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+/*
+ * Copyright (c) 2011 The WebRTC project authors. All Rights Reserved.
+ *
+ * Use of this source code is governed by a BSD-style license
+ * that can be found in the LICENSE file in the root of the source
+ * tree. An additional intellectual property rights grant can be found
+ * in the file PATENTS. All contributing project authors may
+ * be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_MODULES_AUDIO_PROCESSING_AGC_MAIN_SOURCE_ANALOG_AGC_H_
+#define WEBRTC_MODULES_AUDIO_PROCESSING_AGC_MAIN_SOURCE_ANALOG_AGC_H_
+
+#include "typedefs.h"
+#include "gain_control.h"
+#include "digital_agc.h"
+
+//#define AGC_DEBUG
+//#define MIC_LEVEL_FEEDBACK
+#ifdef AGC_DEBUG
+#include <stdio.h>
+#endif
+
+/* Analog Automatic Gain Control variables:
+ * Constant declarations (inner limits inside which no changes are done)
+ * In the beginning the range is narrower to widen as soon as the measure
+ * 'Rxx160_LP' is inside it. Currently the starting limits are -22.2+/-1dBm0
+ * and the final limits -22.2+/-2.5dBm0. These levels makes the speech signal
+ * go towards -25.4dBm0 (-31.4dBov). Tuned with wbfile-31.4dBov.pcm
+ * The limits are created by running the AGC with a file having the desired
+ * signal level and thereafter plotting Rxx160_LP in the dBm0-domain defined
+ * by out=10*log10(in/260537279.7); Set the target level to the average level
+ * of our measure Rxx160_LP. Remember that the levels are in blocks of 16 in
+ * Q(-7). (Example matlab code: round(db2pow(-21.2)*16/2^7) )
+ */
+#define RXX_BUFFER_LEN 10
+
+static const WebRtc_Word16 kMsecSpeechInner = 520;
+static const WebRtc_Word16 kMsecSpeechOuter = 340;
+
+static const WebRtc_Word16 kNormalVadThreshold = 400;
+
+static const WebRtc_Word16 kAlphaShortTerm = 6; // 1 >> 6 = 0.0156
+static const WebRtc_Word16 kAlphaLongTerm = 10; // 1 >> 10 = 0.000977
+
+typedef struct
+{
+ // Configurable parameters/variables
+ WebRtc_UWord32 fs; // Sampling frequency
+ WebRtc_Word16 compressionGaindB; // Fixed gain level in dB
+ WebRtc_Word16 targetLevelDbfs; // Target level in -dBfs of envelope (default -3)
+ WebRtc_Word16 agcMode; // Hard coded mode (adaptAna/adaptDig/fixedDig)
+ WebRtc_UWord8 limiterEnable; // Enabling limiter (on/off (default off))
+ WebRtcAgc_config_t defaultConfig;
+ WebRtcAgc_config_t usedConfig;
+
+ // General variables
+ WebRtc_Word16 initFlag;
+ WebRtc_Word16 lastError;
+
+ // Target level parameters
+ // Based on the above: analogTargetLevel = round((32767*10^(-22/20))^2*16/2^7)
+ WebRtc_Word32 analogTargetLevel; // = RXX_BUFFER_LEN * 846805; -22 dBfs
+ WebRtc_Word32 startUpperLimit; // = RXX_BUFFER_LEN * 1066064; -21 dBfs
+ WebRtc_Word32 startLowerLimit; // = RXX_BUFFER_LEN * 672641; -23 dBfs
+ WebRtc_Word32 upperPrimaryLimit; // = RXX_BUFFER_LEN * 1342095; -20 dBfs
+ WebRtc_Word32 lowerPrimaryLimit; // = RXX_BUFFER_LEN * 534298; -24 dBfs
+ WebRtc_Word32 upperSecondaryLimit;// = RXX_BUFFER_LEN * 2677832; -17 dBfs
+ WebRtc_Word32 lowerSecondaryLimit;// = RXX_BUFFER_LEN * 267783; -27 dBfs
+ WebRtc_UWord16 targetIdx; // Table index for corresponding target level
+#ifdef MIC_LEVEL_FEEDBACK
+ WebRtc_UWord16 targetIdxOffset; // Table index offset for level compensation
+#endif
+ WebRtc_Word16 analogTarget; // Digital reference level in ENV scale
+
+ // Analog AGC specific variables
+ WebRtc_Word32 filterState[8]; // For downsampling wb to nb
+ WebRtc_Word32 upperLimit; // Upper limit for mic energy
+ WebRtc_Word32 lowerLimit; // Lower limit for mic energy
+ WebRtc_Word32 Rxx160w32; // Average energy for one frame
+ WebRtc_Word32 Rxx16_LPw32; // Low pass filtered subframe energies
+ WebRtc_Word32 Rxx160_LPw32; // Low pass filtered frame energies
+ WebRtc_Word32 Rxx16_LPw32Max; // Keeps track of largest energy subframe
+ WebRtc_Word32 Rxx16_vectorw32[RXX_BUFFER_LEN];// Array with subframe energies
+ WebRtc_Word32 Rxx16w32_array[2][5];// Energy values of microphone signal
+ WebRtc_Word32 env[2][10]; // Envelope values of subframes
+
+ WebRtc_Word16 Rxx16pos; // Current position in the Rxx16_vectorw32
+ WebRtc_Word16 envSum; // Filtered scaled envelope in subframes
+ WebRtc_Word16 vadThreshold; // Threshold for VAD decision
+ WebRtc_Word16 inActive; // Inactive time in milliseconds
+ WebRtc_Word16 msTooLow; // Milliseconds of speech at a too low level
+ WebRtc_Word16 msTooHigh; // Milliseconds of speech at a too high level
+ WebRtc_Word16 changeToSlowMode; // Change to slow mode after some time at target
+ WebRtc_Word16 firstCall; // First call to the process-function
+ WebRtc_Word16 msZero; // Milliseconds of zero input
+ WebRtc_Word16 msecSpeechOuterChange;// Min ms of speech between volume changes
+ WebRtc_Word16 msecSpeechInnerChange;// Min ms of speech between volume changes
+ WebRtc_Word16 activeSpeech; // Milliseconds of active speech
+ WebRtc_Word16 muteGuardMs; // Counter to prevent mute action
+ WebRtc_Word16 inQueue; // 10 ms batch indicator
+
+ // Microphone level variables
+ WebRtc_Word32 micRef; // Remember ref. mic level for virtual mic
+ WebRtc_UWord16 gainTableIdx; // Current position in virtual gain table
+ WebRtc_Word32 micGainIdx; // Gain index of mic level to increase slowly
+ WebRtc_Word32 micVol; // Remember volume between frames
+ WebRtc_Word32 maxLevel; // Max possible vol level, incl dig gain
+ WebRtc_Word32 maxAnalog; // Maximum possible analog volume level
+ WebRtc_Word32 maxInit; // Initial value of "max"
+ WebRtc_Word32 minLevel; // Minimum possible volume level
+ WebRtc_Word32 minOutput; // Minimum output volume level
+ WebRtc_Word32 zeroCtrlMax; // Remember max gain => don't amp low input
+
+ WebRtc_Word16 scale; // Scale factor for internal volume levels
+#ifdef MIC_LEVEL_FEEDBACK
+ WebRtc_Word16 numBlocksMicLvlSat;
+ WebRtc_UWord8 micLvlSat;
+#endif
+ // Structs for VAD and digital_agc
+ AgcVad_t vadMic;
+ DigitalAgc_t digitalAgc;
+
+#ifdef AGC_DEBUG
+ FILE* fpt;
+ FILE* agcLog;
+ WebRtc_Word32 fcount;
+#endif
+
+ WebRtc_Word16 lowLevelSignal;
+} Agc_t;
+
+#endif // WEBRTC_MODULES_AUDIO_PROCESSING_AGC_MAIN_SOURCE_ANALOG_AGC_H_