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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:
~VoEMediaProcess()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:
VoEExternalMedia()79   VoEExternalMedia() {}
~VoEExternalMedia()80   virtual ~VoEExternalMedia() {}
81 };
82 
83 }  // namespace webrtc
84 
85 #endif  //  WEBRTC_VOICE_ENGINE_VOE_EXTERNAL_MEDIA_H
86