content/browser/renderer_host/media/video_capture_manager.cc

   1 // Copyright (c) 2012 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/renderer_host/media/video_capture_manager.h"
   6
   7 #include <set>
   8
   9 #include "base/bind.h"
  10 #include "base/bind_helpers.h"
  11 #include "base/logging.h"
  12 #include "base/message_loop/message_loop.h"
  13 #include "base/stl_util.h"
  14 #include "base/task_runner_util.h"
  15 #include "base/threading/sequenced_worker_pool.h"
  16 #include "content/browser/media/capture/web_contents_video_capture_device.h"
  17 #include "content/browser/renderer_host/media/video_capture_controller.h"
  18 #include "content/browser/renderer_host/media/video_capture_controller_event_handler.h"
  19 #include "content/public/browser/browser_thread.h"
  20 #include "content/public/browser/desktop_media_id.h"
  21 #include "content/public/common/content_switches.h"
  22 #include "content/public/common/media_stream_request.h"
  23 #include "media/base/bind_to_current_loop.h"
  24 #include "media/base/scoped_histogram_timer.h"
  25 #include "media/video/capture/video_capture_device.h"
  26 #include "media/video/capture/video_capture_device_factory.h"
  27
  28 #if defined(ENABLE_SCREEN_CAPTURE)
  29 #include "content/browser/media/capture/desktop_capture_device.h"
  30 #if defined(USE_AURA)
  31 #include "content/browser/media/capture/desktop_capture_device_aura.h"
  32 #endif
  33 #endif
  34
  35 namespace {
  36
  37 // Compares two VideoCaptureFormat by checking smallest frame_size area, then
  38 // by _largest_ frame_rate. Used to order a VideoCaptureFormats vector so that
  39 // the first entry for a given resolution has the largest frame rate, as needed
  40 // by the ConsolidateCaptureFormats() method.
  41 bool IsCaptureFormatSmaller(const media::VideoCaptureFormat& format1,
  42                             const media::VideoCaptureFormat& format2) {
  43   if (format1.frame_size.GetArea() == format2.frame_size.GetArea())
  44     return format1.frame_rate > format2.frame_rate;
  45   return format1.frame_size.GetArea() < format2.frame_size.GetArea();
  46 }
  47
  48 bool IsCaptureFormatSizeEqual(const media::VideoCaptureFormat& format1,
  49                               const media::VideoCaptureFormat& format2) {
  50   return format1.frame_size.GetArea() == format2.frame_size.GetArea();
  51 }
  52
  53 // This function receives a list of capture formats, removes duplicated
  54 // resolutions while keeping the highest frame rate for each, and forcing I420
  55 // pixel format.
  56 void ConsolidateCaptureFormats(media::VideoCaptureFormats* formats) {
  57   if (formats->empty())
  58     return;
  59   std::sort(formats->begin(), formats->end(), IsCaptureFormatSmaller);
  60   // Due to the ordering imposed, the largest frame_rate is kept while removing
  61   // duplicated resolutions.
  62   media::VideoCaptureFormats::iterator last =
  63       std::unique(formats->begin(), formats->end(), IsCaptureFormatSizeEqual);
  64   formats->erase(last, formats->end());
  65   // Mark all formats as I420, since this is what the renderer side will get
  66   // anyhow: the actual pixel format is decided at the device level.
  67   for (media::VideoCaptureFormats::iterator it = formats->begin();
  68        it != formats->end(); ++it) {
  69     it->pixel_format = media::PIXEL_FORMAT_I420;
  70   }
  71 }
  72
  73 // The maximum number of buffers in the capture pipeline.  See
  74 // VideoCaptureController ctor comments for more details.
  75 const int kMaxNumberOfBuffers = 3;
  76 const int kMaxNumberOfBuffersForTabCapture = 5;
  77
  78 // Used for logging capture events.
  79 // Elements in this enum should not be deleted or rearranged; the only
  80 // permitted operation is to add new elements before NUM_VIDEO_CAPTURE_EVENT.
  81 enum VideoCaptureEvent {
  82   VIDEO_CAPTURE_EVENT_START_CAPTURE = 0,
  83   VIDEO_CAPTURE_EVENT_STOP_CAPTURE_NORMAL = 1,
  84   VIDEO_CAPTURE_EVENT_STOP_CAPTURE_DUE_TO_ERROR = 2,
  85   NUM_VIDEO_CAPTURE_EVENT
  86 };
  87
  88 void LogVideoCaptureEvent(VideoCaptureEvent event) {
  89   UMA_HISTOGRAM_ENUMERATION("Media.VideoCaptureManager.Event",
  90                             event,
  91                             NUM_VIDEO_CAPTURE_EVENT);
  92 }
  93
  94 }  // namespace
  95
  96 namespace content {
  97
  98 VideoCaptureManager::DeviceEntry::DeviceEntry(
  99     MediaStreamType stream_type,
 100     const std::string& id,
 101     scoped_ptr<VideoCaptureController> controller)
 102     : stream_type(stream_type),
 103       id(id),
 104       video_capture_controller(controller.Pass()) {}
 105
 106 VideoCaptureManager::DeviceEntry::~DeviceEntry() {}
 107
 108 VideoCaptureManager::DeviceInfo::DeviceInfo() {}
 109
 110 VideoCaptureManager::DeviceInfo::DeviceInfo(
 111     const media::VideoCaptureDevice::Name& name,
 112     const media::VideoCaptureFormats& supported_formats)
 113     : name(name),
 114       supported_formats(supported_formats) {}
 115
 116 VideoCaptureManager::DeviceInfo::~DeviceInfo() {}
 117
 118 VideoCaptureManager::VideoCaptureManager(
 119     scoped_ptr<media::VideoCaptureDeviceFactory> factory)
 120     : listener_(NULL),
 121       new_capture_session_id_(1),
 122       video_capture_device_factory_(factory.Pass()) {
 123 }
 124
 125 VideoCaptureManager::~VideoCaptureManager() {
 126   DCHECK(devices_.empty());
 127 }
 128
 129 void VideoCaptureManager::Register(
 130     MediaStreamProviderListener* listener,
 131     const scoped_refptr<base::SingleThreadTaskRunner>& device_task_runner) {
 132   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 133   DCHECK(!listener_);
 134   DCHECK(!device_task_runner_.get());
 135   listener_ = listener;
 136   device_task_runner_ = device_task_runner;
 137 }
 138
 139 void VideoCaptureManager::Unregister() {
 140   DCHECK(listener_);
 141   listener_ = NULL;
 142 }
 143
 144 void VideoCaptureManager::EnumerateDevices(MediaStreamType stream_type) {
 145   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 146   DVLOG(1) << "VideoCaptureManager::EnumerateDevices, type " << stream_type;
 147   DCHECK(listener_);
 148   DCHECK_EQ(stream_type, MEDIA_DEVICE_VIDEO_CAPTURE);
 149
 150   // Bind a callback to ConsolidateDevicesInfoOnDeviceThread() with an argument
 151   // for another callback to OnDevicesInfoEnumerated() to be run in the current
 152   // loop, i.e. IO loop. Pass a timer for UMA histogram collection.
 153   base::Callback<void(scoped_ptr<media::VideoCaptureDevice::Names>)>
 154       devices_enumerated_callback =
 155           base::Bind(&VideoCaptureManager::ConsolidateDevicesInfoOnDeviceThread,
 156                      this,
 157                      media::BindToCurrentLoop(base::Bind(
 158                          &VideoCaptureManager::OnDevicesInfoEnumerated,
 159                          this,
 160                          stream_type,
 161                          base::Owned(new base::ElapsedTimer()))),
 162                      stream_type,
 163                      devices_info_cache_);
 164   // OK to use base::Unretained() since we own the VCDFactory and |this| is
 165   // bound in |devices_enumerated_callback|.
 166   device_task_runner_->PostTask(FROM_HERE,
 167       base::Bind(&media::VideoCaptureDeviceFactory::EnumerateDeviceNames,
 168                  base::Unretained(video_capture_device_factory_.get()),
 169                  devices_enumerated_callback));
 170 }
 171
 172 int VideoCaptureManager::Open(const StreamDeviceInfo& device_info) {
 173   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 174   DCHECK(listener_);
 175
 176   // Generate a new id for the session being opened.
 177   const media::VideoCaptureSessionId capture_session_id =
 178       new_capture_session_id_++;
 179
 180   DCHECK(sessions_.find(capture_session_id) == sessions_.end());
 181   DVLOG(1) << "VideoCaptureManager::Open, id " << capture_session_id;
 182
 183   // We just save the stream info for processing later.
 184   sessions_[capture_session_id] = device_info.device;
 185
 186   // Notify our listener asynchronously; this ensures that we return
 187   // |capture_session_id| to the caller of this function before using that same
 188   // id in a listener event.
 189   base::MessageLoop::current()->PostTask(FROM_HERE,
 190       base::Bind(&VideoCaptureManager::OnOpened, this,
 191                  device_info.device.type, capture_session_id));
 192   return capture_session_id;
 193 }
 194
 195 void VideoCaptureManager::Close(int capture_session_id) {
 196   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 197   DCHECK(listener_);
 198   DVLOG(1) << "VideoCaptureManager::Close, id " << capture_session_id;
 199
 200   SessionMap::iterator session_it = sessions_.find(capture_session_id);
 201   if (session_it == sessions_.end()) {
 202     NOTREACHED();
 203     return;
 204   }
 205
 206   DeviceEntry* const existing_device = GetDeviceEntryForMediaStreamDevice(
 207       session_it->second);
 208   if (existing_device) {
 209     // Remove any client that is still using the session. This is safe to call
 210     // even if there are no clients using the session.
 211     existing_device->video_capture_controller->StopSession(capture_session_id);
 212
 213     // StopSession() may have removed the last client, so we might need to
 214     // close the device.
 215     DestroyDeviceEntryIfNoClients(existing_device);
 216   }
 217
 218   // Notify listeners asynchronously, and forget the session.
 219   base::MessageLoop::current()->PostTask(FROM_HERE,
 220       base::Bind(&VideoCaptureManager::OnClosed, this, session_it->second.type,
 221                  capture_session_id));
 222   sessions_.erase(session_it);
 223 }
 224
 225 void VideoCaptureManager::DoStartDeviceOnDeviceThread(
 226     media::VideoCaptureSessionId session_id,
 227     DeviceEntry* entry,
 228     const media::VideoCaptureParams& params,
 229     scoped_ptr<media::VideoCaptureDevice::Client> device_client) {
 230   SCOPED_UMA_HISTOGRAM_TIMER("Media.VideoCaptureManager.StartDeviceTime");
 231   DCHECK(IsOnDeviceThread());
 232
 233   scoped_ptr<media::VideoCaptureDevice> video_capture_device;
 234   switch (entry->stream_type) {
 235     case MEDIA_DEVICE_VIDEO_CAPTURE: {
 236       // We look up the device id from the renderer in our local enumeration
 237       // since the renderer does not have all the information that might be
 238       // held in the browser-side VideoCaptureDevice::Name structure.
 239       DeviceInfo* found = FindDeviceInfoById(entry->id, devices_info_cache_);
 240       if (found) {
 241         video_capture_device =
 242             video_capture_device_factory_->Create(found->name);
 243       }
 244       break;
 245     }
 246     case MEDIA_TAB_VIDEO_CAPTURE: {
 247       video_capture_device.reset(
 248           WebContentsVideoCaptureDevice::Create(entry->id));
 249       break;
 250     }
 251     case MEDIA_DESKTOP_VIDEO_CAPTURE: {
 252 #if defined(ENABLE_SCREEN_CAPTURE)
 253       DesktopMediaID id = DesktopMediaID::Parse(entry->id);
 254 #if defined(USE_AURA)
 255       if (id.type == DesktopMediaID::TYPE_AURA_WINDOW) {
 256         video_capture_device.reset(DesktopCaptureDeviceAura::Create(id));
 257       } else
 258 #endif
 259       if (id.type != DesktopMediaID::TYPE_NONE &&
 260           id.type != DesktopMediaID::TYPE_AURA_WINDOW) {
 261         video_capture_device = DesktopCaptureDevice::Create(id);
 262         if (notification_window_ids_.find(session_id) !=
 263             notification_window_ids_.end()) {
 264           static_cast<DesktopCaptureDevice*>(video_capture_device.get())
 265               ->SetNotificationWindowId(notification_window_ids_[session_id]);
 266         }
 267       }
 268 #endif  // defined(ENABLE_SCREEN_CAPTURE)
 269       break;
 270     }
 271     default: {
 272       NOTIMPLEMENTED();
 273       break;
 274     }
 275   }
 276
 277   if (!video_capture_device) {
 278     device_client->OnError("Could not create capture device");
 279     return;
 280   }
 281
 282   video_capture_device->AllocateAndStart(params, device_client.Pass());
 283   entry->video_capture_device = video_capture_device.Pass();
 284 }
 285
 286 void VideoCaptureManager::StartCaptureForClient(
 287     media::VideoCaptureSessionId session_id,
 288     const media::VideoCaptureParams& params,
 289     base::ProcessHandle client_render_process,
 290     VideoCaptureControllerID client_id,
 291     VideoCaptureControllerEventHandler* client_handler,
 292     const DoneCB& done_cb) {
 293   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 294   DVLOG(1) << "VideoCaptureManager::StartCaptureForClient, "
 295            << params.requested_format.frame_size.ToString() << ", "
 296            << params.requested_format.frame_rate << ", #" << session_id << ")";
 297
 298   DeviceEntry* entry = GetOrCreateDeviceEntry(session_id);
 299   if (!entry) {
 300     done_cb.Run(base::WeakPtr<VideoCaptureController>());
 301     return;
 302   }
 303
 304   DCHECK(entry->video_capture_controller);
 305
 306   LogVideoCaptureEvent(VIDEO_CAPTURE_EVENT_START_CAPTURE);
 307
 308   // First client starts the device.
 309   if (entry->video_capture_controller->GetClientCount() == 0) {
 310     DVLOG(1) << "VideoCaptureManager starting device (type = "
 311              << entry->stream_type << ", id = " << entry->id << ")";
 312
 313     device_task_runner_->PostTask(
 314         FROM_HERE,
 315         base::Bind(
 316             &VideoCaptureManager::DoStartDeviceOnDeviceThread,
 317             this,
 318             session_id,
 319             entry,
 320             params,
 321             base::Passed(entry->video_capture_controller->NewDeviceClient())));
 322   }
 323   // Run the callback first, as AddClient() may trigger OnFrameInfo().
 324   done_cb.Run(entry->video_capture_controller->GetWeakPtr());
 325   entry->video_capture_controller->AddClient(
 326       client_id, client_handler, client_render_process, session_id, params);
 327 }
 328
 329 void VideoCaptureManager::StopCaptureForClient(
 330     VideoCaptureController* controller,
 331     VideoCaptureControllerID client_id,
 332     VideoCaptureControllerEventHandler* client_handler,
 333     bool aborted_due_to_error) {
 334   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 335   DCHECK(controller);
 336   DCHECK(client_handler);
 337
 338   LogVideoCaptureEvent(aborted_due_to_error ?
 339       VIDEO_CAPTURE_EVENT_STOP_CAPTURE_DUE_TO_ERROR :
 340       VIDEO_CAPTURE_EVENT_STOP_CAPTURE_NORMAL);
 341
 342   DeviceEntry* entry = GetDeviceEntryForController(controller);
 343   if (!entry) {
 344     NOTREACHED();
 345     return;
 346   }
 347   if (aborted_due_to_error) {
 348     SessionMap::iterator it;
 349     for (it = sessions_.begin(); it != sessions_.end(); ++it) {
 350       if (it->second.type == entry->stream_type &&
 351           it->second.id == entry->id) {
 352         listener_->Aborted(it->second.type, it->first);
 353         break;
 354       }
 355     }
 356   }
 357
 358   // Detach client from controller.
 359   media::VideoCaptureSessionId session_id =
 360       controller->RemoveClient(client_id, client_handler);
 361   DVLOG(1) << "VideoCaptureManager::StopCaptureForClient, session_id = "
 362            << session_id;
 363
 364   // If controller has no more clients, delete controller and device.
 365   DestroyDeviceEntryIfNoClients(entry);
 366 }
 367
 368 bool VideoCaptureManager::GetDeviceSupportedFormats(
 369     media::VideoCaptureSessionId capture_session_id,
 370     media::VideoCaptureFormats* supported_formats) {
 371   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 372   DCHECK(supported_formats->empty());
 373
 374   SessionMap::iterator it = sessions_.find(capture_session_id);
 375   if (it == sessions_.end())
 376     return false;
 377   DVLOG(1) << "GetDeviceSupportedFormats for device: " << it->second.name;
 378
 379   // Return all available formats of the device, regardless its started state.
 380   DeviceInfo* existing_device =
 381       FindDeviceInfoById(it->second.id, devices_info_cache_);
 382   if (existing_device)
 383     *supported_formats = existing_device->supported_formats;
 384   return true;
 385 }
 386
 387 bool VideoCaptureManager::GetDeviceFormatsInUse(
 388     media::VideoCaptureSessionId capture_session_id,
 389     media::VideoCaptureFormats* formats_in_use) {
 390   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 391   DCHECK(formats_in_use->empty());
 392
 393   SessionMap::iterator it = sessions_.find(capture_session_id);
 394   if (it == sessions_.end())
 395     return false;
 396   DVLOG(1) << "GetDeviceFormatsInUse for device: " << it->second.name;
 397
 398   // Return the currently in-use format(s) of the device, if it's started.
 399   DeviceEntry* device_in_use =
 400       GetDeviceEntryForMediaStreamDevice(it->second);
 401   if (device_in_use) {
 402     // Currently only one format-in-use is supported at the VCC level.
 403     formats_in_use->push_back(
 404         device_in_use->video_capture_controller->GetVideoCaptureFormat());
 405   }
 406   return true;
 407 }
 408
 409 void VideoCaptureManager::SetDesktopCaptureWindowId(
 410     media::VideoCaptureSessionId session_id,
 411     gfx::NativeViewId window_id) {
 412   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 413   SessionMap::iterator session_it = sessions_.find(session_id);
 414   if (session_it == sessions_.end()) {
 415     device_task_runner_->PostTask(
 416         FROM_HERE,
 417         base::Bind(
 418             &VideoCaptureManager::SaveDesktopCaptureWindowIdOnDeviceThread,
 419             this,
 420             session_id,
 421             window_id));
 422     return;
 423   }
 424
 425   DeviceEntry* const existing_device =
 426       GetDeviceEntryForMediaStreamDevice(session_it->second);
 427   if (!existing_device)
 428     return;
 429
 430   DCHECK_EQ(MEDIA_DESKTOP_VIDEO_CAPTURE, existing_device->stream_type);
 431   DesktopMediaID id = DesktopMediaID::Parse(existing_device->id);
 432   if (id.type == DesktopMediaID::TYPE_NONE ||
 433       id.type == DesktopMediaID::TYPE_AURA_WINDOW) {
 434     return;
 435   }
 436
 437   device_task_runner_->PostTask(
 438       FROM_HERE,
 439       base::Bind(&VideoCaptureManager::SetDesktopCaptureWindowIdOnDeviceThread,
 440                  this,
 441                  existing_device,
 442                  window_id));
 443 }
 444
 445 void VideoCaptureManager::DoStopDeviceOnDeviceThread(DeviceEntry* entry) {
 446   SCOPED_UMA_HISTOGRAM_TIMER("Media.VideoCaptureManager.StopDeviceTime");
 447   DCHECK(IsOnDeviceThread());
 448   if (entry->video_capture_device) {
 449     entry->video_capture_device->StopAndDeAllocate();
 450   }
 451   entry->video_capture_device.reset();
 452 }
 453
 454 void VideoCaptureManager::OnOpened(
 455     MediaStreamType stream_type,
 456     media::VideoCaptureSessionId capture_session_id) {
 457   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 458   if (!listener_) {
 459     // Listener has been removed.
 460     return;
 461   }
 462   listener_->Opened(stream_type, capture_session_id);
 463 }
 464
 465 void VideoCaptureManager::OnClosed(
 466     MediaStreamType stream_type,
 467     media::VideoCaptureSessionId capture_session_id) {
 468   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 469   if (!listener_) {
 470     // Listener has been removed.
 471     return;
 472   }
 473   listener_->Closed(stream_type, capture_session_id);
 474 }
 475
 476 void VideoCaptureManager::OnDevicesInfoEnumerated(
 477     MediaStreamType stream_type,
 478     base::ElapsedTimer* timer,
 479     const DeviceInfos& new_devices_info_cache) {
 480   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 481   UMA_HISTOGRAM_TIMES(
 482       "Media.VideoCaptureManager.GetAvailableDevicesInfoOnDeviceThreadTime",
 483       timer->Elapsed());
 484   if (!listener_) {
 485     // Listener has been removed.
 486     return;
 487   }
 488   devices_info_cache_ = new_devices_info_cache;
 489
 490   // Walk the |devices_info_cache_| and transform from VCD::Name to
 491   // StreamDeviceInfo for return purposes.
 492   StreamDeviceInfoArray devices;
 493   for (DeviceInfos::const_iterator it = devices_info_cache_.begin();
 494        it != devices_info_cache_.end(); ++it) {
 495     devices.push_back(StreamDeviceInfo(
 496         stream_type, it->name.GetNameAndModel(), it->name.id()));
 497   }
 498   listener_->DevicesEnumerated(stream_type, devices);
 499 }
 500
 501 bool VideoCaptureManager::IsOnDeviceThread() const {
 502   return device_task_runner_->BelongsToCurrentThread();
 503 }
 504
 505 void VideoCaptureManager::ConsolidateDevicesInfoOnDeviceThread(
 506     base::Callback<void(const DeviceInfos&)> on_devices_enumerated_callback,
 507     MediaStreamType stream_type,
 508     const DeviceInfos& old_device_info_cache,
 509     scoped_ptr<media::VideoCaptureDevice::Names> names_snapshot) {
 510   DCHECK(IsOnDeviceThread());
 511   // Construct |new_devices_info_cache| with the cached devices that are still
 512   // present in the system, and remove their names from |names_snapshot|, so we
 513   // keep there the truly new devices.
 514   DeviceInfos new_devices_info_cache;
 515   for (DeviceInfos::const_iterator it_device_info =
 516            old_device_info_cache.begin();
 517        it_device_info != old_device_info_cache.end(); ++it_device_info) {
 518      for (media::VideoCaptureDevice::Names::iterator it =
 519          names_snapshot->begin();
 520           it != names_snapshot->end(); ++it) {
 521       if (it_device_info->name.id() == it->id()) {
 522         new_devices_info_cache.push_back(*it_device_info);
 523         names_snapshot->erase(it);
 524         break;
 525       }
 526     }
 527   }
 528
 529   // Get the supported capture formats for the new devices in |names_snapshot|.
 530   for (media::VideoCaptureDevice::Names::const_iterator it =
 531       names_snapshot->begin();
 532        it != names_snapshot->end(); ++it) {
 533     media::VideoCaptureFormats supported_formats;
 534     DeviceInfo device_info(*it, media::VideoCaptureFormats());
 535     video_capture_device_factory_->GetDeviceSupportedFormats(
 536         *it, &(device_info.supported_formats));
 537     ConsolidateCaptureFormats(&device_info.supported_formats);
 538     new_devices_info_cache.push_back(device_info);
 539   }
 540
 541   on_devices_enumerated_callback.Run(new_devices_info_cache);
 542 }
 543
 544 VideoCaptureManager::DeviceEntry*
 545 VideoCaptureManager::GetDeviceEntryForMediaStreamDevice(
 546     const MediaStreamDevice& device_info) {
 547   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 548
 549   for (DeviceEntries::iterator it = devices_.begin();
 550        it != devices_.end(); ++it) {
 551     DeviceEntry* device = *it;
 552     if (device_info.type == device->stream_type &&
 553         device_info.id == device->id) {
 554       return device;
 555     }
 556   }
 557   return NULL;
 558 }
 559
 560 VideoCaptureManager::DeviceEntry*
 561 VideoCaptureManager::GetDeviceEntryForController(
 562     const VideoCaptureController* controller) const {
 563   // Look up |controller| in |devices_|.
 564   for (DeviceEntries::const_iterator it = devices_.begin();
 565        it != devices_.end(); ++it) {
 566     if ((*it)->video_capture_controller.get() == controller) {
 567       return *it;
 568     }
 569   }
 570   return NULL;
 571 }
 572
 573 void VideoCaptureManager::DestroyDeviceEntryIfNoClients(DeviceEntry* entry) {
 574   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 575   // Removal of the last client stops the device.
 576   if (entry->video_capture_controller->GetClientCount() == 0) {
 577     DVLOG(1) << "VideoCaptureManager stopping device (type = "
 578              << entry->stream_type << ", id = " << entry->id << ")";
 579
 580     // The DeviceEntry is removed from |devices_| immediately. The controller is
 581     // deleted immediately, and the device is freed asynchronously. After this
 582     // point, subsequent requests to open this same device ID will create a new
 583     // DeviceEntry, VideoCaptureController, and VideoCaptureDevice.
 584     devices_.erase(entry);
 585     entry->video_capture_controller.reset();
 586     device_task_runner_->PostTask(
 587         FROM_HERE,
 588         base::Bind(&VideoCaptureManager::DoStopDeviceOnDeviceThread, this,
 589                    base::Owned(entry)));
 590   }
 591 }
 592
 593 VideoCaptureManager::DeviceEntry* VideoCaptureManager::GetOrCreateDeviceEntry(
 594     media::VideoCaptureSessionId capture_session_id) {
 595   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 596
 597   SessionMap::iterator session_it = sessions_.find(capture_session_id);
 598   if (session_it == sessions_.end()) {
 599     return NULL;
 600   }
 601   const MediaStreamDevice& device_info = session_it->second;
 602
 603   // Check if another session has already opened this device. If so, just
 604   // use that opened device.
 605   DeviceEntry* const existing_device =
 606       GetDeviceEntryForMediaStreamDevice(device_info);
 607   if (existing_device) {
 608     DCHECK_EQ(device_info.type, existing_device->stream_type);
 609     return existing_device;
 610   }
 611
 612   const int max_buffers = device_info.type == MEDIA_TAB_VIDEO_CAPTURE ?
 613       kMaxNumberOfBuffersForTabCapture : kMaxNumberOfBuffers;
 614   scoped_ptr<VideoCaptureController> video_capture_controller(
 615       new VideoCaptureController(max_buffers));
 616   DeviceEntry* new_device = new DeviceEntry(device_info.type,
 617                                             device_info.id,
 618                                             video_capture_controller.Pass());
 619   devices_.insert(new_device);
 620   return new_device;
 621 }
 622
 623 VideoCaptureManager::DeviceInfo* VideoCaptureManager::FindDeviceInfoById(
 624     const std::string& id,
 625     DeviceInfos& device_vector) {
 626   for (DeviceInfos::iterator it = device_vector.begin();
 627        it != device_vector.end(); ++it) {
 628     if (it->name.id() == id)
 629       return &(*it);
 630   }
 631   return NULL;
 632 }
 633
 634 void VideoCaptureManager::SetDesktopCaptureWindowIdOnDeviceThread(
 635     DeviceEntry* entry,
 636     gfx::NativeViewId window_id) {
 637   DCHECK(IsOnDeviceThread());
 638   DCHECK(entry->stream_type == MEDIA_DESKTOP_VIDEO_CAPTURE);
 639 #if defined(ENABLE_SCREEN_CAPTURE)
 640   DesktopCaptureDevice* device =
 641       static_cast<DesktopCaptureDevice*>(entry->video_capture_device.get());
 642   device->SetNotificationWindowId(window_id);
 643 #endif
 644 }
 645
 646 void VideoCaptureManager::SaveDesktopCaptureWindowIdOnDeviceThread(
 647     media::VideoCaptureSessionId session_id,
 648     gfx::NativeViewId window_id) {
 649   DCHECK(IsOnDeviceThread());
 650   DCHECK(notification_window_ids_.find(session_id) ==
 651          notification_window_ids_.end());
 652   notification_window_ids_[session_id] = window_id;
 653 }
 654
 655 }  // namespace content