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authormarkster <markster@f38db490-d61c-443f-a65b-d21fe96a405b>2001-12-07 22:57:34 +0000
committermarkster <markster@f38db490-d61c-443f-a65b-d21fe96a405b>2001-12-07 22:57:34 +0000
commitafbca6b478628803ab7a9768c8b7bf3c846e3b01 (patch)
treeabb0e18c8355f757f2621516d64d71fbf88cb2f4 /tdd.c
parent3607024782adf8abf822c89bb2198d6157528b1e (diff)
Version 0.1.10 from FTP
git-svn-id: http://svn.digium.com/svn/asterisk/trunk@390 f38db490-d61c-443f-a65b-d21fe96a405b
Diffstat (limited to 'tdd.c')
-rwxr-xr-xtdd.c306
1 files changed, 306 insertions, 0 deletions
diff --git a/tdd.c b/tdd.c
new file mode 100755
index 000000000..6ff6c0fbd
--- /dev/null
+++ b/tdd.c
@@ -0,0 +1,306 @@
+/*
+ * Asterisk -- A telephony toolkit for Linux.
+ *
+ * TTY/TDD Generation support
+ *
+ * Copyright (C) 2001, Linux Support Services, Inc.
+ *
+ * Mark Spencer <markster@linux-support.net>
+ *
+ * This program is free software, distributed under the terms of
+ * the GNU General Public License.
+ *
+ * Includes code and algorithms from the Zapata library.
+ *
+ */
+
+#include <time.h>
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <math.h>
+#include <ctype.h>
+#include <asterisk/ulaw.h>
+#include <asterisk/tdd.h>
+#include <asterisk/logger.h>
+#include <asterisk/fskmodem.h>
+#include "ecdisa.h"
+
+
+struct tdd_state {
+ fsk_data fskd;
+ char rawdata[256];
+ short oldstuff[4096];
+ int oldlen;
+ int pos;
+ int modo;
+ int mode;
+};
+
+static float dr[4], di[4];
+static float tddsb = 176.0; /* 45.5 baud */
+
+#define TDD_SPACE 1800.0 /* 1800 hz for "0" */
+#define TDD_MARK 1400.0 /* 1400 hz for "1" */
+
+static int tdd_decode_baudot(struct tdd_state *tdd,unsigned char data) /* covert baudot into ASCII */
+{
+ static char ltrs[32]={'<','E','\n','A',' ','S','I','U',
+ '\n','D','R','J','N','F','C','K',
+ 'T','Z','L','W','H','Y','P','Q',
+ 'O','B','G','^','M','X','V','^'};
+ static char figs[32]={'<','3','\n','-',' ',',','8','7',
+ '\n','$','4','\'',',','',':','(',
+ '5','+',')','2','','6','0','1',
+ '9','7','','^','.','/','=','^'};
+ int d;
+ d=0; /* return 0 if not decodeable */
+ switch (data) {
+ case 0x1f : tdd->modo=0; break;
+ case 0x1b : tdd->modo=1; break;
+ default: if (tdd->modo==0) d=ltrs[data]; else d=figs[data]; break;
+ }
+ return d;
+}
+
+void tdd_init(void)
+{
+ /* Initialize stuff for inverse FFT */
+ dr[0] = cos(TDD_SPACE * 2.0 * M_PI / 8000.0);
+ di[0] = sin(TDD_SPACE * 2.0 * M_PI / 8000.0);
+ dr[1] = cos(TDD_MARK * 2.0 * M_PI / 8000.0);
+ di[1] = sin(TDD_MARK * 2.0 * M_PI / 8000.0);
+}
+
+struct tdd_state *tdd_new(void)
+{
+ struct tdd_state *tdd;
+ tdd = malloc(sizeof(struct tdd_state));
+ memset(tdd, 0, sizeof(struct tdd_state));
+ if (tdd) {
+ tdd->fskd.spb = 176; /* 45.5 baud */
+ tdd->fskd.hdlc = 0; /* Async */
+ tdd->fskd.nbit = 5; /* 5 bits */
+ tdd->fskd.nstop = 1.5; /* 1.5 stop bits */
+ tdd->fskd.paridad = 0; /* No parity */
+ tdd->fskd.bw=0; /* Filter 75 Hz */
+ tdd->fskd.f_mark_idx = 0; /* 1400 Hz */
+ tdd->fskd.f_space_idx = 1; /* 1800 Hz */
+ tdd->fskd.pcola = 0; /* No clue */
+ tdd->fskd.cont = 0; /* Digital PLL reset */
+ tdd->fskd.x0 = 0.0;
+ tdd->fskd.state = 0;
+ tdd->pos = 0;
+ tdd->mode = 2;
+ } else
+ ast_log(LOG_WARNING, "Out of memory\n");
+ return tdd;
+}
+
+int ast_tdd_gen_ecdisa(unsigned char *outbuf, int len)
+{
+ int pos = 0;
+ int cnt;
+ while(len) {
+ cnt = len;
+ if (cnt > sizeof(ecdisa))
+ cnt = sizeof(ecdisa);
+ memcpy(outbuf + pos, ecdisa, cnt);
+ pos += cnt;
+ len -= cnt;
+ }
+ return 0;
+}
+
+int tdd_feed(struct tdd_state *tdd, unsigned char *ubuf, int len)
+{
+ int mylen = len;
+ int olen;
+ int b = 'X';
+ int res;
+ int c,x;
+ short *buf = malloc(2 * len + tdd->oldlen);
+ short *obuf = buf;
+ if (!buf) {
+ ast_log(LOG_WARNING, "Out of memory\n");
+ return -1;
+ }
+ memset(buf, 0, 2 * len + tdd->oldlen);
+ memcpy(buf, tdd->oldstuff, tdd->oldlen);
+ mylen += tdd->oldlen/2;
+ for (x=0;x<len;x++)
+ buf[x+tdd->oldlen/2] = AST_MULAW(ubuf[x]);
+ c = res = 0;
+ while(mylen >= 1320) { /* has to have enough to work on */
+ olen = mylen;
+ res = fsk_serie(&tdd->fskd, buf, &mylen, &b);
+ if (mylen < 0) {
+ ast_log(LOG_ERROR, "fsk_serie made mylen < 0 (%d) (olen was %d)\n", mylen,olen);
+ free(obuf);
+ return -1;
+ }
+ buf += (olen - mylen);
+ if (res < 0) {
+ ast_log(LOG_NOTICE, "fsk_serie failed\n");
+ free(obuf);
+ return -1;
+ }
+ if (res == 1) {
+ /* Ignore invalid bytes */
+ if (b > 0x7f)
+ continue;
+ c = tdd_decode_baudot(tdd,b);
+ if ((c < 1) || (c > 126)) continue; /* if not valid */
+ break;
+ }
+ }
+ if (mylen) {
+ memcpy(tdd->oldstuff, buf, mylen * 2);
+ tdd->oldlen = mylen * 2;
+ } else
+ tdd->oldlen = 0;
+ free(obuf);
+ if (res) {
+ tdd->mode = 2; /* put it in mode where it
+ reliably puts teleprinter in correct shift mode */
+ return(c);
+ }
+ return 0;
+}
+
+void tdd_free(struct tdd_state *tdd)
+{
+ free(tdd);
+}
+
+static inline float tdd_getcarrier(float *cr, float *ci, int bit)
+{
+ /* Move along. There's nothing to see here... */
+ float t;
+ t = *cr * dr[bit] - *ci * di[bit];
+ *ci = *cr * di[bit] + *ci * dr[bit];
+ *cr = t;
+
+ t = 2.0 - (*cr * *cr + *ci * *ci);
+ *cr *= t;
+ *ci *= t;
+ return *cr;
+}
+
+#define PUT_BYTE(a) do { \
+ *(buf++) = (a); \
+ bytes++; \
+} while(0)
+
+#define PUT_AUDIO_SAMPLE(y) do { \
+ int index = (short)(rint(8192.0 * (y))); \
+ *(buf++) = AST_LIN2MU(index); \
+ bytes++; \
+} while(0)
+
+#define PUT_TDD_MARKMS do { \
+ int x; \
+ for (x=0;x<8;x++) \
+ PUT_AUDIO_SAMPLE(tdd_getcarrier(&cr, &ci, 1)); \
+} while(0)
+
+#define PUT_TDD_BAUD(bit) do { \
+ while(scont < tddsb) { \
+ PUT_AUDIO_SAMPLE(tdd_getcarrier(&cr, &ci, bit)); \
+ scont += 1.0; \
+ } \
+ scont -= tddsb; \
+} while(0)
+
+#define PUT_TDD_STOP do { \
+ while(scont < (tddsb * 1.5)) { \
+ PUT_AUDIO_SAMPLE(tdd_getcarrier(&cr, &ci, 1)); \
+ scont += 1.0; \
+ } \
+ scont -= (tddsb * 1.5); \
+} while(0)
+
+
+#define PUT_TDD(byte) do { \
+ int z; \
+ unsigned char b = (byte); \
+ PUT_TDD_BAUD(0); /* Start bit */ \
+ for (z=0;z<5;z++) { \
+ PUT_TDD_BAUD(b & 1); \
+ b >>= 1; \
+ } \
+ PUT_TDD_STOP; /* Stop bit */ \
+} while(0);
+
+int tdd_generate(struct tdd_state *tdd, unsigned char *buf, char *str)
+{
+ int bytes=0;
+ int i,x;
+ char c;
+ static unsigned char lstr[31] = "\000E\nA SIU\rDRJNFCKTZLWHYPQOBG\000MXV";
+ static unsigned char fstr[31] = "\0003\n- \00787\r$4',!:(5\")2\0006019?&\000./;";
+ /* Initial carriers (real/imaginary) */
+ float cr = 1.0;
+ float ci = 0.0;
+ float scont = 0.0;
+
+ for(x = 0; str[x]; x++) {
+ c = toupper(str[x]);
+#if 0
+ printf("%c",c); fflush(stdout);
+#endif
+ if (c == 0) /* send null */
+ {
+ PUT_TDD(0);
+ continue;
+ }
+ if (c == '\r') /* send c/r */
+ {
+ PUT_TDD(8);
+ continue;
+ }
+ if (c == '\n') /* send c/r and l/f */
+ {
+ PUT_TDD(8);
+ PUT_TDD(2);
+ continue;
+ }
+ if (c == ' ') /* send space */
+ {
+ PUT_TDD(4);
+ continue;
+ }
+ for(i = 0; i < 31; i++)
+ {
+ if (lstr[i] == c) break;
+ }
+ if (i < 31) /* if we found it */
+ {
+ if (tdd->mode) /* if in figs mode, change it */
+ {
+ PUT_TDD(31); /* Send LTRS */
+ tdd->mode = 0;
+ }
+ PUT_TDD(i);
+ continue;
+ }
+ for(i = 0; i < 31; i++)
+ {
+ if (fstr[i] == c) break;
+ }
+ if (i < 31) /* if we found it */
+ {
+ if (tdd->mode != 1) /* if in ltrs mode, change it */
+ {
+ PUT_TDD(27); /* send FIGS */
+ tdd->mode = 1;
+ }
+ PUT_TDD(i); /* send byte */
+ continue;
+ }
+ }
+ return bytes;
+}
+
+