Wed Apr 6 11:29:40 2011

Asterisk developer's documentation


bridge_simple.c

Go to the documentation of this file.
00001 /*
00002  * Asterisk -- An open source telephony toolkit.
00003  *
00004  * Copyright (C) 2007, Digium, Inc.
00005  *
00006  * Joshua Colp <jcolp@digium.com>
00007  *
00008  * See http://www.asterisk.org for more information about
00009  * the Asterisk project. Please do not directly contact
00010  * any of the maintainers of this project for assistance;
00011  * the project provides a web site, mailing lists and IRC
00012  * channels for your use.
00013  *
00014  * This program is free software, distributed under the terms of
00015  * the GNU General Public License Version 2. See the LICENSE file
00016  * at the top of the source tree.
00017  */
00018 
00019 /*! \file
00020  *
00021  * \brief Simple two channel bridging module
00022  *
00023  * \author Joshua Colp <jcolp@digium.com>
00024  *
00025  * \ingroup bridges
00026  */
00027 
00028 #include "asterisk.h"
00029 
00030 ASTERISK_FILE_VERSION(__FILE__, "$Revision: 180369 $")
00031 
00032 #include <stdio.h>
00033 #include <stdlib.h>
00034 #include <string.h>
00035 #include <sys/types.h>
00036 #include <sys/stat.h>
00037 
00038 #include "asterisk/module.h"
00039 #include "asterisk/channel.h"
00040 #include "asterisk/bridging.h"
00041 #include "asterisk/bridging_technology.h"
00042 #include "asterisk/frame.h"
00043 
00044 static int simple_bridge_join(struct ast_bridge *bridge, struct ast_bridge_channel *bridge_channel)
00045 {
00046    struct ast_channel *c0 = AST_LIST_FIRST(&bridge->channels)->chan, *c1 = AST_LIST_LAST(&bridge->channels)->chan;
00047 
00048    /* If this is the first channel we can't make it compatible... unless we make it compatible with itself O.o */
00049    if (AST_LIST_FIRST(&bridge->channels) == AST_LIST_LAST(&bridge->channels)) {
00050       return 0;
00051    }
00052 
00053    /* See if we need to make these compatible */
00054    if (((c0->writeformat == c1->readformat) && (c0->readformat == c1->writeformat) && (c0->nativeformats == c1->nativeformats))) {
00055       return 0;
00056    }
00057 
00058    /* BOOM! We do. */
00059    return ast_channel_make_compatible(c0, c1);
00060 }
00061 
00062 static enum ast_bridge_write_result simple_bridge_write(struct ast_bridge *bridge, struct ast_bridge_channel *bridge_channel, struct ast_frame *frame)
00063 {
00064    struct ast_bridge_channel *other = NULL;
00065 
00066    /* If this is the only channel in this bridge then immediately exit */
00067    if (AST_LIST_FIRST(&bridge->channels) == AST_LIST_LAST(&bridge->channels)) {
00068       return AST_BRIDGE_WRITE_FAILED;
00069    }
00070 
00071    /* Find the channel we actually want to write to */
00072    if (!(other = (AST_LIST_FIRST(&bridge->channels) == bridge_channel ? AST_LIST_LAST(&bridge->channels) : AST_LIST_FIRST(&bridge->channels)))) {
00073       return AST_BRIDGE_WRITE_FAILED;
00074    }
00075 
00076    /* Write the frame out if they are in the waiting state... don't worry about freeing it, the bridging core will take care of it */
00077    if (other->state == AST_BRIDGE_CHANNEL_STATE_WAIT) {
00078       ast_write(other->chan, frame);
00079    }
00080 
00081    return AST_BRIDGE_WRITE_SUCCESS;
00082 }
00083 
00084 static struct ast_bridge_technology simple_bridge = {
00085    .name = "simple_bridge",
00086    .capabilities = AST_BRIDGE_CAPABILITY_1TO1MIX | AST_BRIDGE_CAPABILITY_THREAD,
00087    .preference = AST_BRIDGE_PREFERENCE_MEDIUM,
00088    .formats = AST_FORMAT_AUDIO_MASK | AST_FORMAT_VIDEO_MASK | AST_FORMAT_TEXT_MASK,
00089    .join = simple_bridge_join,
00090    .write = simple_bridge_write,
00091 };
00092 
00093 static int unload_module(void)
00094 {
00095    return ast_bridge_technology_unregister(&simple_bridge);
00096 }
00097 
00098 static int load_module(void)
00099 {
00100    return ast_bridge_technology_register(&simple_bridge);
00101 }
00102 
00103 AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Simple two channel bridging module");

Generated on Wed Apr 6 11:29:40 2011 for Asterisk - The Open Source Telephony Project by  doxygen 1.4.7