Reputation: 81

High quality graph/waveform display component in C#

I'm looking for a fast, professionally looking and customizable waveform display component in C#.

I'm wanting to display mainly real-time audio waveforms (fast!) in both time and frequency domain. I would like the ability to zoom, change axis settings, display multiple channels, customize the feel and colors etc...

Anybody knows of anything, whether commercial or not?

Thank you!

Diego

Upvotes: 8

Answers (6)

Daniël Teunkens

Reputation: 391

Based on Illaya's code:

public void CreateWaveForm(string audioFilePath, string audioWaveFormFilePath)
    {
        try
        {
            int bytesPerSample = 0;
            using (NAudio.Wave.Mp3FileReader reader = new NAudio.Wave.Mp3FileReader(audioFilePath, wf => new NAudio.FileFormats.Mp3.DmoMp3FrameDecompressor(wf)))
            {
                using (NAudio.Wave.WaveChannel32 channelStream = new NAudio.Wave.WaveChannel32(reader))
                {
                    bytesPerSample = (reader.WaveFormat.BitsPerSample / 8) * channelStream.WaveFormat.Channels;
                    //Give a size to the bitmap; either a fixed size, or something based on the length of the audio
                    using (Bitmap bitmap = new Bitmap((int)Math.Round(reader.TotalTime.TotalSeconds * 40), 200))
                    {
                        int width = bitmap.Width;
                        int height = bitmap.Height;

                        using (Graphics graphics = Graphics.FromImage(bitmap))
                        {
                            graphics.Clear(Color.White);
                            Pen bluePen = new Pen(Color.Blue);

                            int samplesPerPixel = (int)(reader.Length / (double)(width * bytesPerSample));
                            int bytesPerPixel = bytesPerSample * samplesPerPixel;
                            int bytesRead;
                            byte[] waveData = new byte[bytesPerPixel];

                            for (float x = 0; x < width; x++)
                            {
                                bytesRead = reader.Read(waveData, 0, bytesPerPixel);
                                if (bytesRead == 0)
                                    break;

                                short low = 0;
                                short high = 0;
                                for (int n = 0; n < bytesRead; n += 2)
                                {
                                    short sample = BitConverter.ToInt16(waveData, n);
                                    if (sample < low) low = sample;
                                    if (sample > high) high = sample;
                                }
                                float lowPercent = ((((float)low) - short.MinValue) / ushort.MaxValue);
                                float highPercent = ((((float)high) - short.MinValue) / ushort.MaxValue);
                                float lowValue = height * lowPercent;
                                float highValue = height * highPercent;
                                graphics.DrawLine(bluePen, x, lowValue, x, highValue);
                            }
                        }

                        bitmap.Save(audioWaveFormFilePath);
                    }
                }
            }
        }
        catch
        {
        }
    }

Upvotes: 2

Illaya

Reputation: 666

This will generate waveform from audio file using nAudio...

using NAudio.Wave;
using System;
using System.Collections.Generic;
using System.Drawing;
using System.IO;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

public partial class test : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
    string strPath = Server.MapPath("audio/060.mp3");
    string SongID = "2";
    byte[] bytes = File.ReadAllBytes(strPath);
    WriteToFile(SongID,strPath, bytes);
    Response.Redirect("Main.aspx");
    }

private void WriteToFile(string SongID, string strPath, byte[] Buffer)
{
    try
    {
        int samplesPerPixel = 128;
        long startPosition = 0;
        //FileStream newFile = new FileStream(GeneralUtils.Get_SongFilePath() + "/" + strPath, FileMode.Create);
        float[] data = FloatArrayFromByteArray(Buffer);

        Bitmap bmp = new Bitmap(1170, 200);

        int BORDER_WIDTH = 5;
        int width = bmp.Width - (2 * BORDER_WIDTH);
        int height = bmp.Height - (2 * BORDER_WIDTH);

        NAudio.Wave.Mp3FileReader reader = new NAudio.Wave.Mp3FileReader(strPath, wf => new NAudio.FileFormats.Mp3.DmoMp3FrameDecompressor(wf));
        NAudio.Wave.WaveChannel32 channelStream = new NAudio.Wave.WaveChannel32(reader);

        int bytesPerSample = (reader.WaveFormat.BitsPerSample / 8) * channelStream.WaveFormat.Channels;

        using (Graphics g = Graphics.FromImage(bmp))
        {

            g.Clear(Color.White);
            Pen pen1 = new Pen(Color.Gray);
            int size = data.Length;

            string hexValue1 = "#009adf";
            Color colour1 = System.Drawing.ColorTranslator.FromHtml(hexValue1);
            pen1.Color = colour1;

            Stream wavestream = new NAudio.Wave.Mp3FileReader(strPath, wf => new NAudio.FileFormats.Mp3.DmoMp3FrameDecompressor(wf));

            wavestream.Position = 0;
            int bytesRead1;
            byte[] waveData1 = new byte[samplesPerPixel * bytesPerSample];
            wavestream.Position = startPosition + (width * bytesPerSample * samplesPerPixel);

            for (float x = 0; x < width; x++)
            {
                short low = 0;
                short high = 0;
                bytesRead1 = wavestream.Read(waveData1, 0, samplesPerPixel * bytesPerSample);
                if (bytesRead1 == 0)
                    break;
                for (int n = 0; n < bytesRead1; n += 2)
                {
                    short sample = BitConverter.ToInt16(waveData1, n);
                    if (sample < low) low = sample;
                    if (sample > high) high = sample;
                }
                float lowPercent = ((((float)low) - short.MinValue) / ushort.MaxValue);
                float highPercent = ((((float)high) - short.MinValue) / ushort.MaxValue);
                float lowValue = height * lowPercent;
                float highValue = height * highPercent;
                g.DrawLine(pen1, x, lowValue, x, highValue);

            }
        }

        string filename = Server.MapPath("image/060.png");
        bmp.Save(filename);
        bmp.Dispose();

    }
catch (Exception e)
    {

    }
}
public float[] FloatArrayFromStream(System.IO.MemoryStream stream)
{
    return FloatArrayFromByteArray(stream.GetBuffer());
}

public float[] FloatArrayFromByteArray(byte[] input)
{
    float[] output = new float[input.Length / 4];
    for (int i = 0; i < output.Length; i++)
    {
        output[i] = BitConverter.ToSingle(input, i * 4);
    }
    return output;
}

}

Upvotes: 1

Davido

Reputation: 2931

Check out Zedgraph. It's a free graphing library that works great. There are lots of code samples on their website that allow you to do what you're asking. Zedgraph Downloads Their website seems to be having issues right now, but the download session works and contains all of their sample files.

Upvotes: 1