Line data    Source code

       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_CONFERENCE_MIXER_INCLUDE_AUDIO_CONFERENCE_MIXER_H_
      12             : #define WEBRTC_MODULES_AUDIO_CONFERENCE_MIXER_INCLUDE_AUDIO_CONFERENCE_MIXER_H_
      13             : 
      14             : #include "webrtc/modules/audio_conference_mixer/include/audio_conference_mixer_defines.h"
      15             : #include "webrtc/modules/include/module.h"
      16             : #include "webrtc/modules/include/module_common_types.h"
      17             : 
      18             : namespace webrtc {
      19             : class AudioMixerOutputReceiver;
      20             : class MixerParticipant;
      21             : class Trace;
      22             : 
      23             : class AudioConferenceMixer : public Module
      24             : {
      25             : public:
      26             :     enum {kMaximumAmountOfMixedParticipants = 3};
      27             :     enum Frequency
      28             :     {
      29             :         kNbInHz           = 8000,
      30             :         kWbInHz           = 16000,
      31             :         kSwbInHz          = 32000,
      32             :         kFbInHz           = 48000,
      33             :         kLowestPossible   = -1,
      34             :         kDefaultFrequency = kWbInHz
      35             :     };
      36             : 
      37             :     // Factory method. Constructor disabled.
      38             :     static AudioConferenceMixer* Create(int id);
      39           0 :     virtual ~AudioConferenceMixer() {}
      40             : 
      41             :     // Module functions
      42             :     int64_t TimeUntilNextProcess() override = 0;
      43             :     void Process() override = 0;
      44             : 
      45             :     // Register/unregister a callback class for receiving the mixed audio.
      46             :     virtual int32_t RegisterMixedStreamCallback(
      47             :         AudioMixerOutputReceiver* receiver) = 0;
      48             :     virtual int32_t UnRegisterMixedStreamCallback() = 0;
      49             : 
      50             :     // Add/remove participants as candidates for mixing.
      51             :     virtual int32_t SetMixabilityStatus(MixerParticipant* participant,
      52             :                                         bool mixable) = 0;
      53             :     // Returns true if a participant is a candidate for mixing.
      54             :     virtual bool MixabilityStatus(
      55             :         const MixerParticipant& participant) const = 0;
      56             : 
      57             :     // Inform the mixer that the participant should always be mixed and not
      58             :     // count toward the number of mixed participants. Note that a participant
      59             :     // must have been added to the mixer (by calling SetMixabilityStatus())
      60             :     // before this function can be successfully called.
      61             :     virtual int32_t SetAnonymousMixabilityStatus(
      62             :         MixerParticipant* participant, bool mixable) = 0;
      63             :     // Returns true if the participant is mixed anonymously.
      64             :     virtual bool AnonymousMixabilityStatus(
      65             :         const MixerParticipant& participant) const = 0;
      66             : 
      67             :     // Set the minimum sampling frequency at which to mix. The mixing algorithm
      68             :     // may still choose to mix at a higher samling frequency to avoid
      69             :     // downsampling of audio contributing to the mixed audio.
      70             :     virtual int32_t SetMinimumMixingFrequency(Frequency freq) = 0;
      71             : 
      72             : protected:
      73           0 :     AudioConferenceMixer() {}
      74             : };
      75             : }  // namespace webrtc
      76             : 
      77             : #endif // WEBRTC_MODULES_AUDIO_CONFERENCE_MIXER_INCLUDE_AUDIO_CONFERENCE_MIXER_H_