asterisk/formats/format_g726.c

290 lines
6.9 KiB
C

/*
* Asterisk -- An open source telephony toolkit.
*
* Copyright (c) 2004 - 2005, inAccess Networks
*
* Michael Manousos <manousos@inaccessnetworks.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 Headerless G.726 (16/24/32/40kbps) data format for Asterisk.
*
* File name extensions:
* \arg 40 kbps: g726-40
* \arg 32 kbps: g726-32
* \arg 24 kbps: g726-24
* \arg 16 kbps: g726-16
* \ingroup formats
*/
/*** MODULEINFO
<support_level>core</support_level>
***/
#include "asterisk.h"
#include "asterisk/mod_format.h"
#include "asterisk/module.h"
#include "asterisk/endian.h"
#include "asterisk/format_cache.h"
#define RATE_40 0
#define RATE_32 1
#define RATE_24 2
#define RATE_16 3
/* We can only read/write chunks of FRAME_TIME ms G.726 data */
#define FRAME_TIME 10 /* 10 ms size */
#define BUF_SIZE (5*FRAME_TIME) /* max frame size in bytes ? */
/* Frame sizes in bytes */
static int frame_size[4] = {
FRAME_TIME * 5,
FRAME_TIME * 4,
FRAME_TIME * 3,
FRAME_TIME * 2
};
struct g726_desc {
int rate; /* RATE_* defines */
};
/*
* Rate dependant format functions (open, rewrite)
*/
static int g726_open(struct ast_filestream *tmp, int rate)
{
struct g726_desc *s = (struct g726_desc *)tmp->_private;
s->rate = rate;
ast_debug(1, "Created filestream G.726-%dk.\n", 40 - s->rate * 8);
return 0;
}
static int g726_40_open(struct ast_filestream *s)
{
return g726_open(s, RATE_40);
}
static int g726_32_open(struct ast_filestream *s)
{
return g726_open(s, RATE_32);
}
static int g726_24_open(struct ast_filestream *s)
{
return g726_open(s, RATE_24);
}
static int g726_16_open(struct ast_filestream *s)
{
return g726_open(s, RATE_16);
}
static int g726_40_rewrite(struct ast_filestream *s, const char *comment)
{
return g726_open(s, RATE_40);
}
static int g726_32_rewrite(struct ast_filestream *s, const char *comment)
{
return g726_open(s, RATE_32);
}
static int g726_24_rewrite(struct ast_filestream *s, const char *comment)
{
return g726_open(s, RATE_24);
}
static int g726_16_rewrite(struct ast_filestream *s, const char *comment)
{
return g726_open(s, RATE_16);
}
/*
* Rate independent format functions (read, write)
*/
static struct ast_frame *g726_read(struct ast_filestream *s, int *whennext)
{
size_t res;
struct g726_desc *fs = (struct g726_desc *)s->_private;
/* Send a frame from the file to the appropriate channel */
AST_FRAME_SET_BUFFER(&s->fr, s->buf, AST_FRIENDLY_OFFSET, frame_size[fs->rate]);
s->fr.samples = 8 * FRAME_TIME;
if ((res = fread(s->fr.data.ptr, 1, s->fr.datalen, s->f)) != s->fr.datalen) {
if (res) {
ast_log(LOG_WARNING, "Short read of %s data (expected %d bytes, read %zu): %s\n",
ast_format_get_name(s->fr.subclass.format), s->fr.datalen, res,
strerror(errno));
}
return NULL;
}
*whennext = s->fr.samples;
return &s->fr;
}
static int g726_write(struct ast_filestream *s, struct ast_frame *f)
{
int res;
struct g726_desc *fs = (struct g726_desc *)s->_private;
if (f->datalen % frame_size[fs->rate]) {
ast_log(LOG_WARNING, "Invalid data length %d, should be multiple of %d\n",
f->datalen, frame_size[fs->rate]);
return -1;
}
if ((res = fwrite(f->data.ptr, 1, f->datalen, s->f)) != f->datalen) {
ast_log(LOG_WARNING, "Bad write (%d/%d): %s\n",
res, frame_size[fs->rate], strerror(errno));
return -1;
}
return 0;
}
static int g726_seek(struct ast_filestream *fs, off_t sample_offset, int whence)
{
off_t offset = 0, min = 0, cur, max, distance;
if ((cur = ftello(fs->f)) < 0) {
ast_log(AST_LOG_WARNING, "Unable to determine current position in g726 filestream %p: %s\n", fs, strerror(errno));
return -1;
}
if (fseeko(fs->f, 0, SEEK_END) < 0) {
ast_log(AST_LOG_WARNING, "Unable to seek to end of g726 filestream %p: %s\n", fs, strerror(errno));
return -1;
}
if ((max = ftello(fs->f)) < 0) {
ast_log(AST_LOG_WARNING, "Unable to determine max position in g726 filestream %p: %s\n", fs, strerror(errno));
return -1;
}
/* have to fudge to frame here, so not fully to sample */
distance = sample_offset / 2;
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;
}
if (whence != SEEK_FORCECUR) {
offset = offset > max ? max : offset;
offset = offset < min ? min : offset;
}
return fseeko(fs->f, offset, SEEK_SET);
}
static int g726_trunc(struct ast_filestream *fs)
{
return -1;
}
static off_t g726_tell(struct ast_filestream *fs)
{
return ftello(fs->f) << 1;
}
static struct ast_format_def f_def[] = {
{
.name = "g726-40",
.exts = "g726-40",
.open = g726_40_open,
.rewrite = g726_40_rewrite,
.write = g726_write,
.seek = g726_seek,
.trunc = g726_trunc,
.tell = g726_tell,
.read = g726_read,
.buf_size = BUF_SIZE + AST_FRIENDLY_OFFSET,
.desc_size = sizeof(struct g726_desc),
},
{
.name = "g726-32",
.exts = "g726-32",
.open = g726_32_open,
.rewrite = g726_32_rewrite,
.write = g726_write,
.seek = g726_seek,
.trunc = g726_trunc,
.tell = g726_tell,
.read = g726_read,
.buf_size = BUF_SIZE + AST_FRIENDLY_OFFSET,
.desc_size = sizeof(struct g726_desc),
},
{
.name = "g726-24",
.exts = "g726-24",
.open = g726_24_open,
.rewrite = g726_24_rewrite,
.write = g726_write,
.seek = g726_seek,
.trunc = g726_trunc,
.tell = g726_tell,
.read = g726_read,
.buf_size = BUF_SIZE + AST_FRIENDLY_OFFSET,
.desc_size = sizeof(struct g726_desc),
},
{
.name = "g726-16",
.exts = "g726-16",
.open = g726_16_open,
.rewrite = g726_16_rewrite,
.write = g726_write,
.seek = g726_seek,
.trunc = g726_trunc,
.tell = g726_tell,
.read = g726_read,
.buf_size = BUF_SIZE + AST_FRIENDLY_OFFSET,
.desc_size = sizeof(struct g726_desc),
},
{ .desc_size = 0 } /* terminator */
};
static int unload_module(void)
{
int i;
for (i = 0; f_def[i].desc_size ; i++) {
if (ast_format_def_unregister(f_def[i].name))
ast_log(LOG_WARNING, "Failed to unregister format %s.\n", f_def[i].name);
}
return(0);
}
static int load_module(void)
{
int i;
for (i = 0; f_def[i].desc_size ; i++) {
f_def[i].format = ast_format_g726;
if (ast_format_def_register(&f_def[i])) { /* errors are fatal */
ast_log(LOG_WARNING, "Failed to register format %s.\n", f_def[i].name);
unload_module();
return AST_MODULE_LOAD_DECLINE;
}
}
return AST_MODULE_LOAD_SUCCESS;
}
AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_LOAD_ORDER, "Raw G.726 (16/24/32/40kbps) data",
.support_level = AST_MODULE_SUPPORT_CORE,
.load = load_module,
.unload = unload_module,
.load_pri = AST_MODPRI_APP_DEPEND
);