shallow zip-file copy from codec2 e9d726bf20

1 files changed, 175 insertions, 0 deletions

diff --git a/stm32/src/morse.c b/stm32/src/morse.c
new file mode 100644
index 0000000..2522993
--- /dev/null
+++ b/stm32/src/morse.c
@@ -0,0 +1,175 @@
+/*!
+ * Morse code library.
+ *
+ * This implements a state machine for playing back morse code messages.
+ * 
+ * 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 <stdlib.h>
+#include "morse.h"
+
+#include <stdio.h>
+
+/*! Symbol table element definition */
+struct morse_sym_table_t {
+	uint8_t code; uint8_t len;
+};
+
+/*! Symbol table: "digits" */
+static const struct morse_sym_table_t morse_digits[] = {
+	{	.code = 0xf8,	.len = 5	},	/* 0: ----- */
+	{	.code = 0x78,	.len = 5	},	/* 1: .---- */
+	{	.code = 0x38,	.len = 5	},	/* 2: ..--- */
+	{	.code = 0x18,	.len = 5	},	/* 3: ...-- */
+	{	.code = 0x08,	.len = 5	},	/* 4: ....- */
+	{	.code = 0x00,	.len = 5	},	/* 5: ..... */
+	{	.code = 0x80,	.len = 5	},	/* 6: -.... */
+	{	.code = 0xc0,	.len = 5	},	/* 7: --... */
+	{	.code = 0xe0,	.len = 5	},	/* 8: ---.. */
+	{	.code = 0xf0,	.len = 5	},	/* 9: ----. */
+};
+
+/*! Symbol table: "letters" */
+static const struct morse_sym_table_t morse_letters[] = {
+	{	.code = 0x40,	.len = 2	},	/* A: .-    */
+	{	.code = 0x80,	.len = 4	},	/* B: -...  */
+	{	.code = 0xa0,	.len = 4	},	/* C: -.-.  */
+	{	.code = 0x80,	.len = 3	},	/* D: -..   */
+	{	.code = 0x00,	.len = 1	},	/* E: .     */
+	{	.code = 0x20,	.len = 4	},	/* F: ..-.  */
+	{	.code = 0xc0,	.len = 3	},	/* G: --.   */
+	{	.code = 0x00,	.len = 4	},	/* H: ....  */
+	{	.code = 0x00,	.len = 2	},	/* I: ..    */
+	{	.code = 0x70,	.len = 4	},	/* J: .---  */
+	{	.code = 0xa0,	.len = 3	},	/* K: -.-   */
+	{	.code = 0x40,	.len = 4	},	/* L: .-..  */
+	{	.code = 0xc0,	.len = 2	},	/* M: --    */
+	{	.code = 0x80,	.len = 2	},	/* N: -.    */
+	{	.code = 0xe0,	.len = 3	},	/* O: ---   */
+	{	.code = 0x60,	.len = 4	},	/* P: .--.  */
+	{	.code = 0xd0,	.len = 4	},	/* Q: --.-  */
+	{	.code = 0x40,	.len = 3	},	/* R: .-.   */
+	{	.code = 0x00,	.len = 3	},	/* S: ...   */
+	{	.code = 0x80,	.len = 1	},	/* T: -     */
+	{	.code = 0x20,	.len = 3	},	/* U: ..-   */
+	{	.code = 0x10,	.len = 4	},	/* V: ...-  */
+	{	.code = 0x60,	.len = 3	},	/* W: .--   */
+	{	.code = 0x90,	.len = 4	},	/* X: -..-  */
+	{	.code = 0xb0,	.len = 4	},	/* Y: -.--  */
+	{	.code = 0xc0,	.len = 4	},	/* Z: --..  */
+};
+
+static void morse_next_sym(struct morse_player_t* const morse_player)
+{
+	struct sfx_player_t* sfx_player = &(morse_player->sfx_player);
+
+	if (!morse_player->msg) {
+		sfx_play(sfx_player, NULL);
+		return;
+	}
+
+	uint8_t sym_rem = 0;
+	uint8_t sym_code = 0;
+	const struct morse_sym_table_t* sym = NULL;
+	const char* c = morse_player->msg;
+
+	while(!sym) {
+		if ((*c >= 'A') && (*c <= 'Z'))
+			/* Play a letter. (capitals) */
+			sym = &morse_letters[*c - 'A'];
+		else if ((*c >= 'a') && (*c <= 'z'))
+			/* Play a letter. (lowercase) */
+			sym = &morse_letters[*c - 'a'];
+		else if ((*c >= '0') && (*c <= '9'))
+			/* Play a digit. */
+			sym = &morse_digits[*c - '0'];
+		else if (*c == 0) {
+			morse_player->msg = NULL;
+			return;
+		}
+		c++;
+	}
+	morse_player->msg = c;
+
+	struct sfx_note_t* note = morse_player->sym;
+	sym_rem = sym->len;
+	sym_code = sym->code;
+
+	while(sym_rem) {
+		note->freq = morse_player->freq;
+		if (sym_code & 0x80)
+			/* Play a "dah" */
+			note->duration = morse_player->dit_time*3;
+		else
+			/* Play a "dit" */
+			note->duration = morse_player->dit_time;
+		note++;
+		sym_code <<= 1;
+		sym_rem--;
+
+		/* A gap follows */
+		note->freq = 0;
+
+		if (sym_rem) {
+			/* More of the character */
+			note->duration = morse_player->dit_time;
+			note++;
+		}
+	}
+
+	/* What comes next? */
+	if (*c == ' ') {
+		/* End of word */
+		note->duration = morse_player->dit_time*7;
+		note++;
+	} else if (*c) {
+		/* End of character */
+		note->duration = morse_player->dit_time*3;
+		note++;
+	}
+
+	/* Terminate the sequence */
+	note->freq = 0;
+	note->duration = 0;
+
+	/* Set the player up */
+	sfx_play(sfx_player, morse_player->sym);
+}
+
+/*!
+ * Start playing a particular effect.
+ * @param	sfx_player	Effect player state machine
+ * @param	effect		Pointer to sound effect (NULL == stop)
+ */
+void morse_play(struct morse_player_t* const morse_player,
+		const char* msg)
+{
+	morse_player->msg = msg;
+	morse_next_sym(morse_player);
+}
+
+/*!
+ * Retrieve the next sample to be played.
+ */
+int16_t morse_next(struct morse_player_t* const morse_player)
+{
+	if (!morse_player)
+		return(0);
+	if (!morse_player->sfx_player.note)
+		morse_next_sym(morse_player);
+	return sfx_next(&(morse_player->sfx_player));
+}