new screen: music visualizer

src/visualizer.cpp

@@ -0,0 +1,131 @@
+/***************************************************************************
+ *   Copyright (C) 2008-2009 by Andrzej Rybczak                            *
+ *   electricityispower@gmail.com                                          *
+ *                                                                         *
+ *   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  *
+ *   the Free Software Foundation; either version 2 of the License, or     *
+ *   (at your option) any later version.                                   *
+ *                                                                         *
+ *   This program is distributed in the hope that it will be useful,       *
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
+ *   GNU General Public License for more details.                          *
+ *                                                                         *
+ *   You should have received a copy of the GNU General Public License     *
+ *   along with this program; if not, write to the                         *
+ *   Free Software Foundation, Inc.,                                       *
+ *   51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.              *
+ ***************************************************************************/
+
+#include "visualizer.h"
+
+#ifdef ENABLE_VISUALIZER
+
+#include "global.h"
+
+#include <cerrno>
+#include <cmath>
+#include <cstring>
+#include <fstream>
+#include <fcntl.h>
+
+using Global::myScreen;
+using Global::MainStartY;
+using Global::MainHeight;
+
+Visualizer *myVisualizer = new Visualizer;
+
+const unsigned Visualizer::Samples = 2048;
+const unsigned Visualizer::FFTResults = Samples/2+1;
+
+void Visualizer::Init()
+{
+	w = new Window(0, MainStartY, COLS, MainHeight, "", Config.main_color, brNone);
+	w->SetTimeout(Config.visualizer_fifo_path.empty() ? ncmpcpp_window_timeout : 40 /* this gives us 25 fps */);
+	
+	itsFifo = -1;
+	itsFreqsMagnitude = new unsigned[FFTResults];
+	itsInput = static_cast<double *>(fftw_malloc(sizeof(double)*Samples));
+	itsOutput = static_cast<fftw_complex *>(fftw_malloc(sizeof(fftw_complex)*FFTResults));
+	itsPlan = fftw_plan_dft_r2c_1d(Samples, itsInput, itsOutput, FFTW_ESTIMATE);
+	
+	isInitialized = 1;
+}
+
+void Visualizer::SwitchTo()
+{
+	if (myScreen == this)
+		return;
+	
+	if (!isInitialized)
+		Init();
+	
+	if (hasToBeResized)
+		Resize();
+	
+	myScreen = this;
+	w->Clear();
+	
+	if (itsFifo < 0 && (itsFifo = open(Config.visualizer_fifo_path.c_str(), O_RDONLY | O_NONBLOCK)) < 0)
+		ShowMessage("Couldn't open fifo for reading PCM data: %s", strerror(errno));
+	
+	Global::RedrawHeader = 1;
+}
+
+void Visualizer::Resize()
+{
+	w->Resize(COLS, MainHeight);
+	w->MoveTo(0, MainStartY);
+	hasToBeResized = 0;
+}
+
+std::basic_string<my_char_t> Visualizer::Title()
+{
+	return U("Music visualizer");
+}
+
+void Visualizer::Update()
+{
+	if (itsFifo < 0)
+		return;
+	
+	// if mpd is stopped, clear the screen
+	if (Mpd.GetState() < MPD::psPlay)
+	{
+		w->Clear();
+		return;
+	}
+	
+	// it supports only PCM in format 44100:16:1
+	static int16_t buf[Samples];
+	ssize_t data = read(itsFifo, buf, sizeof(buf));
+	if (data < 0) // no data available in fifo
+		return;
+	
+	// zero old values
+	std::fill(buf+data/sizeof(int16_t), buf+Samples, 0);
+	for (unsigned i = 0; i < Samples; ++i)
+		itsInput[i] = buf[i];
+	
+	fftw_execute(itsPlan);
+	
+	// count magnitude of each frequency and scale it to fit the screen
+	for (unsigned i = 0; i < FFTResults; ++i)
+		itsFreqsMagnitude[i] = sqrt(itsOutput[i][0]*itsOutput[i][0] + itsOutput[i][1]*itsOutput[i][1])/1e5*LINES/5;
+	
+	w->Clear(0);
+	const int freqs_per_col = FFTResults/COLS /* cut bandwidth a little to achieve better look */ * 4/5;
+	for (int i = 0; i < COLS; ++i)
+	{
+		size_t bar_height = 0;
+		for (int j = 0; j < freqs_per_col; ++j)
+			bar_height += itsFreqsMagnitude[i*freqs_per_col+j];
+		bar_height = std::min(bar_height/freqs_per_col, Global::MainHeight);
+		mvwvline(w->Raw(), Global::MainHeight-bar_height, i, 0, bar_height);
+	}
+	w->Refresh();
+}
+
+#endif // ENABLE_VISUALIZER
+