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      1 /*
      2  *  Copyright 2004 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 #include "webrtc/sound/nullsoundsystem.h"
     12 
     13 #include "webrtc/sound/sounddevicelocator.h"
     14 #include "webrtc/sound/soundinputstreaminterface.h"
     15 #include "webrtc/sound/soundoutputstreaminterface.h"
     16 #include "webrtc/base/logging.h"
     17 
     18 namespace rtc {
     19 
     20 class Thread;
     21 
     22 }
     23 
     24 namespace rtc {
     25 
     26 // Name used for the single device and the sound system itself.
     27 static const char kNullName[] = "null";
     28 
     29 class NullSoundDeviceLocator : public SoundDeviceLocator {
     30  public:
     31   NullSoundDeviceLocator() : SoundDeviceLocator(kNullName, kNullName) {}
     32 
     33   virtual SoundDeviceLocator *Copy() const {
     34     return new NullSoundDeviceLocator();
     35   }
     36 };
     37 
     38 class NullSoundInputStream : public SoundInputStreamInterface {
     39  public:
     40   virtual bool StartReading() {
     41     return true;
     42   }
     43 
     44   virtual bool StopReading() {
     45     return true;
     46   }
     47 
     48   virtual bool GetVolume(int *volume) {
     49     *volume = SoundSystemInterface::kMinVolume;
     50     return true;
     51   }
     52 
     53   virtual bool SetVolume(int volume) {
     54     return false;
     55   }
     56 
     57   virtual bool Close() {
     58     return true;
     59   }
     60 
     61   virtual int LatencyUsecs() {
     62     return 0;
     63   }
     64 };
     65 
     66 class NullSoundOutputStream : public SoundOutputStreamInterface {
     67  public:
     68   virtual bool EnableBufferMonitoring() {
     69     return true;
     70   }
     71 
     72   virtual bool DisableBufferMonitoring() {
     73     return true;
     74   }
     75 
     76   virtual bool WriteSamples(const void *sample_data,
     77                             size_t size) {
     78     LOG(LS_VERBOSE) << "Got " << size << " bytes of playback samples";
     79     return true;
     80   }
     81 
     82   virtual bool GetVolume(int *volume) {
     83     *volume = SoundSystemInterface::kMinVolume;
     84     return true;
     85   }
     86 
     87   virtual bool SetVolume(int volume) {
     88     return false;
     89   }
     90 
     91   virtual bool Close() {
     92     return true;
     93   }
     94 
     95   virtual int LatencyUsecs() {
     96     return 0;
     97   }
     98 };
     99 
    100 NullSoundSystem::~NullSoundSystem() {
    101 }
    102 
    103 bool NullSoundSystem::Init() {
    104   return true;
    105 }
    106 
    107 void NullSoundSystem::Terminate() {
    108   // Nothing to do.
    109 }
    110 
    111 bool NullSoundSystem::EnumeratePlaybackDevices(
    112       SoundSystemInterface::SoundDeviceLocatorList *devices) {
    113   ClearSoundDeviceLocatorList(devices);
    114   SoundDeviceLocator *device;
    115   GetDefaultPlaybackDevice(&device);
    116   devices->push_back(device);
    117   return true;
    118 }
    119 
    120 bool NullSoundSystem::EnumerateCaptureDevices(
    121       SoundSystemInterface::SoundDeviceLocatorList *devices) {
    122   ClearSoundDeviceLocatorList(devices);
    123   SoundDeviceLocator *device;
    124   GetDefaultCaptureDevice(&device);
    125   devices->push_back(device);
    126   return true;
    127 }
    128 
    129 bool NullSoundSystem::GetDefaultPlaybackDevice(
    130     SoundDeviceLocator **device) {
    131   *device = new NullSoundDeviceLocator();
    132   return true;
    133 }
    134 
    135 bool NullSoundSystem::GetDefaultCaptureDevice(
    136     SoundDeviceLocator **device) {
    137   *device = new NullSoundDeviceLocator();
    138   return true;
    139 }
    140 
    141 SoundOutputStreamInterface *NullSoundSystem::OpenPlaybackDevice(
    142       const SoundDeviceLocator *device,
    143       const OpenParams &params) {
    144   return new NullSoundOutputStream();
    145 }
    146 
    147 SoundInputStreamInterface *NullSoundSystem::OpenCaptureDevice(
    148       const SoundDeviceLocator *device,
    149       const OpenParams &params) {
    150   return new NullSoundInputStream();
    151 }
    152 
    153 const char *NullSoundSystem::GetName() const {
    154   return kNullName;
    155 }
    156 
    157 }  // namespace rtc
    158