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