Thu Sep 7 01:02:50 2017

Asterisk developer's documentation


app_milliwatt.c

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00001 /*
00002  * Asterisk -- An open source telephony toolkit.
00003  *
00004  * Copyright (C) 1999 - 2005, Digium, Inc.
00005  *
00006  * Mark Spencer <markster@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 Digital Milliwatt Test
00022  *
00023  * \author Mark Spencer <markster@digium.com>
00024  * 
00025  * \ingroup applications
00026  */
00027 
00028 /*** MODULEINFO
00029    <support_level>core</support_level>
00030  ***/
00031 
00032 #include "asterisk.h"
00033 
00034 ASTERISK_FILE_VERSION(__FILE__, "$Revision: 361142 $")
00035 
00036 #include "asterisk/module.h"
00037 #include "asterisk/channel.h"
00038 #include "asterisk/pbx.h"
00039 #include "asterisk/indications.h"
00040 
00041 /*** DOCUMENTATION
00042    <application name="Milliwatt" language="en_US">
00043       <synopsis>
00044          Generate a Constant 1004Hz tone at 0dbm (mu-law).
00045       </synopsis>
00046       <syntax>
00047          <parameter name="options">
00048             <optionlist>
00049                <option name="o">
00050                   <para>Generate the tone at 1000Hz like previous version.</para>
00051                </option>
00052             </optionlist>
00053          </parameter>
00054       </syntax>
00055       <description>
00056          <para>Previous versions of this application generated the tone at 1000Hz.  If for
00057          some reason you would prefer that behavior, supply the <literal>o</literal> option to get the
00058          old behavior.</para>
00059       </description>
00060    </application>
00061  ***/
00062 
00063 static const char app[] = "Milliwatt";
00064 
00065 static const char digital_milliwatt[] = {0x1e,0x0b,0x0b,0x1e,0x9e,0x8b,0x8b,0x9e} ;
00066 
00067 static void *milliwatt_alloc(struct ast_channel *chan, void *params)
00068 {
00069    return ast_calloc(1, sizeof(int));
00070 }
00071 
00072 static void milliwatt_release(struct ast_channel *chan, void *data)
00073 {
00074    ast_free(data);
00075    return;
00076 }
00077 
00078 static int milliwatt_generate(struct ast_channel *chan, void *data, int len, int samples)
00079 {
00080    unsigned char buf[AST_FRIENDLY_OFFSET + 640];
00081    const int maxsamples = ARRAY_LEN(buf) - (AST_FRIENDLY_OFFSET / sizeof(buf[0]));
00082    int i, *indexp = (int *) data;
00083    struct ast_frame wf = {
00084       .frametype = AST_FRAME_VOICE,
00085       .subclass.codec = AST_FORMAT_ULAW,
00086       .offset = AST_FRIENDLY_OFFSET,
00087       .src = __FUNCTION__,
00088    };
00089    wf.data.ptr = buf + AST_FRIENDLY_OFFSET;
00090 
00091    /* Instead of len, use samples, because channel.c generator_force
00092    * generate(chan, tmp, 0, 160) ignores len. In any case, len is
00093    * a multiple of samples, given by number of samples times bytes per
00094    * sample. In the case of ulaw, len = samples. for signed linear
00095    * len = 2 * samples */
00096    if (samples > maxsamples) {
00097       ast_log(LOG_WARNING, "Only doing %d samples (%d requested)\n", maxsamples, samples);
00098       samples = maxsamples;
00099    }
00100 
00101    len = samples * sizeof (buf[0]);
00102    wf.datalen = len;
00103    wf.samples = samples;
00104 
00105    /* create a buffer containing the digital milliwatt pattern */
00106    for (i = 0; i < len; i++) {
00107       buf[AST_FRIENDLY_OFFSET + i] = digital_milliwatt[(*indexp)++];
00108       *indexp &= 7;
00109    }
00110 
00111    if (ast_write(chan,&wf) < 0) {
00112       ast_log(LOG_WARNING,"Failed to write frame to '%s': %s\n",chan->name,strerror(errno));
00113       return -1;
00114    }
00115 
00116    return 0;
00117 }
00118 
00119 static struct ast_generator milliwattgen = {
00120    .alloc = milliwatt_alloc,
00121    .release = milliwatt_release,
00122    .generate = milliwatt_generate,
00123 };
00124 
00125 static int old_milliwatt_exec(struct ast_channel *chan)
00126 {
00127    ast_set_write_format(chan, AST_FORMAT_ULAW);
00128    ast_set_read_format(chan, AST_FORMAT_ULAW);
00129 
00130    if (chan->_state != AST_STATE_UP) {
00131       ast_answer(chan);
00132    }
00133 
00134    if (ast_activate_generator(chan,&milliwattgen,"milliwatt") < 0) {
00135       ast_log(LOG_WARNING,"Failed to activate generator on '%s'\n",chan->name);
00136       return -1;
00137    }
00138 
00139    while (!ast_safe_sleep(chan, 10000))
00140       ;
00141 
00142    ast_deactivate_generator(chan);
00143 
00144    return -1;
00145 }
00146 
00147 static int milliwatt_exec(struct ast_channel *chan, const char *data)
00148 {
00149    const char *options = data;
00150    int res = -1;
00151 
00152    if (!ast_strlen_zero(options) && strchr(options, 'o')) {
00153       return old_milliwatt_exec(chan);
00154    }
00155 
00156    res = ast_playtones_start(chan, 23255, "1004/1000", 0);
00157 
00158    while (!res) {
00159       res = ast_safe_sleep(chan, 10000);
00160    }
00161 
00162    return res;
00163 }
00164 
00165 static int unload_module(void)
00166 {
00167    return ast_unregister_application(app);
00168 }
00169 
00170 static int load_module(void)
00171 {
00172    return ast_register_application_xml(app, milliwatt_exec);
00173 }
00174 
00175 AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Digital Milliwatt (mu-law) Test Application");

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