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Posted to commits@nuttx.apache.org by ma...@apache.org on 2022/08/25 11:30:03 UTC
[incubator-nuttx-apps] 03/03: examples/fmsynth: Add examples for FM synthesizer lib
This is an automated email from the ASF dual-hosted git repository.
masayuki pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/incubator-nuttx-apps.git
commit 4d86c69a22092e803340f4c22c1a5dee4c592843
Author: Takayoshi Koizumi <ta...@gmail.com>
AuthorDate: Tue Aug 16 09:03:39 2022 +0000
examples/fmsynth: Add examples for FM synthesizer lib
Add examples to show how to use fmsynth library.
There are 2 samples.
One is a music keyboard, and the other is music player decording MML.
---
examples/fmsynth/Kconfig | 42 +++
examples/fmsynth/Make.defs | 23 ++
examples/fmsynth/Makefile | 44 +++
examples/fmsynth/keyboard_main.c | 449 +++++++++++++++++++++++++++
examples/fmsynth/mmlplayer_main.c | 563 ++++++++++++++++++++++++++++++++++
examples/fmsynth/mmlplayer_score.h | 58 ++++
examples/fmsynth/music_scale.c | 97 ++++++
examples/fmsynth/music_scale.h | 62 ++++
examples/fmsynth/operator_algorithm.c | 188 ++++++++++++
examples/fmsynth/operator_algorithm.h | 39 +++
10 files changed, 1565 insertions(+)
diff --git a/examples/fmsynth/Kconfig b/examples/fmsynth/Kconfig
new file mode 100644
index 000000000..6038fb033
--- /dev/null
+++ b/examples/fmsynth/Kconfig
@@ -0,0 +1,42 @@
+#
+# For a description of the syntax of this configuration file,
+# see the file kconfig-language.txt in the NuttX tools repository.
+#
+
+config EXAMPLES_FMSYNTH
+ tristate "FM Synthesizer examples"
+ default n
+ ---help---
+ Examples for fmsynth library.
+
+if EXAMPLES_FMSYNTH
+
+config EXAMPLES_FMSYNTH_KEYBOARD_PROGNAME
+ string "Simple music keyboard Program name"
+ default "keyboard"
+ ---help---
+ Command name of this "Simple music keyboard".
+
+config EXAMPLES_FMSYNTH_KEYBOARD_PRIORITY
+ int "Simple music keyboard task priority"
+ default 100
+
+config EXAMPLES_FMSYNTH_KEYBOARD_STACKSIZE
+ int "Simple music keyboard stack size"
+ default 2048
+
+config EXAMPLES_FMSYNTH_MMLPLAYER_PROGNAME
+ string "MML Player Program name"
+ default "mmlplayer"
+ ---help---
+ Command name of this "MML Player".
+
+config EXAMPLES_FMSYNTH_MMLPLAYER_PRIORITY
+ int "MML Player task priority"
+ default 100
+
+config EXAMPLES_FMSYNTH_MMLPLAYER_STACKSIZE
+ int "MML Player stack size"
+ default 2048
+
+endif
diff --git a/examples/fmsynth/Make.defs b/examples/fmsynth/Make.defs
new file mode 100644
index 000000000..25be117b1
--- /dev/null
+++ b/examples/fmsynth/Make.defs
@@ -0,0 +1,23 @@
+############################################################################
+# apps/examples/fmsynth/Make.defs
+#
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements. See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership. The
+# ASF licenses this file to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance with the
+# License. You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+#
+############################################################################
+
+ifneq ($(CONFIG_EXAMPLES_FMSYNTH),)
+CONFIGURED_APPS += $(APPDIR)/examples/fmsynth
+endif
diff --git a/examples/fmsynth/Makefile b/examples/fmsynth/Makefile
new file mode 100644
index 000000000..d89a7df17
--- /dev/null
+++ b/examples/fmsynth/Makefile
@@ -0,0 +1,44 @@
+############################################################################
+# apps/examples/fmsynth/Makefile
+#
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements. See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership. The
+# ASF licenses this file to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance with the
+# License. You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+#
+############################################################################
+
+include $(APPDIR)/Make.defs
+
+# For fmsynth utilities
+
+ASRCS =
+CSRCS = music_scale.c operator_algorithm.c
+
+# For fmsynth_keyboard
+
+PROGNAME = $(CONFIG_EXAMPLES_FMSYNTH_KEYBOARD_PROGNAME)
+PRIORITY = $(CONFIG_EXAMPLES_FMSYNTH_KEYBOARD_PRIORITY)
+STACKSIZE = $(CONFIG_EXAMPLES_FMSYNTH_KEYBOARD_STACKSIZE)
+MAINSRC = keyboard_main.c
+
+# For fmsynth_mmlplayer
+
+PROGNAME += $(CONFIG_EXAMPLES_FMSYNTH_MMLPLAYER_PROGNAME)
+PRIORITY += $(CONFIG_EXAMPLES_FMSYNTH_MMLPLAYER_PRIORITY)
+STACKSIZE += $(CONFIG_EXAMPLES_FMSYNTH_MMLPLAYER_STACKSIZE)
+MAINSRC += mmlplayer_main.c
+
+MODULE = $(CONFIG_EXAMPLES_FMSYNTH)
+
+include $(APPDIR)/Application.mk
diff --git a/examples/fmsynth/keyboard_main.c b/examples/fmsynth/keyboard_main.c
new file mode 100644
index 000000000..d3f0c9bc4
--- /dev/null
+++ b/examples/fmsynth/keyboard_main.c
@@ -0,0 +1,449 @@
+/****************************************************************************
+ * apps/examples/fmsynth/keyboard_main.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <errno.h>
+#include <pthread.h>
+#include <sched.h>
+#include <limits.h>
+
+#include <nuttx/audio/audio.h>
+#include <audioutils/fmsynth.h>
+#include <audioutils/nxaudio.h>
+
+#include "operator_algorithm.h"
+#include "music_scale.h"
+
+/****************************************************************************
+ * Pre-processor
+ ****************************************************************************/
+
+#define APP_FS (48000)
+#define APP_BPS (16)
+#define APP_CHNUM (2)
+
+#define APP_DEFAULT_VOL (400)
+
+/****************************************************************************
+ * Private Data Type
+ ****************************************************************************/
+
+struct app_options
+{
+ int volume;
+ int mode;
+};
+
+struct kbd_s
+{
+ struct nxaudio_s nxaudio;
+
+ FAR fmsynth_sound_t *sound;
+ FAR fmsynth_op_t *carrier;
+
+ volatile int request_scale;
+};
+
+struct key_convert_s
+{
+ int key;
+ char key_str;
+ FAR const char *dispstr;
+};
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+extern int board_external_amp_mute_control(bool en);
+static void app_dequeue_cb(unsigned long arg,
+ FAR struct ap_buffer_s *apb);
+static void app_complete_cb(unsigned long arg);
+static void app_user_cb(unsigned long arg,
+ FAR struct audio_msg_s *msg, FAR bool *running);
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+static struct kbd_s g_kbd;
+
+static struct nxaudio_callbacks_s cbs =
+{
+ app_dequeue_cb,
+ app_complete_cb,
+ app_user_cb
+};
+
+static struct key_convert_s key_convert[] =
+{
+ { OCTAVE(4, MUSIC_SCALE_C), 'a', "O4C" },
+ { OCTAVE(4, MUSIC_SCALE_CS), 'w', "O4C+" },
+ { OCTAVE(4, MUSIC_SCALE_D), 's', "O4D" },
+ { OCTAVE(4, MUSIC_SCALE_DS), 'e', "O4D+" },
+ { OCTAVE(4, MUSIC_SCALE_E), 'd', "O4E" },
+ { OCTAVE(4, MUSIC_SCALE_F), 'f', "O4F" },
+ { OCTAVE(4, MUSIC_SCALE_FS), 't', "O4F+" },
+ { OCTAVE(4, MUSIC_SCALE_G), 'g', "O4G" },
+ { OCTAVE(4, MUSIC_SCALE_GS), 'y', "O4G+" },
+ { OCTAVE(4, MUSIC_SCALE_A), 'h', "O4A" },
+ { OCTAVE(4, MUSIC_SCALE_AS), 'u', "O4A+" },
+ { OCTAVE(4, MUSIC_SCALE_B), 'j', "O4B" },
+ { OCTAVE(5, MUSIC_SCALE_C), 'k', "O5C" },
+ { OCTAVE(5, MUSIC_SCALE_CS), 'o', "O5C+" },
+ { OCTAVE(5, MUSIC_SCALE_D), 'l', "O5D" },
+ { OCTAVE(5, MUSIC_SCALE_DS), 'p', "O5D+" },
+ { OCTAVE(5, MUSIC_SCALE_E), ';', "O5E" },
+};
+
+#define MAX_KEYCONVERT (sizeof(key_convert)/sizeof(key_convert[0]))
+
+/****************************************************************************
+ * Private functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * name: convert_key2idx
+ ****************************************************************************/
+
+static int convert_key2idx(char key)
+{
+ int i;
+
+ for (i = 0; i < MAX_KEYCONVERT; i++)
+ {
+ if (key == key_convert[i].key_str)
+ {
+ return i;
+ }
+ }
+
+ return -1;
+}
+
+/****************************************************************************
+ * name: tick_callback
+ ****************************************************************************/
+
+static void tick_callback(unsigned long arg)
+{
+ FAR struct kbd_s *kbd = (FAR struct kbd_s *)(uintptr_t)arg;
+ int scale = kbd->request_scale;
+
+ if (scale != -1)
+ {
+ fmsynthsnd_set_soundfreq(kbd->sound,
+ musical_scale[scale]);
+ kbd->request_scale = -1;
+ }
+}
+
+/****************************************************************************
+ * name: app_dequeue_cb
+ ****************************************************************************/
+
+static void app_dequeue_cb(unsigned long arg,
+ FAR struct ap_buffer_s *apb)
+{
+ FAR struct kbd_s *kbd = (FAR struct kbd_s *)(uintptr_t)arg;
+
+ apb->curbyte = 0;
+ apb->flags = 0;
+
+ if (kbd->request_scale != -1)
+ {
+ apb->nbytes = fmsynth_rendering(kbd->sound,
+ (FAR int16_t *)apb->samp,
+ apb->nmaxbytes / sizeof(int16_t),
+ kbd->nxaudio.chnum,
+ tick_callback, (unsigned long)kbd);
+ }
+ else
+ {
+ apb->nbytes = fmsynth_rendering(kbd->sound,
+ (FAR int16_t *)apb->samp,
+ apb->nmaxbytes / sizeof(int16_t),
+ kbd->nxaudio.chnum,
+ NULL, 0);
+ }
+
+ nxaudio_enqbuffer(&kbd->nxaudio, apb);
+}
+
+/****************************************************************************
+ * name: app_complete_cb
+ ****************************************************************************/
+
+static void app_complete_cb(unsigned long arg)
+{
+ /* Do nothing.. */
+
+ printf("Audio loop is Done\n");
+}
+
+/****************************************************************************
+ * name: app_user_cb
+ ****************************************************************************/
+
+static void app_user_cb(unsigned long arg,
+ FAR struct audio_msg_s *msg, FAR bool *running)
+{
+ /* Do nothing.. */
+}
+
+/****************************************************************************
+ * name: audio_loop_thread
+ ****************************************************************************/
+
+static FAR void *audio_loop_thread(pthread_addr_t arg)
+{
+ FAR struct kbd_s *kbd = (FAR struct kbd_s *)arg;
+
+ nxaudio_start(&kbd->nxaudio);
+ nxaudio_msgloop(&kbd->nxaudio, &cbs, (unsigned long)kbd);
+
+ return NULL;
+}
+
+/****************************************************************************
+ * name: create_audio_thread
+ ****************************************************************************/
+
+static pthread_t create_audio_thread(FAR struct kbd_s *kbd)
+{
+ pthread_t pid;
+ pthread_attr_t tattr;
+ struct sched_param sparam;
+
+ pthread_attr_init(&tattr);
+ sparam.sched_priority = sched_get_priority_max(SCHED_FIFO) - 9;
+ pthread_attr_setschedparam(&tattr, &sparam);
+ pthread_attr_setstacksize(&tattr, 4096);
+
+ pthread_create(&pid, &tattr, audio_loop_thread,
+ (pthread_addr_t)kbd);
+ pthread_setname_np(pid, "musickeyboard_thread");
+
+ return pid;
+}
+
+/****************************************************************************
+ * name: init_fmmusi_soundsc
+ ****************************************************************************/
+
+static int init_keyboard_sound(FAR struct kbd_s *kbd, int fs, int mode)
+{
+ int ret = ERROR;
+
+ fmsynth_initialize(fs);
+
+ kbd->sound = fmsynthsnd_create();
+ if (kbd->sound)
+ {
+ kbd->carrier = mode == 0 ? fmsynthutil_algorithm0() :
+ mode == 1 ? fmsynthutil_algorithm1() :
+ mode == 2 ? fmsynthutil_algorithm2() :
+ NULL;
+ if (!kbd->carrier)
+ {
+ fmsynthsnd_delete(kbd->sound);
+ return ret;
+ }
+
+ fmsynthsnd_set_operator(kbd->sound, kbd->carrier);
+ kbd->request_scale = -1;
+ ret = OK;
+ }
+
+ return ret;
+}
+
+/****************************************************************************
+ * name: fin_keyboard
+ ****************************************************************************/
+
+static void fin_keyboard(FAR struct kbd_s *kbd)
+{
+ fin_nxaudio(&kbd->nxaudio);
+ fmsynthutil_delete_ops(kbd->carrier);
+ fmsynthsnd_delete(kbd->sound);
+}
+
+/****************************************************************************
+ * name: print_help
+ ****************************************************************************/
+
+static void print_help(FAR char *name)
+{
+ printf("nsh> %s ([-v (volume from 0 to 100)]) ([-m (mode 0, 1 or 2)])\n",
+ name);
+}
+
+/****************************************************************************
+ * name: configure_option
+ ****************************************************************************/
+
+static int configure_option(FAR struct app_options *option,
+ int argc, FAR char **argv)
+{
+ int opt;
+
+ option->volume = APP_DEFAULT_VOL;
+ option->mode = 0;
+ while ((opt = getopt(argc, argv, "hv:m:")) != ERROR)
+ {
+ switch (opt)
+ {
+ case 'v':
+ option->volume = atoi(optarg) * 10;
+ if (option->volume < 0 || option->volume > 1000)
+ {
+ option->volume = 400;
+ }
+ break;
+
+ case 'm':
+ option->mode = atoi(optarg);
+ if (option->mode < 0 || option->mode > 3)
+ {
+ option->mode = 0;
+ }
+ break;
+
+ default:
+ return ERROR;
+ }
+ }
+
+ return OK;
+}
+
+/****************************************************************************
+ * name: print_keyusage()
+ ****************************************************************************/
+
+static void print_keyusage(void)
+{
+ int i;
+
+ printf("press any key below to make a sound.\n");
+ for (i = 0; i < MAX_KEYCONVERT; i++)
+ {
+ printf(" [KEY]: %c, [CODE]: %s\n",
+ key_convert[i].key_str,
+ key_convert[i].dispstr);
+ }
+ printf("\n");
+}
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * name: main
+ ****************************************************************************/
+
+int main(int argc, FAR char *argv[])
+{
+ int i;
+ int ret;
+ char key;
+ bool running = true;
+ pthread_t pid;
+ struct app_options appopt;
+ int key_idx;
+
+ if (configure_option(&appopt, argc, argv) != OK)
+ {
+ print_help(argv[0]);
+ return -1;
+ }
+
+ ret = init_nxaudio(&g_kbd.nxaudio, APP_FS, APP_BPS, APP_CHNUM);
+ if (ret < 0)
+ {
+ printf("init_nxaoud() returned with error!!\n");
+ return -1;
+ }
+
+ nxaudio_setvolume(&g_kbd.nxaudio, appopt.volume);
+
+ ret = init_keyboard_sound(&g_kbd, APP_FS, appopt.mode);
+ if (ret != OK)
+ {
+ fin_nxaudio(&g_kbd.nxaudio);
+ printf("init_keyboard_sound() error!!\n");
+ return -1;
+ }
+
+ /* Render audio samples in audio buffers */
+
+ for (i = 0; i < g_kbd.nxaudio.abufnum; i++)
+ {
+ app_dequeue_cb((unsigned long)&g_kbd,
+ g_kbd.nxaudio.abufs[i]);
+ }
+
+ pid = create_audio_thread(&g_kbd);
+
+ printf("Start %s\n", argv[0]);
+ print_keyusage();
+
+ while (running)
+ {
+ key = (char)getchar();
+ if (key != EOF)
+ {
+ switch (key)
+ {
+ case 'q':
+ running = false;
+ break;
+
+ default:
+ key_idx = convert_key2idx(key);
+ if (key_idx >= 0)
+ {
+ g_kbd.request_scale = key_convert[key_idx].key;
+ printf("%s \n", key_convert[key_idx].dispstr);
+ fflush(stdout);
+ }
+ break;
+ }
+ }
+ }
+
+ board_external_amp_mute_control(true);
+
+ nxaudio_stop(&g_kbd.nxaudio);
+ pthread_join(pid, NULL);
+
+ fin_keyboard(&g_kbd);
+
+ return ret;
+}
diff --git a/examples/fmsynth/mmlplayer_main.c b/examples/fmsynth/mmlplayer_main.c
new file mode 100644
index 000000000..edab3cb9a
--- /dev/null
+++ b/examples/fmsynth/mmlplayer_main.c
@@ -0,0 +1,563 @@
+/****************************************************************************
+ * apps/examples/fmsynth/mmlplayer_main.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <errno.h>
+#include <pthread.h>
+#include <sched.h>
+#include <limits.h>
+
+#include <nuttx/audio/audio.h>
+#include <audioutils/fmsynth.h>
+#include <audioutils/nxaudio.h>
+#include <audioutils/mml_parser.h>
+
+#include "operator_algorithm.h"
+#include "music_scale.h"
+#include "mmlplayer_score.h"
+
+/****************************************************************************
+ * Pre-processor
+ ****************************************************************************/
+
+#define APP_FS (48000)
+#define APP_BPS (16)
+#define APP_CHNUM (2)
+#define CARRIER_LEVEL (25.f / 100.f)
+
+#define APP_DEFAULT_VOL (1000)
+
+/****************************************************************************
+ * Private Data Type
+ ****************************************************************************/
+
+struct app_options
+{
+ int volume;
+ int mode;
+};
+
+struct mmlplayer_s
+{
+ struct nxaudio_s nxaudio;
+
+ /* Right hand sound */
+
+ FAR fmsynth_sound_t *rsound[2]; /* Need 2 sounds for CHORD */
+ FAR fmsynth_op_t *rop[2]; /* Need 2 sounds for CHORD */
+
+ int rtick;
+ FAR char *rscore;
+ struct music_macro_lang_s rmml;
+
+ /* Left hand sound */
+
+ FAR fmsynth_sound_t *lsound;
+ FAR fmsynth_op_t *lop;
+ int ltick;
+ FAR char *lscore;
+ struct music_macro_lang_s lmml;
+};
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+static void app_dequeue_cb(unsigned long arg,
+ FAR struct ap_buffer_s *apb);
+static void app_complete_cb(unsigned long arg);
+static void app_user_cb(unsigned long arg,
+ FAR struct audio_msg_s *msg, FAR bool *running);
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+static struct mmlplayer_s g_mmlplayer;
+
+static struct nxaudio_callbacks_s cbs =
+{
+ app_dequeue_cb,
+ app_complete_cb,
+ app_user_cb
+};
+
+/****************************************************************************
+ * Private functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * name: print_note
+ ****************************************************************************/
+
+static void print_note(bool LR, int index, int length)
+{
+ printf("%c: O%d%c : %d\n", LR ? 'R' : 'L',
+ index / 12, "CcDdEFfGgAaB"[index % 12], length);
+}
+
+/****************************************************************************
+ * name: print_chord
+ ****************************************************************************/
+
+static void print_chord(bool LR, int index1, int index2, int length)
+{
+ printf("%c: [O%d%c, O%d%c] : %d\n", LR ? 'R' : 'L',
+ index1 / 12, "CcDdEFfGgAaB"[index1 % 12],
+ index2 / 12, "CcDdEFfGgAaB"[index2 % 12],
+ length);
+}
+
+/****************************************************************************
+ * name: update_righthand_note
+ ****************************************************************************/
+
+static void update_righthand_note(FAR struct mmlplayer_s *fmmsc)
+{
+ int mml_ret;
+ struct mml_result_s mml_result;
+
+ fmmsc->rtick = 0;
+ do
+ {
+ mml_ret = parse_mml(&fmmsc->rmml, &fmmsc->rscore, &mml_result);
+ switch (mml_ret)
+ {
+ case MML_TYPE_NOTE:
+ fmmsc->rtick = mml_result.length;
+ fmsynthsnd_set_soundfreq(fmmsc->rsound[0],
+ musical_scale[mml_result.note_idx[0]]);
+ fmsynthsnd_set_volume(fmmsc->rsound[0], CARRIER_LEVEL);
+ fmsynthsnd_set_volume(fmmsc->rsound[1], 0.f);
+ print_note(1, mml_result.note_idx[0], mml_result.length);
+ break;
+
+ case MML_TYPE_CHORD:
+ fmmsc->rtick = mml_result.length;
+ fmsynthsnd_set_soundfreq(fmmsc->rsound[0],
+ musical_scale[mml_result.note_idx[0]]);
+ fmsynthsnd_set_soundfreq(fmmsc->rsound[1],
+ musical_scale[mml_result.note_idx[1]]);
+ fmsynthsnd_set_volume(fmmsc->rsound[0], CARRIER_LEVEL);
+ fmsynthsnd_set_volume(fmmsc->rsound[1], CARRIER_LEVEL);
+ print_chord(1, mml_result.note_idx[0], mml_result.note_idx[1],
+ mml_result.length);
+ break;
+
+ case MML_TYPE_REST:
+ fmmsc->rtick = mml_result.length;
+ fmsynthsnd_set_volume(fmmsc->rsound[0], 0.f);
+ fmsynthsnd_set_volume(fmmsc->rsound[1], 0.f);
+ printf("R: Rest : %d\n", mml_result.length);
+ break;
+
+ default:
+
+ /* Do nothing */
+
+ break;
+ }
+ }
+ while (!fmmsc->rtick && mml_ret != MML_TYPE_EOF);
+}
+
+/****************************************************************************
+ * name: update_lefthand_note
+ ****************************************************************************/
+
+static void update_lefthand_note(FAR struct mmlplayer_s *fmmsc)
+{
+ int mml_ret;
+ struct mml_result_s mml_result;
+
+ fmmsc->ltick = 0;
+ do
+ {
+ mml_ret = parse_mml(&fmmsc->lmml, &fmmsc->lscore, &mml_result);
+ switch (mml_ret)
+ {
+ case MML_TYPE_NOTE:
+ fmmsc->ltick = mml_result.length;
+ fmsynthsnd_set_soundfreq(fmmsc->lsound,
+ musical_scale[mml_result.note_idx[0]]);
+ fmsynthsnd_set_volume(fmmsc->lsound, CARRIER_LEVEL);
+ print_note(0, mml_result.note_idx[0], mml_result.length);
+ break;
+
+ case MML_TYPE_REST:
+ fmmsc->ltick = mml_result.length;
+ fmsynthsnd_set_volume(fmmsc->lsound, 0.f);
+ printf("L: Rest : %d\n", mml_result.length);
+ break;
+
+ default:
+
+ /* Do nothing */
+
+ break;
+ }
+ }
+ while (!fmmsc->ltick && mml_ret != MML_TYPE_EOF);
+}
+
+/****************************************************************************
+ * name: tick_callback
+ ****************************************************************************/
+
+static void tick_callback(unsigned long arg)
+{
+ FAR struct mmlplayer_s *fmmsc = (FAR struct mmlplayer_s *)(uintptr_t)arg;
+
+ fmmsc->rtick--;
+ fmmsc->ltick--;
+
+ if (fmmsc->rtick <= 0)
+ {
+ update_righthand_note(fmmsc);
+ }
+
+ if (fmmsc->ltick <= 0)
+ {
+ update_lefthand_note(fmmsc);
+ }
+}
+
+/****************************************************************************
+ * name: app_dequeue_cb
+ ****************************************************************************/
+
+static void app_dequeue_cb(unsigned long arg,
+ FAR struct ap_buffer_s *apb)
+{
+ FAR struct mmlplayer_s *mmlplayer = (struct mmlplayer_s *)(uintptr_t)arg;
+
+ apb->curbyte = 0;
+ apb->flags = 0;
+ apb->nbytes = fmsynth_rendering(mmlplayer->lsound,
+ (FAR int16_t *)apb->samp,
+ apb->nmaxbytes / sizeof(int16_t),
+ mmlplayer->nxaudio.chnum,
+ tick_callback,
+ (unsigned long)(uintptr_t)mmlplayer);
+ nxaudio_enqbuffer(&mmlplayer->nxaudio, apb);
+}
+
+/****************************************************************************
+ * name: app_complete_cb
+ ****************************************************************************/
+
+static void app_complete_cb(unsigned long arg)
+{
+ /* Do nothing.. */
+
+ printf("Audio loop is Done\n");
+}
+
+/****************************************************************************
+ * name: app_user_cb
+ ****************************************************************************/
+
+static void app_user_cb(unsigned long arg,
+ FAR struct audio_msg_s *msg, FAR bool *running)
+{
+ /* Do nothing.. */
+}
+
+/****************************************************************************
+ * name: autio_loop_thread
+ ****************************************************************************/
+
+static FAR void *audio_loop_thread(pthread_addr_t arg)
+{
+ struct mmlplayer_s *mmlplayer = (FAR struct mmlplayer_s *)arg;
+
+ nxaudio_start(&mmlplayer->nxaudio);
+ nxaudio_msgloop(&mmlplayer->nxaudio, &cbs,
+ (unsigned long)(uintptr_t)mmlplayer);
+
+ return NULL;
+}
+
+/****************************************************************************
+ * name: create_audio_thread
+ ****************************************************************************/
+
+static pthread_t create_audio_thread(FAR struct mmlplayer_s *mmlplayer)
+{
+ pthread_t pid;
+ pthread_attr_t tattr;
+ struct sched_param sparam;
+
+ pthread_attr_init(&tattr);
+ sparam.sched_priority = sched_get_priority_max(SCHED_FIFO) - 9;
+ pthread_attr_setschedparam(&tattr, &sparam);
+ pthread_attr_setstacksize(&tattr, 4096);
+
+ pthread_create(&pid, &tattr, audio_loop_thread,
+ (pthread_addr_t)mmlplayer);
+ pthread_setname_np(pid, "mmlplayer_thread");
+
+ return pid;
+}
+
+/****************************************************************************
+ * name: delete_sounds
+ ****************************************************************************/
+
+static void delete_sounds(FAR struct mmlplayer_s *mmlplayer)
+{
+ if (mmlplayer->rop[0])
+ {
+ fmsynthutil_delete_ops(mmlplayer->rop[0]);
+ }
+
+ if (mmlplayer->rop[1])
+ {
+ fmsynthutil_delete_ops(mmlplayer->rop[1]);
+ }
+
+ if (mmlplayer->lop)
+ {
+ fmsynthutil_delete_ops(mmlplayer->lop);
+ }
+
+ if (mmlplayer->rsound[0])
+ {
+ fmsynthsnd_delete(mmlplayer->rsound[0]);
+ }
+
+ if (mmlplayer->rsound[1])
+ {
+ fmsynthsnd_delete(mmlplayer->rsound[1]);
+ }
+
+ if (mmlplayer->lsound)
+ {
+ fmsynthsnd_delete(mmlplayer->lsound);
+ }
+}
+
+/****************************************************************************
+ * name: init_fmmusi_soundsc
+ ****************************************************************************/
+
+static int init_mmlplayer_sound(FAR struct mmlplayer_s *mmlplayer, int fs,
+ int mode)
+{
+ CODE fmsynth_op_t *(*opfunc)(void);
+
+ opfunc = mode == 0 ? fmsynthutil_algorithm0 :
+ mode == 1 ? fmsynthutil_algorithm1 :
+ mode == 2 ? fmsynthutil_algorithm2 :
+ NULL;
+
+ fmsynth_initialize(fs);
+
+ mmlplayer->rop[0] = NULL;
+ mmlplayer->rop[1] = NULL;
+ mmlplayer->lop = NULL;
+
+ mmlplayer->rsound[0] = fmsynthsnd_create();
+ mmlplayer->rsound[1] = fmsynthsnd_create();
+ mmlplayer->lsound = fmsynthsnd_create();
+
+ if (mmlplayer->rsound[0] && mmlplayer->rsound[1] && mmlplayer->lsound)
+ {
+ mmlplayer->rop[0] = opfunc();
+ mmlplayer->rop[1] = opfunc();
+ mmlplayer->lop = opfunc();
+
+ if (mmlplayer->rop[0] && mmlplayer->rop[1] && mmlplayer->lop)
+ {
+ fmsynthsnd_set_operator(mmlplayer->rsound[0], mmlplayer->rop[0]);
+ fmsynthsnd_set_operator(mmlplayer->rsound[1], mmlplayer->rop[1]);
+ fmsynthsnd_set_operator(mmlplayer->lsound, mmlplayer->lop);
+ fmsynthsnd_set_operator(mmlplayer->lsound, mmlplayer->lop);
+
+ fmsynthsnd_add_subsound(mmlplayer->lsound, mmlplayer->rsound[0]);
+ fmsynthsnd_add_subsound(mmlplayer->lsound, mmlplayer->rsound[1]);
+ }
+ else
+ {
+ delete_sounds(mmlplayer);
+ return ERROR;
+ }
+ }
+ else
+ {
+ delete_sounds(mmlplayer);
+ return ERROR;
+ }
+
+ mmlplayer->rtick = 0;
+ mmlplayer->ltick = 0;
+
+ init_mml(&mmlplayer->rmml, fs, 120, 4, 4);
+ init_mml(&mmlplayer->lmml, fs, 120, 4, 3);
+
+ mmlplayer->rscore = (FAR char *)floh_walzer_right;
+ mmlplayer->lscore = (FAR char *)floh_walzer_left;
+
+ return OK;
+}
+
+/****************************************************************************
+ * name: fin_mmlplayer
+ ****************************************************************************/
+
+static void fin_mmlplayer(FAR struct mmlplayer_s *mmlplayer)
+{
+ fin_nxaudio(&mmlplayer->nxaudio);
+ delete_sounds(mmlplayer);
+}
+
+/****************************************************************************
+ * name: print_help
+ ****************************************************************************/
+
+static void print_help(FAR char *name)
+{
+ printf("nsh> %s ([-v (volume)]) ([-m (mode)])\n", name);
+}
+
+/****************************************************************************
+ * name: configure_option
+ ****************************************************************************/
+
+static int configure_option(FAR struct app_options *option,
+ int argc, char **argv)
+{
+ int opt;
+
+ option->volume = APP_DEFAULT_VOL;
+ option->mode = 0;
+ while ((opt = getopt(argc, argv, "hv:m:")) != ERROR)
+ {
+ switch (opt)
+ {
+ case 'v':
+ option->volume = atoi(optarg) * 10;
+ if (option->volume < 0 || option->volume > 1000)
+ {
+ option->volume = 400;
+ }
+
+ break;
+
+ case 'm':
+ option->mode = atoi(optarg);
+ if (option->mode < 0 || option->mode >= 3)
+ {
+ option->mode = 0;
+ }
+
+ break;
+
+ case 'h':
+ return ERROR;
+ break;
+
+ default:
+ return ERROR;
+ break;
+ }
+ }
+
+ return OK;
+}
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * name: main
+ ****************************************************************************/
+
+int main(int argc, FAR char *argv[])
+{
+ int i;
+ int ret;
+ char key;
+ bool running = true;
+ pthread_t pid;
+ struct app_options appopt;
+
+ printf("Start %s\n", argv[0]);
+
+ if (configure_option(&appopt, argc, argv) != OK)
+ {
+ print_help(argv[0]);
+ return -1;
+ }
+
+ ret = init_nxaudio(&g_mmlplayer.nxaudio, APP_FS, APP_BPS, APP_CHNUM);
+ if (ret < 0)
+ {
+ printf("init_nxaoud() returned with error!!\n");
+ return -1;
+ }
+
+ nxaudio_setvolume(&g_mmlplayer.nxaudio, appopt.volume);
+
+ ret = init_mmlplayer_sound(&g_mmlplayer, APP_FS, appopt.mode);
+ if (ret != OK)
+ {
+ printf("init_mmlplayer_sound() returned error.\n");
+ fin_nxaudio(&g_mmlplayer.nxaudio);
+ return -1;
+ }
+
+ for (i = 0; i < g_mmlplayer.nxaudio.abufnum; i++)
+ {
+ app_dequeue_cb((unsigned long)&g_mmlplayer,
+ g_mmlplayer.nxaudio.abufs[i]);
+ }
+
+ pid = create_audio_thread(&g_mmlplayer);
+
+ while (running)
+ {
+ key = (char)getchar();
+ if (key != EOF)
+ {
+ switch (key)
+ {
+ case 'q':
+ running = false;
+ break;
+ }
+ }
+ }
+
+ nxaudio_stop(&g_mmlplayer.nxaudio);
+ pthread_join(pid, NULL);
+
+ fin_mmlplayer(&g_mmlplayer);
+
+ return ret;
+}
diff --git a/examples/fmsynth/mmlplayer_score.h b/examples/fmsynth/mmlplayer_score.h
new file mode 100644
index 000000000..f9e757846
--- /dev/null
+++ b/examples/fmsynth/mmlplayer_score.h
@@ -0,0 +1,58 @@
+/****************************************************************************
+ * apps/examples/fmsynth/mmlplayer_score.h
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+#ifndef __APPS_EXAMPLES_FMSYNTH_MMLPLAYER_SCORE_H
+#define __APPS_EXAMPLES_FMSYNTH_MMLPLAYER_SCORE_H
+
+static const char *floh_walzer_right =
+ "T120 L4 O4"
+ "R8 {D#C#}8"
+ "R8{[<A#>F#][<A#>F#]}{D#C#}8 R8{[<A#>F#][<A#>F#]}{D#C#}8"
+ "R8[<A#>F#]8R8[<A#>F#]8 R8{[<B>F][<B>F]} {D#C#}8"
+ "R8{[<B>F][<B>F]}{D#C#}8 R8{[<B>F][<B>F]}{D#C#}8 "
+ "R8[<B>F]8R8[<B>F]8 R8{[<A#>F#][<A#>F#]} {D#C#}8"
+ "R8{[<A#>F#][<A#>F#]}{D#C#}8 R8{[<A#>F#][<A#>F#]}{D#C#}8"
+ "R8[<A#>F#]8R8[<A#>F#]8 R8{[<B>F][<B>F]} {D#C#}8"
+ "R8{[<B>F][<B>F]}{D#C#}8 R8{[<B>F][<B>F]}{D#C#}8 "
+ "R8[<B>F]8R8[<B>F]8 R8{[<A#>F#][<A#>F#]} {D#C#}8"
+ "R8[<A#>F#]8R8[<A#>F#]8 R8[<A#>F#]8R8[<A#>F#]8 "
+ "R2 R8{[<B>F][<B>F]} {D#C#}8"
+ "R8[<B>F]8R8[<B>F]8 R8[<B>F]8R8[<B>F]8 "
+ "R2 R8{[<A#>F#][<A#>F#]} {D#C#}8"
+ "R8{[<A#>F#][<A#>F#]}{D#C#}8 R8{[<A#>F#][<A#>F#]}{D#C#}8"
+ "R8[<A#>F#]8R8[<A#>F#]8 R8{[<B>F][<B>F]} {D#C#}8"
+ "R8{[<B>F][<B>F]}{D#C#}8 R8{[<B>F][<B>F]}{D#C#}8 "
+ "R8[<B>F]8R8[<B>F]8 R8{[<A#>F#][<A#>F#]} {D#C#}8"
+ "[<A#>F#]8{CC}8{C#C} R8[<B>F]8[<A#>F#]8R8";
+
+static const char *floh_walzer_left =
+ "T120 L4 O3"
+ "R4"
+ "F#.R8 F#.R8 F#D# C#.R8"
+ "C#.R8 C#.R8 C#D# F#.R8"
+ ">A#.R8 A#.R8 A#>C# D#.R8"
+ "D#.R8 D#.R8 D#C# <A#.R8"
+ "<F#C# F#C# {F#F}{F#G} G#R"
+ "G#C# G#C# {G#G}{G#A} A#R"
+ "F#.R8 F#.R8 F#D# C#.R8"
+ "C#.R8 C#.R8 C#D# F#.R8"
+ "C#8R8R R8C#8<F#8R8";
+
+#endif /* __APPS_EXAMPLES_FMSYNTH_MMLPLAYER_SCORE_H */
diff --git a/examples/fmsynth/music_scale.c b/examples/fmsynth/music_scale.c
new file mode 100644
index 000000000..7ec2e7709
--- /dev/null
+++ b/examples/fmsynth/music_scale.c
@@ -0,0 +1,97 @@
+/****************************************************************************
+ * apps/examples/fmsynth/music_scale.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Data
+ ****************************************************************************/
+
+/* Musical Scale frequency
+ * Negative value means not supported.
+ */
+
+const float musical_scale[] =
+{
+ /* Octave 0 */
+
+ -1.f, -1.f, -1.f,
+ -1.f, -1.f, -1.f,
+ -1.f, -1.f, -1.f,
+ 27.5f, 29.13523509f, 30.86770631f,
+
+ /* Octave 1 */
+
+ 32.70319563f, 34.64782883f, 36.70809593f,
+ 38.89087289f, 41.20344452f, 43.65352881f,
+ 46.2493027f, 48.99942933f, 51.913087f,
+ 55.f, 58.27047017f, 61.73541262f,
+
+ /* Octave 2 */
+
+ 65.40639126f, 69.29565765f, 73.41619185f,
+ 77.78174577f, 82.40688903f, 87.30705762f,
+ 92.4986054f, 97.99885866f, 103.826174f,
+ 110.f, 116.5409403f, 123.4708252f,
+
+ /* Octave 3 */
+
+ 130.8127825f, 138.5913153f, 146.8323837f,
+ 155.5634915f, 164.8137781f, 174.6141152f,
+ 184.9972108f, 195.9977173f, 207.652348f,
+ 220.f, 233.0818807f, 246.9416505f,
+
+ /* Octave 4 */
+
+ 261.625565f, 277.1826306f, 293.6647674f,
+ 311.1269831f, 329.6275561f, 349.2282305f,
+ 369.9944216f, 391.9954347f, 415.304696f,
+ 440.f, 466.1637614f, 493.8833009f,
+
+ /* Octave 5 */
+
+ 523.2511301f, 554.3652612f, 587.3295348f,
+ 622.2539662f, 659.2551123f, 698.456461f,
+ 739.9888432f, 783.9908693f, 830.6093921f,
+ 880.f, 932.3275227f, 987.7666018f,
+
+ /* Octave 6 */
+
+ 1046.50226f, 1108.730522f, 1174.65907f,
+ 1244.507932f, 1318.510225f, 1396.912922f,
+ 1479.977686f, 1567.981739f, 1661.218784f,
+ 1760.f, 1864.655045f, 1975.533204f,
+
+ /* Octave 7 */
+
+ 2093.00452f, 2217.461045f, 2349.318139f,
+ 2489.015865f, 2637.020449f, 2793.825844f,
+ 2959.955373f, 3135.963477f, 3322.437568f,
+ 3520.f, 3729.310091f, 3951.066407f,
+
+ /* Octave 8 */
+
+ 4186.009041f, -1.f, -1.f,
+ -1.f, -1.f, -1.f,
+ -1.f, -1.f, -1.f,
+ -1.f, -1.f, -1.f,
+};
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
diff --git a/examples/fmsynth/music_scale.h b/examples/fmsynth/music_scale.h
new file mode 100644
index 000000000..577564a3c
--- /dev/null
+++ b/examples/fmsynth/music_scale.h
@@ -0,0 +1,62 @@
+/****************************************************************************
+ * apps/examples/fmsynth/music_scale.h
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+#ifndef __APPS_EXAMPLES_FMSYNTH_UTILS_MUSIC_SCALE_H
+#define __APPS_EXAMPLES_FMSYNTH_UTILS_MUSIC_SCALE_H
+
+/****************************************************************************
+ * Pre-processor definisions
+ ****************************************************************************/
+
+#define MUSIC_SCALE_C (0)
+#define MUSIC_SCALE_CS (1)
+#define MUSIC_SCALE_D (2)
+#define MUSIC_SCALE_DS (3)
+#define MUSIC_SCALE_E (4)
+#define MUSIC_SCALE_F (5)
+#define MUSIC_SCALE_FS (6)
+#define MUSIC_SCALE_G (7)
+#define MUSIC_SCALE_GS (8)
+#define MUSIC_SCALE_A (9)
+#define MUSIC_SCALE_AS (10)
+#define MUSIC_SCALE_B (11)
+#define OCTAVE(n, s) ((s) + ((n) * 12))
+
+/****************************************************************************
+ * Public Data
+ ****************************************************************************/
+
+#undef EXTERN
+#if defined(__cplusplus)
+#define EXTERN extern "C"
+extern "C"
+{
+#else
+#define EXTERN extern
+#endif
+
+EXTERN const float musical_scale[];
+
+#undef EXTERN
+#if defined(__cplusplus)
+}
+#endif
+
+#endif /* __APPS_EXAMPLES_FMSYNTH_UTILS_MUSIC_SCALE_H */
diff --git a/examples/fmsynth/operator_algorithm.c b/examples/fmsynth/operator_algorithm.c
new file mode 100644
index 000000000..2d6b6068e
--- /dev/null
+++ b/examples/fmsynth/operator_algorithm.c
@@ -0,0 +1,188 @@
+/****************************************************************************
+ * apps/examples/fmsynth/operator_algorithm.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <stddef.h>
+
+#include <audioutils/fmsynth.h>
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * name: fmsynthutil_algorithm0
+ ****************************************************************************/
+
+FAR fmsynth_op_t *fmsynthutil_algorithm0(void)
+{
+ /* [Simple sin operator]
+ *
+ * +--------------+
+ * | OP (carrier) | ----> Audio out
+ * +--------------+
+ */
+
+ FAR fmsynth_op_t *carrier;
+ fmsynth_eglevels_t level;
+
+ /* Attack level and period time : 1.0, 40ms
+ * Decay Break level and period time : 0.3, 200ms
+ * Decay level and period time : 0.1, 100ms
+ * Sustain level and period time : 0.1, 100ms
+ * Release level : 0.0, 0ms
+ *
+ */
+
+ level.attack.level = 1.0f;
+ level.attack.period_ms = 40;
+ level.decaybrk.level = 0.3f;
+ level.decaybrk.period_ms = 200;
+ level.decay.level = 0.1f;
+ level.decay.period_ms = 100;
+ level.sustain.level = 0.1f;
+ level.sustain.period_ms = 100;
+ level.release.level = 0.f;
+ level.release.period_ms = 0;
+
+ carrier = fmsynthop_create();
+ if (carrier)
+ {
+ fmsynthop_set_envelope(carrier, &level);
+ fmsynthop_select_opfunc(carrier, FMSYNTH_OPFUNC_SIN);
+ }
+
+ return carrier;
+}
+
+/****************************************************************************
+ * name: fmsynthutil_algorithm1
+ ****************************************************************************/
+
+FAR fmsynth_op_t *fmsynthutil_algorithm1(void)
+{
+ /* feed back
+ * +--------------------+
+ * | |
+ * | +--------------+ |
+ * +->| OP (carrier) | -+--> Audio out
+ * +--------------+
+ */
+
+ FAR fmsynth_op_t *carrier;
+ fmsynth_eglevels_t level;
+
+ level.attack.level = 1.0f;
+ level.attack.period_ms = 40;
+ level.decaybrk.level = 0.3f;
+ level.decaybrk.period_ms = 200;
+ level.decay.level = 0.1f;
+ level.decay.period_ms = 100;
+ level.sustain.level = 0.1f;
+ level.sustain.period_ms = 100;
+ level.release.level = 0.f;
+ level.release.period_ms = 0;
+
+ carrier = fmsynthop_create();
+ if (carrier)
+ {
+ fmsynthop_set_envelope(carrier, &level);
+ fmsynthop_select_opfunc(carrier, FMSYNTH_OPFUNC_SIN);
+ fmsynthop_bind_feedback(carrier, carrier, 0.6f);
+ }
+
+ return carrier;
+}
+
+/****************************************************************************
+ * name: fmsynthutil_algorithm2
+ ****************************************************************************/
+
+FAR fmsynth_op_t *fmsynthutil_algorithm2(void)
+{
+ /* feed back
+ * +--------------------+
+ * | |
+ * | +--------------+ | +--------------+
+ * +->| OP (subop) | -+-> | OP (carrier) | ----> Audio out
+ * +--------------+ +--------------+
+ */
+
+ FAR fmsynth_op_t *carrier;
+ FAR fmsynth_op_t *subop;
+ fmsynth_eglevels_t level;
+
+ level.attack.level = 1.0f;
+ level.attack.period_ms = 40;
+ level.decaybrk.level = 0.3f;
+ level.decaybrk.period_ms = 200;
+ level.decay.level = 0.1f;
+ level.decay.period_ms = 100;
+ level.sustain.level = 0.f;
+ level.sustain.period_ms = 0;
+ level.release.level = 0.f;
+ level.release.period_ms = 0;
+
+ carrier = fmsynthop_create();
+ if (carrier)
+ {
+ subop = fmsynthop_create();
+ if (!subop)
+ {
+ fmsynthop_delete(carrier);
+ return NULL;
+ }
+
+ fmsynthop_set_envelope(carrier, &level);
+ fmsynthop_select_opfunc(carrier, FMSYNTH_OPFUNC_SIN);
+
+ fmsynthop_set_soundfreqrate(subop, 3.7f);
+ fmsynthop_select_opfunc(subop, FMSYNTH_OPFUNC_SIN);
+
+ fmsynthop_cascade_subop(carrier, subop);
+ }
+
+ return carrier;
+}
+
+/****************************************************************************
+ * name: fmsynthutil_delete_ops
+ ****************************************************************************/
+
+void FAR fmsynthutil_delete_ops(FAR fmsynth_op_t *op)
+{
+ FAR fmsynth_op_t *tmp;
+
+ while (op != NULL)
+ {
+ tmp = op->parallelop;
+
+ if (op->cascadeop)
+ {
+ fmsynthutil_delete_ops(op->cascadeop);
+ }
+
+ fmsynthop_delete(op);
+ op = tmp;
+ }
+}
diff --git a/examples/fmsynth/operator_algorithm.h b/examples/fmsynth/operator_algorithm.h
new file mode 100644
index 000000000..94594d027
--- /dev/null
+++ b/examples/fmsynth/operator_algorithm.h
@@ -0,0 +1,39 @@
+/****************************************************************************
+ * apps/examples/fmsynth/operator_algorithm.h
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+#ifndef __APPS_EXAMPLES_FMSYNTH_OPERATOR_ALGORITHM_H
+#define __APPS_EXAMPLES_FMSYNTH_OPERATOR_ALGORITHM_H
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <audioutils/fmsynth.h>
+
+/****************************************************************************
+ * Public Function Prototypes
+ ****************************************************************************/
+
+FAR fmsynth_op_t *fmsynthutil_algorithm0(void);
+FAR fmsynth_op_t *fmsynthutil_algorithm1(void);
+FAR fmsynth_op_t *fmsynthutil_algorithm2(void);
+void FAR fmsynthutil_delete_ops(FAR fmsynth_op_t *op);
+
+#endif /* __APPS_EXAMPLES_FMSYNTH_OPERATOR_ALGORITHM_H */