#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <time.h>
#include "fft.h"
//ref:https://raw.githubusercontent.com/cxong/tinydir/master/tinydir.h
#include "tinydir.h"
#include "timing.h"
#define DR_WAV_IMPLEMENTATION
//ref:https://raw.githubusercontent.com/mackron/dr_libs/master/dr_wav.h
#include "dr_wav.h"int16_t *wavRead_int16(char *filename, uint32_t *sampleRate, uint64_t *totalSampleCount) {unsigned int channels;int16_t *buffer = drwav_open_and_read_file_s16(filename, &channels, sampleRate, totalSampleCount);if (buffer == 0) {fprintf(stderr, "ERROR\n");exit(1);}if (channels == 2) {int16_t *bufferSave = buffer;for (int i = 0; i < *totalSampleCount; i += 2) {*bufferSave++ = (int16_t) ((buffer[i] + buffer[i + 1]) >> 1);}*totalSampleCount = *totalSampleCount >> 1;}return buffer;
}unsigned long hash(unsigned char *str) {unsigned long hash = 5381;int c;while (c = *str++)hash = ((hash << 5) + hash) + c;return hash;
}int generateHashes(char *input_file, int **hashtable, int songid, size_t N, int freqbandWidth, int maxElems) {printf("reading %s \n", input_file);uint32_t sampleRate = 0;uint64_t samplesize = 0;int16_t *pcmdata = wavRead_int16(input_file, &sampleRate, &samplesize);float *inputBuffer = (float *) calloc(sizeof(float), N);fft_complex *outBuffer = (fft_complex *) calloc(sizeof(fft_complex), N);int sect = 0;int cnt = 0;int numHashes = 0;for (int i = 0; i < samplesize; i++) {if (sect < N) {inputBuffer[sect] = (float) pcmdata[i];sect++;} else {sect = 0;i -= 1;cnt++;fft_plan plan = fft_plan_dft_r2c_1d(N, inputBuffer, outBuffer, 0);fft_execute(plan);fft_destroy_plan(plan);int freq1 = 0, freq2 = 0, freq3 = 0, freq4 = 0, freq5 = 0;int pt1 = 0, pt2 = 0, pt3 = 0, pt4 = 0, pt5 = 0;int freqbandWidth2 = freqbandWidth * 2;int freqbandWidth3 = freqbandWidth * 3;int freqbandWidth4 = freqbandWidth * 4;int freqbandWidth5 = freqbandWidth * 5;int freqbandWidth6 = freqbandWidth * 6;for (int k = freqbandWidth; k < freqbandWidth6; k++) {int freq = (outBuffer[k].real > 0) ? (int) outBuffer[k].real : (int) (0 - outBuffer[k].real);int Magnitude = (int) (log10f((freq + 1)) * 1000);if (k >= freqbandWidth && k < freqbandWidth2 && Magnitude > freq1) {freq1 = Magnitude;pt1 = k;} else if (k >= freqbandWidth2 && k < freqbandWidth3 && Magnitude > freq2) {freq2 = Magnitude;pt2 = k;} else if (k >= freqbandWidth3 && k < freqbandWidth4 && Magnitude > freq3) {freq3 = Magnitude;pt3 = k;} else if (k >= freqbandWidth4 && k < freqbandWidth5 && Magnitude > freq4) {freq4 = Magnitude;pt4 = k;} else if (k >= freqbandWidth5 && k < freqbandWidth6 && Magnitude > freq5) {freq5 = Magnitude;pt5 = k;}}char buffer[50];sprintf(buffer, "%d%d%d%d%d", pt1, pt2, pt3, pt4, pt5);unsigned long hashresult = hash(buffer) % maxElems;int key = (int) hashresult;if (key < 0)printf("Invalid key %d\n", key);hashtable[key][songid]++;numHashes++;}}free(pcmdata);free(inputBuffer);free(outBuffer);return numHashes;
}int main(int argc, char *argv[]) {printf("Audio Processing\n");printf("shazam audio hash\n");printf("blog: http://cpuimage.cnblogs.com/\n");int N = 512;int freqbandWidth = 50;int maxSongs = 10;size_t maxElems = 200000;int **hashTable;int i = 0, n = 0;float count = 0;int numsongs = 0;char filenames[maxSongs + 1][_TINYDIR_FILENAME_MAX];int filesizes[maxSongs + 1];int songScores[maxSongs + 1];float songMatch[maxSongs + 1];printf("running... \n");if (argc < 2) {printf("no excerpt file to open \n");exit(1);}double start_total = now();hashTable = (int **) calloc(maxElems, sizeof(int *));for (i = 0; i < maxElems; i++)hashTable[i] = (int *) calloc(maxSongs + 1, sizeof(int));printf("Generating hashes for original files.. \n");tinydir_dir dir;tinydir_open(&dir, "data");while (dir.has_next) {tinydir_file file;tinydir_readfile(&dir, &file);if (file.is_reg) {numsongs++;double startTime = now();filesizes[numsongs] = generateHashes(file.path, hashTable, numsongs, N, freqbandWidth, maxElems);size_t time_interval = (size_t) (calcElapsed(startTime, now()) * 1000);songScores[numsongs] = 0;printf("%d:%d hashes for %s\n", numsongs, filesizes[numsongs], file.path);printf("Time taken: %d seconds %d milliseconds\n", time_interval / 1000, time_interval % 1000);strcpy(filenames[numsongs], file.name);}tinydir_next(&dir);}tinydir_close(&dir);printf("Generating hashes for recorded file.. \n");generateHashes(argv[1], hashTable, 0, N, freqbandWidth, maxElems);printf("Calculating score.. \n");for (i = 0; i < maxElems; i++) {if (hashTable[i][0] > 0) {for (n = 1; n <= maxSongs; n++) {if (hashTable[i][n] >= hashTable[i][0])songScores[n] = songScores[n] + hashTable[i][0];elsesongScores[n] = songScores[n] + hashTable[i][n];;}}}for (i = 1; i <= numsongs; i++) {songMatch[i] = ((float) songScores[i]) / ((float) filesizes[i]);printf("Score for %s = %f\n", filenames[i], songMatch[i]);if (songMatch[i] > count) {count = songMatch[i];n = i;}}printf("Best Score: %s\n", filenames[n]);for (i = 0; i < maxElems; i++)free(hashTable[i]);free(hashTable);size_t msec = (size_t) (calcElapsed(start_total, now()) * 1000);printf("Total time taken: %d seconds %d milliseconds\n", msec / 1000, msec % 1000);return 0;
}