src/media/video/capture/mac/avfoundation_glue.mm

   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 #import "media/video/capture/mac/avfoundation_glue.h"
   6
   7 #include <dlfcn.h>
   8
   9 #include "base/command_line.h"
  10 #include "base/lazy_instance.h"
  11 #include "base/mac/mac_util.h"
  12 #include "base/metrics/field_trial.h"
  13 #include "media/base/media_switches.h"
  14
  15 namespace {
  16
  17 // This class is used to retrieve AVFoundation NSBundle and library handle. It
  18 // must be used as a LazyInstance so that it is initialised once and in a
  19 // thread-safe way. Normally no work is done in constructors: LazyInstance is
  20 // an exception.
  21 class AVFoundationInternal {
  22  public:
  23   AVFoundationInternal() {
  24     bundle_ = [NSBundle
  25         bundleWithPath:@"/System/Library/Frameworks/AVFoundation.framework"];
  26
  27     const char* path = [[bundle_ executablePath] fileSystemRepresentation];
  28     CHECK(path);
  29     library_handle_ = dlopen(path, RTLD_LAZY | RTLD_LOCAL);
  30     CHECK(library_handle_) << dlerror();
  31
  32     struct {
  33       NSString** loaded_string;
  34       const char* symbol;
  35     } av_strings[] = {
  36         {&AVCaptureDeviceWasConnectedNotification_,
  37          "AVCaptureDeviceWasConnectedNotification"},
  38         {&AVCaptureDeviceWasDisconnectedNotification_,
  39          "AVCaptureDeviceWasDisconnectedNotification"},
  40         {&AVMediaTypeVideo_, "AVMediaTypeVideo"},
  41         {&AVMediaTypeAudio_, "AVMediaTypeAudio"},
  42         {&AVMediaTypeMuxed_, "AVMediaTypeMuxed"},
  43         {&AVCaptureSessionRuntimeErrorNotification_,
  44          "AVCaptureSessionRuntimeErrorNotification"},
  45         {&AVCaptureSessionDidStopRunningNotification_,
  46          "AVCaptureSessionDidStopRunningNotification"},
  47         {&AVCaptureSessionErrorKey_, "AVCaptureSessionErrorKey"},
  48         {&AVVideoScalingModeKey_, "AVVideoScalingModeKey"},
  49         {&AVVideoScalingModeResizeAspectFill_,
  50          "AVVideoScalingModeResizeAspectFill"},
  51     };
  52     for (size_t i = 0; i < arraysize(av_strings); ++i) {
  53       *av_strings[i].loaded_string = *reinterpret_cast<NSString**>(
  54           dlsym(library_handle_, av_strings[i].symbol));
  55       DCHECK(*av_strings[i].loaded_string) << dlerror();
  56     }
  57   }
  58
  59   NSBundle* bundle() const { return bundle_; }
  60   void* library_handle() const { return library_handle_; }
  61
  62   NSString* AVCaptureDeviceWasConnectedNotification() const {
  63     return AVCaptureDeviceWasConnectedNotification_;
  64   }
  65   NSString* AVCaptureDeviceWasDisconnectedNotification() const {
  66     return AVCaptureDeviceWasDisconnectedNotification_;
  67   }
  68   NSString* AVMediaTypeVideo() const { return AVMediaTypeVideo_; }
  69   NSString* AVMediaTypeAudio() const { return AVMediaTypeAudio_; }
  70   NSString* AVMediaTypeMuxed() const { return AVMediaTypeMuxed_; }
  71   NSString* AVCaptureSessionRuntimeErrorNotification() const {
  72     return AVCaptureSessionRuntimeErrorNotification_;
  73   }
  74   NSString* AVCaptureSessionDidStopRunningNotification() const {
  75     return AVCaptureSessionDidStopRunningNotification_;
  76   }
  77   NSString* AVCaptureSessionErrorKey() const {
  78     return AVCaptureSessionErrorKey_;
  79   }
  80   NSString* AVVideoScalingModeKey() const { return AVVideoScalingModeKey_; }
  81   NSString* AVVideoScalingModeResizeAspectFill() const {
  82     return AVVideoScalingModeResizeAspectFill_;
  83   }
  84
  85  private:
  86   NSBundle* bundle_;
  87   void* library_handle_;
  88   // The following members are replicas of the respectives in AVFoundation.
  89   NSString* AVCaptureDeviceWasConnectedNotification_;
  90   NSString* AVCaptureDeviceWasDisconnectedNotification_;
  91   NSString* AVMediaTypeVideo_;
  92   NSString* AVMediaTypeAudio_;
  93   NSString* AVMediaTypeMuxed_;
  94   NSString* AVCaptureSessionRuntimeErrorNotification_;
  95   NSString* AVCaptureSessionDidStopRunningNotification_;
  96   NSString* AVCaptureSessionErrorKey_;
  97   NSString* AVVideoScalingModeKey_;
  98   NSString* AVVideoScalingModeResizeAspectFill_;
  99
 100   DISALLOW_COPY_AND_ASSIGN(AVFoundationInternal);
 101 };
 102
 103 }  // namespace
 104
 105 static base::LazyInstance<AVFoundationInternal> g_avfoundation_handle =
 106     LAZY_INSTANCE_INITIALIZER;
 107
 108 bool AVFoundationGlue::IsAVFoundationSupported() {
 109   // DeviceMonitorMac will initialize this static bool from the main UI thread
 110   // once, during Chrome startup so this construction is thread safe.
 111   // Use AVFoundation if possible, enabled, and QTKit is not explicitly forced.
 112   static CommandLine* command_line = CommandLine::ForCurrentProcess();
 113
 114   // AVFoundation is only available on OS Lion and above.
 115   if (!base::mac::IsOSLionOrLater())
 116     return false;
 117
 118   // The force-qtkit flag takes precedence over enable-avfoundation.
 119   if (command_line->HasSwitch(switches::kForceQTKit))
 120     return false;
 121
 122   // Next in precedence is the enable-avfoundation flag.
 123   // TODO(vrk): Does this really need to be static?
 124   static bool should_enable_avfoundation =
 125       command_line->HasSwitch(switches::kEnableAVFoundation) ||
 126       base::FieldTrialList::FindFullName("AVFoundationMacVideoCapture")
 127           == "Enabled";
 128   // Try to load AVFoundation. Save result in static bool to avoid loading
 129   // AVFoundationBundle every call.
 130   static bool loaded_successfully = [AVFoundationBundle() load];
 131   return should_enable_avfoundation && loaded_successfully;
 132 }
 133
 134 NSBundle const* AVFoundationGlue::AVFoundationBundle() {
 135   return g_avfoundation_handle.Get().bundle();
 136 }
 137
 138 void* AVFoundationGlue::AVFoundationLibraryHandle() {
 139   return g_avfoundation_handle.Get().library_handle();
 140 }
 141
 142 NSString* AVFoundationGlue::AVCaptureDeviceWasConnectedNotification() {
 143   return g_avfoundation_handle.Get().AVCaptureDeviceWasConnectedNotification();
 144 }
 145
 146 NSString* AVFoundationGlue::AVCaptureDeviceWasDisconnectedNotification() {
 147   return
 148       g_avfoundation_handle.Get().AVCaptureDeviceWasDisconnectedNotification();
 149 }
 150
 151 NSString* AVFoundationGlue::AVMediaTypeVideo() {
 152   return g_avfoundation_handle.Get().AVMediaTypeVideo();
 153 }
 154
 155 NSString* AVFoundationGlue::AVMediaTypeAudio() {
 156   return g_avfoundation_handle.Get().AVMediaTypeAudio();
 157 }
 158
 159 NSString* AVFoundationGlue::AVMediaTypeMuxed() {
 160   return g_avfoundation_handle.Get().AVMediaTypeMuxed();
 161 }
 162
 163 NSString* AVFoundationGlue::AVCaptureSessionRuntimeErrorNotification() {
 164   return g_avfoundation_handle.Get().AVCaptureSessionRuntimeErrorNotification();
 165 }
 166
 167 NSString* AVFoundationGlue::AVCaptureSessionDidStopRunningNotification() {
 168   return
 169       g_avfoundation_handle.Get().AVCaptureSessionDidStopRunningNotification();
 170 }
 171
 172 NSString* AVFoundationGlue::AVCaptureSessionErrorKey() {
 173   return g_avfoundation_handle.Get().AVCaptureSessionErrorKey();
 174 }
 175
 176 NSString* AVFoundationGlue::AVVideoScalingModeKey() {
 177   return g_avfoundation_handle.Get().AVVideoScalingModeKey();
 178 }
 179
 180 NSString* AVFoundationGlue::AVVideoScalingModeResizeAspectFill() {
 181   return g_avfoundation_handle.Get().AVVideoScalingModeResizeAspectFill();
 182 }
 183
 184 Class AVFoundationGlue::AVCaptureSessionClass() {
 185   return [AVFoundationBundle() classNamed:@"AVCaptureSession"];
 186 }
 187
 188 Class AVFoundationGlue::AVCaptureVideoDataOutputClass() {
 189   return [AVFoundationBundle() classNamed:@"AVCaptureVideoDataOutput"];
 190 }
 191
 192 @implementation AVCaptureDeviceGlue
 193
 194 + (NSArray*)devices {
 195   Class avcClass =
 196       [AVFoundationGlue::AVFoundationBundle() classNamed:@"AVCaptureDevice"];
 197   if ([avcClass respondsToSelector:@selector(devices)]) {
 198     return [avcClass performSelector:@selector(devices)];
 199   }
 200   return nil;
 201 }
 202
 203 + (CrAVCaptureDevice*)deviceWithUniqueID:(NSString*)deviceUniqueID {
 204   Class avcClass =
 205       [AVFoundationGlue::AVFoundationBundle() classNamed:@"AVCaptureDevice"];
 206   return [avcClass performSelector:@selector(deviceWithUniqueID:)
 207                         withObject:deviceUniqueID];
 208 }
 209
 210 @end  // @implementation AVCaptureDeviceGlue
 211
 212 @implementation AVCaptureDeviceInputGlue
 213
 214 + (CrAVCaptureDeviceInput*)deviceInputWithDevice:(CrAVCaptureDevice*)device
 215                                            error:(NSError**)outError {
 216   return [[AVFoundationGlue::AVFoundationBundle()
 217       classNamed:@"AVCaptureDeviceInput"] deviceInputWithDevice:device
 218                                                           error:outError];
 219 }
 220
 221 @end  // @implementation AVCaptureDeviceInputGlue