How to play audio samples without writing it into to a file?

Question

I get audio samples (as float array) from another method and I want to play this float array without writing any files to disk.

For this example I get samples from audio file:

var file = new AudioFileReader(stereoFile);

int startPos = 0;
int endPos = 138890;

var sampleArray = new float[endPos - startPos];

file.Read(sampleArray, startPos, sampleArray.Length);

How can I play sampleArray?

Does this answer your question? [How can I play byte array of audio raw data using NAudio?](https://stackoverflow.com/questions/28792548/how-can-i-play-byte-array-of-audio-raw-data-using-naudio) — Sinatr, Feb 04 '21 at 09:36
@00110001 this is byte array, not float sample array. this answer not work with samples — Deim, Feb 04 '21 at 09:38
Sinatr's answer should work once you have converted those floating-point samples to e.g. 16-bit signed samples. — AKX, Feb 04 '21 at 09:48
@AKX This is possible way, but if I correctly understand this question https://stackoverflow.com/questions/18689410/convert-32-bit-float-audio-to-16-bit-byte-array this way not easyest. Maybe there's a better way to do this? — Deim, Feb 04 '21 at 10:13
It's not really particularly _hard_ ... but you could also try if using a [float data format](https://github.com/naudio/NAudio/blob/889ec87e1e8153504de330cacb2e7ca3e6437c5a/NAudio/Wave/WaveFormats/WaveFormat.cs#L135) would work directly. — AKX, Feb 04 '21 at 11:16

score 0 · Accepted Answer · answered Feb 04 '21 at 15:54

I find next solution and it work for me:

        var file = new AudioFileReader(stereoFile);

        WaveFormat waveFormat = file.WaveFormat;

        int startPos = 2403;
        int endPos = 41265;

        if (startPos % 2 != 0)
        {
            startPos += 1;
        }

        if (endPos % 2 != 0)
        {
            endPos += 1;
        }

        if (waveFormat.Channels == 2)
        {
            startPos *= 2;
            endPos *= 2;
        }

        var allSamples = new float[file.Length / (file.WaveFormat.BitsPerSample / 8)];

        file.Read(allSamples, 0, allSamples.Length);

        Span<float> samplesSpan = allSamples;
        Span<float> trackSpan = samplesSpan.Slice(startPos, endPos - startPos);

^ upper code to take correct samples for tests. code below - my solution

        MemoryStream ms = new MemoryStream();
        IgnoreDisposeStream ids = new IgnoreDisposeStream(ms);

        using (WaveFileWriter waveFileWriter = new WaveFileWriter(ids, waveFormat))
        {
            waveFileWriter.WriteSamples(trackSpan.ToArray(), 0, endPos-startPos);
        }


        ms.Position = 0;
        WaveStream waveStream = new WaveFileReader(ms);
        WaveOutEvent waveOutEvent = new WaveOutEvent();
        waveOutEvent.Init(waveStream);
        waveOutEvent.Play();

score 0 · Answer 2 · answered Feb 05 '21 at 07:59

0

RawSourceWaveStream is designed for the situation where you have audio in a byte array or MemoryStream and want to play it directly. You can learn more about it and see an example of how to use it here

answered Feb 05 '21 at 07:59

Mark Heath

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How can i play sample array with RawSourceWaveStream? RawSourceWaveStream can work with byte[] or Stream but not with float[] – Deim Feb 05 '21 at 12:35
You can use the WaveBuffer class as a way to cast between the two, or use something like Buffer.BlockCopy to copy float samples into a byte[] – Mark Heath Feb 06 '21 at 16:49

How to play audio samples without writing it into to a file?

2 Answers2