Incorrect keys at start of sequence about dtmfdetection

[bert2]

Hi, thanks for the report! Could you provide me with the WAV file you are trying?

[rwil02]

testwav.zip
Here's the "decode" loop for the received bytes:

for (int index = offset; index < sample.Length; index++)
{
	short pcm = MuLawDecoder.MuLawToLinearSample(sample[index]);
	byte[] pcmSample = {(byte) (pcm & 0xFF), (byte) (pcm >> 8)};
	m_WaveInEvent.RaiseDataAvailable(pcmSample);
}

Here's the "encode" loop for the sent bytes:

byte[] sample = new byte[sampleRaw.Length/2];
int sampleIndex = 0;

for (int index = 0; index < sampleRaw.Length; index += 2)
{
	byte ulawByte = MuLawEncoder.LinearToMuLawSample(BitConverter.ToInt16(sampleRaw, index));
	sample[sampleIndex++] = ulawByte;
}

[bert2]

That does not appear to be a problem with the DtmfDetection library but rather with your decoding/encoding step.

When I feed it to the DtmfDetector test program all DMTF tones are detected correctly:

PS> .\DtmfDetector.exe C:\Users\bert\Desktop\test.wav
00.051 s (0): One key (duration: 00.103 s)
00.231 s (0): Two key (duration: 00.102 s)
00.410 s (0): Three key (duration: 00.103 s)
00.589 s (0): Four key (duration: 00.103 s)
00.769 s (0): Five key (duration: 00.102 s)
00.948 s (0): Six key (duration: 00.103 s)
01.128 s (0): Seven key (duration: 00.102 s)
01.307 s (0): Eight key (duration: 00.077 s)
01.486 s (0): Nine key (duration: 00.103 s)
01.691 s (0): Zero key (duration: 00.103 s)
01.871 s (0): Hash key (duration: 00.102 s)
02.076 s (0): Star key (duration: 00.077 s)

Here is a screenshot of test.wav loaded in Audacity for comparison:

I'm afraid you will have to try your luck on Stack Overflow.