[Speex-dev] WaveIn/WaveOut and Speex

[Evgueni Tsygankov]

Hello,

 

I know my question has been asked before because I spent the last week
searching the web for how to use Speex in combination with
WaveIn/WaveOut and I ran into a few posts, but none of them answer the
question. There is still a lot of confusion how to use WaveIn/WaveOut
and Speex by junior developers such as myself. Even after examining code
for SpeexDec and SpeexEnc, I cannot get clear sound when I try to

 

Get PCM Char buffer from the microphone

Encode Char buffer using Speex

Decode Speex Char buffer into PCM char buffer

Play PCM char buffer using WaveOut

 

The end-result is very distorted sound.

 

 

I use the following PCM format:

 

waveFormat.nChannels = 1;

waveFormat.nSamplesPerSec = 8000;

waveFormat.wBitsPerSample = 8;

 

Once sound is aquired by the mic, I send it to Speex in a Char buffer.
It looks something like this:

 

Encode(char* inBuffer, DWORD bufferLength)

...

float* input = new float[frameSize];

ZeroMemory(input, frameSize);

...

for(    )

{

input[..] = inBuffer[..];

}

...

speex_encode(enc_state, input, &bits);

int bytesWritten = speex_bits_nbytes(&bits);

speex_bits_write(&bits, encBuffer, bytesWritten);

 

 

 

Then, my decoding routine accepts the char buffer that was encoded with
Speex:

 

Decode(char* encBuffer, DWORD bufferLength)

...

float* output = new float[frameSize];

...

speex_bits_read_from(&bits, encBuffer + offset, bytesToRead);

speex_decode(dec_state, &bits, output);

 

char* outBuffer=...

for(UINT i = 0; i < frameSize; i++)

{

outBuffer[retValIndex] = output[i];

retValIndex++;

}

 

When I try to play outBuffer with waveOut, I can hear the voice
"somewhere far", but there is a lot of distortion noise. Any help would
be greatly appreciated!!!

 

Thank you,

 

Evgueni Tsygankov

www.sqlanswers.com <http://www.sqlanswers.com/> 

 

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