1 files changed, 63 insertions, 0 deletions
diff --git a/stm32/inc/sfx.h b/stm32/inc/sfx.h
new file mode 100644
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--- /dev/null
+++ b/stm32/inc/sfx.h
@@ -0,0 +1,63 @@
+#ifndef _SFX_H
+#define _SFX_H
+/*!
+ * Sound effect player library.
+ *
+ * This implements a state machine for playing back various monophonic
+ * sound effects such as morse code symbols, clicks and alert tones.
+ *
+ * Author Stuart Longland <[email protected]>
+ * Copyright (C) 2015 FreeDV project.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License version 2.1,
+ * as published by the Free Software Foundation.  This program is
+ * distributed in the hope that it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this program; if not, see
+ * <http://www.gnu.org/licenses/>.
+ */
+
+#include "tone.h"
+
+/*!
+ * A sound effect "note"
+ */
+struct sfx_note_t {
+	/*! Note frequency.  0 == pause */
+	uint16_t	freq;
+	/*! Note duration in msec.   0 == end of effect */
+	uint16_t	duration;
+};
+
+/*!
+ * Sound effect player state machine
+ */
+struct sfx_player_t {
+	/*!
+	 * Pointer to the current "note".  When this is NULL,
+	 * playback is complete.
+	 */
+	const struct sfx_note_t*	note;
+	/*! Tone generator state machine */
+	struct tone_gen_t		tone_gen;
+};
+
+/*!
+ * Start playing a particular effect.
+ * @param	sfx_player	Effect player state machine
+ * @param	effect		Pointer to sound effect (NULL == stop)
+ */
+void sfx_play(struct sfx_player_t* const sfx_player,
+		const struct sfx_note_t* effect);
+
+/*!
+ * Retrieve the next sample to be played.
+ */
+int16_t sfx_next(struct sfx_player_t* const sfx_player);
+
+#endif