156 lines
5.2 KiB
C
156 lines
5.2 KiB
C
/*
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* Copyright (c) 2011 The WebRTC project authors. All Rights Reserved.
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*
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* Use of this source code is governed by a BSD-style license
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* that can be found in the LICENSE file in the root of the source
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* tree. An additional intellectual property rights grant can be found
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* in the file PATENTS. All contributing project authors may
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* be found in the AUTHORS file in the root of the source tree.
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*/
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/*
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* This file contains the function for obtaining comfort noise from noise parameters
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* according to IETF RFC 3389.
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*/
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#include "dsp.h"
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#include "signal_processing_library.h"
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#include "webrtc_cng.h"
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#include "dsp_helpfunctions.h"
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#include "neteq_error_codes.h"
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/****************************************************************************
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* WebRtcNetEQ_Cng(...)
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*
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* This function produces CNG according to RFC 3389.
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*
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* Input:
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* - inst : NetEQ DSP instance
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* - len : Number of samples to produce (max 640 or
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* 640 - fsHz*5/8000 for first-time CNG, governed by
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* the definition of WEBRTC_CNG_MAX_OUTSIZE_ORDER in
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* webrtc_cng.h)
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*
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* Output:
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* - pw16_outData : Output CNG
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*
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* Return value : 0 - Ok
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* <0 - Error
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*/
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#ifdef NETEQ_CNG_CODEC
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/* Must compile NetEQ with CNG support to enable this function */
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int WebRtcNetEQ_Cng(DSPInst_t *inst, WebRtc_Word16 *pw16_outData, int len)
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{
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WebRtc_Word16 w16_winMute = 0; /* mixing factor for overlap data */
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WebRtc_Word16 w16_winUnMute = 0; /* mixing factor for comfort noise */
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WebRtc_Word16 w16_winMuteInc = 0; /* mixing factor increment (negative) */
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WebRtc_Word16 w16_winUnMuteInc = 0; /* mixing factor increment */
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int i;
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/*
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* Check if last RecOut call was other than RFC3389,
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* that is, this call is the first of a CNG period.
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*/
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if (inst->w16_mode != MODE_RFC3389CNG)
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{
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/* Reset generation and overlap slightly with old data */
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/* Generate len samples + overlap */
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if (WebRtcCng_Generate(inst->CNG_Codec_inst, pw16_outData,
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(WebRtc_Word16) (len + inst->ExpandInst.w16_overlap), 1) < 0)
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{
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/* error returned */
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return -WebRtcCng_GetErrorCodeDec(inst->CNG_Codec_inst);
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}
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/* Set windowing parameters depending on sample rate */
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if (inst->fs == 8000)
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{
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/* Windowing in Q15 */
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w16_winMute = NETEQ_OVERLAP_WINMUTE_8KHZ_START;
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w16_winMuteInc = NETEQ_OVERLAP_WINMUTE_8KHZ_INC;
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w16_winUnMute = NETEQ_OVERLAP_WINUNMUTE_8KHZ_START;
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w16_winUnMuteInc = NETEQ_OVERLAP_WINUNMUTE_8KHZ_INC;
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#ifdef NETEQ_WIDEBAND
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}
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else if (inst->fs == 16000)
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{
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/* Windowing in Q15 */
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w16_winMute = NETEQ_OVERLAP_WINMUTE_16KHZ_START;
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w16_winMuteInc = NETEQ_OVERLAP_WINMUTE_16KHZ_INC;
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w16_winUnMute = NETEQ_OVERLAP_WINUNMUTE_16KHZ_START;
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w16_winUnMuteInc = NETEQ_OVERLAP_WINUNMUTE_16KHZ_INC;
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#endif
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#ifdef NETEQ_32KHZ_WIDEBAND
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}
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else if (inst->fs == 32000)
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{
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/* Windowing in Q15 */
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w16_winMute = NETEQ_OVERLAP_WINMUTE_32KHZ_START;
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w16_winMuteInc = NETEQ_OVERLAP_WINMUTE_32KHZ_INC;
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w16_winUnMute = NETEQ_OVERLAP_WINUNMUTE_32KHZ_START;
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w16_winUnMuteInc = NETEQ_OVERLAP_WINUNMUTE_32KHZ_INC;
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#endif
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#ifdef NETEQ_48KHZ_WIDEBAND
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}
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else if (inst->fs == 48000)
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{
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/* Windowing in Q15 */
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w16_winMute = NETEQ_OVERLAP_WINMUTE_48KHZ_START;
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w16_winMuteInc = NETEQ_OVERLAP_WINMUTE_48KHZ_INC;
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w16_winUnMute = NETEQ_OVERLAP_WINUNMUTE_48KHZ_START;
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w16_winUnMuteInc = NETEQ_OVERLAP_WINUNMUTE_48KHZ_INC;
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#endif
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}
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else
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{
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/* Unsupported sample rate (should not be possible) */
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return NETEQ_OTHER_ERROR;
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}
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/* Do overlap add between new vector and overlap */
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for (i = 0; i < inst->ExpandInst.w16_overlap; i++)
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{
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/* overlapVec[i] = WinMute * overlapVec[i] + WinUnMute * outData[i] */
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inst->ExpandInst.pw16_overlapVec[i] = (WebRtc_Word16) WEBRTC_SPL_RSHIFT_W32(
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WEBRTC_SPL_MUL_16_16(
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inst->ExpandInst.pw16_overlapVec[i], w16_winMute) +
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WEBRTC_SPL_MUL_16_16(pw16_outData[i], w16_winUnMute)
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+ 16384, 15); /* shift with proper rounding */
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w16_winMute += w16_winMuteInc; /* decrease mute factor (inc<0) */
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w16_winUnMute += w16_winUnMuteInc; /* increase unmute factor (inc>0) */
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}
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/*
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* Shift the contents of the outData buffer by overlap samples, since we
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* already used these first samples in the overlapVec above
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*/
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WEBRTC_SPL_MEMMOVE_W16(pw16_outData, pw16_outData+inst->ExpandInst.w16_overlap, len);
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}
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else
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{
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/* This is a subsequent CNG call; no special overlap needed */
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/* Generate len samples */
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if (WebRtcCng_Generate(inst->CNG_Codec_inst, pw16_outData, (WebRtc_Word16) len, 0) < 0)
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{
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/* error returned */
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return -WebRtcCng_GetErrorCodeDec(inst->CNG_Codec_inst);
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}
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}
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return 0;
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}
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#endif /* NETEQ_CNG_CODEC */
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