[Speex-dev] Speex VAD always returning 1

[Ken Smith]

For what it's worth, I've had significantly better luck with the WebRtc VAD.
It's pretty good.

http://code.google.com/p/webrtc/source/browse/#svn%2Ftrunk%2Fsrc%2Fcommon_audio%2Fvad%2Fmain%2Fsource

In general, the WebRTC voice engine seems to be more sophisticated and
mature than the Speex preprocessor (as opposed to the Speex codec, which is
pretty good).

Ken Smith
Cell: 425-443-2359
Email: ken at alanta.com
Blog: http://blog.wouldbetheologian.com/


On Mon, Aug 29, 2011 at 1:36 PM, Yanick Bourbeau <ybourbeau at mrgtech.ca>wrote:

>  From 1.2rc1 source code:
>
> preprocess.c:
>
> /* FIXME: This VAD is a kludge */
> st->speech_prob = Pframe;
> if (st->vad_enabled)
> {
> if (st->speech_prob > st->speech_prob_start || (st->was_speech &&
> st->speech_prob > st->speech_prob_continue))
> {
> st->was_speech=1;
> return 1;
> } else
> {
> st->was_speech=0;
> return 0;
> }
> } else {
> return 1;
> }
>
> AND
>
> case SPEEX_PREPROCESS_SET_VAD:
> speex_warning("The VAD has been replaced by a hack pending a complete
> rewrite");
> st->vad_enabled = (*(spx_int32_t*)ptr);
> break;
>
>
> As you can see, it is a hack, not supposed to be very good. Still, weird
> that you get
> this result. If you want a sample to test it, check speexenc.c file in
> speex source code package.
> I usually implement this kind of feature outside of speex becauses I want a
> better control
> on how it happens and when to do something about it :)
>
> Yanick Bourbeau
>
>
>
>
>
> On 11-08-29 04:16 PM, Clifton Craig wrote:
>
> +1 on this question as I wanted to start playing with it as well.
>
>  On Aug 29, 2011, at 9:41 AM, Shridhar, Vasant wrote:
>
>   I have been trying to understand how to get the VAD algorithm working.
> I sent an input stream of all zeros into the preprocessor but still got a
> return value of 1 indicating that speech was detected.  Is this feature not
> available with the latest release?  I thought at the very least it would
> detect this as silence and return 0 but that does not seem to be the case.
> ****
> ** **
> Does anyone have any information on how to use this or some example code to
> set this up I might try.****
> ** **
> Thanks,****
> ** **
> Vas****
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