics array
 	std::size_t age; ///< age
-	Tone(); 
+	Tone();
 	void print() const; ///< prints Tone
 	bool operator==(double f) const; ///< equality operator
 	void update(Tone const& t); ///< update Tone
@@ -47,8 +49,11 @@ class Analyzer {
 	Analyzer(double rate, std::size_t step = 200);
 	/** Add input data to buffer. This is thread-safe (against other functions). **/
 	template <typename InIt> void input(InIt begin, InIt end) {
+		std::vector<float> tempbuf; // Values to be inserted to the pass-through buffer
+		tempbuf.reserve(1024); // Let's reserve some space already in advance
 		while (begin != end) {
 			float s = *begin;
+			tempbuf.push_back(s); // Add to pass-through buffer
 			++begin;
 			m_peak *= 0.999;
 			float p = s * s;
@@ -60,6 +65,10 @@ class Analyzer {
 			m_buf[w] = s;
 			m_bufWrite = w2;
 		}
+		// No need to lock the mutex before this
+		boost::mutex::scoped_lock l(m_mutex);
+		// Insert the new values to the pass-through buffer
+		outbuf.insert(outbuf.end(), tempbuf.begin(), tempbuf.end());
 	}
 	/** Call this to process all data input so far. **/
 	void process();
@@ -87,8 +96,12 @@ class Analyzer {
 		m_oldfreq = (best ? best->freq : 0.0);
 		return best;
 	}
+	/** Give data away for mic pass-through */
+	void output(float* begin, float* end);
 
   private:
+	boost::mutex m_mutex;
+	std::deque<float> outbuf;
 	std::size_t m_step;
 	double m_rate;
 	std::vector<float> m_window;