Mean amplitude of a .wav in C#

Question

Does anyone know a way to get the mean amplitude of a .wav file using C# (even if it means calling an outside command line program and parsing the output)? Thanks!

Forgot to mention that the .wav is mono, if that makes the situation any easier/different. — BarrettJ

Nifle Nifle · Accepted Answer · 2009-06-30T15:41:42

Here is a snip that reads in a stereo wav and puts the data in two arrays. It's untested because I had to remove some code (converting to mono and calculate a moving average)

    /// <summary>
    ///  Read in wav file and put into Left and right array
    /// </summary>
    /// <param name="fileName"></param>
    private void ReadWavfiles(string fileName)
    {
        byte[] fa = File.ReadAllBytes(fileName);

        int startByte = 0;

        // look for data header
        {
            var x = 0;
            while (x < fa.Length)
            {
                if (fa[x]     == 'd' && fa[x + 1] == 'a' && 
                    fa[x + 2] == 't' && fa[x + 3] == 'a')
                {
                    startByte = x + 8;
                    break;
                }
                x++;
            }
        }

        // Split out channels from sample
        var sLeft = new short[fa.Length / 4];
        var sRight = new short[fa.Length / 4];

        {
            var x = 0;
            var length = fa.Length;
            for (int s = startByte; s < length; s = s + 4)
            {
                sLeft[x] = (short)(fa[s + 1] * 0x100 + fa[s]);
                sRight[x] = (short)(fa[s + 3] * 0x100 + fa[s + 2]);
                x++;
            }
        }

        // do somthing with the wav data in sLeft and sRight
    }

Mean amplitude of a .wav in C#

3 Answers