Speex dev - Feb 2008 - Voice activity detection

hi guys,
  i am trying to develop an application having a capability to detect voice
activity in voice stream and then record only portion of this stream which
contains the activity. i went through these steps.
  1. Captured voice through Waveform Functions of Windows Multimedia API
  2. Started Speex Preprocessing liberary
  3. Turned on preprocessor by calling speex_preprocess_state_init and passing
it 20 ms frame size and sampling rate
  4. Set VAD on 
  5. Copied byte data into  __int16 variables and  passed it to
speex_preprocess_run function.
  in return of these steps i got wrong date back to me. could you please send me
the sample code or could you identify the problem?
  i'll be thankful
  regards

       
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Abdul Basit a ?crit :
> hi guys,
>   i am trying to develop an application having a capability to detect voice
activity in voice stream and then record only portion of this stream which
contains the activity. i went through these steps.
>   1. Captured voice through Waveform Functions of Windows Multimedia API
>   2. Started Speex Preprocessing liberary
>   3. Turned on preprocessor by calling speex_preprocess_state_init and
passing it 20 ms frame size and sampling rate
>   4. Set VAD on 
>   5. Copied byte data into  __int16 variables and  passed it to
speex_preprocess_run function.
>   in return of these steps i got wrong date back to me. could you please
send me the sample code or could you identify the problem?
>   i'll be thankful
...and what's the actual problem you're seeing?

	Jean-Marc

This must be a simple issue, but I cannot figure it out.

I want to use VAD, but I don't know how to check if the actual frame has
voice in it or not.

So, in my code, I do:

int tmp = 1;
speex_preprocess_ctl(preprocess_state, SPEEX_PREPROCESS_SET_VAD, &tmp);
speex_preprocess_ctl(preprocess_state, SPEEX_PREPROCESS_SET_DENOISE,
&tmp);

then later, for each frame

speex_preprocess_run(preprocess_state, shortPointer);

but how do I know if the frame contained voice? I tried 

if (preprocess_state->was_voice == 1)
{
	...Do voice present code...
}

But the compiler complains that was_voice is not defined, which, I
assume, comes from the fact that preprocess_state is declared in
speech_preprocess.h as struct SpeexPreprocessState_;

How do I check the preprocessor for the presence of voice in a frame? 

Thanks,

Evgueni