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asterisk/formats/format_gsm.c

281 lines
6.7 KiB
C

/*
* 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.
*/
/*! \file
*
* \brief Save to raw, headerless GSM data.
* \arg File name extension: gsm
* \ingroup formats
*/
#include <unistd.h>
#include <netinet/in.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"
#include "msgsm.h"
/* Some Ideas for this code came from makegsme.c by Jeffrey Chilton */
/* Portions of the conversion code are by guido@sienanet.it */
/* 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 */
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 */
FILE *f; /* Descriptor */
struct ast_frame fr; /* Frame information */
char waste[AST_FRIENDLY_OFFSET]; /* Buffer for sending frames, etc */
char empty; /* Empty character */
unsigned char gsm[66]; /* Two Real GSM Frames */
};
AST_MUTEX_DEFINE_STATIC(gsm_lock);
static int glistcnt = 0;
static char *name = "gsm";
static char *desc = "Raw GSM data";
static char *exts = "gsm";
static struct ast_filestream *gsm_open(FILE *f)
{
/* 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 (ast_mutex_lock(&gsm_lock)) {
ast_log(LOG_WARNING, "Unable to lock gsm list\n");
free(tmp);
return NULL;
}
tmp->f = f;
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;
glistcnt++;
ast_mutex_unlock(&gsm_lock);
ast_update_use_count();
}
return tmp;
}
static struct ast_filestream *gsm_rewrite(FILE *f, const 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 (ast_mutex_lock(&gsm_lock)) {
ast_log(LOG_WARNING, "Unable to lock gsm list\n");
free(tmp);
return NULL;
}
tmp->f = f;
glistcnt++;
ast_mutex_unlock(&gsm_lock);
ast_update_use_count();
} else
ast_log(LOG_WARNING, "Out of memory\n");
return tmp;
}
static void gsm_close(struct ast_filestream *s)
{
if (ast_mutex_lock(&gsm_lock)) {
ast_log(LOG_WARNING, "Unable to lock gsm list\n");
return;
}
glistcnt--;
ast_mutex_unlock(&gsm_lock);
ast_update_use_count();
fclose(s->f);
free(s);
}
static struct ast_frame *gsm_read(struct ast_filestream *s, int *whennext)
{
int res;
s->fr.frametype = AST_FRAME_VOICE;
s->fr.subclass = AST_FORMAT_GSM;
s->fr.offset = AST_FRIENDLY_OFFSET;
s->fr.samples = 160;
s->fr.datalen = 33;
s->fr.mallocd = 0;
s->fr.data = s->gsm;
if ((res = fread(s->gsm, 1, 33, s->f)) != 33) {
if (res)
ast_log(LOG_WARNING, "Short read (%d) (%s)!\n", res, strerror(errno));
return NULL;
}
*whennext = 160;
return &s->fr;
}
static int gsm_write(struct ast_filestream *fs, struct ast_frame *f)
{
int res;
unsigned char gsm[66];
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, 66, fs->f)) != 66) {
ast_log(LOG_WARNING, "Bad write (%d/66): %s\n", res, strerror(errno));
return -1;
}
len += 65;
}
} else {
if (f->datalen % 33) {
ast_log(LOG_WARNING, "Invalid data length, %d, should be multiple of 33\n", f->datalen);
return -1;
}
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;
}
}
return 0;
}
static int gsm_seek(struct ast_filestream *fs, long sample_offset, int whence)
{
off_t offset=0,min,cur,max,distance;
min = 0;
cur = ftell(fs->f);
fseek(fs->f, 0, SEEK_END);
max = ftell(fs->f);
/* have to fudge to frame here, so not fully to sample */
distance = (sample_offset/160) * 33;
if(whence == SEEK_SET)
offset = distance;
else if(whence == SEEK_CUR || whence == SEEK_FORCECUR)
offset = distance + cur;
else if(whence == SEEK_END)
offset = max - distance;
/* Always protect against seeking past the begining. */
offset = (offset < min)?min:offset;
if (whence != SEEK_FORCECUR) {
offset = (offset > max)?max:offset;
} else if (offset > max) {
int i;
fseek(fs->f, 0, SEEK_END);
for (i=0; i< (offset - max) / 33; i++) {
fwrite(gsm_silence, 1, 33, fs->f);
}
}
return fseek(fs->f, offset, SEEK_SET);
}
static int gsm_trunc(struct ast_filestream *fs)
{
return ftruncate(fileno(fs->f), ftell(fs->f));
}
static long gsm_tell(struct ast_filestream *fs)
{
off_t offset;
offset = ftell(fs->f);
return (offset/33)*160;
}
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_write,
gsm_seek,
gsm_trunc,
gsm_tell,
gsm_read,
gsm_close,
gsm_getcomment);
}
int unload_module()
{
return ast_format_unregister(name);
}
int usecount()
{
return glistcnt;
}
char *description()
{
return desc;
}
char *key()
{
return ASTERISK_GPL_KEY;
}