How to detect silence using G.729 Voice Activity Detection code

I would like to know if there is a code of how many seconds of silence is used in a video.

If there is a video of two people speaking using G.729 Voice Activity Detection would there be a code the could get the result of down below??

speaking time -30s silence 10s speaking time 80s silence 15s

total speaking time = 110s

total silence time = 25s??

Thank you

Answer 1

[Sachin Lodhi]

Hi 홍근 김,

Based on my understanding, it seems that you want to generate an output using G.729 Voice Activity Detection (VAD) code, that sequentially lists the duration of speech, followed by the duration of silence, and then repeats this pattern.

To achieve this, you have to check the value returned by vadG729 function. It returns ‘1’ for speech and ‘0’ for silence. Using this value, you can get the desired functionality. Here is a sample code to demonstrate the logic -

% Initialize VAD parameters
VAD_cst_param = vadInitCstParams;
clear vadG729
% Run for 10 seconds
numTSteps = 1000;
silenceT = 0;
speechT = 0;
while(numTSteps)
    % Retrieve 10 ms of speech data from the audio recorder
    speech = audioSource();
    % Call the VAD algorithm
    decision = vadG729(speech, VAD_cst_param);
    % Plot speech frame and decision: 1 for speech, 0 for silence
    if (decision == 1) 
        if (silenceT == 0)
            speechT = speechT + 1;
        else
            disp(['Silence for ', num2str(silenceT)]);
            silenceT = 0;
            speechT = 1;
        end
    else
        if (speechT == 0) 
          silenceT = silenceT + 1;
        else
            disp(['Speech for ', num2str(speechT)]);
            speechT = 0;
            silenceT = 1;
        end
    end
    scope(decision, speech);
    numTSteps = numTSteps - 1;
end

Please refer to the following example for additional information - https://www.mathworks.com/help/dsp/ug/g-729-voice-activity-detection.html#:~:text=%27Scroll%27)%3B-,Stream%20Processing%20Loop,-Get

I hope this helps.

Best Regards,

Sachin