int main(void)
{
FLOATING freq;
InitGoertzel();
/* Demo 1 */
GenerateAndTest(TARGET_FREQUENCY - 250);
GenerateAndTest(TARGET_FREQUENCY);
GenerateAndTest(TARGET_FREQUENCY + 250);
/* Demo 2 */
for (freq = TARGET_FREQUENCY - 300; freq <= TARGET_FREQUENCY + 300; freq += 15)
{
GenerateAndTest2(freq);
}
return 0;
}
// returns -1 if no conclusive data could be produced, returns 0 - 15 depending on which tone is heard (row 1 of DTMF tones contains 0 - 3, etc.)
static int determine(const SAMPLE *input) // the input[] should be of length MAX_N
{
int i;
int max_Low_Power_Index;
int max_High_Power_Index;
int second_To_mLPI;
int second_To_mHPI;
setUpConstants();
for( i = 0; i < MAX_BINS; i++) {
InitGoertzel(i);
powers[i] = Test( i, input);
}
// Test to conclude winners for each half of frequencies
max_Low_Power_Index= 0;
max_High_Power_Index = MAX_BINS/2;
second_To_mLPI = -1;
second_To_mHPI = -1;
for( i = 1; i < (MAX_BINS/2); i++) {
if( powers[max_Low_Power_Index] <= powers[i]) {
second_To_mLPI = max_Low_Power_Index;
max_Low_Power_Index = i;
}
}
for( i = (MAX_BINS/2 + 1); i < MAX_BINS; i++) {
if( powers[max_High_Power_Index] <= powers[i]) {
second_To_mHPI = max_High_Power_Index;
max_High_Power_Index = i;
}
}
if(powers[max_Low_Power_Index] < powers[second_To_mLPI] * THRESHOLD_COEFF_LOW || powers[max_High_Power_Index] < powers[second_To_mHPI] * THRESHOLD_COEFF_HIGH) {
return -1;
} else {
return 4*max_Low_Power_Index + (max_High_Power_Index - 4);
}
}