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source: webrtc/webrtc/modules/audio_coding/neteq/cng_internal.c @ 0:4bda6873e34c

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Last change on this file since 0:4bda6873e34c was 0:4bda6873e34c, checked in by Michael Prittie <mprittie@…>, 6 years ago

Scrubbed password for publication.

File size: 5.2 KB
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1/*
2 *  Copyright (c) 2011 The WebRTC project authors. All Rights Reserved.
3 *
4 *  Use of this source code is governed by a BSD-style license
5 *  that can be found in the LICENSE file in the root of the source
6 *  tree. An additional intellectual property rights grant can be found
7 *  in the file PATENTS.  All contributing project authors may
8 *  be found in the AUTHORS file in the root of the source tree.
9 */
10
11/*
12 * This file contains the function for obtaining comfort noise from noise parameters
13 * according to IETF RFC 3389.
14 */
15
16#include "dsp.h"
17
18#include "signal_processing_library.h"
19#include "webrtc_cng.h"
20
21#include "dsp_helpfunctions.h"
22#include "neteq_error_codes.h"
23
24/****************************************************************************
25 * WebRtcNetEQ_Cng(...)
26 *
27 * This function produces CNG according to RFC 3389.
28 *
29 * Input:
30 *      - inst          : NetEQ DSP instance
31 *      - len           : Number of samples to produce (max 640 or
32 *                        640 - fsHz*5/8000 for first-time CNG, governed by
33 *                        the definition of WEBRTC_CNG_MAX_OUTSIZE_ORDER in
34 *                        webrtc_cng.h)
35 *
36 * Output:
37 *      - pw16_outData  : Output CNG
38 *
39 * Return value         :  0 - Ok
40 *                        <0 - Error
41 */
42
43#ifdef NETEQ_CNG_CODEC
44/* Must compile NetEQ with CNG support to enable this function */
45
46int WebRtcNetEQ_Cng(DSPInst_t *inst, int16_t *pw16_outData, int len)
47{
48    int16_t w16_winMute = 0; /* mixing factor for overlap data */
49    int16_t w16_winUnMute = 0; /* mixing factor for comfort noise */
50    int16_t w16_winMuteInc = 0; /* mixing factor increment (negative) */
51    int16_t w16_winUnMuteInc = 0; /* mixing factor increment */
52    int i;
53
54    /*
55     * Check if last RecOut call was other than RFC3389,
56     * that is, this call is the first of a CNG period.
57     */
58    if (inst->w16_mode != MODE_RFC3389CNG)
59    {
60        /* Reset generation and overlap slightly with old data */
61
62        /* Generate len samples + overlap */
63        if (WebRtcCng_Generate(inst->CNG_Codec_inst, pw16_outData,
64            (int16_t) (len + inst->ExpandInst.w16_overlap), 1) < 0)
65        {
66            /* error returned */
67            return -WebRtcCng_GetErrorCodeDec(inst->CNG_Codec_inst);
68        }
69
70        /* Set windowing parameters depending on sample rate */
71        if (inst->fs == 8000)
72        {
73            /* Windowing in Q15 */
74            w16_winMute = NETEQ_OVERLAP_WINMUTE_8KHZ_START;
75            w16_winMuteInc = NETEQ_OVERLAP_WINMUTE_8KHZ_INC;
76            w16_winUnMute = NETEQ_OVERLAP_WINUNMUTE_8KHZ_START;
77            w16_winUnMuteInc = NETEQ_OVERLAP_WINUNMUTE_8KHZ_INC;
78#ifdef NETEQ_WIDEBAND
79        }
80        else if (inst->fs == 16000)
81        {
82            /* Windowing in Q15 */
83            w16_winMute = NETEQ_OVERLAP_WINMUTE_16KHZ_START;
84            w16_winMuteInc = NETEQ_OVERLAP_WINMUTE_16KHZ_INC;
85            w16_winUnMute = NETEQ_OVERLAP_WINUNMUTE_16KHZ_START;
86            w16_winUnMuteInc = NETEQ_OVERLAP_WINUNMUTE_16KHZ_INC;
87#endif
88#ifdef NETEQ_32KHZ_WIDEBAND
89        }
90        else if (inst->fs == 32000)
91        {
92            /* Windowing in Q15 */
93            w16_winMute = NETEQ_OVERLAP_WINMUTE_32KHZ_START;
94            w16_winMuteInc = NETEQ_OVERLAP_WINMUTE_32KHZ_INC;
95            w16_winUnMute = NETEQ_OVERLAP_WINUNMUTE_32KHZ_START;
96            w16_winUnMuteInc = NETEQ_OVERLAP_WINUNMUTE_32KHZ_INC;
97#endif
98#ifdef NETEQ_48KHZ_WIDEBAND
99        }
100        else if (inst->fs == 48000)
101        {
102            /* Windowing in Q15 */
103            w16_winMute = NETEQ_OVERLAP_WINMUTE_48KHZ_START;
104            w16_winMuteInc = NETEQ_OVERLAP_WINMUTE_48KHZ_INC;
105            w16_winUnMute = NETEQ_OVERLAP_WINUNMUTE_48KHZ_START;
106            w16_winUnMuteInc = NETEQ_OVERLAP_WINUNMUTE_48KHZ_INC;
107#endif
108        }
109        else
110        {
111            /* Unsupported sample rate (should not be possible) */
112            return NETEQ_OTHER_ERROR;
113        }
114
115        /* Do overlap add between new vector and overlap */
116        for (i = 0; i < inst->ExpandInst.w16_overlap; i++)
117        {
118            /* overlapVec[i] = WinMute * overlapVec[i] + WinUnMute * outData[i] */
119            inst->ExpandInst.pw16_overlapVec[i] = (int16_t) WEBRTC_SPL_RSHIFT_W32(
120                WEBRTC_SPL_MUL_16_16(
121                    inst->ExpandInst.pw16_overlapVec[i], w16_winMute) +
122                WEBRTC_SPL_MUL_16_16(pw16_outData[i], w16_winUnMute)
123                + 16384, 15); /* shift with proper rounding */
124
125            w16_winMute += w16_winMuteInc; /* decrease mute factor (inc<0) */
126            w16_winUnMute += w16_winUnMuteInc; /* increase unmute factor (inc>0) */
127
128        }
129
130        /*
131         * Shift the contents of the outData buffer by overlap samples, since we
132         * already used these first samples in the overlapVec above
133         */
134
135        WEBRTC_SPL_MEMMOVE_W16(pw16_outData, pw16_outData+inst->ExpandInst.w16_overlap, len);
136
137    }
138    else
139    {
140        /* This is a subsequent CNG call; no special overlap needed */
141
142        /* Generate len samples */
143        if (WebRtcCng_Generate(inst->CNG_Codec_inst, pw16_outData, (int16_t) len, 0) < 0)
144        {
145            /* error returned */
146            return -WebRtcCng_GetErrorCodeDec(inst->CNG_Codec_inst);
147        }
148    }
149
150    return 0;
151
152}
153
154#endif /* NETEQ_CNG_CODEC */
155
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