ajout effets audio

Appli/Core/Inc/audio_effects.h

@@ -0,0 +1,26 @@
+#ifndef AUDIO_EFFECTS_H
+#define AUDIO_EFFECTS_H
+
+#include "fx_equalizer.h"
+#include "fx_overdrive.h"
+#include "fx_saturation.h"
+#include "fx_echo.h"
+#include "fx_reverb.h"
+
+/* Structure regroupant les parametres de tous les effets. Modifiable directement
+ * (ex: depuis l'IHM) via AudioEffects_GetParams(). L'ordre de traitement fixe est :
+ * egaliseur -> overdrive -> saturation -> echo -> reverberation. */
+typedef struct
+{
+    FxEqualizerParams equalizer;
+    FxOverdriveParams overdrive;
+    FxSaturationParams saturation;
+    FxEchoParams echo;
+    FxReverbParams reverb;
+} AudioEffectsParams;
+
+void AudioEffects_Init(void);
+float AudioEffects_Process(float input);
+AudioEffectsParams *AudioEffects_GetParams(void);
+
+#endif /* AUDIO_EFFECTS_H */

Appli/Core/Inc/fx_echo.h

@@ -0,0 +1,28 @@
+#ifndef FX_ECHO_H
+#define FX_ECHO_H
+
+#include <stdbool.h>
+#include <stdint.h>
+
+#define FX_ECHO_SAMPLE_RATE      48000U
+#define FX_ECHO_MAX_DELAY_MS     1000U
+#define FX_ECHO_BUFFER_SIZE      (FX_ECHO_SAMPLE_RATE * FX_ECHO_MAX_DELAY_MS / 1000U)
+
+typedef struct
+{
+    bool  enabled;
+    float delay_ms;   /* 0 a FX_ECHO_MAX_DELAY_MS */
+    float feedback;   /* 0.0 a <1.0 */
+    float mix;        /* 0.0 (sec) a 1.0 (100% repetitions) */
+} FxEchoParams;
+
+typedef struct
+{
+    int16_t  buffer[FX_ECHO_BUFFER_SIZE];
+    uint32_t write_idx;
+} FxEchoState;
+
+void  FxEcho_Init(FxEchoState *state, FxEchoParams *params);
+float FxEcho_Process(FxEchoState *state, const FxEchoParams *params, float input);
+
+#endif /* FX_ECHO_H */

Appli/Core/Inc/fx_equalizer.h

@@ -0,0 +1,44 @@
+#ifndef FX_EQUALIZER_H
+#define FX_EQUALIZER_H
+
+#include <stdbool.h>
+
+#define FX_EQ_NUM_BANDS 10U
+
+typedef struct
+{
+    float freq_hz;   /* frequence centrale de la bande */
+    float gain_db;   /* -24.0 a +24.0 dB */
+    float q;         /* facteur de qualite, typiquement 0.5 a 5.0 */
+} FxEqBand;
+
+typedef struct
+{
+    bool     enabled;
+    FxEqBand bands[FX_EQ_NUM_BANDS];
+} FxEqualizerParams;
+
+typedef struct
+{
+    /* coefficients biquad mis en cache, recalcules seulement si les parametres changent */
+    float b0, b1, b2, a1, a2;
+    /* dernieres valeurs de parametres utilisees pour calculer les coefficients ci-dessus */
+    float last_freq_hz;
+    float last_gain_db;
+    float last_q;
+} FxEqBandState;
+
+typedef struct
+{
+    FxEqBandState band_state[FX_EQ_NUM_BANDS];
+    /* etat du filtre (direct form 1), par bande */
+    float x1[FX_EQ_NUM_BANDS];
+    float x2[FX_EQ_NUM_BANDS];
+    float y1[FX_EQ_NUM_BANDS];
+    float y2[FX_EQ_NUM_BANDS];
+} FxEqualizerState;
+
+void  FxEqualizer_Init(FxEqualizerState *state, FxEqualizerParams *params);
+float FxEqualizer_Process(FxEqualizerState *state, const FxEqualizerParams *params, float input);
+
+#endif /* FX_EQUALIZER_H */

Appli/Core/Inc/fx_overdrive.h

@@ -0,0 +1,22 @@
+#ifndef FX_OVERDRIVE_H
+#define FX_OVERDRIVE_H
+
+#include <stdbool.h>
+
+typedef struct
+{
+    bool  enabled;
+    float drive;   /* 0.0 a 1.0 : quantite de distorsion */
+    float tone;    /* 0.0 (sombre) a 1.0 (brillant) : filtre passe-bas post-distorsion */
+    float level;   /* gain de compensation en sortie */
+} FxOverdriveParams;
+
+typedef struct
+{
+    float tone_lp_state;
+} FxOverdriveState;
+
+void  FxOverdrive_Init(FxOverdriveState *state, FxOverdriveParams *params);
+float FxOverdrive_Process(FxOverdriveState *state, const FxOverdriveParams *params, float input);
+
+#endif /* FX_OVERDRIVE_H */

Appli/Core/Inc/fx_reverb.h

@@ -0,0 +1,42 @@
+#ifndef FX_REVERB_H
+#define FX_REVERB_H
+
+#include <stdbool.h>
+#include <stdint.h>
+
+#define FX_REVERB_NUM_COMBS    8U
+#define FX_REVERB_NUM_ALLPASS  4U
+
+typedef struct
+{
+    bool  enabled;
+    float room_size;  /* 0.0 a 1.0 */
+    float damping;    /* 0.0 (brillant) a 1.0 (etouffe) */
+    float mix;        /* 0.0 (sec) a 1.0 (100% reverbere) */
+} FxReverbParams;
+
+typedef struct
+{
+    float   *buffer;
+    uint32_t size;
+    uint32_t idx;
+    float    filter_store;
+} FxCombState;
+
+typedef struct
+{
+    float   *buffer;
+    uint32_t size;
+    uint32_t idx;
+} FxAllpassState;
+
+typedef struct
+{
+    FxCombState    combs[FX_REVERB_NUM_COMBS];
+    FxAllpassState allpass[FX_REVERB_NUM_ALLPASS];
+} FxReverbState;
+
+void  FxReverb_Init(FxReverbState *state, FxReverbParams *params);
+float FxReverb_Process(FxReverbState *state, const FxReverbParams *params, float input);
+
+#endif /* FX_REVERB_H */

Appli/Core/Inc/fx_saturation.h

@@ -0,0 +1,22 @@
+#ifndef FX_SATURATION_H
+#define FX_SATURATION_H
+
+#include <stdbool.h>
+
+typedef struct
+{
+    bool  enabled;
+    float drive;   /* 0.0 (aucun effet) a 1.0 (saturation maximale) */
+    float level;   /* gain de compensation en sortie, typiquement 0.0 - 1.0 */
+} FxSaturationParams;
+
+typedef struct
+{
+    float dc_block_x1;
+    float dc_block_y1;
+} FxSaturationState;
+
+void  FxSaturation_Init(FxSaturationState *state, FxSaturationParams *params);
+float FxSaturation_Process(FxSaturationState *state, const FxSaturationParams *params, float input);
+
+#endif /* FX_SATURATION_H */