FFTData FFTransformer::analyze(AudioData audioData)
{
float *data = audioData.data;
int dataLen = audioData.dataLen;
int sampleRate = audioData.sampleRate;
if(this->frequency != NULL)
delete frequency;
if(this->internalData != NULL)
delete internalData;
int internalCount = (int)pow(2, ceil(log2(dataLen)));
internalCount *= 2;
internalData = new float[internalCount];
memset(internalData, 0, internalCount);
for (int i=0; i < dataLen; i++)
internalData[i*2] = data[i];
resolution = ((float)sampleRate) / dataLen * audioData.numChannels;
FFT(internalData, internalCount);
countFrequency(internalData, internalCount);
outputData.data = data;
outputData.dataLen = dataLen;
outputData.frequency = frequency;
outputData.frequencyLen = frequencyLen;
outputData.resolution = resolution;
outputData.fundamentalFrequency = fundamentalFrequency;
return outputData;
}
int main(void)
{
char *str = "Rqfh pruh lqwr wkh euhdfk,ghdu iulhqgv,rqfh pruh;Ru forvh wkh zdoo xs zlwk rxu Hqjolvk ghdg.Lq shdfh wkhuh'v qrwklqj vr ehfrphv d pdq dv prghvw uwlooqhvv dqg kxplolwb:Exw zkhq wkh eodvw ri zdu eorzv lq rxu hduv,Wkhq lplwdwh wkh dfwlrq ri wkh wljhu;Vwliihq wkh vlqhzv,vxpprq xs wkh eorrg.";
int frequency[26] = {0}; //存放频数
//调用函数
countFrequency(str,frequency);
}
int main(int argc, char **argv) {
if (argc < 2) {
printf("\nInput file needed. Exiting...\n");
return 0;
}
FILE *input = fopen(argv[1], "r");
char pt, c;
int i = 0, numChars, shifts[3] = {0};
float charCount[26] = {0};
table *alphabet = NULL;
alphabet = readInFile(alphabet, "letterFrequencies.txt");
numChars = countFrequency(input, charCount);
computeFrequency(numChars, charCount);
printf("\nFREQUENCY ANALYSIS ATTACK ON THE SHIFT CIPHER"
"\n--------------------------------------");
table *inputFrequencies = NULL;
int a = 0;
while (a < 26) {
inputFrequencies = loadTable(inputFrequencies, a+97, charCount[a], 0);
a++;
}
pickTopShifts(inputFrequencies, shifts);
table *temp = inputFrequencies;
printf("\nTESTING TOP 3 SHIFT POSSIBILITIES\n");
for (i = 0; i < 3; i++) {
rewind(input);
printf("\nDecryption %d/3; Shift :%d\t", i+1, shifts[i]-4);
while((c = getc(input)) != EOF){
pt = decrypt(c, shifts[i]-4);
putchar(pt);
}
}
printf("\n");
fclose(input);
return 0;
}
bool isPermutationOfPallindrome1( const std::string & str )
{
int frequency[ 26 ] = { 0 };
countFrequency( str, frequency );
/*
* We will check here that letter frequencies are all even or all even except one odd.
*/
bool oddAppeared = false;
std::cout << std::endl;
for ( int i = 0 ; i < 26; ++i ) {
if ( frequency[i] % 2 && oddAppeared ) {
return false;
} else if ( frequency[i] % 2 && !oddAppeared ) {
oddAppeared = true;
}
}
return true;
}
