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      1 /*
      2  *  Copyright (c) 2012 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 // This sub-API supports the following functionalities:
     12 //
     13 //  - Noise Suppression (NS).
     14 //  - Automatic Gain Control (AGC).
     15 //  - Echo Control (EC).
     16 //  - Receiving side VAD, NS and AGC.
     17 //  - Measurements of instantaneous speech, noise and echo levels.
     18 //  - Generation of AP debug recordings.
     19 //  - Detection of keyboard typing which can disrupt a voice conversation.
     20 //
     21 // Usage example, omitting error checking:
     22 //
     23 //  using namespace webrtc;
     24 //  VoiceEngine* voe = VoiceEngine::Create();
     25 //  VoEBase* base = VoEBase::GetInterface();
     26 //  VoEAudioProcessing* ap = VoEAudioProcessing::GetInterface(voe);
     27 //  base->Init();
     28 //  ap->SetEcStatus(true, kAgcAdaptiveAnalog);
     29 //  ...
     30 //  base->Terminate();
     31 //  base->Release();
     32 //  ap->Release();
     33 //  VoiceEngine::Delete(voe);
     34 //
     35 #ifndef WEBRTC_VOICE_ENGINE_VOE_AUDIO_PROCESSING_H
     36 #define WEBRTC_VOICE_ENGINE_VOE_AUDIO_PROCESSING_H
     37 
     38 #include <stdio.h>
     39 
     40 #include "webrtc/common_types.h"
     41 
     42 namespace webrtc {
     43 
     44 class VoiceEngine;
     45 
     46 // VoERxVadCallback
     47 class WEBRTC_DLLEXPORT VoERxVadCallback
     48 {
     49 public:
     50     virtual void OnRxVad(int channel, int vadDecision) = 0;
     51 
     52 protected:
     53     virtual ~VoERxVadCallback() {}
     54 };
     55 
     56 // VoEAudioProcessing
     57 class WEBRTC_DLLEXPORT VoEAudioProcessing
     58 {
     59 public:
     60     // Factory for the VoEAudioProcessing sub-API. Increases an internal
     61     // reference counter if successful. Returns NULL if the API is not
     62     // supported or if construction fails.
     63     static VoEAudioProcessing* GetInterface(VoiceEngine* voiceEngine);
     64 
     65     // Releases the VoEAudioProcessing sub-API and decreases an internal
     66     // reference counter. Returns the new reference count. This value should
     67     // be zero for all sub-API:s before the VoiceEngine object can be safely
     68     // deleted.
     69     virtual int Release() = 0;
     70 
     71     // Sets Noise Suppression (NS) status and mode.
     72     // The NS reduces noise in the microphone signal.
     73     virtual int SetNsStatus(bool enable, NsModes mode = kNsUnchanged) = 0;
     74 
     75     // Gets the NS status and mode.
     76     virtual int GetNsStatus(bool& enabled, NsModes& mode) = 0;
     77 
     78     // Sets the Automatic Gain Control (AGC) status and mode.
     79     // The AGC adjusts the microphone signal to an appropriate level.
     80     virtual int SetAgcStatus(bool enable, AgcModes mode = kAgcUnchanged) = 0;
     81 
     82     // Gets the AGC status and mode.
     83     virtual int GetAgcStatus(bool& enabled, AgcModes& mode) = 0;
     84 
     85     // Sets the AGC configuration.
     86     // Should only be used in situations where the working environment
     87     // is well known.
     88     virtual int SetAgcConfig(AgcConfig config) = 0;
     89 
     90     // Gets the AGC configuration.
     91     virtual int GetAgcConfig(AgcConfig& config) = 0;
     92 
     93     // Sets the Echo Control (EC) status and mode.
     94     // The EC mitigates acoustic echo where a user can hear their own
     95     // speech repeated back due to an acoustic coupling between the
     96     // speaker and the microphone at the remote end.
     97     virtual int SetEcStatus(bool enable, EcModes mode = kEcUnchanged) = 0;
     98 
     99     // Gets the EC status and mode.
    100     virtual int GetEcStatus(bool& enabled, EcModes& mode) = 0;
    101 
    102     // Enables the compensation of clock drift between the capture and render
    103     // streams by the echo canceller (i.e. only using EcMode==kEcAec). It will
    104     // only be enabled if supported on the current platform; otherwise an error
    105     // will be returned. Check if the platform is supported by calling
    106     // |DriftCompensationSupported()|.
    107     virtual int EnableDriftCompensation(bool enable) = 0;
    108     virtual bool DriftCompensationEnabled() = 0;
    109     static bool DriftCompensationSupported();
    110 
    111     // Sets a delay |offset| in ms to add to the system delay reported by the
    112     // OS, which is used by the AEC to synchronize far- and near-end streams.
    113     // In some cases a system may introduce a delay which goes unreported by the
    114     // OS, but which is known to the user. This method can be used to compensate
    115     // for the unreported delay.
    116     virtual void SetDelayOffsetMs(int offset) = 0;
    117     virtual int DelayOffsetMs() = 0;
    118 
    119     // Modifies settings for the AEC designed for mobile devices (AECM).
    120     virtual int SetAecmMode(AecmModes mode = kAecmSpeakerphone,
    121                             bool enableCNG = true) = 0;
    122 
    123     // Gets settings for the AECM.
    124     virtual int GetAecmMode(AecmModes& mode, bool& enabledCNG) = 0;
    125 
    126     // Enables a high pass filter on the capture signal. This removes DC bias
    127     // and low-frequency noise. Recommended to be enabled.
    128     virtual int EnableHighPassFilter(bool enable) = 0;
    129     virtual bool IsHighPassFilterEnabled() = 0;
    130 
    131     // Sets status and mode of the receiving-side (Rx) NS.
    132     // The Rx NS reduces noise in the received signal for the specified
    133     // |channel|. Intended for advanced usage only.
    134     virtual int SetRxNsStatus(int channel,
    135                               bool enable,
    136                               NsModes mode = kNsUnchanged) = 0;
    137 
    138     // Gets status and mode of the receiving-side NS.
    139     virtual int GetRxNsStatus(int channel,
    140                               bool& enabled,
    141                               NsModes& mode) = 0;
    142 
    143     // Sets status and mode of the receiving-side (Rx) AGC.
    144     // The Rx AGC adjusts the received signal to an appropriate level
    145     // for the specified |channel|. Intended for advanced usage only.
    146     virtual int SetRxAgcStatus(int channel,
    147                                bool enable,
    148                                AgcModes mode = kAgcUnchanged) = 0;
    149 
    150     // Gets status and mode of the receiving-side AGC.
    151     virtual int GetRxAgcStatus(int channel,
    152                                bool& enabled,
    153                                AgcModes& mode) = 0;
    154 
    155     // Modifies the AGC configuration on the receiving side for the
    156     // specified |channel|.
    157     virtual int SetRxAgcConfig(int channel, AgcConfig config) = 0;
    158 
    159     // Gets the AGC configuration on the receiving side.
    160     virtual int GetRxAgcConfig(int channel, AgcConfig& config) = 0;
    161 
    162     // Registers a VoERxVadCallback |observer| instance and enables Rx VAD
    163     // notifications for the specified |channel|.
    164     virtual int RegisterRxVadObserver(int channel,
    165                                       VoERxVadCallback &observer) = 0;
    166 
    167     // Deregisters the VoERxVadCallback |observer| and disables Rx VAD
    168     // notifications for the specified |channel|.
    169     virtual int DeRegisterRxVadObserver(int channel) = 0;
    170 
    171     // Gets the VAD/DTX activity for the specified |channel|.
    172     // The returned value is 1 if frames of audio contains speech
    173     // and 0 if silence. The output is always 1 if VAD is disabled.
    174     virtual int VoiceActivityIndicator(int channel) = 0;
    175 
    176     // Enables or disables the possibility to retrieve echo metrics and delay
    177     // logging values during an active call. The metrics are only supported in
    178     // AEC.
    179     virtual int SetEcMetricsStatus(bool enable) = 0;
    180 
    181     // Gets the current EC metric status.
    182     virtual int GetEcMetricsStatus(bool& enabled) = 0;
    183 
    184     // Gets the instantaneous echo level metrics.
    185     virtual int GetEchoMetrics(int& ERL, int& ERLE, int& RERL, int& A_NLP) = 0;
    186 
    187     // Gets the EC internal |delay_median| and |delay_std| in ms between
    188     // near-end and far-end. The values are calculated over the time period
    189     // since the last GetEcDelayMetrics() call.
    190     virtual int GetEcDelayMetrics(int& delay_median, int& delay_std) = 0;
    191 
    192     // Enables recording of Audio Processing (AP) debugging information.
    193     // The file can later be used for off-line analysis of the AP performance.
    194     virtual int StartDebugRecording(const char* fileNameUTF8) = 0;
    195 
    196     // Same as above but sets and uses an existing file handle. Takes ownership
    197     // of |file_handle| and passes it on to the audio processing module.
    198     virtual int StartDebugRecording(FILE* file_handle) = 0;
    199 
    200     // Disables recording of AP debugging information.
    201     virtual int StopDebugRecording() = 0;
    202 
    203     // Enables or disables detection of disturbing keyboard typing.
    204     // An error notification will be given as a callback upon detection.
    205     virtual int SetTypingDetectionStatus(bool enable) = 0;
    206 
    207     // Gets the current typing detection status.
    208     virtual int GetTypingDetectionStatus(bool& enabled) = 0;
    209 
    210     // Reports the lower of:
    211     // * Time in seconds since the last typing event.
    212     // * Time in seconds since the typing detection was enabled.
    213     // Returns error if typing detection is disabled.
    214     virtual int TimeSinceLastTyping(int &seconds) = 0;
    215 
    216     // Optional setting of typing detection parameters
    217     // Parameter with value == 0 will be ignored
    218     // and left with default config.
    219     // TODO(niklase) Remove default argument as soon as libJingle is updated!
    220     virtual int SetTypingDetectionParameters(int timeWindow,
    221                                              int costPerTyping,
    222                                              int reportingThreshold,
    223                                              int penaltyDecay,
    224                                              int typeEventDelay = 0) = 0;
    225 
    226     // Swaps the capture-side left and right audio channels when enabled. It
    227     // only has an effect when using a stereo send codec. The setting is
    228     // persistent; it will be applied whenever a stereo send codec is enabled.
    229     //
    230     // The swap is applied only to the captured audio, and not mixed files. The
    231     // swap will appear in file recordings and when accessing audio through the
    232     // external media interface.
    233     virtual void EnableStereoChannelSwapping(bool enable) = 0;
    234     virtual bool IsStereoChannelSwappingEnabled() = 0;
    235 
    236 protected:
    237     VoEAudioProcessing() {}
    238     virtual ~VoEAudioProcessing() {}
    239 };
    240 
    241 }  // namespace webrtc
    242 
    243 #endif  // WEBRTC_VOICE_ENGINE_VOE_AUDIO_PROCESSING_H
    244