dom/media/CubebUtils.h

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim:set ts=2 sw=2 sts=2 et cindent: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #if !defined(CubebUtils_h_)
   8 #  define CubebUtils_h_
   9
  10 #  include "cubeb/cubeb.h"
  11
  12 #  include "AudioSampleFormat.h"
  13 #  include "nsString.h"
  14 #  include "nsISupportsImpl.h"
  15
  16 class AudioDeviceInfo;
  17
  18 MOZ_MAKE_ENUM_CLASS_BITWISE_OPERATORS(cubeb_stream_prefs)
  19 MOZ_MAKE_ENUM_CLASS_BITWISE_OPERATORS(cubeb_input_processing_params)
  20
  21 namespace mozilla {
  22
  23 class CallbackThreadRegistry;
  24 class SharedThreadPool;
  25
  26 namespace CubebUtils {
  27
  28 typedef cubeb_devid AudioDeviceID;
  29
  30 template <AudioSampleFormat N>
  31 struct ToCubebFormat {
  32   static const cubeb_sample_format value = CUBEB_SAMPLE_FLOAT32NE;
  33 };
  34
  35 template <>
  36 struct ToCubebFormat<AUDIO_FORMAT_S16> {
  37   static const cubeb_sample_format value = CUBEB_SAMPLE_S16NE;
  38 };
  39
  40 nsCString ProcessingParamsToString(cubeb_input_processing_params aParams);
  41
  42 class CubebHandle {
  43  public:
  44   NS_INLINE_DECL_THREADSAFE_REFCOUNTING(CubebHandle)
  45   explicit CubebHandle(cubeb* aCubeb) : mCubeb(aCubeb) {
  46     MOZ_RELEASE_ASSERT(mCubeb);
  47   };
  48   CubebHandle(const CubebHandle&) = delete;
  49   cubeb* Context() const { return mCubeb.get(); }
  50
  51  private:
  52   struct CubebDeletePolicy {
  53     void operator()(cubeb* aCubeb) { cubeb_destroy(aCubeb); }
  54   };
  55   const UniquePtr<cubeb, CubebDeletePolicy> mCubeb;
  56   ~CubebHandle() = default;
  57 };
  58
  59 // Initialize Audio Library. Some Audio backends require initializing the
  60 // library before using it.
  61 void InitLibrary();
  62
  63 // Shutdown Audio Library. Some Audio backends require shutting down the
  64 // library after using it.
  65 void ShutdownLibrary();
  66
  67 bool SandboxEnabled();
  68
  69 // A thread pool containing only one thread to execute the cubeb operations. We
  70 // should always use this thread to init, destroy, start, or stop cubeb streams,
  71 // to avoid data racing or deadlock issues across platforms.
  72 already_AddRefed<SharedThreadPool> GetCubebOperationThread();
  73
  74 // Returns the maximum number of channels supported by the audio hardware.
  75 uint32_t MaxNumberOfChannels();
  76
  77 // Get the sample rate the hardware/mixer runs at. Thread safe.
  78 uint32_t PreferredSampleRate(bool aShouldResistFingerprinting);
  79
  80 // Initialize a cubeb stream. A pass through wrapper for cubeb_stream_init,
  81 // that can simulate streams that are very slow to start, by setting the pref
  82 // media.cubeb.slow_stream_init_ms.
  83 int CubebStreamInit(cubeb* context, cubeb_stream** stream,
  84                     char const* stream_name, cubeb_devid input_device,
  85                     cubeb_stream_params* input_stream_params,
  86                     cubeb_devid output_device,
  87                     cubeb_stream_params* output_stream_params,
  88                     uint32_t latency_frames, cubeb_data_callback data_callback,
  89                     cubeb_state_callback state_callback, void* user_ptr);
  90
  91 enum Side { Input = 1 << 0, Output = 1 << 1 };
  92
  93 double GetVolumeScale();
  94 bool GetFirstStream();
  95 RefPtr<CubebHandle> GetCubeb();
  96 void ReportCubebStreamInitFailure(bool aIsFirstStream);
  97 void ReportCubebBackendUsed();
  98 uint32_t GetCubebPlaybackLatencyInMilliseconds();
  99 uint32_t GetCubebMTGLatencyInFrames(cubeb_stream_params* params);
 100 bool CubebLatencyPrefSet();
 101 void GetCurrentBackend(nsAString& aBackend);
 102 cubeb_stream_prefs GetDefaultStreamPrefs(cubeb_device_type aType);
 103 char* GetForcedOutputDevice();
 104 // No-op on all platforms but Android, where it tells the device's AudioManager
 105 // to switch to "communication mode", which might change audio routing,
 106 // bluetooth communication type, etc.
 107 void SetInCommunication(bool aInCommunication);
 108 // Returns true if the output streams should be routed like a stream containing
 109 // voice data, and not generic audio. This can influence audio processing and
 110 // device selection.
 111 bool RouteOutputAsVoice();
 112 // Returns, in seconds, the roundtrip latency Gecko thinks there is between the
 113 // default input and output devices. This is for diagnosing purposes, the
 114 // latency figures are best used directly from the cubeb streams themselves, as
 115 // the devices being used matter. This is blocking.
 116 bool EstimatedLatencyDefaultDevices(
 117     double* aMean, double* aStdDev,
 118     Side aSide = static_cast<Side>(Side::Input | Side::Output));
 119
 120 #  ifdef MOZ_WIDGET_ANDROID
 121 int32_t AndroidGetAudioOutputSampleRate();
 122 int32_t AndroidGetAudioOutputFramesPerBuffer();
 123 #  endif
 124
 125 #  ifdef ENABLE_SET_CUBEB_BACKEND
 126 void ForceSetCubebContext(cubeb* aCubebContext);
 127 #  endif
 128 }  // namespace CubebUtils
 129 }  // namespace mozilla
 130
 131 #endif  // CubebUtils_h_