src/content/browser/media/capture/desktop_capture_device.cc

   1 // Copyright (c) 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.h"
   6
   7 #include "base/bind.h"
   8 #include "base/location.h"
   9 #include "base/logging.h"
  10 #include "base/metrics/histogram.h"
  11 #include "base/strings/string_number_conversions.h"
  12 #include "base/synchronization/lock.h"
  13 #include "base/threading/thread.h"
  14 #include "base/timer/timer.h"
  15 #include "content/browser/media/capture/desktop_capture_device_uma_types.h"
  16 #include "content/public/browser/browser_thread.h"
  17 #include "content/public/browser/desktop_media_id.h"
  18 #include "media/base/video_util.h"
  19 #include "third_party/libyuv/include/libyuv/scale_argb.h"
  20 #include "third_party/webrtc/modules/desktop_capture/desktop_and_cursor_composer.h"
  21 #include "third_party/webrtc/modules/desktop_capture/desktop_capture_options.h"
  22 #include "third_party/webrtc/modules/desktop_capture/desktop_capturer.h"
  23 #include "third_party/webrtc/modules/desktop_capture/desktop_frame.h"
  24 #include "third_party/webrtc/modules/desktop_capture/mouse_cursor_monitor.h"
  25 #include "third_party/webrtc/modules/desktop_capture/screen_capturer.h"
  26 #include "third_party/webrtc/modules/desktop_capture/window_capturer.h"
  27
  28 namespace content {
  29
  30 namespace {
  31
  32 // Maximum CPU time percentage of a single core that can be consumed for desktop
  33 // capturing. This means that on systems where screen scraping is slow we may
  34 // need to capture at frame rate lower than requested. This is necessary to keep
  35 // UI responsive.
  36 const int kMaximumCpuConsumptionPercentage = 50;
  37
  38 webrtc::DesktopRect ComputeLetterboxRect(
  39     const webrtc::DesktopSize& max_size,
  40     const webrtc::DesktopSize& source_size) {
  41   gfx::Rect result = media::ComputeLetterboxRegion(
  42       gfx::Rect(0, 0, max_size.width(), max_size.height()),
  43       gfx::Size(source_size.width(), source_size.height()));
  44   return webrtc::DesktopRect::MakeLTRB(
  45       result.x(), result.y(), result.right(), result.bottom());
  46 }
  47
  48 }  // namespace
  49
  50 class DesktopCaptureDevice::Core : public webrtc::DesktopCapturer::Callback {
  51  public:
  52   Core(scoped_refptr<base::SingleThreadTaskRunner> task_runner,
  53        scoped_ptr<webrtc::DesktopCapturer> capturer,
  54        DesktopMediaID::Type type);
  55   virtual ~Core();
  56
  57   // Implementation of VideoCaptureDevice methods.
  58   void AllocateAndStart(const media::VideoCaptureParams& params,
  59                         scoped_ptr<Client> client);
  60
  61   void SetNotificationWindowId(gfx::NativeViewId window_id);
  62
  63  private:
  64
  65   // webrtc::DesktopCapturer::Callback interface
  66   virtual webrtc::SharedMemory* CreateSharedMemory(size_t size) OVERRIDE;
  67   virtual void OnCaptureCompleted(webrtc::DesktopFrame* frame) OVERRIDE;
  68
  69   // Chooses new output properties based on the supplied source size and the
  70   // properties requested to Allocate(), and dispatches OnFrameInfo[Changed]
  71   // notifications.
  72   void RefreshCaptureFormat(const webrtc::DesktopSize& frame_size);
  73
  74   // Method that is scheduled on |task_runner_| to be called on regular interval
  75   // to capture a frame.
  76   void OnCaptureTimer();
  77
  78   // Captures a frame and schedules timer for the next one.
  79   void CaptureFrameAndScheduleNext();
  80
  81   // Captures a single frame.
  82   void DoCapture();
  83
  84   // Task runner used for capturing operations.
  85   scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
  86
  87   // The underlying DesktopCapturer instance used to capture frames.
  88   scoped_ptr<webrtc::DesktopCapturer> desktop_capturer_;
  89
  90   // The device client which proxies device events to the controller. Accessed
  91   // on the task_runner_ thread.
  92   scoped_ptr<Client> client_;
  93
  94   // Requested video capture format (width, height, frame rate, etc).
  95   media::VideoCaptureParams requested_params_;
  96
  97   // Actual video capture format being generated.
  98   media::VideoCaptureFormat capture_format_;
  99
 100   // Size of frame most recently captured from the source.
 101   webrtc::DesktopSize previous_frame_size_;
 102
 103   // DesktopFrame into which captured frames are down-scaled and/or letterboxed,
 104   // depending upon the caller's requested capture capabilities. If frames can
 105   // be returned to the caller directly then this is NULL.
 106   scoped_ptr<webrtc::DesktopFrame> output_frame_;
 107
 108   // Sub-rectangle of |output_frame_| into which the source will be scaled
 109   // and/or letterboxed.
 110   webrtc::DesktopRect output_rect_;
 111
 112   // Timer used to capture the frame.
 113   base::OneShotTimer<Core> capture_timer_;
 114
 115   // True when waiting for |desktop_capturer_| to capture current frame.
 116   bool capture_in_progress_;
 117
 118   // True if the first capture call has returned. Used to log the first capture
 119   // result.
 120   bool first_capture_returned_;
 121
 122   // The type of the capturer.
 123   DesktopMediaID::Type capturer_type_;
 124
 125   scoped_ptr<webrtc::BasicDesktopFrame> black_frame_;
 126
 127   DISALLOW_COPY_AND_ASSIGN(Core);
 128 };
 129
 130 DesktopCaptureDevice::Core::Core(
 131     scoped_refptr<base::SingleThreadTaskRunner> task_runner,
 132     scoped_ptr<webrtc::DesktopCapturer> capturer,
 133     DesktopMediaID::Type type)
 134     : task_runner_(task_runner),
 135       desktop_capturer_(capturer.Pass()),
 136       capture_in_progress_(false),
 137       first_capture_returned_(false),
 138       capturer_type_(type) {
 139 }
 140
 141 DesktopCaptureDevice::Core::~Core() {
 142   DCHECK(task_runner_->BelongsToCurrentThread());
 143   client_.reset();
 144   output_frame_.reset();
 145   previous_frame_size_.set(0, 0);
 146   desktop_capturer_.reset();
 147 }
 148
 149 void DesktopCaptureDevice::Core::AllocateAndStart(
 150     const media::VideoCaptureParams& params,
 151     scoped_ptr<Client> client) {
 152   DCHECK(task_runner_->BelongsToCurrentThread());
 153   DCHECK_GT(params.requested_format.frame_size.GetArea(), 0);
 154   DCHECK_GT(params.requested_format.frame_rate, 0);
 155   DCHECK(desktop_capturer_);
 156   DCHECK(client.get());
 157   DCHECK(!client_.get());
 158
 159   client_ = client.Pass();
 160   requested_params_ = params;
 161
 162   capture_format_ = requested_params_.requested_format;
 163
 164   // This capturer always outputs ARGB, non-interlaced.
 165   capture_format_.pixel_format = media::PIXEL_FORMAT_ARGB;
 166
 167   desktop_capturer_->Start(this);
 168
 169   CaptureFrameAndScheduleNext();
 170 }
 171
 172 void DesktopCaptureDevice::Core::SetNotificationWindowId(
 173     gfx::NativeViewId window_id) {
 174   DCHECK(task_runner_->BelongsToCurrentThread());
 175   DCHECK(window_id);
 176   desktop_capturer_->SetExcludedWindow(window_id);
 177 }
 178
 179 webrtc::SharedMemory*
 180 DesktopCaptureDevice::Core::CreateSharedMemory(size_t size) {
 181   return NULL;
 182 }
 183
 184 void DesktopCaptureDevice::Core::OnCaptureCompleted(
 185     webrtc::DesktopFrame* frame) {
 186   DCHECK(task_runner_->BelongsToCurrentThread());
 187   DCHECK(capture_in_progress_);
 188
 189   if (!first_capture_returned_) {
 190     first_capture_returned_ = true;
 191     if (capturer_type_ == DesktopMediaID::TYPE_SCREEN) {
 192       IncrementDesktopCaptureCounter(frame ? FIRST_SCREEN_CAPTURE_SUCCEEDED
 193                                            : FIRST_SCREEN_CAPTURE_FAILED);
 194     } else {
 195       IncrementDesktopCaptureCounter(frame ? FIRST_WINDOW_CAPTURE_SUCCEEDED
 196                                            : FIRST_WINDOW_CAPTURE_FAILED);
 197     }
 198   }
 199
 200   capture_in_progress_ = false;
 201
 202   if (!frame) {
 203     std::string log("Failed to capture a frame.");
 204     LOG(ERROR) << log;
 205     client_->OnError(log);
 206     return;
 207   }
 208
 209   if (!client_)
 210     return;
 211
 212   base::TimeDelta capture_time(
 213       base::TimeDelta::FromMilliseconds(frame->capture_time_ms()));
 214   UMA_HISTOGRAM_TIMES(
 215       capturer_type_ == DesktopMediaID::TYPE_SCREEN ? kUmaScreenCaptureTime
 216                                                     : kUmaWindowCaptureTime,
 217       capture_time);
 218
 219   scoped_ptr<webrtc::DesktopFrame> owned_frame(frame);
 220
 221   // On OSX We receive a 1x1 frame when the shared window is minimized. It
 222   // cannot be subsampled to I420 and will be dropped downstream. So we replace
 223   // it with a black frame to avoid the video appearing frozen at the last
 224   // frame.
 225   if (frame->size().width() == 1 || frame->size().height() == 1) {
 226     if (!black_frame_.get()) {
 227       black_frame_.reset(
 228           new webrtc::BasicDesktopFrame(
 229               webrtc::DesktopSize(capture_format_.frame_size.width(),
 230                                   capture_format_.frame_size.height())));
 231       memset(black_frame_->data(),
 232              0,
 233              black_frame_->stride() * black_frame_->size().height());
 234     }
 235     owned_frame.reset();
 236     frame = black_frame_.get();
 237   }
 238
 239   // Handle initial frame size and size changes.
 240   RefreshCaptureFormat(frame->size());
 241
 242   webrtc::DesktopSize output_size(capture_format_.frame_size.width(),
 243                                   capture_format_.frame_size.height());
 244   size_t output_bytes = output_size.width() * output_size.height() *
 245       webrtc::DesktopFrame::kBytesPerPixel;
 246   const uint8_t* output_data = NULL;
 247   scoped_ptr<uint8_t[]> flipped_frame_buffer;
 248
 249   if (frame->size().equals(output_size)) {
 250     // If the captured frame matches the output size, we can return the pixel
 251     // data directly, without scaling.
 252     output_data = frame->data();
 253
 254     // If the |frame| generated by the screen capturer is inverted then we need
 255     // to flip |frame|.
 256     // This happens only on a specific platform. Refer to crbug.com/306876.
 257     if (frame->stride() < 0) {
 258       int height = frame->size().height();
 259       int bytes_per_row =
 260           frame->size().width() * webrtc::DesktopFrame::kBytesPerPixel;
 261       flipped_frame_buffer.reset(new uint8_t[output_bytes]);
 262       uint8_t* dest = flipped_frame_buffer.get();
 263       for (int row = 0; row < height; ++row) {
 264         memcpy(dest, output_data, bytes_per_row);
 265         dest += bytes_per_row;
 266         output_data += frame->stride();
 267       }
 268       output_data = flipped_frame_buffer.get();
 269     }
 270   } else {
 271     // Otherwise we need to down-scale and/or letterbox to the target format.
 272
 273     // Allocate a buffer of the correct size to scale the frame into.
 274     // |output_frame_| is cleared whenever |output_rect_| changes, so we don't
 275     // need to worry about clearing out stale pixel data in letterboxed areas.
 276     if (!output_frame_) {
 277       output_frame_.reset(new webrtc::BasicDesktopFrame(output_size));
 278       memset(output_frame_->data(), 0, output_bytes);
 279     }
 280     DCHECK(output_frame_->size().equals(output_size));
 281
 282     // TODO(wez): Optimize this to scale only changed portions of the output,
 283     // using ARGBScaleClip().
 284     uint8_t* output_rect_data = output_frame_->data() +
 285         output_frame_->stride() * output_rect_.top() +
 286         webrtc::DesktopFrame::kBytesPerPixel * output_rect_.left();
 287     libyuv::ARGBScale(frame->data(), frame->stride(),
 288                       frame->size().width(), frame->size().height(),
 289                       output_rect_data, output_frame_->stride(),
 290                       output_rect_.width(), output_rect_.height(),
 291                       libyuv::kFilterBilinear);
 292     output_data = output_frame_->data();
 293   }
 294
 295   client_->OnIncomingCapturedData(
 296       output_data, output_bytes, capture_format_, 0, base::TimeTicks::Now());
 297 }
 298
 299 void DesktopCaptureDevice::Core::RefreshCaptureFormat(
 300     const webrtc::DesktopSize& frame_size) {
 301   if (previous_frame_size_.equals(frame_size))
 302     return;
 303
 304   // Clear the output frame, if any, since it will either need resizing, or
 305   // clearing of stale data in letterbox areas, anyway.
 306   output_frame_.reset();
 307
 308   if (previous_frame_size_.is_empty() ||
 309       requested_params_.allow_resolution_change) {
 310     // If this is the first frame, or the receiver supports variable resolution
 311     // then determine the output size by treating the requested width & height
 312     // as maxima.
 313     if (frame_size.width() >
 314             requested_params_.requested_format.frame_size.width() ||
 315         frame_size.height() >
 316             requested_params_.requested_format.frame_size.height()) {
 317       output_rect_ = ComputeLetterboxRect(
 318           webrtc::DesktopSize(
 319               requested_params_.requested_format.frame_size.width(),
 320               requested_params_.requested_format.frame_size.height()),
 321           frame_size);
 322       output_rect_.Translate(-output_rect_.left(), -output_rect_.top());
 323     } else {
 324       output_rect_ = webrtc::DesktopRect::MakeSize(frame_size);
 325     }
 326     capture_format_.frame_size.SetSize(output_rect_.width(),
 327                                        output_rect_.height());
 328   } else {
 329     // Otherwise the output frame size cannot change, so just scale and
 330     // letterbox.
 331     output_rect_ = ComputeLetterboxRect(
 332         webrtc::DesktopSize(capture_format_.frame_size.width(),
 333                             capture_format_.frame_size.height()),
 334         frame_size);
 335   }
 336
 337   previous_frame_size_ = frame_size;
 338 }
 339
 340 void DesktopCaptureDevice::Core::OnCaptureTimer() {
 341   DCHECK(task_runner_->BelongsToCurrentThread());
 342
 343   if (!client_)
 344     return;
 345
 346   CaptureFrameAndScheduleNext();
 347 }
 348
 349 void DesktopCaptureDevice::Core::CaptureFrameAndScheduleNext() {
 350   DCHECK(task_runner_->BelongsToCurrentThread());
 351
 352   base::TimeTicks started_time = base::TimeTicks::Now();
 353   DoCapture();
 354   base::TimeDelta last_capture_duration = base::TimeTicks::Now() - started_time;
 355
 356   // Limit frame-rate to reduce CPU consumption.
 357   base::TimeDelta capture_period = std::max(
 358     (last_capture_duration * 100) / kMaximumCpuConsumptionPercentage,
 359     base::TimeDelta::FromSeconds(1) / capture_format_.frame_rate);
 360
 361   // Schedule a task for the next frame.
 362   capture_timer_.Start(FROM_HERE, capture_period - last_capture_duration,
 363                        this, &Core::OnCaptureTimer);
 364 }
 365
 366 void DesktopCaptureDevice::Core::DoCapture() {
 367   DCHECK(task_runner_->BelongsToCurrentThread());
 368   DCHECK(!capture_in_progress_);
 369
 370   capture_in_progress_ = true;
 371   desktop_capturer_->Capture(webrtc::DesktopRegion());
 372
 373   // Currently only synchronous implementations of DesktopCapturer are
 374   // supported.
 375   DCHECK(!capture_in_progress_);
 376 }
 377
 378 // static
 379 scoped_ptr<media::VideoCaptureDevice> DesktopCaptureDevice::Create(
 380     const DesktopMediaID& source) {
 381   webrtc::DesktopCaptureOptions options =
 382       webrtc::DesktopCaptureOptions::CreateDefault();
 383   // Leave desktop effects enabled during WebRTC captures.
 384   options.set_disable_effects(false);
 385
 386   scoped_ptr<webrtc::DesktopCapturer> capturer;
 387
 388   switch (source.type) {
 389     case DesktopMediaID::TYPE_SCREEN: {
 390 #if defined(OS_WIN)
 391       options.set_allow_use_magnification_api(true);
 392 #endif
 393       scoped_ptr<webrtc::ScreenCapturer> screen_capturer(
 394           webrtc::ScreenCapturer::Create(options));
 395       if (screen_capturer && screen_capturer->SelectScreen(source.id)) {
 396         capturer.reset(new webrtc::DesktopAndCursorComposer(
 397             screen_capturer.release(),
 398             webrtc::MouseCursorMonitor::CreateForScreen(options, source.id)));
 399         IncrementDesktopCaptureCounter(SCREEN_CAPTURER_CREATED);
 400       }
 401       break;
 402     }
 403
 404     case DesktopMediaID::TYPE_WINDOW: {
 405       scoped_ptr<webrtc::WindowCapturer> window_capturer(
 406           webrtc::WindowCapturer::Create(options));
 407       if (window_capturer && window_capturer->SelectWindow(source.id)) {
 408         window_capturer->BringSelectedWindowToFront();
 409         capturer.reset(new webrtc::DesktopAndCursorComposer(
 410             window_capturer.release(),
 411             webrtc::MouseCursorMonitor::CreateForWindow(options, source.id)));
 412         IncrementDesktopCaptureCounter(WINDOW_CAPTURER_CREATED);
 413       }
 414       break;
 415     }
 416
 417     default: {
 418       NOTREACHED();
 419     }
 420   }
 421
 422   scoped_ptr<media::VideoCaptureDevice> result;
 423   if (capturer)
 424     result.reset(new DesktopCaptureDevice(capturer.Pass(), source.type));
 425
 426   return result.Pass();
 427 }
 428
 429 DesktopCaptureDevice::~DesktopCaptureDevice() {
 430   DCHECK(!core_);
 431 }
 432
 433 void DesktopCaptureDevice::AllocateAndStart(
 434     const media::VideoCaptureParams& params,
 435     scoped_ptr<Client> client) {
 436   thread_.message_loop_proxy()->PostTask(
 437       FROM_HERE,
 438       base::Bind(&Core::AllocateAndStart, base::Unretained(core_.get()), params,
 439                  base::Passed(&client)));
 440 }
 441
 442 void DesktopCaptureDevice::StopAndDeAllocate() {
 443   if (core_) {
 444     thread_.message_loop_proxy()->DeleteSoon(FROM_HERE, core_.release());
 445     thread_.Stop();
 446   }
 447 }
 448
 449 void DesktopCaptureDevice::SetNotificationWindowId(
 450     gfx::NativeViewId window_id) {
 451   thread_.message_loop_proxy()->PostTask(
 452       FROM_HERE,
 453       base::Bind(&Core::SetNotificationWindowId, base::Unretained(core_.get()),
 454                  window_id));
 455 }
 456
 457 DesktopCaptureDevice::DesktopCaptureDevice(
 458     scoped_ptr<webrtc::DesktopCapturer> capturer,
 459     DesktopMediaID::Type type)
 460     : thread_("desktopCaptureThread") {
 461 #if defined(OS_WIN)
 462   // On Windows the thread must be a UI thread.
 463   base::MessageLoop::Type thread_type = base::MessageLoop::TYPE_UI;
 464 #else
 465   base::MessageLoop::Type thread_type = base::MessageLoop::TYPE_DEFAULT;
 466 #endif
 467
 468   thread_.StartWithOptions(base::Thread::Options(thread_type, 0));
 469
 470   core_.reset(new Core(thread_.message_loop_proxy(), capturer.Pass(), type));
 471 }
 472
 473 }  // namespace content