Discrete Fourier Transform impl

1 files changed, 48 insertions, 0 deletions

diff --git a/src/dft.h b/src/dft.h
new file mode 100644
index 0000000..982cc6f
--- /dev/null
+++ b/src/dft.h
@@ -0,0 +1,48 @@
+#pragma once
+
+#include "common.h"
+#include "smrt_arena.h"
+#include "wav.h"
+
+typedef struct {
+    f64 *frequencies;
+    f64 * amplitudes;
+    f64 *     phases;
+    u64   freq_count;
+} dft_data_t;
+
+/// Run DFT algorithm on samples
+dft_data_t discrete_fourier_transform(smrt_arena_t *      arena ,
+                                               f64 *    samples ,
+                                               u64 sample_count ,
+                                               u64  sample_rate);
+
+/// Convert DFT frequency data to unsigned 8-bit PCM WAV amplitude data
+wav_data_t dft_data_to_wav(smrt_arena_t *     arena ,
+                             dft_data_t         dft ,
+                                    u64 sample_rate ,
+                                    f64    duration);
+
+typedef struct {
+    dft_data_t         data;
+           u64 sample_count;
+           u64  start_index;
+} stft_segment_t;
+
+typedef struct {
+    stft_segment_t *    segments;
+               u64 segment_count;
+               u64   sample_rate;
+} stft_data_t;
+
+/// Run STFT algorithm on samples.
+stft_data_t short_time_fourier_transform(smrt_arena_t *             arena ,
+                                                  u64 samples_per_segment ,
+                                                  f64 *           samples ,
+                                                  u64        sample_count ,
+                                                  u64         sample_rate);
+
+/// Convert STFT frequency data to unsigned 8-bit PCM WAV amplitude data
+wav_data_t stft_data_to_wav(smrt_arena_t *      arena ,
+                             stft_data_t         stft ,
+                                     u64 sample_count);