C#•17mo ago

❔ Problem with converting WAV byte[] to MP3 byte[] (and vice versa)

I have this code (using NAudio) for converting a wav byte array to an mp3 byte array:

    public static byte[] ConvertWavToMp3(byte[] wavFile)
    {

        using(var retMs = new MemoryStream())
        using (var ms = new MemoryStream(wavFile))
        using(var rdr = new WaveFileReader(ms))
        using (var wtr = new LameMP3FileWriter(retMs, rdr.WaveFormat, 256))
        {
            rdr.CopyTo(wtr);
            return retMs.ToArray();
        }

    }

    public static byte[] ConvertWavToMp3(byte[] wavFile)
    {

        using(var retMs = new MemoryStream())
        using (var ms = new MemoryStream(wavFile))
        using(var rdr = new WaveFileReader(ms))
        using (var wtr = new LameMP3FileWriter(retMs, rdr.WaveFormat, 256))
        {
            rdr.CopyTo(wtr);
            return retMs.ToArray();
        }

    }

Not sure why, but using the function the end of a wav file just gets cut off (examples attached) How can I fix this or are there any alternative ways of conversion?

sponge_test_1.wav

sponge_test_1_mp3.mp...

14 Replies

basically, i am little cat•17mo ago

Pretty sure all variables in using blocks get disposed before return

molioronOP•17mo ago

Should I move the return statement outside of the using statement?

basically, i am little cat•17mo ago

No, you probably just want to store array before return in some variable and then return it

molioronOP•17mo ago

done but audio still gets cut off

    public static byte[] ConvertWavToMp3(byte[] wavFile)
    {
        using(var retMs = new MemoryStream())
        using (var ms = new MemoryStream(wavFile))
        using(var rdr = new WaveFileReader(ms))
        // originally 128 (as in 128K, but value itself should be 128)
        using (var wtr = new LameMP3FileWriter(retMs, rdr.WaveFormat, 256))
        {
            rdr.CopyTo(wtr);
            byte[] result = retMs.ToArray();
            return result;
        }
        
    }

    public static byte[] ConvertWavToMp3(byte[] wavFile)
    {
        using(var retMs = new MemoryStream())
        using (var ms = new MemoryStream(wavFile))
        using(var rdr = new WaveFileReader(ms))
        // originally 128 (as in 128K, but value itself should be 128)
        using (var wtr = new LameMP3FileWriter(retMs, rdr.WaveFormat, 256))
        {
            rdr.CopyTo(wtr);
            byte[] result = retMs.ToArray();
            return result;
        }
        
    }

basically, i am little cat•17mo ago

Ok then idk how to help, sorry

Kouhai•17mo ago

Call flush before return Because Dispose get's called after ToArray, so wtr isn't flushed

molioronOP•17mo ago

    public static byte[] ConvertWavToMp3(byte[] wavFile)
    {
        using(var retMs = new MemoryStream())
        using (var ms = new MemoryStream(wavFile))
        using(var rdr = new WaveFileReader(ms))
        // originally 128 (as in 128K, but value itself should be 128)
        using (var wtr = new LameMP3FileWriter(retMs, rdr.WaveFormat, 256))
        {
            rdr.CopyTo(wtr);
            byte[] result = retMs.ToArray();
            wtr.Flush();
            return result;
        }
        
    }

    public static byte[] ConvertWavToMp3(byte[] wavFile)
    {
        using(var retMs = new MemoryStream())
        using (var ms = new MemoryStream(wavFile))
        using(var rdr = new WaveFileReader(ms))
        // originally 128 (as in 128K, but value itself should be 128)
        using (var wtr = new LameMP3FileWriter(retMs, rdr.WaveFormat, 256))
        {
            rdr.CopyTo(wtr);
            byte[] result = retMs.ToArray();
            wtr.Flush();
            return result;
        }
        
    }

Still seems like audio gets cut off

Kouhai•17mo ago

Before ToArray not after ThumbsUpSmile

using (var retMs = new MemoryStream())
using (var ms = new MemoryStream(wavFile))
using (var rdr = new WaveFileReader(ms))
using (var wtr = new LameMP3FileWriter(retMs, rdr.WaveFormat, 256))
{
    rdr.CopyTo(wtr);
    wtr.Flush();
    return retMs.ToArray();
}

using (var retMs = new MemoryStream())
using (var ms = new MemoryStream(wavFile))
using (var rdr = new WaveFileReader(ms))
using (var wtr = new LameMP3FileWriter(retMs, rdr.WaveFormat, 256))
{
    rdr.CopyTo(wtr);
    wtr.Flush();
    return retMs.ToArray();
}

You could also do

using var retMs = new MemoryStream();
using (var ms = new MemoryStream(wavFile))
using (var rdr = new WaveFileReader(ms))
using (var wtr = new LameMP3FileWriter(retMs, rdr.WaveFormat, 256))
{
    rdr.CopyTo(wtr);
}
return retMs.ToArray();

using var retMs = new MemoryStream();
using (var ms = new MemoryStream(wavFile))
using (var rdr = new WaveFileReader(ms))
using (var wtr = new LameMP3FileWriter(retMs, rdr.WaveFormat, 256))
{
    rdr.CopyTo(wtr);
}
return retMs.ToArray();

molioronOP•17mo ago

Thanks! It worked. I have a similar function for the other way arround, should it also get the same treatment?

    public static byte[] ConvertMp3ToWav(byte[] mp3File)
    {
        using (var retMs = new MemoryStream())
        using (var ms = new MemoryStream(mp3File))
        using (Mp3FileReader reader = new Mp3FileReader(ms))
        {
            var rs = new RawSourceWaveStream(reader, new WaveFormat(31000, 1));
            using (WaveStream pcmStream = WaveFormatConversionStream.CreatePcmStream(rs))
            {
                WaveFileWriter.WriteWavFileToStream(retMs,pcmStream);
                return retMs.ToArray();
            }
        }
    }

    public static byte[] ConvertMp3ToWav(byte[] mp3File)
    {
        using (var retMs = new MemoryStream())
        using (var ms = new MemoryStream(mp3File))
        using (Mp3FileReader reader = new Mp3FileReader(ms))
        {
            var rs = new RawSourceWaveStream(reader, new WaveFormat(31000, 1));
            using (WaveStream pcmStream = WaveFormatConversionStream.CreatePcmStream(rs))
            {
                WaveFileWriter.WriteWavFileToStream(retMs,pcmStream);
                return retMs.ToArray();
            }
        }
    }

Kouhai•17mo ago

Yeah pretty much, using statement calls Dispose method after we leave the scope, so retMs isn't getting the latest data from pcmStream Typically Flush is called in the Dispose method, and Naudio does follow that, but because ToArray comes before the Dispose call, flush isn't called

molioronOP•17mo ago

so pcmStream.Flush(); should be called before ToArray()?

Kouhai•17mo ago

Yeah, or you could do it like this as well

using var retMs = new MemoryStream();
using (var ms = new MemoryStream(wavFile))
using (var rdr = new WaveFileReader(ms))
using (var wtr = new LameMP3FileWriter(retMs, rdr.WaveFormat, 256))
{
    rdr.CopyTo(wtr);
}
return retMs.ToArray();

using var retMs = new MemoryStream();
using (var ms = new MemoryStream(wavFile))
using (var rdr = new WaveFileReader(ms))
using (var wtr = new LameMP3FileWriter(retMs, rdr.WaveFormat, 256))
{
    rdr.CopyTo(wtr);
}
return retMs.ToArray();

Calling ToArray after wtr is Disposed

molioronOP•17mo ago

I see, thanks!

Accord•17mo ago

Was this issue resolved? If so, run /close - otherwise I will mark this as stale and this post will be archived until there is new activity.

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❔ Problem with converting WAV byte[] to MP3 byte[] (and vice versa)