Length in time of a wave file

Question

I have some simple code generating a wave file using TTS and then playing it:

public void TestSpeech()
{
    SpeechSynthesizer synth = new SpeechSynthesizer();
    using (MemoryStream stream = new MemoryStream())
    {
        synth.SetOutputToWaveStream(stream);
        synth.Speak("Hello world");
        stream.Seek(0, SeekOrigin.Begin);
        IWaveSource source = new WaveFileReader(stream);
        EventWaitHandle waitHandle = new EventWaitHandle(false, EventResetMode.AutoReset);
        var soundOut = new WasapiOut();
        soundOut.Initialize(source);
        soundOut.Stopped += (s, e) => waitHandle.Set();
        soundOut.Play();
        waitHandle.WaitOne();
        soundOut.Dispose();
        source.Dispose();
    }
}

Everything is working fine, but I want to know before I start to play the wave file how long it will go on for. Is there some way of calculating this, or is it available somewhere?

If it is available somewhere, how is it calculated? I assume that it's related to the amount of data in the stream, but how?

Immortalize

similar question was already answered here #82819 – Longwood

There will be a way, nothing is impossible. This one has me hooked. I'll post what I come up with, if I come up with anything - on that event I will walk into the distance with my tail between my legs. – Karinekariotta

As posted in the linked article there is no reliable way of doing it prior, however Genti's solution is a good way of achieving your results. See Comments of Genti's description for length calculation details. – Karinekariotta

Answer 1

You can use CSCore or NAudio:

CSCore (extracted from this sample, current playback position and total duration are used here):

using System;
using CSCore;
using CSCore.Codecs.WAV;

IWaveSource wavSource = new WaveFileReader(stream);
TimeSpan totalTime = wavSource.GetLength();

NAudio:

using System;
using NAudio.Wave;

using (var wfr = new WaveFileReader(stream))
{
    TimeSpan totalTime = wfr.TotalTime;
}

Also see the MSDN docs for TimeSpan.

The duration is calculated from the total length of the WAVE data (which can be an estimate for compressed files) and the average bytes per second (as per the NAudio source in property TotalTime):

totalTimeInSeconds = LengthInBytes / AverageBytesPerSecond;

Invertase

He has access to the stream though. The synthesizer writes to the stream. – Invertase

I deleted my comment directly after posting it as I saw the error of my logic as I clicked "add". Sorry my friend. – Karinekariotta

Thanks for this. "The duration is calculated from the total length of the WAVE data (which can be an estimate for compressed files) and the average bytes per seconds" Where do I find the average bytes per second? This is using CSCore. – Immortalize

It is in the WAV file header, but I'll take a look at how you can do that in CSCore. – Invertase

AverageBtyesPerSecond for NAudio HERE This is what I've found so far, based off SampleRate and Length Just follow the source code back to where each of those are defined and you'll find your answer pretty quickly, could even peek at the definitions in VS, would be faster – Karinekariotta

In CSCore you can obtain it with wavSource.WaveFormat.BytesPerSecond. – Invertase

After running it with a few samples this gives a close enough answer to use. Thanks! – Immortalize

Answer 2

using CSCore;

IWaveSource waveSource = new WaveFileReader(stream);
TimeSpan totalTime = waveSource.GetLength( ); //get length returns a timespan

Olivaolivaceous

Answer 3

In case someone's looking for a workaround, I've handeled it like this: (pardon my first StackOverflow comment)

1. I created bool mouseScrewsAround = false
2. timer event, that changes trackBar position while playing, fires only if !mouseScrewsAround
3. trackBar_MouseDown -> mouseScrewsAround = true
4. trackBar_MouseUp -> change track position, then mouseScrewsAround = false

Dystrophy