I'm trying to make a web audio recorder using getUserMedia and .NET MVC.

I got as far as recording it and sending the chunks of data to the server. The problem is that i can't play the results. The code below is the closer I got from playing it correctly, I can record and hear my voice in the recording but I'm getting a lot of white noise in it. I'm probably messing around with the enconding or parsing of the data. Here are some of the code:

chan = e.inputBuffer.getChannelData(channel);
var conv_buffer = convertFloat32ToInt16(chan);

    function convertFloat32ToInt16(buffer) {
    l = buffer.length;
    buf = new Int16Array(l);
    while (l--) {
        buf[l] = Math.min(1, buffer[l]) * 0x7FFF;
    return buf;

At the server side I'm storing the chunks with their order into a Session (don't know if I should use anything else here. Session doesn't sound right for me):

 if (Session["wave"] == null)
            Session["wave"] = new Dictionary<string, string>();
 if (Request.Files.Count == 0)
            ((Dictionary<string, string>)Session["wave"]).Add(Request.Form[0], Request.Form[1]);

After the end of the recording I'm just parsing the string I streamed to a float array, encoding with NAudio and saving to disk:

 List<float> list = new List<float>();
            foreach (var item in ((Dictionary<string, string>)Session["wave"]).OrderBy(c => c.Key))
            Random rand = new Random();

            WaveFormat waveFormat = new WaveFormat(48000, 16, 1);
            string fileName = "teste" + rand.Next(0, 999999).ToString() + ".wav";

            WaveFileWriter writer = new WaveFileWriter("c:\\" + fileName, waveFormat);

            writer.WriteSamples(list.ToArray(), 0, list.Count());


The parsing:

        private float[] StringToFloatArray(string input)
        var strs = input.Split(',');
        float[] arr = new float[strs.Length];
        for (int i = 0; i < (strs.Length - 1)/2; i++)
            arr[i] = float.Parse(strs[i]);
        return arr;

It would make me very happy if anyone could help me or point in any direction. I already tried changing the enconding in a lot of ways without success...

I also tryed to give the .net NAudio the raw array from recording, without success. One thing I noticed is that some of the precision is lost when converting to float. Probably it won't happen if I convert it to double but the NAudio just cant receive in that format. Any ideias??

closed as off-topic by audionuma, AJ Henderson Aug 3 '17 at 16:41

  • This question does not appear to be about sound design, within the scope defined in the help center.
If this question can be reworded to fit the rules in the help center, please edit the question.

  • I think this question would be better suited to StackOverflow as a software development question. – Simon Bosley Aug 3 '17 at 10:13
  • You are totaly right! I did try post it to Stackoverflow some weeks ago though...I thought I could've more luck with ppl that has more audio skills... – Kim Lage Aug 3 '17 at 13:45
  • I'm voting to close this question as off-topic because it is about coding for audio rather than audio production or sound design. – AJ Henderson Aug 3 '17 at 16:41
  • Put another way, this is where we talk about how to make use of tools, not how to build them. This is really a software development question and is well outside the scope of this site. – AJ Henderson Aug 3 '17 at 16:43