app_voicechanger.c

/*
 * Voice Changer for Asterisk 1.6+
 * Copyright (C) 2005-2012 Justine Tunney
 *
 * Justine Tunney <jtunney@lobstertech.com>
 *
 * This program is free software, distributed under the terms of the GNU
 * General Public License version 2.0 or later.
 *
 */

#define AST_MODULE "app_voicechanger"

#include <asterisk.h>
#include <asterisk/file.h>
#include <asterisk/logger.h>
#include <asterisk/channel.h>
#include <asterisk/audiohook.h>
#include <asterisk/pbx.h>
#include <asterisk/module.h>
#include <asterisk/lock.h>
#include <asterisk/cli.h>
#include <asterisk/options.h>
#include <asterisk/app.h>
#include <asterisk/linkedlists.h>
#include <asterisk/utils.h>

#include "voicechanger.h"

struct voicechanger {
    void *st8k;
    void *st16k;
    struct ast_audiohook ah[1];
};

static const char *app = "VoiceChanger";
static const char *synopsis = "Adjusts the pitch of your voice";
static const char *desc = ""
    "  VoiceChanger(<pitch>)\n\n"
    "Specify a pitch in semitones.  Like -5 for deeper and 5 for higher.\n"
    "";

static const char *stop_app = "StopVoiceChanger";
static const char *stop_synopsis = "Removes voice changer";
static const char *stop_desc = ""
    "  StopVoiceChanger()\n\n"
    "Removes the voice change effect from a channel, if there is any.\n"
    "";

static struct ast_datastore_info dsinfo[1];

static int audio_callback(struct ast_audiohook *audiohook,
                          struct ast_channel *chan,
                          struct ast_frame *frame,
                          enum ast_audiohook_direction direction)
{
    struct ast_datastore *ds;
    struct voicechanger *vc;
    void *st;

    if (!audiohook || !chan || !frame ||
        direction != AST_AUDIOHOOK_DIRECTION_READ) {
        return 0;
    }

    ast_channel_lock(chan);
    if (!(ds = ast_channel_datastore_find(chan, dsinfo, app)) ||
        !(vc = (struct voicechanger *)ds->data) ||
        !vc->st8k || !vc->st16k) {
        ast_channel_unlock(chan);
        ast_log(LOG_WARNING, "where my data at\n");
        return 0;
    }
    ast_channel_unlock(chan);

    if (frame->data.ptr == NULL || frame->samples == 0 ||
        frame->frametype != AST_FRAME_VOICE) {
        ast_log(LOG_WARNING, "got incompatible frame\n");
        return 0;
    }

    switch (frame->subclass.format.id) {
    case AST_FORMAT_SLINEAR:
        st = vc->st8k;
        break;
    case AST_FORMAT_SLINEAR16:
        st = vc->st16k;
        break;
    default:
        ast_log(LOG_WARNING, "only 8khz and 16khz slinear audio supported!\n");
        return 0;
    }

    float fbuf[frame->samples];
    vc_voice_change(st, fbuf, (int16_t *)frame->data.ptr,
                    frame->samples, frame->datalen);

    return 0;
}

static void voicechanger_free(void *data)
{
    struct voicechanger *vc;
    if (data) {
        vc = (struct voicechanger *)data;
        vc_soundtouch_free(vc->st8k); vc->st8k = NULL;
        vc_soundtouch_free(vc->st16k); vc->st16k = NULL;
        ast_audiohook_detach(vc->ah);
        ast_audiohook_destroy(vc->ah);
        ast_free(data);
    }
    ast_log(LOG_DEBUG, "freed voice changer resources\n");
}

static int install_vc(struct ast_channel *chan, float pitch)
{
    struct ast_datastore *ds;
    struct voicechanger *vc;

    ast_log(LOG_DEBUG, "pitch is %f\n", pitch);
    if (-0.1 < pitch && pitch < 0.1) {
        return 0;
    }

    /* create soundtouch object */
    vc = ast_calloc(1, sizeof(struct voicechanger));
    if (!(vc->st8k = vc_soundtouch_create(8000, pitch)) ||
        !(vc->st16k = vc_soundtouch_create(16000, pitch))) {
        ast_log(LOG_ERROR, "failed to make soundtouch\n");
        return -1;
    }

    /* create audiohook */
    ast_log(LOG_DEBUG, "Creating AudioHook object...\n");
    if (ast_audiohook_init(vc->ah, AST_AUDIOHOOK_TYPE_MANIPULATE,
                           "VoiceChanger", 0)) {
        voicechanger_free(vc);
        ast_log(LOG_WARNING, "failed to make audiohook\n");
        return -1;
    }

    ast_audiohook_lock(vc->ah);
    vc->ah->manipulate_callback = audio_callback;
    ast_set_flag(vc->ah, AST_AUDIOHOOK_WANTS_DTMF);
    ast_audiohook_unlock(vc->ah);

    /* glue audiohook to channel */
    if (ast_audiohook_attach(chan, vc->ah) == -1) {
        voicechanger_free(vc);
        ast_log(LOG_WARNING, "failed to attach hook\n");
        return -1;
    }

    /* glue our data thing to channel */
    ds = ast_datastore_alloc(dsinfo, app);
    ds->data = vc;
    ast_channel_lock(chan);
    ast_channel_datastore_add(chan, ds);
    ast_channel_unlock(chan);

    return 0;
}

static int voicechanger_exec(struct ast_channel *chan, const char *data)
{
    int rc;
    struct ast_module_user *u;
    float pitch;
    if (ast_strlen_zero(data)) {
        ast_log(LOG_WARNING, "voicechanger() missing argument\n");
        return -1;
    }
    pitch = strtof(data, NULL);
    u = ast_module_user_add(chan);
    rc = install_vc(chan, pitch);
    ast_module_user_remove(u);
    return rc;
}

static int uninstall_vc(struct ast_channel *chan)
{
    struct ast_datastore *ds;
    ast_log(LOG_DEBUG, "Detaching Voice Changer from channel...\n");
    ast_channel_lock(chan);
    ds = ast_channel_datastore_find(chan, dsinfo, app);
    if (ds) {
        ast_channel_datastore_remove(chan, ds);
        ast_datastore_free(ds);
    }
    ast_channel_unlock(chan);
    return 0;
}

static int stop_voicechanger_exec(struct ast_channel *chan, const char *data)
{
    int rc;
    struct ast_module_user *u;
    u = ast_module_user_add(chan);
    rc = uninstall_vc(chan);
    ast_module_user_remove(u);
    return rc;
}

static int unload_module(void)
{
    int res;
    res  = ast_unregister_application(app);
    res |= ast_unregister_application(stop_app);
    ast_module_user_hangup_all();
    return res;
}

static int load_module(void)
{
    int res;
    dsinfo->type = app;
    dsinfo->destroy = voicechanger_free;
    res = ast_register_application(
        app, voicechanger_exec, synopsis, desc);
    res |= ast_register_application(
        stop_app, stop_voicechanger_exec, stop_synopsis, stop_desc);
    return res;
}

AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Voice Changer");

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