Use native sample rate for MP3 playback

Makefile

@@ -39,6 +39,7 @@ SRCS = \
 	menu/png_decoder.c \
 	menu/rom_database.c \
 	menu/settings.c \
+	menu/sound.c \
 	menu/views/browser.c \
 	menu/views/credits.c \
 	menu/views/error.c \

libdragon

@@ -1 +1 @@
-Subproject commit a04292bf16db0931dc3ef616fa189c59f200bc1c
+Subproject commit 251c821158cfc6099baa5577680223dc9897ef57

src/menu/menu.c

@@ -13,6 +13,7 @@
 #include "mp3_player.h"
 #include "png_decoder.h"
 #include "settings.h"
+#include "sound.h"
 #include "utils/fs.h"
 #include "views/views.h"
 
@@ -55,13 +56,10 @@ static void menu_init (boot_params_t *boot_params) {
     controller_init();
     timer_init();
     rtc_init();
-    audio_init(44100, 2);
-    mixer_init(2);
     rspq_init();
     rdpq_init();
-
     fonts_init();
-    mp3player_mixer_init();
+    sound_init_default();
 
     boot_pending = false;
 
@@ -114,10 +112,9 @@ static void menu_deinit (menu_t *menu) {
 
     flashcart_deinit();
 
+    sound_close();
     rdpq_close();
     rspq_close();
-    mixer_close();
-    audio_close();
     rtc_close();
     timer_close();
 
@@ -150,8 +147,6 @@ static struct views_s {
 void menu_run (boot_params_t *boot_params) {
     menu_init(boot_params);
 
-    int audio_buffer_length = audio_get_buffer_length();
-
     while (!boot_pending && (exception_reset_time() < RESET_TIME_LENGTH)) {
         surface_t *display = (frame_counter >= FRAMERATE_DIVIDER) ? display_try_get() : NULL;
 
@@ -182,11 +177,7 @@ void menu_run (boot_params_t *boot_params) {
             time(&menu->current_time);
         }
 
-        while (audio_can_write()) {
+        sound_poll();
-            short *audio_buffer = audio_write_begin();
-            mixer_poll(audio_buffer, audio_buffer_length);
-            audio_write_end();
-        }
 
         png_decoder_poll();
     }

src/menu/mp3_player.c

@@ -2,6 +2,7 @@
 #include <libdragon.h>
 
 #include "mp3_player.h"
+#include "sound.h"
 #include "utils/fs.h"
 #include "utils/utils.h"
 
@@ -11,7 +12,6 @@
 #include <minimp3/minimp3.h>
 
 
-#define MIXER_CHANNEL           (0)
 #define SEEK_PREDECODE_FRAMES   (5)
 
 
@@ -119,7 +119,7 @@ void mp3player_mixer_init (void) {
     // NOTE: Deliberately setting max_frequency to twice of actual maximum samplerate of mp3 file.
     //       It's tricking mixer into creating buffer long enough for appending data created by mp3dec_decode_frame.
 
-    mixer_ch_set_limits(MIXER_CHANNEL, 16, 96000, 0);
+    mixer_ch_set_limits(SOUND_MP3_PLAYER_CHANNEL, 16, 96000, 0);
 }
 
 mp3player_err_t mp3player_init (void) {
@@ -230,7 +230,7 @@ mp3player_err_t mp3player_process (void) {
 }
 
 bool mp3player_is_playing (void) {
-    return mixer_ch_playing(MIXER_CHANNEL);
+    return mixer_ch_playing(SOUND_MP3_PLAYER_CHANNEL);
 }
 
 bool mp3player_is_finished (void) {
@@ -249,14 +249,14 @@ mp3player_err_t mp3player_play (void) {
             }
             mp3player_reset_decoder();
         }
-        mixer_ch_play(MIXER_CHANNEL, &p->wave);
+        mixer_ch_play(SOUND_MP3_PLAYER_CHANNEL, &p->wave);
     }
     return MP3PLAYER_OK;
 }
 
 void mp3player_stop (void) {
     if (mp3player_is_playing()) {
-        mixer_ch_stop(MIXER_CHANNEL);
+        mixer_ch_stop(SOUND_MP3_PLAYER_CHANNEL);
     }
 }
 
@@ -271,7 +271,7 @@ mp3player_err_t mp3player_toggle (void) {
 
 void mp3player_mute (bool mute) {
     float volume = mute ? 0.0f : 1.0f;
-    mixer_ch_set_vol(MIXER_CHANNEL, volume, volume);
+    mixer_ch_set_vol(SOUND_MP3_PLAYER_CHANNEL, volume, volume);
 }
 
 mp3player_err_t mp3player_seek (int seconds) {

src/menu/sound.c

@@ -0,0 +1,57 @@
+#include <stdbool.h>
+
+#include <libdragon.h>
+
+#include "mp3_player.h"
+
+
+#define DEFAULT_FREQUENCY   (44100)
+#define NUM_BUFFERS         (2)
+#define NUM_CHANNELS        (2)
+
+
+static bool sound_initialized = false;
+
+
+void sound_init_default (void) {
+    if (audio_get_frequency() != DEFAULT_FREQUENCY) {
+        if (sound_initialized) {
+            mixer_close();
+            audio_close();
+        }
+        audio_init(DEFAULT_FREQUENCY, NUM_BUFFERS);
+        mixer_init(NUM_CHANNELS);
+        mp3player_mixer_init();
+        sound_initialized = true;
+    }
+}
+
+void sound_init_mp3_playback (void) {
+    int frequency = mp3player_get_samplerate();
+    if ((frequency > 0) && (audio_get_frequency() != frequency)) {
+        if (sound_initialized) {
+            mixer_close();
+            audio_close();
+        }
+        audio_init(frequency, NUM_BUFFERS);
+        mixer_init(NUM_CHANNELS);
+        mp3player_mixer_init();
+        sound_initialized = true;
+    }
+}
+
+void sound_poll (void) {
+    if (sound_initialized && audio_can_write()) {
+        short *audio_buffer = audio_write_begin();
+        mixer_poll(audio_buffer, audio_get_buffer_length());
+        audio_write_end();
+    }
+}
+
+void sound_close (void) {
+    if (sound_initialized) {
+        mixer_close();
+        audio_close();
+        sound_initialized = false;
+    }
+}

src/menu/sound.h

@@ -0,0 +1,20 @@
+/**
+ * @file sound.h
+ * @brief Menu Sound
+ * @ingroup menu
+ */
+
+#ifndef SOUND_H__
+#define SOUND_H__
+
+
+#define SOUND_MP3_PLAYER_CHANNEL    (0)
+
+
+void sound_init_default (void);
+void sound_init_mp3_playback (void);
+void sound_poll (void);
+void sound_close (void);
+
+
+#endif

src/menu/views/music_player.c

@@ -1,4 +1,5 @@
 #include "../mp3_player.h"
+#include "../sound.h"
 #include "views.h"
 
 
@@ -109,6 +110,7 @@ static void draw (menu_t *menu, surface_t *d) {
 }
 
 static void deinit (void) {
+    sound_init_default();
     mp3player_deinit();
 }
 
@@ -130,8 +132,13 @@ void view_music_player_init (menu_t *menu) {
         menu_show_error(menu, convert_error_message(err));
         mp3player_deinit();
     } else {
+        sound_init_mp3_playback();
         mp3player_mute(false);
-        mp3player_play();
+        err = mp3player_play();
+        if (err != MP3PLAYER_OK) {
+            menu_show_error(menu, convert_error_message(err));
+            mp3player_deinit();
+        }
     }
 
     path_free(path);