197 lines
6.4 KiB
C
197 lines
6.4 KiB
C
/*
|
|
* Asterisk -- An open source telephony toolkit.
|
|
*
|
|
* Copyright (C) 2011, Digium, Inc.
|
|
*
|
|
* David Vossel <dvossel@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 Put a jitterbuffer on the read side of a channel
|
|
*
|
|
* \author David Vossel <dvossel@digium.com>
|
|
*
|
|
* \ingroup functions
|
|
*/
|
|
|
|
/*** MODULEINFO
|
|
<support_level>core</support_level>
|
|
***/
|
|
|
|
#include "asterisk.h"
|
|
|
|
#include "asterisk/module.h"
|
|
#include "asterisk/channel.h"
|
|
#include "asterisk/framehook.h"
|
|
#include "asterisk/frame.h"
|
|
#include "asterisk/pbx.h"
|
|
#include "asterisk/abstract_jb.h"
|
|
#include "asterisk/timing.h"
|
|
#include "asterisk/app.h"
|
|
|
|
/*** DOCUMENTATION
|
|
<function name="JITTERBUFFER" language="en_US">
|
|
<synopsis>
|
|
Add a Jitterbuffer to the Read side of the channel. This dejitters the audio stream before it reaches the Asterisk core. This is a write only function.
|
|
</synopsis>
|
|
<syntax>
|
|
<parameter name="jitterbuffer type" required="true">
|
|
<optionlist>
|
|
<option name="fixed">
|
|
<para>Set a fixed jitterbuffer on the channel.</para>
|
|
</option>
|
|
<option name="adaptive">
|
|
<para>Set an adaptive jitterbuffer on the channel.</para>
|
|
</option>
|
|
<option name="disabled">
|
|
<para>Remove a previously set jitterbuffer from the channel.</para>
|
|
</option>
|
|
</optionlist>
|
|
</parameter>
|
|
</syntax>
|
|
<description>
|
|
<para>Jitterbuffers are constructed in two different ways.
|
|
The first always take four arguments: <replaceable>max_size</replaceable>,
|
|
<replaceable>resync_threshold</replaceable>, <replaceable>target_extra</replaceable>,
|
|
and <replaceable>sync_video</replaceable>.
|
|
Alternatively, a single argument of <literal>default</literal> can be provided,
|
|
which will construct the default jitterbuffer for the given
|
|
<replaceable>jitterbuffer type</replaceable>.</para>
|
|
<para>The arguments are:</para>
|
|
<para><replaceable>max_size</replaceable>: Length in milliseconds of the buffer.
|
|
Defaults to 200 ms.</para>
|
|
<para><replaceable>resync_threshold</replaceable>: The length in milliseconds over
|
|
which a timestamp difference will result in resyncing the jitterbuffer.
|
|
Defaults to 1000ms.</para>
|
|
<para>target_extra: This option only affects the adaptive jitterbuffer. It represents
|
|
the amount time in milliseconds by which the new jitter buffer will pad its size.
|
|
Defaults to 40ms.</para>
|
|
<para>sync_video: This option enables video synchronization with the audio stream. It can be
|
|
turned on and off. Defaults to off.</para>
|
|
<example title="Fixed with defaults" language="text">
|
|
exten => 1,1,Set(JITTERBUFFER(fixed)=default)
|
|
</example>
|
|
<example title="Fixed with 200ms max size" language="text">
|
|
exten => 1,1,Set(JITTERBUFFER(fixed)=200)
|
|
</example>
|
|
<example title="Fixed with 200ms max size and video sync support" language="text">
|
|
exten => 1,1,Set(JITTERBUFFER(fixed)=200,,,yes)
|
|
</example>
|
|
<example title="Fixed with 200ms max size, resync threshold 1500" language="text">
|
|
exten => 1,1,Set(JITTERBUFFER(fixed)=200,1500)
|
|
</example>
|
|
<example title="Adaptive with defaults" language="text">
|
|
exten => 1,1,Set(JITTERBUFFER(adaptive)=default)
|
|
</example>
|
|
<example title="Adaptive with 200ms max size, 60ms target extra" language="text">
|
|
exten => 1,1,Set(JITTERBUFFER(adaptive)=200,,60)
|
|
</example>
|
|
<example title="Adaptive with 200ms max size and video sync support" language="text">
|
|
exten => 1,1,Set(JITTERBUFFER(adaptive)=200,,,yes)
|
|
</example>
|
|
<example title="Set a fixed jitterbuffer with defaults; then remove it" language="text">
|
|
exten => 1,1,Set(JITTERBUFFER(fixed)=default)
|
|
exten => 1,n,Set(JITTERBUFFER(disabled)=)
|
|
</example>
|
|
<note><para>If a channel specifies a jitterbuffer due to channel driver configuration and
|
|
the JITTERBUFFER function has set a jitterbuffer for that channel, the jitterbuffer set by
|
|
the JITTERBUFFER function will take priority and the jitterbuffer set by the channel
|
|
configuration will not be applied.</para></note>
|
|
</description>
|
|
</function>
|
|
***/
|
|
|
|
static int jb_helper(struct ast_channel *chan, const char *cmd, char *data, const char *value)
|
|
{
|
|
struct ast_jb_conf jb_conf;
|
|
|
|
if (!chan) {
|
|
ast_log(LOG_WARNING, "No channel was provided to %s function.\n", cmd);
|
|
return -1;
|
|
}
|
|
|
|
/* Initialize and set jb_conf */
|
|
ast_jb_conf_default(&jb_conf);
|
|
|
|
/* Now check user options to see if any of the defaults need to change. */
|
|
if (!ast_strlen_zero(data)) {
|
|
if (strcasecmp(data, "fixed") &&
|
|
strcasecmp(data, "adaptive") &&
|
|
strcasecmp(data, "disabled")) {
|
|
ast_log(LOG_WARNING, "Unknown Jitterbuffer type %s. Failed to create jitterbuffer.\n", data);
|
|
return -1;
|
|
}
|
|
ast_copy_string(jb_conf.impl, data, sizeof(jb_conf.impl));
|
|
}
|
|
|
|
if (!ast_strlen_zero(value) && strcasecmp(value, "default")) {
|
|
char *parse = ast_strdupa(value);
|
|
int res = 0;
|
|
AST_DECLARE_APP_ARGS(args,
|
|
AST_APP_ARG(max_size);
|
|
AST_APP_ARG(resync_threshold);
|
|
AST_APP_ARG(target_extra);
|
|
AST_APP_ARG(sync_video);
|
|
);
|
|
|
|
AST_STANDARD_APP_ARGS(args, parse);
|
|
if (!ast_strlen_zero(args.max_size)) {
|
|
res |= ast_jb_read_conf(&jb_conf,
|
|
"jbmaxsize",
|
|
args.max_size);
|
|
}
|
|
if (!ast_strlen_zero(args.resync_threshold)) {
|
|
res |= ast_jb_read_conf(&jb_conf,
|
|
"jbresyncthreshold",
|
|
args.resync_threshold);
|
|
}
|
|
if (!ast_strlen_zero(args.target_extra)) {
|
|
res |= ast_jb_read_conf(&jb_conf,
|
|
"jbtargetextra",
|
|
args.target_extra);
|
|
}
|
|
if (!ast_strlen_zero(args.sync_video)) {
|
|
res |= ast_jb_read_conf(&jb_conf,
|
|
"jbsyncvideo",
|
|
args.sync_video);
|
|
}
|
|
if (res) {
|
|
ast_log(LOG_WARNING, "Invalid jitterbuffer parameters %s\n", value);
|
|
}
|
|
}
|
|
|
|
ast_jb_create_framehook(chan, &jb_conf, 0);
|
|
|
|
return 0;
|
|
}
|
|
|
|
|
|
static struct ast_custom_function jb_function = {
|
|
.name = "JITTERBUFFER",
|
|
.write = jb_helper,
|
|
};
|
|
|
|
static int unload_module(void)
|
|
{
|
|
return ast_custom_function_unregister(&jb_function);
|
|
}
|
|
|
|
static int load_module(void)
|
|
{
|
|
int res = ast_custom_function_register(&jb_function);
|
|
return res ? AST_MODULE_LOAD_DECLINE : AST_MODULE_LOAD_SUCCESS;
|
|
}
|
|
|
|
AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Jitter buffer for read side of channel.");
|