QAM add constellation plot

wav/wav.c

@@ -0,0 +1,76 @@
+#include <stdio.h>
+#include <math.h>
+#include <stdlib.h>
+
+#define FS 44100
+
+// Fonction pour écrire un fichier WAV 16 bits PCM
+void write_wav(const char* filename, double* data, int len) {
+    FILE* f = fopen(filename, "wb");
+    if (!f) {
+        return;
+    }
+
+    int32_t chunk_size = 36 + len * 2;
+    int16_t audio_format = 1; // PCM
+    int16_t num_channels = 1;
+    int32_t sample_rate = FS;
+    int32_t byte_rate = FS * num_channels * 2;
+    int16_t block_align = num_channels * 2;
+    int16_t bits_per_sample = 16;
+    int32_t subchunk2_size = len * 2;
+
+    // En-tête WAV
+    fwrite("RIFF", 1, 4, f);
+    fwrite(&chunk_size, 4, 1, f);
+    fwrite("WAVE", 1, 4, f);
+    fwrite("fmt ", 1, 4, f);
+
+    int32_t subchunk1_size = 16;
+    fwrite(&subchunk1_size, 4, 1, f);
+    fwrite(&audio_format, 2, 1, f);
+    fwrite(&num_channels, 2, 1, f);
+    fwrite(&sample_rate, 4, 1, f);
+    fwrite(&byte_rate, 4, 1, f);
+    fwrite(&block_align, 2, 1, f);
+    fwrite(&bits_per_sample, 2, 1, f);
+
+    fwrite("data", 1, 4, f);
+    fwrite(&subchunk2_size, 4, 1, f);
+
+    for (int i = 0; i < len; i++) {
+        int16_t sample = (int16_t)(data[i]);
+        fwrite(&sample, sizeof(int16_t), 1, f);
+    }
+
+    fclose(f);
+}
+
+
+double* read_wav(const char* filename, int* out_len) {
+    FILE* f = fopen(filename, "rb");
+    if (!f) {
+        perror("Fail to open .wav");
+        return NULL;
+    }
+
+    fseek(f, 0, SEEK_END);
+    long filesize = ftell(f);
+    fseek(f, 0, SEEK_SET);
+
+    fseek(f, 44, SEEK_SET);
+
+    int len = (filesize - 44) / 2;
+    double* data = malloc(sizeof(double) * len);
+    int16_t sample;
+
+    for (int i = 0; i < len; i++) {
+        fread(&sample, sizeof(int16_t), 1, f);
+        data[i] = (double)sample;
+    }
+
+    fclose(f);
+
+    *out_len = len;
+    return data;
+}

wav/wav.h

@@ -0,0 +1,3 @@
+void write_wav(const char* filename, double* data, int len);
+
+double* read_wav(const char* filename, int* out_len);