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/yuv_convert.h"
  13
  14 namespace media {
  15
  16 namespace internal {
  17 // Platform specific initialization method.
  18 extern bool InitializeMediaLibraryInternal(const base::FilePath& module_dir);
  19 }  // namespace internal
  20
  21 // Media must only be initialized once, so use a LazyInstance to ensure this.
  22 class MediaInitializer {
  23  public:
  24   bool Initialize(const base::FilePath& module_dir) {
  25     base::AutoLock auto_lock(lock_);
  26     if (!tried_initialize_) {
  27       tried_initialize_ = true;
  28       initialized_ = internal::InitializeMediaLibraryInternal(module_dir);
  29     }
  30     return initialized_;
  31   }
  32
  33   bool IsInitialized() {
  34     base::AutoLock auto_lock(lock_);
  35     return initialized_;
  36   }
  37
  38  private:
  39   friend struct base::DefaultLazyInstanceTraits<MediaInitializer>;
  40
  41   MediaInitializer()
  42       : initialized_(false),
  43         tried_initialize_(false) {
  44     // Perform initialization of libraries which require runtime CPU detection.
  45     InitializeCPUSpecificYUVConversions();
  46   }
  47
  48   ~MediaInitializer() {
  49     NOTREACHED() << "MediaInitializer should be leaky!";
  50   }
  51
  52   base::Lock lock_;
  53   bool initialized_;
  54   bool tried_initialize_;
  55
  56   DISALLOW_COPY_AND_ASSIGN(MediaInitializer);
  57 };
  58
  59 static base::LazyInstance<MediaInitializer>::Leaky g_media_library =
  60     LAZY_INSTANCE_INITIALIZER;
  61
  62 bool InitializeMediaLibrary(const base::FilePath& module_dir) {
  63   return g_media_library.Get().Initialize(module_dir);
  64 }
  65
  66 void InitializeMediaLibraryForTesting() {
  67   base::FilePath module_dir;
  68   CHECK(PathService::Get(base::DIR_EXE, &module_dir));
  69   CHECK(g_media_library.Get().Initialize(module_dir));
  70 }
  71
  72 bool IsMediaLibraryInitialized() {
  73   return g_media_library.Get().IsInitialized();
  74 }
  75
  76 void InitializeCPUSpecificMediaFeatures() {
  77   // Force initialization of the media initializer, but don't call Initialize().
  78   g_media_library.Get();
  79 }
  80
  81 }  // namespace media