wakeup_word.cpp

// g++ -O3 -std=c++11 -o ps_boilerplate mic.cpp \
    -DMODELDIR=\"`pkg-config --variable=modeldir pocketsphinx`\" \
    `pkg-config --cflags --libs pocketsphinx sphinxbase`
#include <iostream>
#include <string>
#include <pocketsphinx.h>
#include <sphinxbase/ad.h>
#include <sphinxbase/err.h>

using namespace std;

void recognize_from_microphone();

ps_decoder_t *ps;                  // create pocketsphinx decoder structure
cmd_ln_t *config;                  // create configuration structure
ad_rec_t *ad;                      // create audio recording structure - for use with ALSA functions

int16 adbuf[4096];                 // buffer array to hold audio data
uint8 utt_started, in_speech;      // flags for tracking active speech - has speech started? - is speech currently happening?
int32 k;                           // holds the number of frames in the audio buffer
// char const *hyp;                   // pointer to "hypothesis" (best guess at the decoded result)


int main(int argc, char *argv[]) {

  config = cmd_ln_init(NULL, ps_args(), TRUE,                   // Load the configuration structure - ps_args() passes the default values
    "-hmm", MODELDIR "/en-us/en-us",
    "-kws", "./keyphrase.file",
    "-dict", MODELDIR "/en-us/cmudict-en-us.dict",
    "-logfn", "/dev/null",                                      // suppress log info from being sent to screen
     NULL);

  ps = ps_init(config);                                                        // initialize the pocketsphinx decoder
  ad = ad_open_dev("sysdefault", (int) cmd_ln_float32_r(config, "-samprate")); // open default microphone at default samplerate

  while(1){                                                                   
    // string decoded_speech = recognize_from_microphone();          // call the function to capture and decode speech           
    // cout << "Decoded Speech: "<< decoded_speech << "\n" <<endl;   // send decoded speech to screen
    cout << "calling recognize_from_microphone " <<endl;
    recognize_from_microphone();          // call the function to capture and decode speech           
    
   }

 ad_close(ad);                                                    // close the microphone
}
 
void recognize_from_microphone(){
    const char* hyp;
    string wakeup("zane");
    ad_start_rec(ad);                                // start recording
    ps_start_utt(ps);                                // mark the start of the utterance
    utt_started = FALSE;                             // clear the utt_started flag

    while(1) {                                       
        k = ad_read(ad, adbuf, 4096);                // capture the number of frames in the audio buffer
        ps_process_raw(ps, adbuf, k, FALSE, FALSE);  // send the audio buffer to the pocketsphinx decoder

        in_speech = ps_get_in_speech(ps);            // test to see if speech is being detected

        if (in_speech && !utt_started) {             // if speech has started and utt_started flag is false                            
            utt_started = TRUE;                      // then set the flag
        }
 
        if (!in_speech && utt_started) {             // if speech has ended and the utt_started flag is true 
            ps_end_utt(ps);                          // then mark the end of the utterance
            ad_stop_rec(ad);                         // stop recording
            hyp = ps_get_hyp(ps, NULL );             // query pocketsphinx for "hypothesis" of decoded statement
            // return hyp;                              // the function returns the hypothesis
            // cout << "Decoded Speech: "<< hyp << "\n" <<endl;   // send decoded speech to screen
            if (hyp != NULL)
            {
                string str(hyp);
                if (str.compare(wakeup) != 0) {
                    // printf("Recognized: %s\n", hyp);
                    cout << "Wake up word detected" << endl;
                }
            }
            break;                                   // exit the while loop and return to main
        }
    }

}