Implement all resolution change policies for desktop and tab capture.

content/browser/media/capture/desktop_capture_device.cc

 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/media/capture/desktop_capture_device.h"
 
 #include "base/bind.h"
 #include "base/location.h"
 #include "base/logging.h"
 #include "base/metrics/histogram.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/synchronization/lock.h"
 #include "base/threading/thread.h"
 #include "base/timer/timer.h"
+#include "content/browser/media/capture/capture_resolution_evaluator.h"
 #include "content/browser/media/capture/desktop_capture_device_uma_types.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/desktop_media_id.h"
 #include "content/public/browser/power_save_blocker.h"
 #include "media/base/video_util.h"
 #include "third_party/libyuv/include/libyuv/scale_argb.h"
 #include "third_party/webrtc/modules/desktop_capture/cropping_window_capturer.h"
 #include "third_party/webrtc/modules/desktop_capture/desktop_and_cursor_composer.h"
 #include "third_party/webrtc/modules/desktop_capture/desktop_capture_options.h"
 #include "third_party/webrtc/modules/desktop_capture/desktop_capturer.h"
@@ skipping 40 matching lines @@
                         scoped_ptr<Client> client);
 
   void SetNotificationWindowId(gfx::NativeViewId window_id);
 
  private:
 
   // webrtc::DesktopCapturer::Callback interface
   webrtc::SharedMemory* CreateSharedMemory(size_t size) override;
   void OnCaptureCompleted(webrtc::DesktopFrame* frame) override;
 
-  // Chooses new output properties based on the supplied source size and the
-  // properties requested to Allocate(), and dispatches OnFrameInfo[Changed]
-  // notifications.
-  void RefreshCaptureFormat(const webrtc::DesktopSize& frame_size);
-
   // Method that is scheduled on |task_runner_| to be called on regular interval
   // to capture a frame.
   void OnCaptureTimer();
 
   // Captures a frame and schedules timer for the next one.
   void CaptureFrameAndScheduleNext();
 
   // Captures a single frame.
   void DoCapture();
 
   // Task runner used for capturing operations.
   scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
 
   // The underlying DesktopCapturer instance used to capture frames.
   scoped_ptr<webrtc::DesktopCapturer> desktop_capturer_;
 
   // The device client which proxies device events to the controller. Accessed
   // on the task_runner_ thread.
   scoped_ptr<Client> client_;
 
-  // Requested video capture format (width, height, frame rate, etc).
-  media::VideoCaptureParams requested_params_;
-
-  // Actual video capture format being generated.
-  media::VideoCaptureFormat capture_format_;
+  // Requested video capture frame rate.
+  float requested_frame_rate_;
 
   // Size of frame most recently captured from the source.
   webrtc::DesktopSize previous_frame_size_;
 
+  // Determines the size of frames to deliver to the |client_|.
+  scoped_ptr<CaptureResolutionEvaluator> resolution_evaluator_;
+
   // DesktopFrame into which captured frames are down-scaled and/or letterboxed,
   // depending upon the caller's requested capture capabilities. If frames can
   // be returned to the caller directly then this is NULL.
   scoped_ptr<webrtc::DesktopFrame> output_frame_;
 
-  // Sub-rectangle of |output_frame_| into which the source will be scaled
-  // and/or letterboxed.
-  webrtc::DesktopRect output_rect_;
-
   // Timer used to capture the frame.
   base::OneShotTimer<Core> capture_timer_;
 
   // True when waiting for |desktop_capturer_| to capture current frame.
   bool capture_in_progress_;
 
   // True if the first capture call has returned. Used to log the first capture
   // result.
   bool first_capture_returned_;
 
@@ skipping 32 matching lines @@
     const media::VideoCaptureParams& params,
     scoped_ptr<Client> client) {
   DCHECK(task_runner_->BelongsToCurrentThread());
   DCHECK_GT(params.requested_format.frame_size.GetArea(), 0);
   DCHECK_GT(params.requested_format.frame_rate, 0);
   DCHECK(desktop_capturer_);
   DCHECK(client.get());
   DCHECK(!client_.get());
 
   client_ = client.Pass();
-  requested_params_ = params;
-
-  capture_format_ = requested_params_.requested_format;
-
-  // This capturer always outputs ARGB, non-interlaced.
-  capture_format_.pixel_format = media::PIXEL_FORMAT_ARGB;
+  requested_frame_rate_ = params.requested_format.frame_rate;
+  resolution_evaluator_.reset(new CaptureResolutionEvaluator(
+      params.requested_format.frame_size,
+      params.resolution_change_policy));
 
   power_save_blocker_.reset(
       PowerSaveBlocker::Create(
           PowerSaveBlocker::kPowerSaveBlockPreventDisplaySleep,
           PowerSaveBlocker::kReasonOther,
           "DesktopCaptureDevice is running").release());
 
   desktop_capturer_->Start(this);
 
   CaptureFrameAndScheduleNext();
@@ skipping 45 matching lines @@
   // The two UMA_ blocks must be put in its own scope since it creates a static
   // variable which expected constant histogram name.
   if (capturer_type_ == DesktopMediaID::TYPE_SCREEN) {
     UMA_HISTOGRAM_TIMES(kUmaScreenCaptureTime, capture_time);
   } else {
     UMA_HISTOGRAM_TIMES(kUmaWindowCaptureTime, capture_time);
   }
 
   scoped_ptr<webrtc::DesktopFrame> owned_frame(frame);
 
+  // If the frame size has changed, drop the output frame (if any), and
+  // determine the new output size.
+  if (!previous_frame_size_.equals(frame->size())) {
+    output_frame_.reset();
+    resolution_evaluator_->UpdateForNewSourceSize(
+        gfx::Size(frame->size().width(), frame->size().height()));
+    previous_frame_size_ = frame->size();
+  }
+  // Align to 2x2 pixel boundaries, as required by OnIncomingCapturedData() so
+  // it can convert the frame to I420 format.
+  const webrtc::DesktopSize output_size(
+      resolution_evaluator_->capture_size().width() & ~1,
+      resolution_evaluator_->capture_size().height() & ~1);
+  if (output_size.is_empty())
+    return;
+
   // On OSX We receive a 1x1 frame when the shared window is minimized. It
   // cannot be subsampled to I420 and will be dropped downstream. So we replace
   // it with a black frame to avoid the video appearing frozen at the last
   // frame.
   if (frame->size().width() == 1 || frame->size().height() == 1) {
     if (!black_frame_.get()) {
-      black_frame_.reset(
-          new webrtc::BasicDesktopFrame(
-              webrtc::DesktopSize(capture_format_.frame_size.width(),
-                                  capture_format_.frame_size.height())));
+      black_frame_.reset(new webrtc::BasicDesktopFrame(output_size));
       memset(black_frame_->data(),
              0,
              black_frame_->stride() * black_frame_->size().height());
     }
     owned_frame.reset();
     frame = black_frame_.get();
   }
 
-  // Handle initial frame size and size changes.
-  RefreshCaptureFormat(frame->size());
-
-  webrtc::DesktopSize output_size(capture_format_.frame_size.width(),
-                                  capture_format_.frame_size.height());
   size_t output_bytes = output_size.width() * output_size.height() *
       webrtc::DesktopFrame::kBytesPerPixel;
   const uint8_t* output_data = NULL;
 
   if (!frame->size().equals(output_size)) {
     // Down-scale and/or letterbox to the target format if the frame does not
     // match the output size.
 
     // Allocate a buffer of the correct size to scale the frame into.
-    // |output_frame_| is cleared whenever |output_rect_| changes, so we don't
+    // |output_frame_| is cleared whenever the output size changes, so we don't
     // need to worry about clearing out stale pixel data in letterboxed areas.
     if (!output_frame_) {
       output_frame_.reset(new webrtc::BasicDesktopFrame(output_size));
       memset(output_frame_->data(), 0, output_bytes);
     }
     DCHECK(output_frame_->size().equals(output_size));
 
     // TODO(wez): Optimize this to scale only changed portions of the output,
     // using ARGBScaleClip().
+    const webrtc::DesktopRect output_rect =
+        ComputeLetterboxRect(output_size, frame->size());
     uint8_t* output_rect_data = output_frame_->data() +
-        output_frame_->stride() * output_rect_.top() +
-        webrtc::DesktopFrame::kBytesPerPixel * output_rect_.left();
+        output_frame_->stride() * output_rect.top() +
+        webrtc::DesktopFrame::kBytesPerPixel * output_rect.left();
     libyuv::ARGBScale(frame->data(), frame->stride(),
                       frame->size().width(), frame->size().height(),
                       output_rect_data, output_frame_->stride(),
-                      output_rect_.width(), output_rect_.height(),
+                      output_rect.width(), output_rect.height(),
                       libyuv::kFilterBilinear);
     output_data = output_frame_->data();
   } else if (IsFrameUnpackedOrInverted(frame)) {
     // If |frame| is not packed top-to-bottom then create a packed top-to-bottom
     // copy.
     // This is required if the frame is inverted (see crbug.com/306876), or if
     // |frame| is cropped form a larger frame (see crbug.com/437740).
     if (!output_frame_) {
       output_frame_.reset(new webrtc::BasicDesktopFrame(output_size));
       memset(output_frame_->data(), 0, output_bytes);
     }
 
     output_frame_->CopyPixelsFrom(
         *frame,
         webrtc::DesktopVector(),
         webrtc::DesktopRect::MakeSize(frame->size()));
     output_data = output_frame_->data();
   } else {
     // If the captured frame matches the output size, we can return the pixel
     // data directly.
     output_data = frame->data();
   }
 
   client_->OnIncomingCapturedData(
-      output_data, output_bytes, capture_format_, 0, base::TimeTicks::Now());
-}
-
-void DesktopCaptureDevice::Core::RefreshCaptureFormat(
-    const webrtc::DesktopSize& frame_size) {
-  if (previous_frame_size_.equals(frame_size))
-    return;
-
-  // Clear the output frame, if any, since it will either need resizing, or
-  // clearing of stale data in letterbox areas, anyway.
-  output_frame_.reset();
-
-  if (previous_frame_size_.is_empty() ||
-      requested_params_.resolution_change_policy ==
-      media::RESOLUTION_POLICY_ANY_WITHIN_LIMIT) {
-    // If this is the first frame, or the receiver supports variable resolution
-    // then determine the output size by treating the requested width & height
-    // as maxima.
-    if (frame_size.width() >
-            requested_params_.requested_format.frame_size.width() ||
-        frame_size.height() >
-            requested_params_.requested_format.frame_size.height()) {
-      output_rect_ = ComputeLetterboxRect(
-          webrtc::DesktopSize(
-              requested_params_.requested_format.frame_size.width(),
-              requested_params_.requested_format.frame_size.height()),
-          frame_size);
-      output_rect_.Translate(-output_rect_.left(), -output_rect_.top());
-    } else {
-      output_rect_ = webrtc::DesktopRect::MakeSize(frame_size);
-    }
-    capture_format_.frame_size.SetSize(output_rect_.width(),
-                                       output_rect_.height());
-  } else {
-    // Otherwise the output frame size cannot change, so just scale and
-    // letterbox.
-    output_rect_ = ComputeLetterboxRect(
-        webrtc::DesktopSize(capture_format_.frame_size.width(),
-                            capture_format_.frame_size.height()),
-        frame_size);
-  }
-
-  previous_frame_size_ = frame_size;
+      output_data,
+      output_bytes,
+      media::VideoCaptureFormat(gfx::Size(output_size.width(),
+                                          output_size.height()),
+                                requested_frame_rate_,
+                                media::PIXEL_FORMAT_ARGB),
+      0,
+      base::TimeTicks::Now());
 }
 
 void DesktopCaptureDevice::Core::OnCaptureTimer() {
   DCHECK(task_runner_->BelongsToCurrentThread());
 
   if (!client_)
     return;
 
   CaptureFrameAndScheduleNext();
 }
 
 void DesktopCaptureDevice::Core::CaptureFrameAndScheduleNext() {
   DCHECK(task_runner_->BelongsToCurrentThread());
 
   base::TimeTicks started_time = base::TimeTicks::Now();
   DoCapture();
   base::TimeDelta last_capture_duration = base::TimeTicks::Now() - started_time;
 
   // Limit frame-rate to reduce CPU consumption.
   base::TimeDelta capture_period = std::max(
     (last_capture_duration * 100) / kMaximumCpuConsumptionPercentage,
-    base::TimeDelta::FromSeconds(1) / capture_format_.frame_rate);
+    base::TimeDelta::FromMicroseconds(static_cast<int64>(
+        1000000.0 / requested_frame_rate_ + 0.5 /* round to nearest int */)));
 
   // Schedule a task for the next frame.
   capture_timer_.Start(FROM_HERE, capture_period - last_capture_duration,
                        this, &Core::OnCaptureTimer);
 }
 
 void DesktopCaptureDevice::Core::DoCapture() {
   DCHECK(task_runner_->BelongsToCurrentThread());
   DCHECK(!capture_in_progress_);
 
@@ skipping 99 matching lines @@
 #else
   base::MessageLoop::Type thread_type = base::MessageLoop::TYPE_DEFAULT;
 #endif
 
   thread_.StartWithOptions(base::Thread::Options(thread_type, 0));
 
   core_.reset(new Core(thread_.task_runner(), capturer.Pass(), type));
 }
 
 }  // namespace content