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asterisk/formats/format_pcm.c

299 lines
6.9 KiB
C
Executable File

/*
* Asterisk -- A telephony toolkit for Linux.
*
* Flat, binary, ulaw PCM file format.
*
* Copyright (C) 1999, Mark Spencer
*
* Mark Spencer <markster@linux-support.net>
*
* This program is free software, distributed under the terms of
* the GNU General Public License
*/
#include <asterisk/channel.h>
#include <asterisk/file.h>
#include <asterisk/logger.h>
#include <asterisk/sched.h>
#include <asterisk/module.h>
#include <arpa/inet.h>
#include <stdlib.h>
#include <sys/time.h>
#include <stdio.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <pthread.h>
#include <endian.h>
#define BUF_SIZE 160 /* 160 samples */
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 */
int fd; /* Descriptor */
struct ast_channel *owner;
struct ast_frame fr; /* Frame information */
char waste[AST_FRIENDLY_OFFSET]; /* Buffer for sending frames, etc */
char empty; /* Empty character */
unsigned char buf[BUF_SIZE]; /* Output Buffer */
int lasttimeout;
struct timeval last;
int adj;
struct ast_filestream *next;
};
static struct ast_filestream *glist = NULL;
static pthread_mutex_t pcm_lock = PTHREAD_MUTEX_INITIALIZER;
static int glistcnt = 0;
static char *name = "pcm";
static char *desc = "Raw uLaw 8khz Audio support (PCM)";
static char *exts = "pcm|ulaw|ul|mu";
static struct ast_filestream *pcm_open(int fd)
{
/* 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 (pthread_mutex_lock(&pcm_lock)) {
ast_log(LOG_WARNING, "Unable to lock pcm list\n");
free(tmp);
return NULL;
}
tmp->next = glist;
glist = tmp;
tmp->fd = fd;
tmp->owner = NULL;
tmp->fr.data = tmp->buf;
tmp->fr.frametype = AST_FRAME_VOICE;
tmp->fr.subclass = AST_FORMAT_ULAW;
/* datalen will vary for each frame */
tmp->fr.src = name;
tmp->fr.mallocd = 0;
tmp->lasttimeout = -1;
glistcnt++;
pthread_mutex_unlock(&pcm_lock);
ast_update_use_count();
}
return tmp;
}
static struct ast_filestream *pcm_rewrite(int fd, 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 (pthread_mutex_lock(&pcm_lock)) {
ast_log(LOG_WARNING, "Unable to lock pcm list\n");
free(tmp);
return NULL;
}
tmp->next = glist;
glist = tmp;
tmp->fd = fd;
tmp->owner = NULL;
tmp->lasttimeout = -1;
glistcnt++;
pthread_mutex_unlock(&pcm_lock);
ast_update_use_count();
} else
ast_log(LOG_WARNING, "Out of memory\n");
return tmp;
}
static struct ast_frame *pcm_read(struct ast_filestream *s)
{
return NULL;
}
static void pcm_close(struct ast_filestream *s)
{
struct ast_filestream *tmp, *tmpl = NULL;
if (pthread_mutex_lock(&pcm_lock)) {
ast_log(LOG_WARNING, "Unable to lock pcm list\n");
return;
}
tmp = glist;
while(tmp) {
if (tmp == s) {
if (tmpl)
tmpl->next = tmp->next;
else
glist = tmp->next;
break;
}
tmpl = tmp;
tmp = tmp->next;
}
glistcnt--;
if (s->owner) {
s->owner->stream = NULL;
if (s->owner->streamid > -1)
ast_sched_del(s->owner->sched, s->owner->streamid);
s->owner->streamid = -1;
}
pthread_mutex_unlock(&pcm_lock);
ast_update_use_count();
if (!tmp)
ast_log(LOG_WARNING, "Freeing a filestream we don't seem to own\n");
close(s->fd);
free(s);
}
static int ast_read_callback(void *data)
{
int retval = 0;
int res;
int delay;
struct ast_filestream *s = data;
struct timeval tv;
/* Send a frame from the file to the appropriate channel */
s->fr.frametype = AST_FRAME_VOICE;
s->fr.subclass = AST_FORMAT_ULAW;
s->fr.offset = AST_FRIENDLY_OFFSET;
s->fr.mallocd = 0;
s->fr.data = s->buf;
if ((res = read(s->fd, s->buf, BUF_SIZE)) < 1) {
if (res)
ast_log(LOG_WARNING, "Short read (%d) (%s)!\n", res, strerror(errno));
s->owner->streamid = -1;
return 0;
}
s->fr.timelen = res / 8;
s->fr.datalen = res;
delay = s->fr.timelen;
/* Lastly, process the frame */
if (ast_write(s->owner, &s->fr)) {
ast_log(LOG_WARNING, "Failed to write frame\n");
s->owner->streamid = -1;
return 0;
}
if (s->last.tv_usec || s->last.tv_usec) {
int ms;
gettimeofday(&tv, NULL);
ms = 1000 * (tv.tv_sec - s->last.tv_sec) +
(tv.tv_usec - s->last.tv_usec) / 1000;
s->last.tv_sec = tv.tv_sec;
s->last.tv_usec = tv.tv_usec;
if ((ms - delay) * (ms - delay) > 4) {
/* Compensate if we're more than 2 ms off */
s->adj -= (ms - delay);
}
#if 0
fprintf(stdout, "Delay is %d, adjustment is %d, last was %d\n", delay, s->adj, ms);
#endif
delay += s->adj;
if (delay < 1)
delay = 1;
} else
gettimeofday(&s->last, NULL);
if (s->lasttimeout != delay) {
/* We'll install the next timeout now. */
s->owner->streamid = ast_sched_add(s->owner->sched,
delay, ast_read_callback, s);
s->lasttimeout = delay;
} else {
/* Just come back again at the same time */
retval = -1;
}
return retval;
}
static int pcm_apply(struct ast_channel *c, struct ast_filestream *s)
{
/* Select our owner for this stream, and get the ball rolling. */
s->owner = c;
ast_read_callback(s);
return 0;
}
static int pcm_write(struct ast_filestream *fs, struct ast_frame *f)
{
int res;
if (f->frametype != AST_FRAME_VOICE) {
ast_log(LOG_WARNING, "Asked to write non-voice frame!\n");
return -1;
}
if (f->subclass != AST_FORMAT_ULAW) {
ast_log(LOG_WARNING, "Asked to write non-ulaw frame (%d)!\n", f->subclass);
return -1;
}
if ((res = write(fs->fd, f->data, f->datalen)) != f->datalen) {
ast_log(LOG_WARNING, "Bad write (%d/%d): %s\n", res, f->datalen, strerror(errno));
return -1;
}
return 0;
}
static char *pcm_getcomment(struct ast_filestream *s)
{
return NULL;
}
int load_module()
{
return ast_format_register(name, exts, AST_FORMAT_ULAW,
pcm_open,
pcm_rewrite,
pcm_apply,
pcm_write,
pcm_read,
pcm_close,
pcm_getcomment);
}
int unload_module()
{
struct ast_filestream *tmp, *tmpl;
if (pthread_mutex_lock(&pcm_lock)) {
ast_log(LOG_WARNING, "Unable to lock pcm list\n");
return -1;
}
tmp = glist;
while(tmp) {
if (tmp->owner)
ast_softhangup(tmp->owner);
tmpl = tmp;
tmp = tmp->next;
free(tmpl);
}
pthread_mutex_unlock(&pcm_lock);
return ast_format_unregister(name);
}
int usecount()
{
int res;
if (pthread_mutex_lock(&pcm_lock)) {
ast_log(LOG_WARNING, "Unable to lock pcm list\n");
return -1;
}
res = glistcnt;
pthread_mutex_unlock(&pcm_lock);
return res;
}
char *description()
{
return desc;
}
char *key()
{
return ASTERISK_GPL_KEY;
}