webrtc/modules/audio_coding/neteq/mute_signal.c

/*
 *  Copyright (c) 2011 The WebRTC project authors. All Rights Reserved.
 *
 *  Use of this source code is governed by a BSD-style license
 *  that can be found in the LICENSE file in the root of the source
 *  tree. An additional intellectual property rights grant can be found
 *  in the file PATENTS.  All contributing project authors may
 *  be found in the AUTHORS file in the root of the source tree.
 */

/*
 * This function mutes a signal linearly on a sample by sample basis.
 */

#include "dsp_helpfunctions.h"

#include "signal_processing_library.h"

void WebRtcNetEQ_MuteSignal(WebRtc_Word16 *pw16_inout, WebRtc_Word16 muteSlope,
                            WebRtc_Word16 N)
{
    int i;
    WebRtc_Word32 w32_tmp = 1048608; /* (16384<<6 + 32) */

    for (i = 0; i < N; i++)
    {
        pw16_inout[i]
            = (WebRtc_Word16) ((WEBRTC_SPL_MUL_16_16((WebRtc_Word16)(w32_tmp>>6), pw16_inout[i])
                + 8192) >> 14);
        w32_tmp -= muteSlope;
    }
}