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/*
* Copyright (c) 2017 The WebRTC project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#include "modules/desktop_capture/blank_detector_desktop_capturer_wrapper.h"
#include <stdint.h>
#include <utility>
#include "modules/desktop_capture/desktop_geometry.h"
#include "modules/desktop_capture/desktop_region.h"
#include "rtc_base/checks.h"
#include "system_wrappers/include/metrics.h"
namespace webrtc {
BlankDetectorDesktopCapturerWrapper::BlankDetectorDesktopCapturerWrapper(
std::unique_ptr<DesktopCapturer> capturer,
RgbaColor blank_pixel,
bool check_per_capture)
: capturer_(std::move(capturer)),
blank_pixel_(blank_pixel),
check_per_capture_(check_per_capture) {
RTC_DCHECK(capturer_);
}
BlankDetectorDesktopCapturerWrapper::~BlankDetectorDesktopCapturerWrapper() =
default;
void BlankDetectorDesktopCapturerWrapper::Start(
DesktopCapturer::Callback* callback) {
callback_ = callback;
capturer_->Start(this);
}
void BlankDetectorDesktopCapturerWrapper::SetSharedMemoryFactory(
std::unique_ptr<SharedMemoryFactory> shared_memory_factory) {
capturer_->SetSharedMemoryFactory(std::move(shared_memory_factory));
}
void BlankDetectorDesktopCapturerWrapper::CaptureFrame() {
RTC_DCHECK(callback_);
capturer_->CaptureFrame();
}
void BlankDetectorDesktopCapturerWrapper::SetExcludedWindow(WindowId window) {
capturer_->SetExcludedWindow(window);
}
bool BlankDetectorDesktopCapturerWrapper::GetSourceList(SourceList* sources) {
return capturer_->GetSourceList(sources);
}
bool BlankDetectorDesktopCapturerWrapper::SelectSource(SourceId id) {
if (check_per_capture_) {
// If we start capturing a new source, we must reset these members
// so we don't short circuit the blank detection logic.
is_first_frame_ = true;
non_blank_frame_received_ = false;
}
return capturer_->SelectSource(id);
}
bool BlankDetectorDesktopCapturerWrapper::FocusOnSelectedSource() {
return capturer_->FocusOnSelectedSource();
}
bool BlankDetectorDesktopCapturerWrapper::IsOccluded(const DesktopVector& pos) {
return capturer_->IsOccluded(pos);
}
void BlankDetectorDesktopCapturerWrapper::OnCaptureResult(
Result result,
std::unique_ptr<DesktopFrame> frame) {
RTC_DCHECK(callback_);
if (result != Result::SUCCESS || non_blank_frame_received_) {
callback_->OnCaptureResult(result, std::move(frame));
return;
}
if (!frame) {
// Capturer can call the blank detector with empty frame. Blank
// detector regards it as a blank frame.
callback_->OnCaptureResult(Result::ERROR_TEMPORARY,
std::unique_ptr<DesktopFrame>());
return;
}
// If nothing has been changed in current frame, we do not need to check it
// again.
if (!frame->updated_region().is_empty() || is_first_frame_) {
last_frame_is_blank_ = IsBlankFrame(*frame);
is_first_frame_ = false;
}
RTC_HISTOGRAM_BOOLEAN("WebRTC.DesktopCapture.BlankFrameDetected",
last_frame_is_blank_);
if (!last_frame_is_blank_) {
non_blank_frame_received_ = true;
callback_->OnCaptureResult(Result::SUCCESS, std::move(frame));
return;
}
callback_->OnCaptureResult(Result::ERROR_TEMPORARY,
std::unique_ptr<DesktopFrame>());
}
bool BlankDetectorDesktopCapturerWrapper::IsBlankFrame(
const DesktopFrame& frame) const {
// We will check 7489 pixels for a frame with 1024 x 768 resolution.
for (int i = 0; i < frame.size().width() * frame.size().height(); i += 105) {
const int x = i % frame.size().width();
const int y = i / frame.size().width();
if (!IsBlankPixel(frame, x, y)) {
return false;
}
}
// We are verifying the pixel in the center as well.
return IsBlankPixel(frame, frame.size().width() / 2,
frame.size().height() / 2);
}
bool BlankDetectorDesktopCapturerWrapper::IsBlankPixel(
const DesktopFrame& frame,
int x,
int y) const {
uint8_t* pixel_data = frame.GetFrameDataAtPos(DesktopVector(x, y));
return RgbaColor(pixel_data) == blank_pixel_;
}
} // namespace webrtc