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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 #ifndef WEBRTC_MODULES_AUDIO_PROCESSING_AGC_LEGACY_ANALOG_AGC_H_
12 #define WEBRTC_MODULES_AUDIO_PROCESSING_AGC_LEGACY_ANALOG_AGC_H_
13 
14 //#define MIC_LEVEL_FEEDBACK
15 #ifdef WEBRTC_AGC_DEBUG_DUMP
16 #include <stdio.h>
17 #endif
18 
19 #include "webrtc/modules/audio_processing/agc/legacy/digital_agc.h"
20 #include "webrtc/modules/audio_processing/agc/legacy/gain_control.h"
21 #include "webrtc/typedefs.h"
22 
23 /* Analog Automatic Gain Control variables:
24  * Constant declarations (inner limits inside which no changes are done)
25  * In the beginning the range is narrower to widen as soon as the measure
26  * 'Rxx160_LP' is inside it. Currently the starting limits are -22.2+/-1dBm0
27  * and the final limits -22.2+/-2.5dBm0. These levels makes the speech signal
28  * go towards -25.4dBm0 (-31.4dBov). Tuned with wbfile-31.4dBov.pcm
29  * The limits are created by running the AGC with a file having the desired
30  * signal level and thereafter plotting Rxx160_LP in the dBm0-domain defined
31  * by out=10*log10(in/260537279.7); Set the target level to the average level
32  * of our measure Rxx160_LP. Remember that the levels are in blocks of 16 in
33  * Q(-7). (Example matlab code: round(db2pow(-21.2)*16/2^7) )
34  */
35 #define RXX_BUFFER_LEN  10
36 
37 static const int16_t kMsecSpeechInner = 520;
38 static const int16_t kMsecSpeechOuter = 340;
39 
40 static const int16_t kNormalVadThreshold = 400;
41 
42 static const int16_t kAlphaShortTerm = 6; // 1 >> 6 = 0.0156
43 static const int16_t kAlphaLongTerm = 10; // 1 >> 10 = 0.000977
44 
45 typedef struct
46 {
47     // Configurable parameters/variables
48     uint32_t            fs;                 // Sampling frequency
49     int16_t             compressionGaindB;  // Fixed gain level in dB
50     int16_t             targetLevelDbfs;    // Target level in -dBfs of envelope (default -3)
51     int16_t             agcMode;            // Hard coded mode (adaptAna/adaptDig/fixedDig)
52     uint8_t             limiterEnable;      // Enabling limiter (on/off (default off))
53     WebRtcAgcConfig defaultConfig;
54     WebRtcAgcConfig usedConfig;
55 
56     // General variables
57     int16_t             initFlag;
58     int16_t             lastError;
59 
60     // Target level parameters
61     // Based on the above: analogTargetLevel = round((32767*10^(-22/20))^2*16/2^7)
62     int32_t             analogTargetLevel;  // = RXX_BUFFER_LEN * 846805;       -22 dBfs
63     int32_t             startUpperLimit;    // = RXX_BUFFER_LEN * 1066064;      -21 dBfs
64     int32_t             startLowerLimit;    // = RXX_BUFFER_LEN * 672641;       -23 dBfs
65     int32_t             upperPrimaryLimit;  // = RXX_BUFFER_LEN * 1342095;      -20 dBfs
66     int32_t             lowerPrimaryLimit;  // = RXX_BUFFER_LEN * 534298;       -24 dBfs
67     int32_t             upperSecondaryLimit;// = RXX_BUFFER_LEN * 2677832;      -17 dBfs
68     int32_t             lowerSecondaryLimit;// = RXX_BUFFER_LEN * 267783;       -27 dBfs
69     uint16_t            targetIdx;          // Table index for corresponding target level
70 #ifdef MIC_LEVEL_FEEDBACK
71     uint16_t            targetIdxOffset;    // Table index offset for level compensation
72 #endif
73     int16_t             analogTarget;       // Digital reference level in ENV scale
74 
75     // Analog AGC specific variables
76     int32_t             filterState[8];     // For downsampling wb to nb
77     int32_t             upperLimit;         // Upper limit for mic energy
78     int32_t             lowerLimit;         // Lower limit for mic energy
79     int32_t             Rxx160w32;          // Average energy for one frame
80     int32_t             Rxx16_LPw32;        // Low pass filtered subframe energies
81     int32_t             Rxx160_LPw32;       // Low pass filtered frame energies
82     int32_t             Rxx16_LPw32Max;     // Keeps track of largest energy subframe
83     int32_t             Rxx16_vectorw32[RXX_BUFFER_LEN];// Array with subframe energies
84     int32_t             Rxx16w32_array[2][5];// Energy values of microphone signal
85     int32_t             env[2][10];         // Envelope values of subframes
86 
87     int16_t             Rxx16pos;           // Current position in the Rxx16_vectorw32
88     int16_t             envSum;             // Filtered scaled envelope in subframes
89     int16_t             vadThreshold;       // Threshold for VAD decision
90     int16_t             inActive;           // Inactive time in milliseconds
91     int16_t             msTooLow;           // Milliseconds of speech at a too low level
92     int16_t             msTooHigh;          // Milliseconds of speech at a too high level
93     int16_t             changeToSlowMode;   // Change to slow mode after some time at target
94     int16_t             firstCall;          // First call to the process-function
95     int16_t             msZero;             // Milliseconds of zero input
96     int16_t             msecSpeechOuterChange;// Min ms of speech between volume changes
97     int16_t             msecSpeechInnerChange;// Min ms of speech between volume changes
98     int16_t             activeSpeech;       // Milliseconds of active speech
99     int16_t             muteGuardMs;        // Counter to prevent mute action
100     int16_t             inQueue;            // 10 ms batch indicator
101 
102     // Microphone level variables
103     int32_t             micRef;             // Remember ref. mic level for virtual mic
104     uint16_t            gainTableIdx;       // Current position in virtual gain table
105     int32_t             micGainIdx;         // Gain index of mic level to increase slowly
106     int32_t             micVol;             // Remember volume between frames
107     int32_t             maxLevel;           // Max possible vol level, incl dig gain
108     int32_t             maxAnalog;          // Maximum possible analog volume level
109     int32_t             maxInit;            // Initial value of "max"
110     int32_t             minLevel;           // Minimum possible volume level
111     int32_t             minOutput;          // Minimum output volume level
112     int32_t             zeroCtrlMax;        // Remember max gain => don't amp low input
113     int32_t             lastInMicLevel;
114 
115     int16_t             scale;              // Scale factor for internal volume levels
116 #ifdef MIC_LEVEL_FEEDBACK
117     int16_t             numBlocksMicLvlSat;
118     uint8_t             micLvlSat;
119 #endif
120     // Structs for VAD and digital_agc
121     AgcVad vadMic;
122     DigitalAgc digitalAgc;
123 
124 #ifdef WEBRTC_AGC_DEBUG_DUMP
125     FILE* fpt;
126     FILE* agcLog;
127     int32_t fcount;
128 #endif
129 
130     int16_t             lowLevelSignal;
131 } LegacyAgc;
132 
133 #endif // WEBRTC_MODULES_AUDIO_PROCESSING_AGC_LEGACY_ANALOG_AGC_H_
134