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* Asterisk -- An open source telephony toolkit.
* Copyright (C) 1999 - 2005, Digium, Inc.
* Mark Spencer <markster@digium.com>
* See http://www.asterisk.org for more information about
* the Asterisk project. Please do not directly contact
* any of the maintainers of this project for assistance;
* the project provides a web site, mailing lists and IRC
* channels for your use.
*
* This program is free software, distributed under the terms of
* the GNU General Public License Version 2. See the LICENSE file
* at the top of the source tree.
*/
*
* \brief Save to raw, headerless GSM data.
Kevin P. Fleming
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#include <unistd.h>
#include <arpa/inet.h>
#include <stdlib.h>
#include <sys/time.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
#include "asterisk.h"
ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
#include "asterisk/lock.h"
#include "asterisk/channel.h"
#include "asterisk/file.h"
#include "asterisk/logger.h"
#include "asterisk/sched.h"
#include "asterisk/module.h"
#include "asterisk/endian.h"
/* Some Ideas for this code came from makegsme.c by Jeffrey Chilton */
/* Portions of the conversion code are by guido@sienanet.it */
#define GSM_FRAME_SIZE 33
#define GSM_SAMPLES 160
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/* silent gsm frame */
/* begin binary data: */
char gsm_silence[] = /* 33 */
{0xD8,0x20,0xA2,0xE1,0x5A,0x50,0x00,0x49,0x24,0x92,0x49,0x24,0x50,0x00,0x49
,0x24,0x92,0x49,0x24,0x50,0x00,0x49,0x24,0x92,0x49,0x24,0x50,0x00,0x49,0x24
,0x92,0x49,0x24};
/* end binary data. size = 33 bytes */
static struct ast_frame *gsm_read(struct ast_filestream *s, int *whennext)
s->fr.frametype = AST_FRAME_VOICE;
s->fr.subclass = AST_FORMAT_GSM;
AST_FRAME_SET_BUFFER(&(s->fr), s->buf, AST_FRIENDLY_OFFSET, GSM_FRAME_SIZE)
if ((res = fread(s->fr.data, 1, GSM_FRAME_SIZE, s->f)) != GSM_FRAME_SIZE) {
if (res)
ast_log(LOG_WARNING, "Short read (%d) (%s)!\n", res, strerror(errno));
*whennext = s->fr.samples = GSM_SAMPLES;
}
static int gsm_write(struct ast_filestream *fs, struct ast_frame *f)
{
int res;
unsigned char gsm[2*GSM_FRAME_SIZE];
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 % 65)) {
/* This is in MSGSM format, need to be converted */
int len=0;
while(len < f->datalen) {
conv65(f->data + len, gsm);
if ((res = fwrite(gsm, 1, 2*GSM_FRAME_SIZE, fs->f)) != 2*GSM_FRAME_SIZE) {
ast_log(LOG_WARNING, "Bad write (%d/66): %s\n", res, strerror(errno));
return -1;
}
len += 65;
}
} else {
if (f->datalen % GSM_FRAME_SIZE) {
ast_log(LOG_WARNING, "Invalid data length, %d, should be multiple of 33\n", f->datalen);
if ((res = fwrite(f->data, 1, f->datalen, fs->f)) != f->datalen) {
ast_log(LOG_WARNING, "Bad write (%d/33): %s\n", res, strerror(errno));
return -1;
}
static int gsm_seek(struct ast_filestream *fs, off_t sample_offset, int whence)
off_t offset=0,min,cur,max,distance;
cur = ftello(fs->f);
fseeko(fs->f, 0, SEEK_END);
max = ftello(fs->f);
/* have to fudge to frame here, so not fully to sample */
distance = (sample_offset/GSM_SAMPLES) * GSM_FRAME_SIZE;
/* Always protect against seeking past the begining. */
offset = (offset < min)?min:offset;
Martin Pycko
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} else if (offset > max) {
int i;
for (i=0; i< (offset - max) / GSM_FRAME_SIZE; i++) {
fwrite(gsm_silence, 1, GSM_FRAME_SIZE, fs->f);
Martin Pycko
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}
return fseeko(fs->f, offset, SEEK_SET);
}
static int gsm_trunc(struct ast_filestream *fs)
{
return ftruncate(fileno(fs->f), ftello(fs->f));
static off_t gsm_tell(struct ast_filestream *fs)
off_t offset = ftello(fs->f);
return (offset/GSM_FRAME_SIZE)*GSM_SAMPLES;
static const struct ast_format gsm_f = {
.name = "gsm",
.exts = "gsm",
.format = AST_FORMAT_GSM,
.write = gsm_write,
.seek = gsm_seek,
.trunc = gsm_trunc,
.tell = gsm_tell,
.read = gsm_read,
.buf_size = 2*GSM_FRAME_SIZE + AST_FRIENDLY_OFFSET, /* 2 gsm frames */
.module = &mod_data, /* XXX */
static int load_module(void *mod)
return ast_format_register(&gsm_f);
static int unload_module(void *mod)
return ast_format_unregister(gsm_f.name);
static const char *description(void)
return "Raw GSM data";
static const char *key(void)
STD_MOD1;