media/base/media.cc

   1 // Copyright 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "media/base/media.h"
   6
   7 #include "base/files/file_path.h"
   8 #include "base/lazy_instance.h"
   9 #include "base/path_service.h"
  10 #include "base/synchronization/lock.h"
  11 #include "build/build_config.h"
  12 #include "media/base/sinc_resampler.h"
  13 #include "media/base/vector_math.h"
  14
  15 namespace media {
  16
  17 namespace internal {
  18 // Platform specific initialization method.
  19 extern bool InitializeMediaLibraryInternal(const base::FilePath& module_dir);
  20 }  // namespace internal
  21
  22 // Media must only be initialized once, so use a LazyInstance to ensure this.
  23 class MediaInitializer {
  24  public:
  25   bool Initialize(const base::FilePath& module_dir) {
  26     base::AutoLock auto_lock(lock_);
  27     if (!tried_initialize_) {
  28       tried_initialize_ = true;
  29       initialized_ = internal::InitializeMediaLibraryInternal(module_dir);
  30     }
  31     return initialized_;
  32   }
  33
  34   bool IsInitialized() {
  35     base::AutoLock auto_lock(lock_);
  36     return initialized_;
  37   }
  38
  39  private:
  40   friend struct base::DefaultLazyInstanceTraits<MediaInitializer>;
  41
  42   MediaInitializer()
  43       : initialized_(false),
  44         tried_initialize_(false) {
  45     // Perform initialization of libraries which require runtime CPU detection.
  46     // TODO(dalecurtis): Add initialization of YUV, SincResampler.
  47     vector_math::Initialize();
  48 #if !defined(OS_IOS)
  49     SincResampler::InitializeCPUSpecificFeatures();
  50 #endif
  51   }
  52
  53   ~MediaInitializer() {
  54     NOTREACHED() << "MediaInitializer should be leaky!";
  55   }
  56
  57   base::Lock lock_;
  58   bool initialized_;
  59   bool tried_initialize_;
  60
  61   DISALLOW_COPY_AND_ASSIGN(MediaInitializer);
  62 };
  63
  64 static base::LazyInstance<MediaInitializer>::Leaky g_media_library =
  65     LAZY_INSTANCE_INITIALIZER;
  66
  67 bool InitializeMediaLibrary(const base::FilePath& module_dir) {
  68   return g_media_library.Get().Initialize(module_dir);
  69 }
  70
  71 void InitializeMediaLibraryForTesting() {
  72   base::FilePath module_dir;
  73   CHECK(PathService::Get(base::DIR_EXE, &module_dir));
  74   CHECK(g_media_library.Get().Initialize(module_dir));
  75 }
  76
  77 bool IsMediaLibraryInitialized() {
  78   return g_media_library.Get().IsInitialized();
  79 }
  80
  81 void InitializeCPUSpecificMediaFeatures() {
  82   // Force initialization of the media initializer, but don't call Initialize().
  83   g_media_library.Get();
  84 }
  85
  86 }  // namespace media