asterisk/formats/format_g729.c

160 lines
4.2 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 G729 data.
* \note This is not an encoder/decoder. The codec for g729 is only
* available with a commercial license from Digium, due to patent
* restrictions. Check http://www.digium.com for information.
* \arg Extensions: g729
* \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"
/* Some Ideas for this code came from makeg729e.c by Jeffrey Chilton */
/* Portions of the conversion code are by guido@sienanet.it */
#define BUF_SIZE 20 /* two G729 frames */
#define G729A_SAMPLES 160
static struct ast_frame *g729_read(struct ast_filestream *s, int *whennext)
{
size_t res;
/* Send a frame from the file to the appropriate channel */
s->fr.samples = G729A_SAMPLES;
AST_FRAME_SET_BUFFER(&s->fr, s->buf, AST_FRIENDLY_OFFSET, BUF_SIZE);
if ((res = fread(s->fr.data.ptr, 1, s->fr.datalen, s->f)) != s->fr.datalen) {
if (res && res != 10) /* XXX what for ? */ {
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 g729_write(struct ast_filestream *fs, struct ast_frame *f)
{
int res;
if (f->datalen % 10) {
ast_log(LOG_WARNING, "Invalid data length, %d, should be multiple of 10\n", f->datalen);
return -1;
}
if ((res = fwrite(f->data.ptr, 1, f->datalen, fs->f)) != f->datalen) {
ast_log(LOG_WARNING, "Bad write (%d/10): %s\n", res, strerror(errno));
return -1;
}
return 0;
}
static int g729_seek(struct ast_filestream *fs, off_t sample_offset, int whence)
{
long bytes;
off_t min,cur,max,offset=0;
min = 0;
cur = ftello(fs->f);
fseeko(fs->f, 0, SEEK_END);
max = ftello(fs->f);
bytes = BUF_SIZE * (sample_offset / G729A_SAMPLES);
if (whence == SEEK_SET)
offset = bytes;
else if (whence == SEEK_CUR || whence == SEEK_FORCECUR)
offset = cur + bytes;
else if (whence == SEEK_END)
offset = max - bytes;
if (whence != SEEK_FORCECUR) {
offset = (offset > max)?max:offset;
}
/* protect against seeking beyond begining. */
offset = (offset < min)?min:offset;
if (fseeko(fs->f, offset, SEEK_SET) < 0)
return -1;
return 0;
}
static int g729_trunc(struct ast_filestream *fs)
{
int fd;
off_t cur;
if ((fd = fileno(fs->f)) < 0) {
ast_log(AST_LOG_WARNING, "Unable to determine file descriptor for g729 filestream %p: %s\n", fs, strerror(errno));
return -1;
}
if ((cur = ftello(fs->f)) < 0) {
ast_log(AST_LOG_WARNING, "Unable to determine current position in g729 filestream %p: %s\n", fs, strerror(errno));
return -1;
}
/* Truncate file to current length */
return ftruncate(fd, cur);
}
static off_t g729_tell(struct ast_filestream *fs)
{
off_t offset = ftello(fs->f);
return (offset/BUF_SIZE)*G729A_SAMPLES;
}
static struct ast_format_def g729_f = {
.name = "g729",
.exts = "g729",
.write = g729_write,
.seek = g729_seek,
.trunc = g729_trunc,
.tell = g729_tell,
.read = g729_read,
.buf_size = BUF_SIZE + AST_FRIENDLY_OFFSET,
};
static int load_module(void)
{
g729_f.format = ast_format_g729;
if (ast_format_def_register(&g729_f))
return AST_MODULE_LOAD_DECLINE;
return AST_MODULE_LOAD_SUCCESS;
}
static int unload_module(void)
{
return ast_format_def_unregister(g729_f.name);
}
AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_LOAD_ORDER, "Raw G.729 data",
.support_level = AST_MODULE_SUPPORT_CORE,
.load = load_module,
.unload = unload_module,
.load_pri = AST_MODPRI_APP_DEPEND
);