/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ /* vim:set ts=2 sw=2 sts=2 et cindent: */ /* This Source Code Form is subject to the terms of the Mozilla Public * License, v. 2.0. If a copy of the MPL was not distributed with this * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ #include <stdint.h> #include <algorithm> #include "nsIStringBundle.h" #include "nsDebug.h" #include "nsString.h" #include "mozilla/Preferences.h" #include "mozilla/StaticMutex.h" #include "mozilla/StaticPtr.h" #include "mozilla/Telemetry.h" #include "mozilla/Logging.h" #include "nsThreadUtils.h" #include "CubebUtils.h" #include "nsAutoRef.h" #include "prdtoa.h" #define PREF_VOLUME_SCALE "media.volume_scale" #define PREF_CUBEB_LATENCY_PLAYBACK "media.cubeb_latency_playback_ms" #define PREF_CUBEB_LATENCY_MSG "media.cubeb_latency_msg_frames" namespace mozilla { namespace { LazyLogModule gCubebLog("cubeb"); void CubebLogCallback(const char* aFmt, ...) { char buffer[256]; va_list arglist; va_start(arglist, aFmt); VsprintfLiteral (buffer, aFmt, arglist); MOZ_LOG(gCubebLog, LogLevel::Error, ("%s", buffer)); va_end(arglist); } // This mutex protects the variables below. StaticMutex sMutex; enum class CubebState { Uninitialized = 0, Initialized, Shutdown } sCubebState = CubebState::Uninitialized; cubeb* sCubebContext; double sVolumeScale; uint32_t sCubebPlaybackLatencyInMilliseconds; uint32_t sCubebMSGLatencyInFrames; bool sCubebPlaybackLatencyPrefSet; bool sCubebMSGLatencyPrefSet; bool sAudioStreamInitEverSucceeded = false; StaticAutoPtr<char> sBrandName; const char kBrandBundleURL[] = "chrome://branding/locale/brand.properties"; const char* AUDIOSTREAM_BACKEND_ID_STR[] = { "jack", "pulse", "alsa", "audiounit", "audioqueue", "wasapi", "winmm", "directsound", "sndio", "opensl", "audiotrack", "kai" }; /* Index for failures to create an audio stream the first time. */ const int CUBEB_BACKEND_INIT_FAILURE_FIRST = ArrayLength(AUDIOSTREAM_BACKEND_ID_STR); /* Index for failures to create an audio stream after the first time */ const int CUBEB_BACKEND_INIT_FAILURE_OTHER = CUBEB_BACKEND_INIT_FAILURE_FIRST + 1; /* Index for an unknown backend. */ const int CUBEB_BACKEND_UNKNOWN = CUBEB_BACKEND_INIT_FAILURE_FIRST + 2; // Prefered samplerate, in Hz (characteristic of the hardware, mixer, platform, // and API used). // // sMutex protects *initialization* of this, which must be performed from each // thread before fetching, after which it is safe to fetch without holding the // mutex because it is only written once per process execution (by the first // initialization to complete). Since the init must have been called on a // given thread before fetching the value, it's guaranteed (via the mutex) that // sufficient memory barriers have occurred to ensure the correct value is // visible on the querying thread/CPU. uint32_t sPreferredSampleRate; } // namespace extern LazyLogModule gAudioStreamLog; static const uint32_t CUBEB_NORMAL_LATENCY_MS = 100; // Consevative default that can work on all platforms. static const uint32_t CUBEB_NORMAL_LATENCY_FRAMES = 1024; namespace CubebUtils { void PrefChanged(const char* aPref, void* aClosure) { if (strcmp(aPref, PREF_VOLUME_SCALE) == 0) { nsAdoptingString value = Preferences::GetString(aPref); StaticMutexAutoLock lock(sMutex); if (value.IsEmpty()) { sVolumeScale = 1.0; } else { NS_ConvertUTF16toUTF8 utf8(value); sVolumeScale = std::max<double>(0, PR_strtod(utf8.get(), nullptr)); } } else if (strcmp(aPref, PREF_CUBEB_LATENCY_PLAYBACK) == 0) { // Arbitrary default stream latency of 100ms. The higher this // value, the longer stream volume changes will take to become // audible. sCubebPlaybackLatencyPrefSet = Preferences::HasUserValue(aPref); uint32_t value = Preferences::GetUint(aPref, CUBEB_NORMAL_LATENCY_MS); StaticMutexAutoLock lock(sMutex); sCubebPlaybackLatencyInMilliseconds = std::min<uint32_t>(std::max<uint32_t>(value, 1), 1000); } else if (strcmp(aPref, PREF_CUBEB_LATENCY_MSG) == 0) { sCubebMSGLatencyPrefSet = Preferences::HasUserValue(aPref); uint32_t value = Preferences::GetUint(aPref, CUBEB_NORMAL_LATENCY_FRAMES); StaticMutexAutoLock lock(sMutex); // 128 is the block size for the Web Audio API, which limits how low the // latency can be here. // We don't want to limit the upper limit too much, so that people can // experiment. sCubebMSGLatencyInFrames = std::min<uint32_t>(std::max<uint32_t>(value, 128), 1e6); } } bool GetFirstStream() { static bool sFirstStream = true; StaticMutexAutoLock lock(sMutex); bool result = sFirstStream; sFirstStream = false; return result; } double GetVolumeScale() { StaticMutexAutoLock lock(sMutex); return sVolumeScale; } cubeb* GetCubebContext() { StaticMutexAutoLock lock(sMutex); return GetCubebContextUnlocked(); } bool InitPreferredSampleRate() { StaticMutexAutoLock lock(sMutex); if (sPreferredSampleRate != 0) { return true; } cubeb* context = GetCubebContextUnlocked(); if (!context) { return false; } if (cubeb_get_preferred_sample_rate(context, &sPreferredSampleRate) != CUBEB_OK) { return false; } MOZ_ASSERT(sPreferredSampleRate); return true; } uint32_t PreferredSampleRate() { if (!InitPreferredSampleRate()) { return 44100; } MOZ_ASSERT(sPreferredSampleRate); return sPreferredSampleRate; } void InitBrandName() { if (sBrandName) { return; } nsXPIDLString brandName; nsCOMPtr<nsIStringBundleService> stringBundleService = mozilla::services::GetStringBundleService(); if (stringBundleService) { nsCOMPtr<nsIStringBundle> brandBundle; nsresult rv = stringBundleService->CreateBundle(kBrandBundleURL, getter_AddRefs(brandBundle)); if (NS_SUCCEEDED(rv)) { rv = brandBundle->GetStringFromName(u"brandShortName", getter_Copies(brandName)); NS_WARNING_ASSERTION( NS_SUCCEEDED(rv), "Could not get the program name for a cubeb stream."); } } /* cubeb expects a c-string. */ const char* ascii = NS_LossyConvertUTF16toASCII(brandName).get(); sBrandName = new char[brandName.Length() + 1]; PodCopy(sBrandName.get(), ascii, brandName.Length()); sBrandName[brandName.Length()] = 0; } cubeb* GetCubebContextUnlocked() { sMutex.AssertCurrentThreadOwns(); if (sCubebState != CubebState::Uninitialized) { // If we have already passed the initialization point (below), just return // the current context, which may be null (e.g., after error or shutdown.) return sCubebContext; } if (!sBrandName && NS_IsMainThread()) { InitBrandName(); } else { NS_WARNING_ASSERTION( sBrandName, "Did not initialize sbrandName, and not on the main thread?"); } int rv = cubeb_init(&sCubebContext, sBrandName); NS_WARNING_ASSERTION(rv == CUBEB_OK, "Could not get a cubeb context."); sCubebState = (rv == CUBEB_OK) ? CubebState::Initialized : CubebState::Uninitialized; if (MOZ_LOG_TEST(gCubebLog, LogLevel::Verbose)) { cubeb_set_log_callback(CUBEB_LOG_VERBOSE, CubebLogCallback); } else if (MOZ_LOG_TEST(gCubebLog, LogLevel::Error)) { cubeb_set_log_callback(CUBEB_LOG_NORMAL, CubebLogCallback); } return sCubebContext; } uint32_t GetCubebPlaybackLatencyInMilliseconds() { StaticMutexAutoLock lock(sMutex); return sCubebPlaybackLatencyInMilliseconds; } bool CubebPlaybackLatencyPrefSet() { StaticMutexAutoLock lock(sMutex); return sCubebPlaybackLatencyPrefSet; } bool CubebMSGLatencyPrefSet() { StaticMutexAutoLock lock(sMutex); return sCubebMSGLatencyPrefSet; } Maybe<uint32_t> GetCubebMSGLatencyInFrames() { StaticMutexAutoLock lock(sMutex); if (!sCubebMSGLatencyPrefSet) { return Maybe<uint32_t>(); } MOZ_ASSERT(sCubebMSGLatencyInFrames > 0); return Some(sCubebMSGLatencyInFrames); } void InitLibrary() { PrefChanged(PREF_VOLUME_SCALE, nullptr); Preferences::RegisterCallback(PrefChanged, PREF_VOLUME_SCALE); PrefChanged(PREF_CUBEB_LATENCY_PLAYBACK, nullptr); PrefChanged(PREF_CUBEB_LATENCY_MSG, nullptr); Preferences::RegisterCallback(PrefChanged, PREF_CUBEB_LATENCY_PLAYBACK); Preferences::RegisterCallback(PrefChanged, PREF_CUBEB_LATENCY_MSG); #ifndef MOZ_WIDGET_ANDROID NS_DispatchToMainThread(NS_NewRunnableFunction(&InitBrandName)); #endif } void ShutdownLibrary() { Preferences::UnregisterCallback(PrefChanged, PREF_VOLUME_SCALE); Preferences::UnregisterCallback(PrefChanged, PREF_CUBEB_LATENCY_PLAYBACK); Preferences::UnregisterCallback(PrefChanged, PREF_CUBEB_LATENCY_MSG); StaticMutexAutoLock lock(sMutex); if (sCubebContext) { cubeb_destroy(sCubebContext); sCubebContext = nullptr; } sBrandName = nullptr; // This will ensure we don't try to re-create a context. sCubebState = CubebState::Shutdown; } uint32_t MaxNumberOfChannels() { cubeb* cubebContext = GetCubebContext(); uint32_t maxNumberOfChannels; if (cubebContext && cubeb_get_max_channel_count(cubebContext, &maxNumberOfChannels) == CUBEB_OK) { return maxNumberOfChannels; } return 0; } void GetCurrentBackend(nsAString& aBackend) { cubeb* cubebContext = GetCubebContext(); if (cubebContext) { const char* backend = cubeb_get_backend_id(cubebContext); if (backend) { aBackend.AssignASCII(backend); return; } } aBackend.AssignLiteral("unknown"); } } // namespace CubebUtils } // namespace mozilla