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      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 #ifndef WEBRTC_VOICE_ENGINE_VOE_EXTERNAL_MEDIA_H
     11 #define WEBRTC_VOICE_ENGINE_VOE_EXTERNAL_MEDIA_H
     12 
     13 #include "webrtc/common_types.h"
     14 
     15 namespace webrtc {
     16 
     17 class VoiceEngine;
     18 class AudioFrame;
     19 
     20 class WEBRTC_DLLEXPORT VoEMediaProcess {
     21  public:
     22   // The VoiceEngine user should override the Process() method in a
     23   // derived class. Process() will be called when audio is ready to
     24   // be processed. The audio can be accessed in several different modes
     25   // given by the |type| parameter. The function should modify the
     26   // original data and ensure that it is copied back to the |audio10ms|
     27   // array. The number of samples in the frame cannot be changed.
     28   // The sampling frequency will depend upon the codec used.
     29   // If |isStereo| is true, audio10ms will contain 16-bit PCM data
     30   // samples in interleaved stereo format (L0,R0,L1,R1,...).
     31   virtual void Process(int channel,
     32                        ProcessingTypes type,
     33                        int16_t audio10ms[],
     34                        size_t length,
     35                        int samplingFreq,
     36                        bool isStereo) = 0;
     37 
     38  protected:
     39   virtual ~VoEMediaProcess() {}
     40 };
     41 
     42 class WEBRTC_DLLEXPORT VoEExternalMedia {
     43  public:
     44   // Factory for the VoEExternalMedia sub-API. Increases an internal
     45   // reference counter if successful. Returns NULL if the API is not
     46   // supported or if construction fails.
     47   static VoEExternalMedia* GetInterface(VoiceEngine* voiceEngine);
     48 
     49   // Releases the VoEExternalMedia sub-API and decreases an internal
     50   // reference counter. Returns the new reference count. This value should
     51   // be zero for all sub-API:s before the VoiceEngine object can be safely
     52   // deleted.
     53   virtual int Release() = 0;
     54 
     55   // Installs a VoEMediaProcess derived instance and activates external
     56   // media for the specified |channel| and |type|.
     57   virtual int RegisterExternalMediaProcessing(
     58       int channel,
     59       ProcessingTypes type,
     60       VoEMediaProcess& processObject) = 0;
     61 
     62   // Removes the VoEMediaProcess derived instance and deactivates external
     63   // media for the specified |channel| and |type|.
     64   virtual int DeRegisterExternalMediaProcessing(int channel,
     65                                                 ProcessingTypes type) = 0;
     66 
     67   // Pulls an audio frame from the specified |channel| for external mixing.
     68   // If the |desired_sample_rate_hz| is 0, the signal will be returned with
     69   // its native frequency, otherwise it will be resampled. Valid frequencies
     70   // are 16, 22, 32, 44 or 48 kHz.
     71   virtual int GetAudioFrame(int channel,
     72                             int desired_sample_rate_hz,
     73                             AudioFrame* frame) = 0;
     74 
     75   // Sets the state of external mixing. Cannot be changed during playback.
     76   virtual int SetExternalMixing(int channel, bool enable) = 0;
     77 
     78  protected:
     79   VoEExternalMedia() {}
     80   virtual ~VoEExternalMedia() {}
     81 };
     82 
     83 }  // namespace webrtc
     84 
     85 #endif  //  WEBRTC_VOICE_ENGINE_VOE_EXTERNAL_MEDIA_H
     86