src/content/browser/media/capture/desktop_capture_device_aura.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 "content/browser/media/capture/desktop_capture_device_aura.h"
   6
   7 #include "base/logging.h"
   8 #include "base/metrics/histogram.h"
   9 #include "base/timer/timer.h"
  10 #include "cc/output/copy_output_request.h"
  11 #include "cc/output/copy_output_result.h"
  12 #include "content/browser/compositor/image_transport_factory.h"
  13 #include "content/browser/media/capture/content_video_capture_device_core.h"
  14 #include "content/browser/media/capture/desktop_capture_device_uma_types.h"
  15 #include "content/common/gpu/client/gl_helper.h"
  16 #include "content/public/browser/browser_thread.h"
  17 #include "content/public/browser/power_save_blocker.h"
  18 #include "media/base/video_util.h"
  19 #include "media/video/capture/video_capture_types.h"
  20 #include "skia/ext/image_operations.h"
  21 #include "third_party/skia/include/core/SkBitmap.h"
  22 #include "ui/aura/client/screen_position_client.h"
  23 #include "ui/aura/env.h"
  24 #include "ui/aura/window.h"
  25 #include "ui/aura/window_observer.h"
  26 #include "ui/aura/window_tree_host.h"
  27 #include "ui/base/cursor/cursors_aura.h"
  28 #include "ui/compositor/compositor.h"
  29 #include "ui/compositor/dip_util.h"
  30 #include "ui/compositor/layer.h"
  31 #include "ui/gfx/screen.h"
  32
  33 namespace content {
  34
  35 namespace {
  36
  37 int clip_byte(int x) {
  38   return std::max(0, std::min(x, 255));
  39 }
  40
  41 int alpha_blend(int alpha, int src, int dst) {
  42   return (src * alpha + dst * (255 - alpha)) / 255;
  43 }
  44
  45 // Helper function to composite a cursor bitmap on a YUV420 video frame.
  46 void RenderCursorOnVideoFrame(
  47     const scoped_refptr<media::VideoFrame>& target,
  48     const SkBitmap& cursor_bitmap,
  49     const gfx::Point& cursor_position) {
  50   DCHECK(target);
  51   DCHECK(!cursor_bitmap.isNull());
  52
  53   gfx::Rect rect = gfx::IntersectRects(
  54       gfx::Rect(cursor_bitmap.width(), cursor_bitmap.height()) +
  55           gfx::Vector2d(cursor_position.x(), cursor_position.y()),
  56       target->visible_rect());
  57
  58   cursor_bitmap.lockPixels();
  59   for (int y = rect.y(); y < rect.bottom(); ++y) {
  60     int cursor_y = y - cursor_position.y();
  61     uint8* yplane = target->data(media::VideoFrame::kYPlane) +
  62         y * target->row_bytes(media::VideoFrame::kYPlane);
  63     uint8* uplane = target->data(media::VideoFrame::kUPlane) +
  64         (y / 2) * target->row_bytes(media::VideoFrame::kUPlane);
  65     uint8* vplane = target->data(media::VideoFrame::kVPlane) +
  66         (y / 2) * target->row_bytes(media::VideoFrame::kVPlane);
  67     for (int x = rect.x(); x < rect.right(); ++x) {
  68       int cursor_x = x - cursor_position.x();
  69       SkColor color = cursor_bitmap.getColor(cursor_x, cursor_y);
  70       int alpha = SkColorGetA(color);
  71       int color_r = SkColorGetR(color);
  72       int color_g = SkColorGetG(color);
  73       int color_b = SkColorGetB(color);
  74       int color_y = clip_byte(((color_r * 66 + color_g * 129 + color_b * 25 +
  75                                 128) >> 8) + 16);
  76       yplane[x] = alpha_blend(alpha, color_y, yplane[x]);
  77
  78       // Only sample U and V at even coordinates.
  79       if ((x % 2 == 0) && (y % 2 == 0)) {
  80         int color_u = clip_byte(((color_r * -38 + color_g * -74 +
  81                                   color_b * 112 + 128) >> 8) + 128);
  82         int color_v = clip_byte(((color_r * 112 + color_g * -94 +
  83                                   color_b * -18 + 128) >> 8) + 128);
  84         uplane[x / 2] = alpha_blend(alpha, color_u, uplane[x / 2]);
  85         vplane[x / 2] = alpha_blend(alpha, color_v, vplane[x / 2]);
  86       }
  87     }
  88   }
  89   cursor_bitmap.unlockPixels();
  90 }
  91
  92 class DesktopVideoCaptureMachine
  93     : public VideoCaptureMachine,
  94       public aura::WindowObserver,
  95       public ui::CompositorObserver,
  96       public base::SupportsWeakPtr<DesktopVideoCaptureMachine> {
  97  public:
  98   DesktopVideoCaptureMachine(const DesktopMediaID& source);
  99   virtual ~DesktopVideoCaptureMachine();
 100
 101   // VideoCaptureFrameSource overrides.
 102   virtual bool Start(const scoped_refptr<ThreadSafeCaptureOracle>& oracle_proxy,
 103                      const media::VideoCaptureParams& params) OVERRIDE;
 104   virtual void Stop(const base::Closure& callback) OVERRIDE;
 105
 106   // Implements aura::WindowObserver.
 107   virtual void OnWindowBoundsChanged(aura::Window* window,
 108                                      const gfx::Rect& old_bounds,
 109                                      const gfx::Rect& new_bounds) OVERRIDE;
 110   virtual void OnWindowDestroyed(aura::Window* window) OVERRIDE;
 111   virtual void OnWindowAddedToRootWindow(aura::Window* window) OVERRIDE;
 112   virtual void OnWindowRemovingFromRootWindow(aura::Window* window,
 113                                               aura::Window* new_root) OVERRIDE;
 114
 115   // Implements ui::CompositorObserver.
 116   virtual void OnCompositingDidCommit(ui::Compositor* compositor) OVERRIDE {}
 117   virtual void OnCompositingStarted(ui::Compositor* compositor,
 118                                     base::TimeTicks start_time) OVERRIDE {}
 119   virtual void OnCompositingEnded(ui::Compositor* compositor) OVERRIDE;
 120   virtual void OnCompositingAborted(ui::Compositor* compositor) OVERRIDE {}
 121   virtual void OnCompositingLockStateChanged(
 122       ui::Compositor* compositor) OVERRIDE {}
 123
 124  private:
 125   // Captures a frame.
 126   // |dirty| is false for timer polls and true for compositor updates.
 127   void Capture(bool dirty);
 128
 129   // Update capture size. Must be called on the UI thread.
 130   void UpdateCaptureSize();
 131
 132   // Response callback for cc::Layer::RequestCopyOfOutput().
 133   void DidCopyOutput(
 134       scoped_refptr<media::VideoFrame> video_frame,
 135       base::TimeTicks start_time,
 136       const ThreadSafeCaptureOracle::CaptureFrameCallback& capture_frame_cb,
 137       scoped_ptr<cc::CopyOutputResult> result);
 138
 139   // A helper which does the real work for DidCopyOutput. Returns true if
 140   // succeeded.
 141   bool ProcessCopyOutputResponse(
 142       scoped_refptr<media::VideoFrame> video_frame,
 143       base::TimeTicks start_time,
 144       const ThreadSafeCaptureOracle::CaptureFrameCallback& capture_frame_cb,
 145       scoped_ptr<cc::CopyOutputResult> result);
 146
 147   // Helper function to update cursor state.
 148   // |region_in_frame| defines the desktop bound in the captured frame.
 149   // Returns the current cursor position in captured frame.
 150   gfx::Point UpdateCursorState(const gfx::Rect& region_in_frame);
 151
 152   // Clears cursor state.
 153   void ClearCursorState();
 154
 155   // The window associated with the desktop.
 156   aura::Window* desktop_window_;
 157
 158   // The timer that kicks off period captures.
 159   base::Timer timer_;
 160
 161   // The id of the window being captured.
 162   DesktopMediaID window_id_;
 163
 164   // Makes all the decisions about which frames to copy, and how.
 165   scoped_refptr<ThreadSafeCaptureOracle> oracle_proxy_;
 166
 167   // The capture parameters for this capture.
 168   media::VideoCaptureParams capture_params_;
 169
 170   // YUV readback pipeline.
 171   scoped_ptr<content::ReadbackYUVInterface> yuv_readback_pipeline_;
 172
 173   // Cursor state.
 174   ui::Cursor last_cursor_;
 175   gfx::Point cursor_hot_point_;
 176   SkBitmap scaled_cursor_bitmap_;
 177
 178   // TODO(jiayl): Remove power_save_blocker_ when there is an API to keep the
 179   // screen from sleeping for the drive-by web.
 180   scoped_ptr<PowerSaveBlocker> power_save_blocker_;
 181
 182   DISALLOW_COPY_AND_ASSIGN(DesktopVideoCaptureMachine);
 183 };
 184
 185 DesktopVideoCaptureMachine::DesktopVideoCaptureMachine(
 186     const DesktopMediaID& source)
 187     : desktop_window_(NULL),
 188       timer_(true, true),
 189       window_id_(source) {}
 190
 191 DesktopVideoCaptureMachine::~DesktopVideoCaptureMachine() {}
 192
 193 bool DesktopVideoCaptureMachine::Start(
 194     const scoped_refptr<ThreadSafeCaptureOracle>& oracle_proxy,
 195     const media::VideoCaptureParams& params) {
 196   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 197
 198   desktop_window_ = content::DesktopMediaID::GetAuraWindowById(window_id_);
 199   if (!desktop_window_)
 200     return false;
 201
 202   // If the associated layer is already destroyed then return failure.
 203   ui::Layer* layer = desktop_window_->layer();
 204   if (!layer)
 205     return false;
 206
 207   DCHECK(oracle_proxy.get());
 208   oracle_proxy_ = oracle_proxy;
 209   capture_params_ = params;
 210
 211   // Update capture size.
 212   UpdateCaptureSize();
 213
 214   // Start observing window events.
 215   desktop_window_->AddObserver(this);
 216
 217   // Start observing compositor updates.
 218   if (desktop_window_->GetHost())
 219     desktop_window_->GetHost()->compositor()->AddObserver(this);
 220
 221   power_save_blocker_.reset(PowerSaveBlocker::Create(
 222       PowerSaveBlocker::kPowerSaveBlockPreventDisplaySleep,
 223       "DesktopCaptureDevice is running").release());
 224
 225   // Starts timer.
 226   timer_.Start(FROM_HERE, oracle_proxy_->min_capture_period(),
 227                base::Bind(&DesktopVideoCaptureMachine::Capture, AsWeakPtr(),
 228                           false));
 229
 230   started_ = true;
 231   return true;
 232 }
 233
 234 void DesktopVideoCaptureMachine::Stop(const base::Closure& callback) {
 235   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 236   power_save_blocker_.reset();
 237
 238   // Stop observing compositor and window events.
 239   if (desktop_window_) {
 240     if (desktop_window_->GetHost())
 241       desktop_window_->GetHost()->compositor()->RemoveObserver(this);
 242     desktop_window_->RemoveObserver(this);
 243     desktop_window_ = NULL;
 244   }
 245
 246   // Stop timer.
 247   timer_.Stop();
 248
 249   started_ = false;
 250
 251   callback.Run();
 252 }
 253
 254 void DesktopVideoCaptureMachine::UpdateCaptureSize() {
 255   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 256   if (oracle_proxy_ && desktop_window_) {
 257     ui::Layer* layer = desktop_window_->layer();
 258     gfx::Size capture_size =
 259         ui::ConvertSizeToPixel(layer, layer->bounds().size());
 260 #if defined(OS_CHROMEOS)
 261     // Pad desktop capture size to multiples of 16 pixels to accommodate HW
 262     // encoder. TODO(hshi): remove this hack. See http://crbug.com/402151
 263     capture_size.SetSize((capture_size.width() + 15) & ~15,
 264                          (capture_size.height() + 15) & ~15);
 265 #endif
 266     oracle_proxy_->UpdateCaptureSize(capture_size);
 267   }
 268   ClearCursorState();
 269 }
 270
 271 void DesktopVideoCaptureMachine::Capture(bool dirty) {
 272   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 273
 274   // Do not capture if the desktop window is already destroyed.
 275   if (!desktop_window_)
 276     return;
 277
 278   scoped_refptr<media::VideoFrame> frame;
 279   ThreadSafeCaptureOracle::CaptureFrameCallback capture_frame_cb;
 280
 281   const base::TimeTicks start_time = base::TimeTicks::Now();
 282   const VideoCaptureOracle::Event event =
 283       dirty ? VideoCaptureOracle::kCompositorUpdate
 284             : VideoCaptureOracle::kTimerPoll;
 285   if (oracle_proxy_->ObserveEventAndDecideCapture(
 286           event, gfx::Rect(), start_time, &frame, &capture_frame_cb)) {
 287     scoped_ptr<cc::CopyOutputRequest> request =
 288         cc::CopyOutputRequest::CreateRequest(
 289             base::Bind(&DesktopVideoCaptureMachine::DidCopyOutput,
 290                        AsWeakPtr(), frame, start_time, capture_frame_cb));
 291     gfx::Rect window_rect = gfx::Rect(desktop_window_->bounds().width(),
 292                                       desktop_window_->bounds().height());
 293     request->set_area(window_rect);
 294     desktop_window_->layer()->RequestCopyOfOutput(request.Pass());
 295   }
 296 }
 297
 298 void CopyOutputFinishedForVideo(
 299     base::TimeTicks start_time,
 300     const ThreadSafeCaptureOracle::CaptureFrameCallback& capture_frame_cb,
 301     const scoped_refptr<media::VideoFrame>& target,
 302     const SkBitmap& cursor_bitmap,
 303     const gfx::Point& cursor_position,
 304     scoped_ptr<cc::SingleReleaseCallback> release_callback,
 305     bool result) {
 306   if (!cursor_bitmap.isNull())
 307     RenderCursorOnVideoFrame(target, cursor_bitmap, cursor_position);
 308   release_callback->Run(0, false);
 309   capture_frame_cb.Run(target, start_time, result);
 310 }
 311
 312 void RunSingleReleaseCallback(scoped_ptr<cc::SingleReleaseCallback> cb,
 313                               uint32 sync_point) {
 314   cb->Run(sync_point, false);
 315 }
 316
 317 void DesktopVideoCaptureMachine::DidCopyOutput(
 318     scoped_refptr<media::VideoFrame> video_frame,
 319     base::TimeTicks start_time,
 320     const ThreadSafeCaptureOracle::CaptureFrameCallback& capture_frame_cb,
 321     scoped_ptr<cc::CopyOutputResult> result) {
 322   static bool first_call = true;
 323
 324   bool succeeded = ProcessCopyOutputResponse(
 325       video_frame, start_time, capture_frame_cb, result.Pass());
 326
 327   base::TimeDelta capture_time = base::TimeTicks::Now() - start_time;
 328   UMA_HISTOGRAM_TIMES(
 329       window_id_.type == DesktopMediaID::TYPE_SCREEN ? kUmaScreenCaptureTime
 330                                                      : kUmaWindowCaptureTime,
 331       capture_time);
 332
 333   if (first_call) {
 334     first_call = false;
 335     if (window_id_.type == DesktopMediaID::TYPE_SCREEN) {
 336       IncrementDesktopCaptureCounter(succeeded ? FIRST_SCREEN_CAPTURE_SUCCEEDED
 337                                                : FIRST_SCREEN_CAPTURE_FAILED);
 338     } else {
 339       IncrementDesktopCaptureCounter(succeeded
 340                                          ? FIRST_WINDOW_CAPTURE_SUCCEEDED
 341                                          : FIRST_WINDOW_CAPTURE_FAILED);
 342     }
 343   }
 344 }
 345
 346 bool DesktopVideoCaptureMachine::ProcessCopyOutputResponse(
 347     scoped_refptr<media::VideoFrame> video_frame,
 348     base::TimeTicks start_time,
 349     const ThreadSafeCaptureOracle::CaptureFrameCallback& capture_frame_cb,
 350     scoped_ptr<cc::CopyOutputResult> result) {
 351   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 352   if (result->IsEmpty() || result->size().IsEmpty() || !desktop_window_)
 353     return false;
 354
 355   if (capture_params_.requested_format.pixel_format ==
 356       media::PIXEL_FORMAT_TEXTURE) {
 357     DCHECK(!video_frame);
 358     cc::TextureMailbox texture_mailbox;
 359     scoped_ptr<cc::SingleReleaseCallback> release_callback;
 360     result->TakeTexture(&texture_mailbox, &release_callback);
 361     DCHECK(texture_mailbox.IsTexture());
 362     if (!texture_mailbox.IsTexture())
 363       return false;
 364     video_frame = media::VideoFrame::WrapNativeTexture(
 365         make_scoped_ptr(new gpu::MailboxHolder(texture_mailbox.mailbox(),
 366                                                texture_mailbox.target(),
 367                                                texture_mailbox.sync_point())),
 368         base::Bind(&RunSingleReleaseCallback, base::Passed(&release_callback)),
 369         result->size(),
 370         gfx::Rect(result->size()),
 371         result->size(),
 372         base::TimeDelta(),
 373         media::VideoFrame::ReadPixelsCB());
 374     capture_frame_cb.Run(video_frame, start_time, true);
 375     return true;
 376   }
 377
 378   // Compute the dest size we want after the letterboxing resize. Make the
 379   // coordinates and sizes even because we letterbox in YUV space
 380   // (see CopyRGBToVideoFrame). They need to be even for the UV samples to
 381   // line up correctly.
 382   // The video frame's coded_size() and the result's size() are both physical
 383   // pixels.
 384   gfx::Rect region_in_frame =
 385       media::ComputeLetterboxRegion(gfx::Rect(video_frame->coded_size()),
 386                                     result->size());
 387   region_in_frame = gfx::Rect(region_in_frame.x() & ~1,
 388                               region_in_frame.y() & ~1,
 389                               region_in_frame.width() & ~1,
 390                               region_in_frame.height() & ~1);
 391   if (region_in_frame.IsEmpty())
 392     return false;
 393
 394   ImageTransportFactory* factory = ImageTransportFactory::GetInstance();
 395   GLHelper* gl_helper = factory->GetGLHelper();
 396   if (!gl_helper)
 397     return false;
 398
 399   cc::TextureMailbox texture_mailbox;
 400   scoped_ptr<cc::SingleReleaseCallback> release_callback;
 401   result->TakeTexture(&texture_mailbox, &release_callback);
 402   DCHECK(texture_mailbox.IsTexture());
 403   if (!texture_mailbox.IsTexture())
 404     return false;
 405
 406   gfx::Rect result_rect(result->size());
 407   if (!yuv_readback_pipeline_ ||
 408       yuv_readback_pipeline_->scaler()->SrcSize() != result_rect.size() ||
 409       yuv_readback_pipeline_->scaler()->SrcSubrect() != result_rect ||
 410       yuv_readback_pipeline_->scaler()->DstSize() != region_in_frame.size()) {
 411     yuv_readback_pipeline_.reset(
 412         gl_helper->CreateReadbackPipelineYUV(GLHelper::SCALER_QUALITY_FAST,
 413                                              result_rect.size(),
 414                                              result_rect,
 415                                              video_frame->coded_size(),
 416                                              region_in_frame,
 417                                              true,
 418                                              true));
 419   }
 420
 421   gfx::Point cursor_position_in_frame = UpdateCursorState(region_in_frame);
 422   yuv_readback_pipeline_->ReadbackYUV(
 423       texture_mailbox.mailbox(),
 424       texture_mailbox.sync_point(),
 425       video_frame.get(),
 426       base::Bind(&CopyOutputFinishedForVideo,
 427                  start_time,
 428                  capture_frame_cb,
 429                  video_frame,
 430                  scaled_cursor_bitmap_,
 431                  cursor_position_in_frame,
 432                  base::Passed(&release_callback)));
 433   return true;
 434 }
 435
 436 gfx::Point DesktopVideoCaptureMachine::UpdateCursorState(
 437     const gfx::Rect& region_in_frame) {
 438   const gfx::Rect desktop_bounds = desktop_window_->layer()->bounds();
 439   gfx::NativeCursor cursor =
 440       desktop_window_->GetHost()->last_cursor();
 441   if (last_cursor_ != cursor) {
 442     SkBitmap cursor_bitmap;
 443     if (ui::GetCursorBitmap(cursor, &cursor_bitmap, &cursor_hot_point_)) {
 444       scaled_cursor_bitmap_ = skia::ImageOperations::Resize(
 445           cursor_bitmap,
 446           skia::ImageOperations::RESIZE_BEST,
 447           cursor_bitmap.width() * region_in_frame.width() /
 448               desktop_bounds.width(),
 449           cursor_bitmap.height() * region_in_frame.height() /
 450               desktop_bounds.height());
 451       last_cursor_ = cursor;
 452     } else {
 453       // Clear cursor state if ui::GetCursorBitmap failed so that we do not
 454       // render cursor on the captured frame.
 455       ClearCursorState();
 456     }
 457   }
 458
 459   gfx::Point cursor_position = aura::Env::GetInstance()->last_mouse_location();
 460   aura::client::GetScreenPositionClient(desktop_window_->GetRootWindow())->
 461       ConvertPointFromScreen(desktop_window_, &cursor_position);
 462   const gfx::Point hot_point_in_dip = ui::ConvertPointToDIP(
 463       desktop_window_->layer(), cursor_hot_point_);
 464   cursor_position.Offset(-desktop_bounds.x() - hot_point_in_dip.x(),
 465                          -desktop_bounds.y() - hot_point_in_dip.y());
 466   return gfx::Point(
 467       region_in_frame.x() + cursor_position.x() * region_in_frame.width() /
 468           desktop_bounds.width(),
 469       region_in_frame.y() + cursor_position.y() * region_in_frame.height() /
 470           desktop_bounds.height());
 471 }
 472
 473 void DesktopVideoCaptureMachine::ClearCursorState() {
 474   last_cursor_ = ui::Cursor();
 475   cursor_hot_point_ = gfx::Point();
 476   scaled_cursor_bitmap_.reset();
 477 }
 478
 479 void DesktopVideoCaptureMachine::OnWindowBoundsChanged(
 480     aura::Window* window,
 481     const gfx::Rect& old_bounds,
 482     const gfx::Rect& new_bounds) {
 483   DCHECK(desktop_window_ && window == desktop_window_);
 484
 485   // Post task to update capture size on UI thread.
 486   BrowserThread::PostTask(BrowserThread::UI, FROM_HERE, base::Bind(
 487       &DesktopVideoCaptureMachine::UpdateCaptureSize, AsWeakPtr()));
 488 }
 489
 490 void DesktopVideoCaptureMachine::OnWindowDestroyed(aura::Window* window) {
 491   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 492
 493   Stop(base::Bind(&base::DoNothing));
 494
 495   oracle_proxy_->ReportError("OnWindowDestroyed()");
 496 }
 497
 498 void DesktopVideoCaptureMachine::OnWindowAddedToRootWindow(
 499     aura::Window* window) {
 500   DCHECK(window == desktop_window_);
 501   window->GetHost()->compositor()->AddObserver(this);
 502 }
 503
 504 void DesktopVideoCaptureMachine::OnWindowRemovingFromRootWindow(
 505     aura::Window* window,
 506     aura::Window* new_root) {
 507   DCHECK(window == desktop_window_);
 508   window->GetHost()->compositor()->RemoveObserver(this);
 509 }
 510
 511 void DesktopVideoCaptureMachine::OnCompositingEnded(
 512     ui::Compositor* compositor) {
 513   BrowserThread::PostTask(BrowserThread::UI, FROM_HERE, base::Bind(
 514       &DesktopVideoCaptureMachine::Capture, AsWeakPtr(), true));
 515 }
 516
 517 }  // namespace
 518
 519 DesktopCaptureDeviceAura::DesktopCaptureDeviceAura(
 520     const DesktopMediaID& source)
 521     : core_(new ContentVideoCaptureDeviceCore(scoped_ptr<VideoCaptureMachine>(
 522         new DesktopVideoCaptureMachine(source)))) {}
 523
 524 DesktopCaptureDeviceAura::~DesktopCaptureDeviceAura() {
 525   DVLOG(2) << "DesktopCaptureDeviceAura@" << this << " destroying.";
 526 }
 527
 528 // static
 529 media::VideoCaptureDevice* DesktopCaptureDeviceAura::Create(
 530     const DesktopMediaID& source) {
 531   IncrementDesktopCaptureCounter(source.type == DesktopMediaID::TYPE_SCREEN
 532                                      ? SCREEN_CAPTURER_CREATED
 533                                      : WINDOW_CAPTURER_CREATED);
 534   return new DesktopCaptureDeviceAura(source);
 535 }
 536
 537 void DesktopCaptureDeviceAura::AllocateAndStart(
 538     const media::VideoCaptureParams& params,
 539     scoped_ptr<Client> client) {
 540   DVLOG(1) << "Allocating " << params.requested_format.frame_size.ToString();
 541   core_->AllocateAndStart(params, client.Pass());
 542 }
 543
 544 void DesktopCaptureDeviceAura::StopAndDeAllocate() {
 545   core_->StopAndDeAllocate();
 546 }
 547
 548 }  // namespace content