analog_agc.h (5731B)
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 #include <cstdint> 15 16 #include "modules/audio_processing/agc/legacy/digital_agc.h" 17 #include "modules/audio_processing/agc/legacy/gain_control.h" 18 19 namespace webrtc { 20 21 /* Analog Automatic Gain Control variables: 22 * Constant declarations (inner limits inside which no changes are done) 23 * In the beginning the range is narrower to widen as soon as the measure 24 * 'Rxx160_LP' is inside it. Currently the starting limits are -22.2+/-1dBm0 25 * and the final limits -22.2+/-2.5dBm0. These levels makes the speech signal 26 * go towards -25.4dBm0 (-31.4dBov). Tuned with wbfile-31.4dBov.pcm 27 * The limits are created by running the AGC with a file having the desired 28 * signal level and thereafter plotting Rxx160_LP in the dBm0-domain defined 29 * by out=10*log10(in/260537279.7); Set the target level to the average level 30 * of our measure Rxx160_LP. Remember that the levels are in blocks of 16 in 31 * Q(-7). (Example matlab code: round(db2pow(-21.2)*16/2^7) ) 32 */ 33 constexpr int16_t kRxxBufferLen = 10; 34 35 static const int16_t kMsecSpeechInner = 520; 36 static const int16_t kMsecSpeechOuter = 340; 37 38 static const int16_t kNormalVadThreshold = 400; 39 40 static const int16_t kAlphaShortTerm = 6; // 1 >> 6 = 0.0156 41 static const int16_t kAlphaLongTerm = 10; // 1 >> 10 = 0.000977 42 43 typedef struct { 44 // Configurable parameters/variables 45 uint32_t fs; // Sampling frequency 46 int16_t compressionGaindB; // Fixed gain level in dB 47 int16_t targetLevelDbfs; // Target level in -dBfs of envelope (default -3) 48 int16_t agcMode; // Hard coded mode (adaptAna/adaptDig/fixedDig) 49 uint8_t limiterEnable; // Enabling limiter (on/off (default off)) 50 WebRtcAgcConfig defaultConfig; 51 WebRtcAgcConfig usedConfig; 52 53 // General variables 54 int16_t initFlag; 55 int16_t lastError; 56 57 // Target level parameters 58 // Based on the above: analogTargetLevel = round((32767*10^(-22/20))^2*16/2^7) 59 int32_t analogTargetLevel; // = kRxxBufferLen * 846805; -22 dBfs 60 int32_t startUpperLimit; // = kRxxBufferLen * 1066064; -21 dBfs 61 int32_t startLowerLimit; // = kRxxBufferLen * 672641; -23 dBfs 62 int32_t upperPrimaryLimit; // = kRxxBufferLen * 1342095; -20 dBfs 63 int32_t lowerPrimaryLimit; // = kRxxBufferLen * 534298; -24 dBfs 64 int32_t upperSecondaryLimit; // = kRxxBufferLen * 2677832; -17 dBfs 65 int32_t lowerSecondaryLimit; // = kRxxBufferLen * 267783; -27 dBfs 66 uint16_t targetIdx; // Table index for corresponding target level 67 int16_t analogTarget; // Digital reference level in ENV scale 68 69 // Analog AGC specific variables 70 int32_t filterState[8]; // For downsampling wb to nb 71 int32_t upperLimit; // Upper limit for mic energy 72 int32_t lowerLimit; // Lower limit for mic energy 73 int32_t Rxx160w32; // Average energy for one frame 74 int32_t Rxx16_LPw32; // Low pass filtered subframe energies 75 int32_t Rxx160_LPw32; // Low pass filtered frame energies 76 int32_t Rxx16_LPw32Max; // Keeps track of largest energy subframe 77 int32_t Rxx16_vectorw32[kRxxBufferLen]; // Array with subframe energies 78 int32_t Rxx16w32_array[2][5]; // Energy values of microphone signal 79 int32_t env[2][10]; // Envelope values of subframes 80 81 int16_t Rxx16pos; // Current position in the Rxx16_vectorw32 82 int16_t envSum; // Filtered scaled envelope in subframes 83 int16_t vadThreshold; // Threshold for VAD decision 84 int16_t inActive; // Inactive time in milliseconds 85 int16_t msTooLow; // Milliseconds of speech at a too low level 86 int16_t msTooHigh; // Milliseconds of speech at a too high level 87 int16_t changeToSlowMode; // Change to slow mode after some time at target 88 int16_t firstCall; // First call to the process-function 89 int16_t msZero; // Milliseconds of zero input 90 int16_t msecSpeechOuterChange; // Min ms of speech between volume changes 91 int16_t msecSpeechInnerChange; // Min ms of speech between volume changes 92 int16_t activeSpeech; // Milliseconds of active speech 93 int16_t muteGuardMs; // Counter to prevent mute action 94 int16_t inQueue; // 10 ms batch indicator 95 96 // Microphone level variables 97 int32_t micRef; // Remember ref. mic level for virtual mic 98 uint16_t gainTableIdx; // Current position in virtual gain table 99 int32_t micGainIdx; // Gain index of mic level to increase slowly 100 int32_t micVol; // Remember volume between frames 101 int32_t maxLevel; // Max possible vol level, incl dig gain 102 int32_t maxAnalog; // Maximum possible analog volume level 103 int32_t maxInit; // Initial value of "max" 104 int32_t minLevel; // Minimum possible volume level 105 int32_t minOutput; // Minimum output volume level 106 int32_t zeroCtrlMax; // Remember max gain => don't amp low input 107 int32_t lastInMicLevel; 108 109 int16_t scale; // Scale factor for internal volume levels 110 // Structs for VAD and digital_agc 111 AgcVad vadMic; 112 DigitalAgc digitalAgc; 113 114 int16_t lowLevelSignal; 115 } LegacyAgc; 116 117 } // namespace webrtc 118 119 #endif // MODULES_AUDIO_PROCESSING_AGC_LEGACY_ANALOG_AGC_H_