Question

I have recorded audio to a CaptureBuffer, but I can’t figure out how to save it into wav file. I have tried this (http://www.tek-tips.com/faqs.cfm?fid=4782), but it didn’t work, or I didn’t use it properly. Does anybody know how to solve this? Sample code would be very appreciated.

Answer 1

A WAV file is a RIFF file consisting of two main “chunks”. The first is a format chunk, describing the format of the audio. This will be what sample rate you recorded at (e.g. 44.1kHz), what bit depth (e.g. 16 bits) and how many channels (mono or stereo). WAV also supports compressed formats but it is unlikely you recorded the audio compressed, so your record buffer will contain PCM audio.

Then there is the data chunk. This is the part of the WAV file that contains the actual audio data in your capture buffer. This must be in the format described in the format chunk.

As part of the NAudio project I created a WaveFileWriter class to simplify creating WAV files. You pass in a WaveFormat that describes the format of your captured audio. Then you can simply write the raw captured data in.

Here’s some simple example code for how you might use WaveFileWriter:

WaveFormat format = new WaveFormat(16000, 16, 1); // for mono 16 bit audio captured at 16kHz
using (var writer = new WaveFileWriter("out.wav", format)
{
    writer.WriteData(captureBuffer, 0, captureBuffer.Length);
}