app_milliwatt.c

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/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 1999 - 2005, Digium, Inc.
 *
 * Mark Spencer <markster@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 Digital Milliwatt Test
 *
 * \author Mark Spencer <markster@digium.com>
 *
 * \ingroup applications
 */
 
/*** MODULEINFO
    <support_level>core</support_level>
 ***/
 
#include "asterisk.h"
 
#include "asterisk/module.h"
#include "asterisk/channel.h"
#include "asterisk/pbx.h"
#include "asterisk/indications.h"
#include "asterisk/format_cache.h"
 
/*** DOCUMENTATION
    <application name="Milliwatt" language="en_US">
        <synopsis>
            Generates a 1004 Hz test tone at 0dbm (mu-law).
        </synopsis>
        <syntax>
            <parameter name="options">
                <optionlist>
                    <option name="m">
                        <para>Generate a 1004 Hz Milliwatt test tone at 0dbm, with a
                        1 second silent interval. This option must be specified
                        if you are using this for a milliwatt test line.</para>
                    </option>
                    <option name="o">
                        <para>Generate a constant tone at 1000 Hz like previous version.</para>
                    </option>
                </optionlist>
            </parameter>
        </syntax>
        <description>
            <para>Generates a 1004 Hz test tone.</para>
            <para>By default, this application does not provide a Milliwatt test tone. It simply
            plays a 1004 Hz tone, which is not suitable for performing a milliwatt test.
            The <literal>m</literal> option should be used so that a real Milliwatt test tone
            is provided. This will include a 1 second silent interval every 10 seconds.</para>
            <para>Previous versions of this application generated a constant tone at 1000 Hz. If for
            some reason you would prefer that behavior, supply the <literal>o</literal> option to get the
            old behavior.</para>
        </description>
    </application>
 ***/
 
static const char app[] = "Milliwatt";
 
static const char digital_milliwatt[] = {0x1e,0x0b,0x0b,0x1e,0x9e,0x8b,0x8b,0x9e} ;
 
static void *milliwatt_alloc(struct ast_channel *chan, void *params)
{
    return ast_calloc(1, sizeof(int));
}
 
static void milliwatt_release(struct ast_channel *chan, void *data)
{
    ast_free(data);
    return;
}
 
static int milliwatt_generate(struct ast_channel *chan, void *data, int len, int samples)
{
    unsigned char buf[AST_FRIENDLY_OFFSET + 640];
    const int maxsamples = ARRAY_LEN(buf) - (AST_FRIENDLY_OFFSET / sizeof(buf[0]));
    int i, *indexp = (int *) data, res;
    struct ast_frame wf = {
        .frametype = AST_FRAME_VOICE,
        .offset = AST_FRIENDLY_OFFSET,
        .src = __FUNCTION__,
    };
 
    wf.subclass.format = ast_format_ulaw;
    wf.data.ptr = buf + AST_FRIENDLY_OFFSET;
 
    /* Instead of len, use samples, because channel.c generator_force
    * generate(chan, tmp, 0, 160) ignores len. In any case, len is
    * a multiple of samples, given by number of samples times bytes per
    * sample. In the case of ulaw, len = samples. for signed linear
    * len = 2 * samples */
    if (samples > maxsamples) {
        ast_log(LOG_WARNING, "Only doing %d samples (%d requested)\n", maxsamples, samples);
        samples = maxsamples;
    }
 
    len = samples * sizeof (buf[0]);
    wf.datalen = len;
    wf.samples = samples;
 
    /* create a buffer containing the digital milliwatt pattern */
    for (i = 0; i < len; i++) {
        buf[AST_FRIENDLY_OFFSET + i] = digital_milliwatt[(*indexp)++];
        *indexp &= 7;
    }
 
    res = ast_write(chan, &wf);
    ast_frfree(&wf);
 
    if (res < 0) {
        ast_log(LOG_WARNING,"Failed to write frame to '%s': %s\n",ast_channel_name(chan),strerror(errno));
        return -1;
    }
 
    return 0;
}
 
static struct ast_generator milliwattgen = {
    .alloc = milliwatt_alloc,
    .release = milliwatt_release,
    .generate = milliwatt_generate,
};
 
static int old_milliwatt_exec(struct ast_channel *chan)
{
    ast_set_write_format(chan, ast_format_ulaw);
    ast_set_read_format(chan, ast_format_ulaw);
 
    if (ast_channel_state(chan) != AST_STATE_UP) {
        ast_answer(chan);
    }
 
    if (ast_activate_generator(chan,&milliwattgen,"milliwatt") < 0) {
        ast_log(LOG_WARNING,"Failed to activate generator on '%s'\n",ast_channel_name(chan));
        return -1;
    }
 
    while (!ast_safe_sleep(chan, 10000))
        ;
 
    ast_deactivate_generator(chan);
 
    return -1;
}
 
static int milliwatt_exec(struct ast_channel *chan, const char *data)
{
    const char *options = data;
    int res = -1;
 
    if (!ast_strlen_zero(options) && strchr(options, 'o')) {
        return old_milliwatt_exec(chan);
    }
    if (!ast_strlen_zero(options) && strchr(options, 'm')) {
        res = ast_playtones_start(chan, 23255, "1004/9000,0/1000", 0);
    } else {
        res = ast_playtones_start(chan, 23255, "1004/1000", 0);
    }
 
    while (!res) {
        res = ast_safe_sleep(chan, 10000);
    }
 
    return res;
}
 
static int unload_module(void)
{
    return ast_unregister_application(app);
}
 
static int load_module(void)
{
    return ast_register_application_xml(app, milliwatt_exec);
}
 
AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Digital Milliwatt (mu-law) Test Application");