7b0e3b92fd
This patch is the first cut at adding stream support to the bridging framework. Changes were made to the framework that allows mapping of stream topologies to a bridge's supported media types. The first channel to enter a bridge initially defines the media types for a bridge (i.e. a one to one mapping is created between the bridge and the first channel). Subsequently added channels merge their media types into the bridge's adding to it when necessary. This allows channels with different sized topologies to map correctly to each other according to media type. The bridge drops any frame that does not have a matching index into a given write stream. For now though, bridge_simple will align its two channels according to size or first to join. Once both channels join the bridge the one with the most streams will indicate to the other channel to update its streams to be the same as that of the other. If both channels have the same number of streams then the first channel to join is chosen as the stream base. A topology change source was also added to a channel when a stream toplogy change request is made. This allows subsystems to know whether or not they initiated a change request. Thus avoiding potential recursive situations. ASTERISK-26966 #close Change-Id: I1eb5987921dd80c3cdcf52accc136393ca2d4163
127 lines
3.5 KiB
C
127 lines
3.5 KiB
C
/*
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* Asterisk -- An open source telephony toolkit.
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*
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* Copyright (C) 2007, Digium, Inc.
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*
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* Joshua Colp <jcolp@digium.com>
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*
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* See http://www.asterisk.org for more information about
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* the Asterisk project. Please do not directly contact
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* any of the maintainers of this project for assistance;
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* the project provides a web site, mailing lists and IRC
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* channels for your use.
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*
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* This program is free software, distributed under the terms of
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* the GNU General Public License Version 2. See the LICENSE file
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* at the top of the source tree.
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*/
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/*! \file
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*
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* \brief Simple two channel bridging module
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*
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* \author Joshua Colp <jcolp@digium.com>
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*
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* \ingroup bridges
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*/
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/*** MODULEINFO
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<support_level>core</support_level>
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***/
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#include "asterisk.h"
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <sys/types.h>
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#include <sys/stat.h>
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#include "asterisk/module.h"
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#include "asterisk/channel.h"
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#include "asterisk/bridge.h"
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#include "asterisk/bridge_technology.h"
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#include "asterisk/frame.h"
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#include "asterisk/stream.h"
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static void simple_bridge_stream_topology_changed(struct ast_bridge *bridge,
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struct ast_bridge_channel *bridge_channel);
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static int simple_bridge_join(struct ast_bridge *bridge, struct ast_bridge_channel *bridge_channel)
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{
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struct ast_channel *c0 = AST_LIST_FIRST(&bridge->channels)->chan;
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struct ast_channel *c1 = AST_LIST_LAST(&bridge->channels)->chan;
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/*
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* If this is the first channel we can't make it compatible...
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* unless we make it compatible with itself. O.o
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*/
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if (c0 == c1) {
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return 0;
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}
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if (ast_channel_make_compatible(c0, c1)) {
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return -1;
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}
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/* Align stream topologies */
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simple_bridge_stream_topology_changed(bridge, NULL);
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return 0;
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}
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static int simple_bridge_write(struct ast_bridge *bridge, struct ast_bridge_channel *bridge_channel, struct ast_frame *frame)
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{
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return ast_bridge_queue_everyone_else(bridge, bridge_channel, frame);
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}
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static struct ast_bridge_technology simple_bridge = {
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.name = "simple_bridge",
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.capabilities = AST_BRIDGE_CAPABILITY_1TO1MIX,
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.preference = AST_BRIDGE_PREFERENCE_BASE_1TO1MIX,
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.join = simple_bridge_join,
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.write = simple_bridge_write,
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.stream_topology_changed = simple_bridge_stream_topology_changed,
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};
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static void simple_bridge_stream_topology_changed(struct ast_bridge *bridge,
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struct ast_bridge_channel *bridge_channel)
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{
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struct ast_channel *c0 = AST_LIST_FIRST(&bridge->channels)->chan;
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struct ast_channel *c1 = AST_LIST_LAST(&bridge->channels)->chan;
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struct ast_stream_topology *t0 = ast_channel_get_stream_topology(c0);
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struct ast_stream_topology *t1 = ast_channel_get_stream_topology(c1);
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/*
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* The bridge_channel should only be NULL after both channels join
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* the bridge and their topologies are being aligned.
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*/
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if (bridge_channel && ast_channel_get_stream_topology_change_source(
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bridge_channel->chan) == &simple_bridge) {
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return;
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}
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/* Align topologies according to size or first channel to join */
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if (ast_stream_topology_get_count(t0) < ast_stream_topology_get_count(t1)) {
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ast_channel_request_stream_topology_change(c0, t1, &simple_bridge);
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} else {
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ast_channel_request_stream_topology_change(c1, t0, &simple_bridge);
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}
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}
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static int unload_module(void)
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{
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ast_bridge_technology_unregister(&simple_bridge);
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return 0;
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}
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static int load_module(void)
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{
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if (ast_bridge_technology_register(&simple_bridge)) {
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unload_module();
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return AST_MODULE_LOAD_DECLINE;
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}
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return AST_MODULE_LOAD_SUCCESS;
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}
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AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Simple two channel bridging module");
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