/* Copyright (C) 2008 Jeff Morton (jeffrey.raymond.morton@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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
using System;
using System.Collections;
using System.Drawing;
using System.Drawing.Imaging;
using System.Windows.Forms;
namespace SoundCatcher
{
class AudioFrame
{
private double[] _waveLeft;
private double[] _fftLeft;
private ArrayList _fftLeftSpect = new ArrayList();
private int _maxHeightLeftSpect = 0;
private double[] _waveRight;
private double[] _fftRight;
private ArrayList _fftRightSpect = new ArrayList();
private int _maxHeightRightSpect = 0;
private SignalGenerator _signalGenerator;
private bool _isTest = false;
public bool IsDetectingEvents = false;
public bool IsEventActive = false;
public int AmplitudeThreshold = 16384;
public AudioFrame()
{
}
public AudioFrame(bool isTest)
{
_isTest = isTest;
}
/// <summary>
/// Process 16 bit sample
/// </summary>
/// <param name="wave"></param>
public void Process(ref byte[] wave)
{
IsEventActive = false;
_waveLeft = new double[wave.Length / 4];
_waveRight = new double[wave.Length / 4];
if (_isTest == false)
{
// Split out channels from sample
int h = 0;
for (int i = 0; i < wave.Length; i += 4)
{
_waveLeft[h] = (double)BitConverter.ToInt16(wave, i);
if (IsDetectingEvents == true)
if (_waveLeft[h] > AmplitudeThreshold || _waveLeft[h] < -AmplitudeThreshold)
IsEventActive = true;
_waveRight[h] = (double)BitConverter.ToInt16(wave, i + 2);
if (IsDetectingEvents == true)
if (_waveLeft[h] > AmplitudeThreshold || _waveLeft[h] < -AmplitudeThreshold)
IsEventActive = true;
h++;
}
}
else
{
// Generate artificial sample for testing
_signalGenerator = new SignalGenerator();
_signalGenerator.SetWaveform("Sine");
_signalGenerator.SetSamplingRate(44100);
_signalGenerator.SetSamples(8192);
_signalGenerator.SetFrequency(4096);
_signalGenerator.SetAmplitude(32768);
_waveLeft = _signalGenerator.GenerateSignal();
_waveRight = _signalGenerator.GenerateSignal();
}
// Generate frequency domain data in decibels
_fftLeft = FourierTransform.FFT(ref _waveLeft);
_fftLeftSpect.Add(_fftLeft);
if (_fftLeftSpect.Count > _maxHeightLeftSpect)
_fftLeftSpect.RemoveAt(0);
_fftRight = FourierTransform.FFT(ref _waveRight);
_fftRightSpect.Add(_fftRight);
if (_fftRightSpect.Count > _maxHeightRightSpect)
_fftRightSpect.RemoveAt(0);
}
/// <summary>
/// Render time domain to PictureBox
/// </summary>
/// <param name="pictureBox"></param>
public void RenderTimeDomainLeft(ref PictureBox pictureBox)
{
// Set up for drawing
Bitmap canvas = new Bitmap(pictureBox.Width, pictureBox.Height);
Graphics offScreenDC = Graphics.FromImage(canvas);
Pen pen = new System.Drawing.Pen(Color.WhiteSmoke);
// Determine channnel boundries
int width = canvas.Width;
int height = canvas.Height;
double center = height / 2;
// Draw left channel
double scale = 0.5 * height / 32768; // a 16 bit sample has values from -32768 to 32767
int xPrev = 0, yPrev = 0;
for (int x = 0; x < width; x++)
{
int y = (int)(center + (_waveLeft[_waveLeft.Length / width * x] * scale));
if (x == 0)
{
xPrev = 0;
yPrev = y;
}
else
{
pen.Color = Color.Green;
offScreenDC.DrawLine(pen, xPrev, yPrev, x, y);
xPrev = x;
yPrev = y;
}
}
// Clean up
pictureBox.Image = canvas;
offScreenDC.Dispose();
}
/// <summary>
/// Render time domain to PictureBox
/// </summary>
/// <param name="pictureBox"></param>
public void RenderTimeDomainRight(ref PictureBox pictureBox)
{
// Set up for drawing
Bitmap canvas = new Bitmap(pictureBox.Width, pictureBox.Height);
Graphics offScreenDC = Graphics.FromImage(canvas);
Pen pen = new System.Drawing.Pen(Color.WhiteSmoke);
// Determine channnel boundries
int width = canvas.Width;
int height = canvas.Height;
double center = height / 2;
// Draw left channel
double scale = 0.5 * height / 32768; // a 16 bit sample has values from -32768 to 32767
int xPrev = 0, yPrev = 0;
for (int x = 0; x < width; x++)
{
int y = (int)(center + (_waveRight[_waveRight.Length / width * x] * scale));
if (x == 0)
{
xPrev = 0;
yPrev = y;
}
else
{
pen.Color = Color.Green;
offScreenDC.DrawLine(pen, xPrev, yPrev, x, y);
xPrev = x;
yPrev = y;
}
}
// Clean up
pictureBox.Image = canvas;
offScreenDC.Dispose();
}
/// <summary>
/// Render frequency domain to PictureBox
/// </summary>
/// <param name="pictureBox"></param>
/// <param name="samples"></param>
public void RenderFrequencyDomainLeft(ref PictureBox pictureBox, int samples)
{
// Set up for drawing
Bitmap canvas = new Bitmap(pictureBox.Width, pictureBox.Height);
Graphics offScreenDC = Graphics.FromImage(canvas);
SolidBrush brush = new System.Drawing.SolidBrush(Color.FromArgb(128, 255, 255, 255));
Pen pen = new System.Drawing.Pen(Color.WhiteSmoke);
Font font = new Font("Arial", 10);
// Determine channnel boundries
int width = canvas.Width;
int height = canvas.Height;
double min = double.MaxValue;
double minHz = 0;
double max = double.MinValue;
double maxHz = 0;
double range = 0;
double scale = 0;
double scaleHz = (double)(samples / 2) / (double)_fftLeft.Length;
// get left min/max
for (int x = 0; x < _fftLeft.Length; x++)
{
double amplitude = _fftLeft[x];
if (min > amplitude)
{
min = amplitude;
minHz = (double)x * scaleHz;
}
if (max < amplitude)
{
max = amplitude;
maxHz = (double)x * scaleHz;
}
}
// get left range
if (min < 0 || max < 0)
if (min < 0 && max < 0)
range = max - min;
else
range = Math.Abs(min) + max;
else
range = max - min;
scale = range / height;
// draw left channel
for (int xAxis = 0; xAxis < width; xAxis++)
{
double amplitude = (double)_fftLeft[(int)(((double)(_fftLeft.Length) / (double)(width)) * xAxis)];
if (amplitude == double.NegativeInfinity || amplitude == double.PositiveInfinity || amplitude == double.MinValue || amplitude == double.MaxValue)
amplitude = 0;
int yAxis;
if (amplitude < 0)
yAxis = (int)(height - ((amplitude - min) / scale));
else
yAxis = (int)(0 + ((max - amplitude) / scale));
if (yAxis < 0)
yAxis = 0;
if (yAxis > height)
yAxis = height;
pen.Color = pen.Color = Color.FromArgb(0, GetColor(min, max, range, amplitude), 0);
offScreenDC.DrawLine(pen, xAxis, height, xAxis, yAxis);
}
offScreenDC.DrawString("Min: " + minHz.ToString(".#") + " Hz (�" + scaleHz.ToString(".#") + ") = " + min.ToString(".###") + " dB", font, brush, 0 + 1, 0 + 1);
offScreenDC.DrawString("Max: " + maxHz.ToString(".#") + " Hz (�" + scaleHz.ToString(".#") + ") = " + max.ToString(".###") + " dB", font, brush, 0 + 1, 0 + 18);
// Clean up
pictureBox.Image = canvas;
offScreenDC.Dispose();
}
/// <summary>
/// Render frequency domain to PictureBox
/// </summary>
/// <param name="pictureBox"></param>
/// <param name="samples"></param>
public void RenderFrequencyDomainRight(ref PictureBox pictureBox, int samples)
{
// Set up for drawing
Bitmap canvas = new Bitmap(pictureBox.Width, pictureBox.Height);
Graphics offScreenDC = Graphics.FromImage(canvas);
SolidBrush brush = new System.Drawing.SolidBrush(Color.FromArgb(128, 255, 255, 255));
Pen pen = new System.Drawing.Pen(Color.WhiteSmoke);
Font font = new Font("Arial", 10);
// Determine channnel boundries
int width = canvas.Width;
int height = canvas.Height;
double min = double.MaxValue;
double minHz = 0;
double max = double.MinValue;
double maxHz = 0;
double range = 0;
double scale = 0;
double scaleHz = (double)(samples / 2) / (double)_fftRight.Length;
// get left min/max
for (int x = 0; x < _fftRight.Length; x++)
{
double amplitude = _fftRight[x];
if (min > amplitude && amplitude != double.NegativeInfinity)
{
min = amplitude;
minHz = (double)x * scaleHz;
}
if (max < amplitude && amplitude != double.PositiveInfinity)
{
max = amplitude;
maxHz = (double)x * scaleHz;
}
}
// get right range
if (min < 0 || max < 0)
if (min < 0 && max < 0)
range = max - min;
else
range = Math.Abs(min) + max;
else
range = max - min;
scale = range / height;
// draw right channel
for (int xAxis = 0; xAxis < width; xAxis++)
{
double amplitude = (double)_fftRight[(int)(((double)(_fftRight.Length) / (double)(width)) * xAxis)];
if (amplitude == double.NegativeInfinity || amplitude == double.PositiveInfinity || amplitude == double.MinValue || amplitude == double.MaxValue)
amplitude = 0;
int yAxis;
if (amplitude < 0)
yAxis = (int)(height - ((amplitude - min) / scale));
else
yAxis = (int)(0 + ((max - amplitude) / scale));
if (yAxis < 0)
yAxis = 0;
if (yAxis > height)
yAxis = height;
pen.Color = pen.Color = Color.FromArgb(0, GetColor(min, max, range, amplitude), 0);
offScreenDC.DrawLine(pen, xAxis, height, xAxis, yAxis);
}
offScreenDC.DrawString("Min: " + minHz.ToString(".#") + " Hz (�" + scaleHz.ToString(".#") + ") = " + min.ToString(".###") + " dB", font, brush, 0 + 1, 0 + 1);
offScreenDC.DrawString("Max: " + maxHz.ToString(".#") + " Hz (�" + scaleHz.ToString(".#") + ") = " + max.ToString(".###") + " dB", font, brush, 0 + 1, 0 + 18);
// Clean up
pictureBox.Image = canvas;
offScreenDC.Dispose();
}
/// <summary>
/// Render waterfall spectrogram to PictureBox
/// </summary>
/// <param name="pictureBox"></param>
public void RenderSpectrogramLeft(ref PictureBox pictureBox)
{
Bitmap canvas = new Bitmap(pictureBox.Width, pictureBox.Height);
Graphics offScreenDC = Graphics.FromImage(canvas);
// Determine channnel boundries
int width = canvas.Width;
int height = canvas.Height;
double min = double.MaxValue;
double max = double.MinValue;
double range = 0;
if (height > _maxHeightLeftSpect)
_maxHeightLeftSpect = height;
// get min/max
for (int w = 0; w < _fftLeftSpect.Count; w++)
for (int x = 0; x < ((double[])_fftLeftSpect[w]).Length; x++)
{
double amplitude = ((double[])_fftLeftSpect[w])[x];
if (min > amplitude)
{
min = amplitude;
}
if (max < amplitude)
{
max = amplitude;
}
}
// get range
if (min < 0 || max < 0)
if (min < 0 && max < 0)
range = max - min;
else
range = Math.Abs(min) + max;
else
range = max - min;
// lock image
PixelFormat format = canvas.PixelFormat;
BitmapData data = canvas.LockBits(new Rectangle(0, 0, width, height), ImageLockMode.ReadOnly, format);
int stride = data.Stride;
int offset = stride - width * 4;
try
{
unsafe
{
byte* pixel = (byte*)data.Scan0.ToPointer();
// for each cloumn
for (int y = 0; y <= height; y++)
{
if (y < _fftLeftSpect.Count)
{
// for each row
for (int x = 0; x < width; x++, pixel += 4)
{
double amplitude = ((double[])_fftLeftSpect[_fftLeftSpect.Count - y - 1])[(int)(((double)(_fftLeft.Length) / (double)(width)) * x)];
double color = GetColor(min, max, range, amplitude);
pixel[0] = (byte)0;
pixel[1] = (byte)color;
pixel[2] = (byte)0;
pixel[3] = (byte)255;
}
pixel += offset;
}
}
}
}
catch (Exception ex)
{
Console.WriteLine(ex.ToString());
}
// unlock image
canvas.UnlockBits(data);
// Clean up
pictureBox.Image = canvas;
offScreenDC.Dispose();
}
/// <summary>
/// Render waterfall spectrogram to PictureBox
/// </summary>
/// <param name="pictureBox"></param>
public void RenderSpectrogramRight(ref PictureBox pictureBox)
{
Bitmap canvas = new Bitmap(pictureBox.Width, pictureBox.Height);
Graphics offScreenDC = Graphics.FromImage(canvas);
// Determine channnel boundries
int width = canvas.Width;
int height = canvas.Height;
double min = double.MaxValue;
double max = double.MinValue;
double range = 0;
if (height > _maxHeightRightSpect)
_maxHeightRightSpect = height;
// get min/max
for (int w = 0; w < _fftRightSpect.Count; w++)
for (int x = 0; x < ((double[])_fftRightSpect[w]).Length; x++)
{
double amplitude = ((double[])_fftRightSpect[w])[x];
if (min > amplitude)
{
min = amplitude;
}
if (max < amplitude)
{
max = amplitude;
}
}
// get range
if (min < 0 || max < 0)
if (min < 0 && max < 0)
range = max - min;
else
range = Math.Abs(min) + max;
else
range = max - min;
// lock image
PixelFormat format = canvas.PixelFormat;
BitmapData data = canvas.LockBits(new Rectangle(0, 0, width, height), ImageLockMode.ReadOnly, format);
int stride = data.Stride;
int offset = stride - width * 4;
try
{
unsafe
{
byte* pixel = (byte*)data.Scan0.ToPointer();
// for each cloumn
for (int y = 0; y <= height; y++)
{
if (y < _fftRightSpect.Count)
{
// for each row
for (int x = 0; x < width; x++, pixel += 4)
{
double amplitude = ((double[])_fftRightSpect[_fftRightSpect.Count - y - 1])[(int)(((double)(_fftRight.Length) / (double)(width)) * x)];
double color = GetColor(min, max, range, amplitude);
pixel[0] = (byte)0;
pixel[1] = (byte)color;
pixel[2] = (byte)0;
pixel[3] = (byte)255;
}
pixel += offset;
}
}
}
}
catch (Exception ex)
{
Console.WriteLine(ex.ToString());
}
// unlock image
canvas.UnlockBits(data);
// Clean up
pictureBox.Image = canvas;
offScreenDC.Dispose();
}
/// <summary>
/// Get color in the range of 0-255 for amplitude sample
/// </summary>
/// <param name="min"></param>
/// <param name="max"></param>
/// <param name="range"></param>
/// <param name="amplitude"></param>
/// <returns></returns>
private static int GetColor(double min, double max, double range, double amplitude)
{
double color;
if (min != double.NegativeInfinity && min != double.MaxValue & max != double.PositiveInfinity && max != double.MinValue && range != 0)
{
if (min < 0 || max < 0)
if (min < 0 && max < 0)
color = (255 / range) * (Math.Abs(min) - Math.Abs(amplitude));
else
if (amplitude < 0)
color = (255 / range) * (Math.Abs(min) - Math.Abs(amplitude));
else
color = (255 / range) * (amplitude + Math.Abs(min));
else
color = (255 / range) * (amplitude - min);
}
else
color = 0;
return (int)color;
}
}
}
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