asterisk/formats/format_g723.c

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2023-05-25 18:45:57 +00:00
/*
* 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 Old-style G.723.1 frame/timestamp format.
*
* \arg Extensions: g723, g723sf
* \ingroup formats
*/
/*** MODULEINFO
<support_level>core</support_level>
***/
#include "asterisk.h"
#include "asterisk/mod_format.h"
#include "asterisk/module.h"
#include "asterisk/format_cache.h"
#define G723_MAX_SIZE 1024
static struct ast_frame *g723_read(struct ast_filestream *s, int *whennext)
{
unsigned short size;
size_t res;
int delay;
/* Read the delay for the next packet, and schedule again if necessary */
/* XXX is this ignored ? */
if (fread(&delay, 1, 4, s->f) == 4)
delay = ntohl(delay);
else
delay = -1;
if (fread(&size, 1, 2, s->f) != 2) {
/* Out of data, or the file is no longer valid. In any case
go ahead and stop the stream */
return NULL;
}
/* Looks like we have a frame to read from here */
size = ntohs(size);
if (size > G723_MAX_SIZE) {
ast_log(LOG_WARNING, "Size %d is invalid\n", size);
/* The file is apparently no longer any good, as we
shouldn't ever get frames even close to this
size. */
return NULL;
}
/* Read the data into the buffer */
AST_FRAME_SET_BUFFER(&s->fr, s->buf, AST_FRIENDLY_OFFSET, size);
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 = 240;
return &s->fr;
}
static int g723_write(struct ast_filestream *s, struct ast_frame *f)
{
uint32_t delay;
uint16_t size;
int res;
/* XXX there used to be a check s->fr means a read stream */
delay = 0;
if (f->datalen <= 0) {
ast_log(LOG_WARNING, "Short frame ignored (%d bytes long?)\n", f->datalen);
return 0;
}
if ((res = fwrite(&delay, 1, 4, s->f)) != 4) {
ast_log(LOG_WARNING, "Unable to write delay: res=%d (%s)\n", res, strerror(errno));
return -1;
}
size = htons(f->datalen);
if ((res = fwrite(&size, 1, 2, s->f)) != 2) {
ast_log(LOG_WARNING, "Unable to write size: res=%d (%s)\n", res, strerror(errno));
return -1;
}
if ((res = fwrite(f->data.ptr, 1, f->datalen, s->f)) != f->datalen) {
ast_log(LOG_WARNING, "Unable to write frame: res=%d (%s)\n", res, strerror(errno));
return -1;
}
return 0;
}
static int g723_seek(struct ast_filestream *fs, off_t sample_offset, int whence)
{
return -1;
}
static int g723_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 g723 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 g723 filestream %p: %s\n", fs, strerror(errno));
return -1;
}
/* Truncate file to current length */
return ftruncate(fd, cur);
}
static off_t g723_tell(struct ast_filestream *fs)
{
return -1;
}
static struct ast_format_def g723_1_f = {
.name = "g723sf",
.exts = "g723|g723sf",
.write = g723_write,
.seek = g723_seek,
.trunc = g723_trunc,
.tell = g723_tell,
.read = g723_read,
.buf_size = G723_MAX_SIZE + AST_FRIENDLY_OFFSET,
};
static int load_module(void)
{
g723_1_f.format = ast_format_g723;
if (ast_format_def_register(&g723_1_f))
return AST_MODULE_LOAD_DECLINE;
return AST_MODULE_LOAD_SUCCESS;
}
static int unload_module(void)
{
return ast_format_def_unregister(g723_1_f.name);
}
AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_LOAD_ORDER, "G.723.1 Simple Timestamp File Format",
.support_level = AST_MODULE_SUPPORT_CORE,
.load = load_module,
.unload = unload_module,
.load_pri = AST_MODPRI_APP_DEPEND
);