aboutsummaryrefslogtreecommitdiffstats
path: root/formats/format_gsm.c
blob: 6a06627fb20ccb4a286758f1c2d109037fa686e0 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
/*
 * Asterisk -- A telephony toolkit for Linux.
 *
 * Save to raw, headerless GSM data.
 * 
 * Copyright (C) 1999, Mark Spencer
 *
 * Mark Spencer <markster@linux-support.net>
 *
 * This program is free software, distributed under the terms of
 * the GNU General Public License
 */
 
#include <asterisk/channel.h>
#include <asterisk/file.h>
#include <asterisk/logger.h>
#include <asterisk/sched.h>
#include <asterisk/module.h>
#include <arpa/inet.h>
#include <stdlib.h>
#include <sys/time.h>
#include <stdio.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <pthread.h>
#include <endian.h>

/* Some Ideas for this code came from makegsme.c by Jeffery Chilton */

/* Portions of the conversion code are by guido@sienanet.it */

struct ast_filestream {
	void *reserved[AST_RESERVED_POINTERS];
	/* Believe it or not, we must decode/recode to account for the
	   weird MS format */
	/* This is what a filestream means to us */
	int fd; /* Descriptor */
	struct ast_channel *owner;
	struct ast_frame fr;				/* Frame information */
	char waste[AST_FRIENDLY_OFFSET];	/* Buffer for sending frames, etc */
	char empty;							/* Empty character */
	unsigned char gsm[33];				/* Two Real GSM Frames */
	int lasttimeout;
	struct timeval last;
	int adj;
	struct ast_filestream *next;
};


static struct ast_filestream *glist = NULL;
static pthread_mutex_t gsm_lock = PTHREAD_MUTEX_INITIALIZER;
static int glistcnt = 0;

static char *name = "gsm";
static char *desc = "Raw GSM data";
static char *exts = "gsm";

static struct ast_filestream *gsm_open(int fd)
{
	/* We don't have any header to read or anything really, but
	   if we did, it would go here.  We also might want to check
	   and be sure it's a valid file.  */
	struct ast_filestream *tmp;
	if ((tmp = malloc(sizeof(struct ast_filestream)))) {
		memset(tmp, 0, sizeof(struct ast_filestream));
		if (pthread_mutex_lock(&gsm_lock)) {
			ast_log(LOG_WARNING, "Unable to lock gsm list\n");
			free(tmp);
			return NULL;
		}
		tmp->next = glist;
		glist = tmp;
		tmp->fd = fd;
		tmp->owner = NULL;
		tmp->fr.data = tmp->gsm;
		tmp->fr.frametype = AST_FRAME_VOICE;
		tmp->fr.subclass = AST_FORMAT_GSM;
		/* datalen will vary for each frame */
		tmp->fr.src = name;
		tmp->fr.mallocd = 0;
		tmp->lasttimeout = -1;
		glistcnt++;
		pthread_mutex_unlock(&gsm_lock);
		ast_update_use_count();
	}
	return tmp;
}

static struct ast_filestream *gsm_rewrite(int fd, char *comment)
{
	/* We don't have any header to read or anything really, but
	   if we did, it would go here.  We also might want to check
	   and be sure it's a valid file.  */
	struct ast_filestream *tmp;
	if ((tmp = malloc(sizeof(struct ast_filestream)))) {
		memset(tmp, 0, sizeof(struct ast_filestream));
		if (pthread_mutex_lock(&gsm_lock)) {
			ast_log(LOG_WARNING, "Unable to lock gsm list\n");
			free(tmp);
			return NULL;
		}
		tmp->next = glist;
		glist = tmp;
		tmp->fd = fd;
		tmp->owner = NULL;
		tmp->lasttimeout = -1;
		glistcnt++;
		pthread_mutex_unlock(&gsm_lock);
		ast_update_use_count();
	} else
		ast_log(LOG_WARNING, "Out of memory\n");
	return tmp;
}

static struct ast_frame *gsm_read(struct ast_filestream *s)
{
	return NULL;
}

static void gsm_close(struct ast_filestream *s)
{
	struct ast_filestream *tmp, *tmpl = NULL;
	if (pthread_mutex_lock(&gsm_lock)) {
		ast_log(LOG_WARNING, "Unable to lock gsm list\n");
		return;
	}
	tmp = glist;
	while(tmp) {
		if (tmp == s) {
			if (tmpl)
				tmpl->next = tmp->next;
			else
				glist = tmp->next;
			break;
		}
		tmpl = tmp;
		tmp = tmp->next;
	}
	glistcnt--;
	if (s->owner) {
		s->owner->stream = NULL;
		if (s->owner->streamid > -1)
			ast_sched_del(s->owner->sched, s->owner->streamid);
		s->owner->streamid = -1;
	}
	pthread_mutex_unlock(&gsm_lock);
	ast_update_use_count();
	if (!tmp) 
		ast_log(LOG_WARNING, "Freeing a filestream we don't seem to own\n");
	close(s->fd);
	free(s);
}

static int ast_read_callback(void *data)
{
	int retval = 0;
	int res;
	int delay = 20;
	struct ast_filestream *s = data;
	struct timeval tv;
	/* Send a frame from the file to the appropriate channel */

	s->fr.frametype = AST_FRAME_VOICE;
	s->fr.subclass = AST_FORMAT_GSM;
	s->fr.offset = AST_FRIENDLY_OFFSET;
	s->fr.timelen = 20;
	s->fr.datalen = 33;
	s->fr.mallocd = 0;
	s->fr.data = s->gsm;
	if ((res = read(s->fd, s->gsm, 33)) != 33) {
		if (res)
			ast_log(LOG_WARNING, "Short read (%d) (%s)!\n", res, strerror(errno));
		s->owner->streamid = -1;
		return 0;
	}
	/* Lastly, process the frame */
	if (ast_write(s->owner, &s->fr)) {
		ast_log(LOG_WARNING, "Failed to write frame\n");
		s->owner->streamid = -1;
		return 0;
	}
	if (s->last.tv_usec || s->last.tv_usec) {
		int ms;
		gettimeofday(&tv, NULL);
		ms = 1000 * (tv.tv_sec - s->last.tv_sec) + 
			(tv.tv_usec - s->last.tv_usec) / 1000;
		s->last.tv_sec = tv.tv_sec;
		s->last.tv_usec = tv.tv_usec;
		if ((ms - delay) * (ms - delay) > 4) {
			/* Compensate if we're more than 2 ms off */
			s->adj -= (ms - delay);
		}
#if 0
		fprintf(stdout, "Delay is %d, adjustment is %d, last was %d\n", delay, s->adj, ms);
#endif
		delay += s->adj;
		if (delay < 1)
			delay = 1;
	} else
		gettimeofday(&s->last, NULL);
	if (s->lasttimeout != delay) {
		/* We'll install the next timeout now. */
		s->owner->streamid = ast_sched_add(s->owner->sched,
				delay, ast_read_callback, s); 
		s->lasttimeout = delay;
	} else {
		/* Just come back again at the same time */
		retval = -1;
	}
	return retval;
}

static int gsm_apply(struct ast_channel *c, struct ast_filestream *s)
{
	/* Select our owner for this stream, and get the ball rolling. */
	s->owner = c;
	ast_read_callback(s);
	return 0;
}

static int gsm_write(struct ast_filestream *fs, struct ast_frame *f)
{
	int res;
	if (f->frametype != AST_FRAME_VOICE) {
		ast_log(LOG_WARNING, "Asked to write non-voice frame!\n");
		return -1;
	}
	if (f->subclass != AST_FORMAT_GSM) {
		ast_log(LOG_WARNING, "Asked to write non-GSM frame (%d)!\n", f->subclass);
		return -1;
	}
	if (f->datalen != 33) {
		ast_log(LOG_WARNING, "Invalid data length, %d, should be 33\n", f->datalen);
		return -1;
	}
	if ((res = write(fs->fd, f->data, f->datalen)) != f->datalen) {
			ast_log(LOG_WARNING, "Bad write (%d/33): %s\n", res, strerror(errno));
			return -1;
	}
	return 0;
}

static char *gsm_getcomment(struct ast_filestream *s)
{
	return NULL;
}

int load_module()
{
	return ast_format_register(name, exts, AST_FORMAT_GSM,
								gsm_open,
								gsm_rewrite,
								gsm_apply,
								gsm_write,
								gsm_read,
								gsm_close,
								gsm_getcomment);
								
								
}

int unload_module()
{
	struct ast_filestream *tmp, *tmpl;
	if (pthread_mutex_lock(&gsm_lock)) {
		ast_log(LOG_WARNING, "Unable to lock gsm list\n");
		return -1;
	}
	tmp = glist;
	while(tmp) {
		if (tmp->owner)
			ast_softhangup(tmp->owner);
		tmpl = tmp;
		tmp = tmp->next;
		free(tmpl);
	}
	pthread_mutex_unlock(&gsm_lock);
	return ast_format_unregister(name);
}	

int usecount()
{
	int res;
	if (pthread_mutex_lock(&gsm_lock)) {
		ast_log(LOG_WARNING, "Unable to lock gsm list\n");
		return -1;
	}
	res = glistcnt;
	pthread_mutex_unlock(&gsm_lock);
	return res;
}

char *description()
{
	return desc;
}