soundviewer.aspx.htm

这个程序开发于C#环境中

        _isTest = isTest;
    }

    <span class="code-SummaryComment">///</span><span class="code-comment"> <span class="code-SummaryComment">&lt;</span><span class="code-SummaryComment">summary</span><span class="code-SummaryComment">&gt;</span>
</span>
    <span class="code-SummaryComment">///</span><span class="code-comment"> Process 16 bit sample
</span>
    <span class="code-SummaryComment">///</span><span class="code-comment"> <span class="code-SummaryComment">&lt;</span><span class="code-SummaryComment">/</span><span class="code-SummaryComment">summary</span><span class="code-SummaryComment">&gt;</span>
</span>
    <span class="code-SummaryComment">///</span><span class="code-comment"> <span class="code-SummaryComment">&lt;</span><span class="code-SummaryComment">param</span> <span class="code-SummaryComment">name="wave"</span><span class="code-SummaryComment">&gt;</span><span class="code-SummaryComment">&lt;</span><span class="code-SummaryComment">/</span><span class="code-SummaryComment">param</span><span class="code-SummaryComment">&gt;</span>
</span>
    <span class="code-keyword">public</span> <span class="code-keyword">void</span> Process(<span class="code-keyword">ref</span> <span class="code-keyword">byte</span>[] wave)
    {
        _waveLeft = <span class="code-keyword">new</span> <span class="code-keyword">double</span>[wave.Length / <span class="code-digit">4</span>];
        _waveRight = <span class="code-keyword">new</span> <span class="code-keyword">double</span>[wave.Length / <span class="code-digit">4</span>];
        <span class="code-keyword">if</span> (_isTest == <span class="code-keyword">false</span>)
        {
            <span class="code-comment">//</span><span class="code-comment"> Split out channels from sample
</span>
            <span class="code-keyword">int</span> h = <span class="code-digit">0</span>;
            <span class="code-keyword">for</span> (<span class="code-keyword">int</span> i = <span class="code-digit">0</span>; i &lt; wave.Length; i += <span class="code-digit">4</span>)
            {
                _waveLeft[h] = (<span class="code-keyword">double</span>)BitConverter.ToInt16(wave, i);
                _waveRight[h] = (<span class="code-keyword">double</span>)BitConverter.ToInt16(wave, i + <span class="code-digit">2</span>);
                h++;
            }
        }
        <span class="code-keyword">else</span>
        {
            <span class="code-comment">//</span><span class="code-comment"> Generate artificial sample for testing
</span>
            _signalGenerator = <span class="code-keyword">new</span> SignalGenerator();
            _signalGenerator.SetWaveform(<span class="code-string">"</span><span class="code-string">Sine"</span>);
            _signalGenerator.SetSamplingRate(<span class="code-digit">44100</span>);
            _signalGenerator.SetSamples(<span class="code-digit">16384</span>);
            _signalGenerator.SetFrequency(<span class="code-digit">5000</span>);
            _signalGenerator.SetAmplitude(<span class="code-digit">32768</span>);
            _waveLeft = _signalGenerator.GenerateSignal();
            _waveRight = _signalGenerator.GenerateSignal();
        }
        <span class="code-comment">//</span><span class="code-comment"> Generate frequency domain data in decibels
</span>
        _fftLeft = FourierTransform.FFTDb(<span class="code-keyword">ref</span> _waveLeft);
        _fftRight = FourierTransform.FFTDb(<span class="code-keyword">ref</span> _waveRight);
    }

    <span class="code-SummaryComment">///</span><span class="code-comment"> <span class="code-SummaryComment">&lt;</span><span class="code-SummaryComment">summary</span><span class="code-SummaryComment">&gt;</span>
</span>
    <span class="code-SummaryComment">///</span><span class="code-comment"> Render time domain to PictureBox
</span>
    <span class="code-SummaryComment">///</span><span class="code-comment"> <span class="code-SummaryComment">&lt;</span><span class="code-SummaryComment">/</span><span class="code-SummaryComment">summary</span><span class="code-SummaryComment">&gt;</span>
</span>
    <span class="code-SummaryComment">///</span><span class="code-comment"> <span class="code-SummaryComment">&lt;</span><span class="code-SummaryComment">param</span> <span class="code-SummaryComment">name="pictureBox"</span><span class="code-SummaryComment">&gt;</span><span class="code-SummaryComment">&lt;</span><span class="code-SummaryComment">/</span><span class="code-SummaryComment">param</span><span class="code-SummaryComment">&gt;</span>
</span>
    <span class="code-keyword">public</span> <span class="code-keyword">void</span> RenderTimeDomain(<span class="code-keyword">ref</span> PictureBox pictureBox)
    {
        <span class="code-comment">//</span><span class="code-comment"> Set up for drawing
</span>
        _canvasTimeDomain = <span class="code-keyword">new</span> Bitmap(pictureBox.Width, pictureBox.Height);
        Graphics offScreenDC = Graphics.FromImage(_canvasTimeDomain);
        SolidBrush brush = <span class="code-keyword">new</span> System.Drawing.SolidBrush
                    (Color.FromArgb(<span class="code-digit">0</span>, <span class="code-digit">0</span>, <span class="code-digit">0</span>));
        Pen pen = <span class="code-keyword">new</span> System.Drawing.Pen(Color.WhiteSmoke);
        <span class="code-comment">//</span><span class="code-comment"> Determine channel boundaries
</span>
        <span class="code-keyword">int</span> width = _canvasTimeDomain.Width;
        <span class="code-keyword">int</span> center = _canvasTimeDomain.Height / <span class="code-digit">2</span>;
        <span class="code-keyword">int</span> height = _canvasTimeDomain.Height;
        offScreenDC.DrawLine(pen, <span class="code-digit">0</span>, center, width, center);
        <span class="code-keyword">int</span> leftLeft = <span class="code-digit">0</span>;
        <span class="code-keyword">int</span> leftTop = <span class="code-digit">0</span>;
        <span class="code-keyword">int</span> leftRight = width;
        <span class="code-keyword">int</span> leftBottom = center - <span class="code-digit">1</span>;
        <span class="code-keyword">int</span> rightLeft = <span class="code-digit">0</span>;
        <span class="code-keyword">int</span> rightTop = center + <span class="code-digit">1</span>;
        <span class="code-keyword">int</span> rightRight = width;
        <span class="code-keyword">int</span> rightBottom = height;
        <span class="code-comment">//</span><span class="code-comment"> Draw left channel
</span>
        <span class="code-keyword">double</span> yCenterLeft = (leftBottom - leftTop) / <span class="code-digit">2</span>;
        <span class="code-keyword">double</span> yScaleLeft = <span class="code-digit">0</span>.<span class="code-digit">5</span> * (leftBottom - leftTop) / <span class="code-digit">32768</span>;  
            <span class="code-comment">//</span><span class="code-comment"> a 16 bit sample has values from -32768 to 32767
</span>
        <span class="code-keyword">int</span> xPrevLeft = <span class="code-digit">0</span>, yPrevLeft = <span class="code-digit">0</span>;
        <span class="code-keyword">for</span> (<span class="code-keyword">int</span> xAxis = leftLeft; xAxis &lt; leftRight; xAxis++)
        {
            <span class="code-keyword">int</span> yAxis = (<span class="code-keyword">int</span>)(yCenterLeft + (_waveLeft[_waveLeft.Length / 
                (leftRight - leftLeft) * xAxis] * yScaleLeft));
            <span class="code-keyword">if</span> (xAxis == <span class="code-digit">0</span>)
            {
                xPrevLeft = <span class="code-digit">0</span>;
                yPrevLeft = yAxis;
            }
            <span class="code-keyword">else</span>
            {
                pen.Color = Color.LimeGreen;
                offScreenDC.DrawLine(pen, xPrevLeft, yPrevLeft, xAxis,yAxis);
                xPrevLeft = xAxis;
                yPrevLeft = yAxis;
            }
        }
        <span class="code-comment">//</span><span class="code-comment"> Draw right channel
</span>
        <span class="code-keyword">int</span> xCenterRight = rightTop + ((rightBottom - rightTop) / <span class="code-digit">2</span>);
        <span class="code-keyword">double</span> yScaleRight = <span class="code-digit">0</span>.<span class="code-digit">5</span> * (rightBottom - rightTop) / <span class="code-digit">32768</span>;  
            <span class="code-comment">//</span><span class="code-comment"> a 16 bit sample has values from -32768 to 32767
</span>
        <span class="code-keyword">int</span> xPrevRight = <span class="code-digit">0</span>, yPrevRight = <span class="code-digit">0</span>;
        <span class="code-keyword">for</span> (<span class="code-keyword">int</span> xAxis = rightLeft; xAxis &lt; rightRight; xAxis++)
        {
            <span class="code-keyword">int</span> yAxis = (<span class="code-keyword">int</span>)(xCenterRight + (_waveRight[_waveRight.Length / 
            (rightRight - rightLeft) * xAxis] * yScaleRight));
            <span class="code-keyword">if</span> (xAxis == <span class="code-digit">0</span>)
            {
                xPrevRight = <span class="code-digit">0</span>;
                yPrevRight = yAxis;
            }
            <span class="code-keyword">else</span>
            {
                pen.Color = Color.LimeGreen;
                offScreenDC.DrawLine
                (pen, xPrevRight, yPrevRight, xAxis, yAxis);
                xPrevRight = xAxis;
                yPrevRight = yAxis;
            }
        }
        <span class="code-comment">//</span><span class="code-comment"> Clean up
</span>
        pictureBox.Image = _canvasTimeDomain;
        offScreenDC.Dispose();
    }

    <span class="code-SummaryComment">///</span><span class="code-comment"> <span class="code-SummaryComment">&lt;</span><span class="code-SummaryComment">summary</span><span class="code-SummaryComment">&gt;</span>
</span>
    <span class="code-SummaryComment">///</span><span class="code-comment"> Render frequency domain to PictureBox
</span>
    <span class="code-SummaryComment">///</span><span class="code-comment"> <span class="code-SummaryComment">&lt;</span><span class="code-SummaryComment">/</span><span class="code-SummaryComment">summary</span><span class="code-SummaryComment">&gt;</span>
</span>
    <span class="code-SummaryComment">///</span><span class="code-comment"> <span class="code-SummaryComment">&lt;</span><span class="code-SummaryComment">param</span> <span class="code-SummaryComment">name="pictureBox"</span><span class="code-SummaryComment">&gt;</span><span class="code-SummaryComment">&lt;</span><span class="code-SummaryComment">/</span><span class="code-SummaryComment">param</span><span class="code-SummaryComment">&gt;</span>
</span>
    <span class="code-keyword">public</span> <span class="code-keyword">void</span> RenderFrequencyDomain(<span class="code-keyword">ref</span> PictureBox pictureBox)
    {
        <span class="code-comment">//</span><span class="code-comment"> Set up for drawing
</span>
        _canvasFrequencyDomain = <span class="code-keyword">new</span> Bitmap
                (pictureBox.Width, pictureBox.Height);
        Graphics offScreenDC = Graphics.FromImage(_canvasFrequencyDomain);
        SolidBrush brush = <span class="code-keyword">new</span> System.Drawing.SolidBrush
                    (Color.FromArgb(<span class="code-digit">0</span>, <span class="code-digit">0</span>, <span class="code-digit">0</span>));
        Pen pen = <span class="code-keyword">new</span> System.Drawing.Pen(Color.WhiteSmoke);
        <span class="code-comment">//</span><span class="code-comment"> Determine channel boundaries
</span>
        <span class="code-keyword">int</span> width = _canvasFrequencyDomain.Width;
        <span class="code-keyword">int</span> center = _canvasFrequencyDomain.Height / <span class="code-digit">2</span>;
        <span class="code-keyword">int</span> height = _canvasFrequencyDomain.Height;
        offScreenDC.DrawLine(pen, <span class="code-digit">0</span>, center, width, center);
        <span class="code-keyword">int</span> leftLeft = <span class="code-digit">0</span>;
        <span class="code-keyword">int</span> leftTop = <span class="code-digit">0</span>;
        <span class="code-keyword">int</span> leftRight = width;
        <span class="code-keyword">int</span> leftBottom = center - <span class="code-digit">1</span>;
        <span class="code-keyword">int</span> rightLeft = <span class="code-digit">0</span>;
        <span class="code-keyword">int</span> rightTop = center + <span class="code-digit">1</span>;
        <span class="code-keyword">int</span> rightRight = width;
        <span class="code-keyword">int</span> rightBottom = height;
        <span class="code-comment">//</span><span class="code-comment"> Draw left channel
</span>
        <span class="code-keyword">for</span> (<span class="code-keyword">int</span> xAxis = leftLeft; xAxis &lt; leftRight; xAxis++)
        {
            <span class="code-keyword">double</span> amplitude = (<span class="code-keyword">int</span>)_fftLeft[(<span class="code-keyword">int</span>)(((<span class="code-keyword">double</span>)(_fftLeft.Length)
                         / (<span class="code-keyword">double</span>)(width)) * xAxis)];
            <span class="code-keyword">if</span> (amplitude &lt; <span class="code-digit">0</span>) <span class="code-comment">//</span><span class="code-comment"> Drop negative values
</span>
            amplitude = <span class="code-digit">0</span>;
            <span class="code-keyword">int</span> yAxis = (<span class="code-keyword">int</span>)(leftTop + 
                ((leftBottom - leftTop) * amplitude) / <span class="code-digit">100</span>);  
                        <span class="code-comment">//</span><span class="code-comment"> Arbitrary factor
</span>
            pen.Color = Color.FromArgb(<span class="code-digit">0</span>, <span class="code-digit">0</span>, (<span class="code-keyword">int</span>)amplitude % <span class="code-digit">255</span>);
            offScreenDC.DrawLine(pen, xAxis, leftTop, xAxis, yAxis);
        }
        <span class="code-comment">//</span><span class="code-comment"> Draw right channel
</span>
        <span class="code-keyword">for</span> (<span class="code-keyword">int</span> xAxis = rightLeft; xAxis &lt; rightRight; xAxis++)
        {
            <span class="code-keyword">double</span> amplitude = (<span class="code-keyword">int</span>)_fftRight[(<span class="code-keyword">int</span>)(((<span class="code-keyword">double</span>)
            (_fftRight.Length) / (<span class="code-keyword">double</span>)(width)) * xAxis)];
            <span class="code-keyword">if</span> (amplitude &lt; <span class="code-digit">0</span>)
            amplitude = <span class="code-digit">0</span>;
            <span class="code-keyword">int</span> yAxis = (<span class="code-keyword">int</span>)(rightBottom - 
            ((rightBottom - rightTop) * amplitude) / <span class="code-digit">100</span>);
            pen.Color = Color.FromArgb(<span class="code-digit">0</span>, <span class="code-digit">0</span>, (<span class="code-keyword">int</span>)amplitude % <span class="code-digit">255</span>);
            offScreenDC.DrawLine(pen, xAxis, rightBottom, xAxis, yAxis);
        }
        <span class="code-comment">//</span><span class="code-comment"> Clean up