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// Copyright (c) 2010 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 "remoting/host/capturer_gdi.h"
#include "remoting/host/differ.h"
#include "ui/gfx/rect.h"
namespace remoting {
// 3780 pixels per meter is equivalent to 96 DPI, typical on desktop monitors.
static const int kPixelsPerMeter = 3780;
// 32 bit RGBA is 4 bytes per pixel.
static const int kBytesPerPixel = 4;
CapturerGdi::CapturerGdi(MessageLoop* message_loop)
: Capturer(message_loop),
desktop_dc_(NULL),
memory_dc_(NULL),
dc_size_(0, 0),
capture_fullscreen_(true) {
memset(target_bitmap_, 0, sizeof(target_bitmap_));
memset(buffers_, 0, sizeof(buffers_));
ScreenConfigurationChanged();
}
CapturerGdi::~CapturerGdi() {
ReleaseBuffers();
}
void CapturerGdi::ReleaseBuffers() {
for (int i = kNumBuffers - 1; i >= 0; i--) {
if (target_bitmap_[i]) {
DeleteObject(target_bitmap_[i]);
target_bitmap_[i] = NULL;
}
if (buffers_[i].data) {
DeleteObject(buffers_[i].data);
buffers_[i].data = NULL;
}
}
desktop_dc_ = NULL;
if (memory_dc_) {
DeleteDC(memory_dc_);
memory_dc_ = NULL;
}
}
void CapturerGdi::ScreenConfigurationChanged() {
// We poll for screen configuration changes, so ignore notifications.
}
void CapturerGdi::UpdateBufferCapture(const gfx::Size& size) {
// Make sure the DCs have the correct dimensions.
if (size != dc_size_) {
// TODO(simonmorris): screen dimensions changing isn't equivalent to needing
// a new DC, but it's good enough for now.
desktop_dc_ = GetDC(GetDesktopWindow());
if (memory_dc_)
DeleteDC(memory_dc_);
memory_dc_ = CreateCompatibleDC(desktop_dc_);
dc_size_ = size;
}
// Make sure the current bitmap has the correct dimensions.
if (size != buffers_[current_buffer_].size) {
ReallocateBuffer(current_buffer_, size);
capture_fullscreen_ = true;
}
}
void CapturerGdi::ReallocateBuffer(int buffer_index, const gfx::Size& size) {
// Delete any previously constructed bitmap.
if (target_bitmap_[buffer_index]) {
DeleteObject(target_bitmap_[buffer_index]);
target_bitmap_[buffer_index] = NULL;
}
if (buffers_[buffer_index].data) {
DeleteObject(buffers_[buffer_index].data);
buffers_[buffer_index].data = NULL;
}
// Create a bitmap to keep the desktop image.
int rounded_width = (size.width() + 3) & (~3);
// Dimensions of screen.
pixel_format_ = media::VideoFrame::RGB32;
int bytes_per_row = rounded_width * kBytesPerPixel;
// Create a device independent bitmap (DIB) that is the same size.
BITMAPINFO bmi;
memset(&bmi, 0, sizeof(bmi));
bmi.bmiHeader.biHeight = -size.height();
bmi.bmiHeader.biWidth = size.width();
bmi.bmiHeader.biPlanes = 1;
bmi.bmiHeader.biBitCount = kBytesPerPixel * 8;
bmi.bmiHeader.biSize = sizeof(bmi.bmiHeader);
bmi.bmiHeader.biSizeImage = bytes_per_row * size.height();
bmi.bmiHeader.biXPelsPerMeter = kPixelsPerMeter;
bmi.bmiHeader.biYPelsPerMeter = kPixelsPerMeter;
// Create memory for the buffers.
target_bitmap_[buffer_index] =
CreateDIBSection(desktop_dc_, &bmi, DIB_RGB_COLORS,
static_cast<void**>(&buffers_[buffer_index].data),
NULL, 0);
buffers_[buffer_index].size = gfx::Size(bmi.bmiHeader.biWidth,
std::abs(bmi.bmiHeader.biHeight));
buffers_[buffer_index].bytes_per_pixel = bmi.bmiHeader.biBitCount / 8;
buffers_[buffer_index].bytes_per_row =
bmi.bmiHeader.biSizeImage / std::abs(bmi.bmiHeader.biHeight);
}
void CapturerGdi::CalculateInvalidRects() {
CaptureImage();
const VideoFrameBuffer& current = buffers_[current_buffer_];
if (IsCaptureFullScreen(current.size.width(), current.size.height()))
capture_fullscreen_ = true;
if (capture_fullscreen_) {
InvalidateFullScreen(current.size.width(), current.size.height());
capture_fullscreen_ = false;
return;
}
// Find the previous and current screens.
int prev_buffer_id = current_buffer_ - 1;
if (prev_buffer_id < 0) {
prev_buffer_id = kNumBuffers - 1;
}
const VideoFrameBuffer& prev = buffers_[prev_buffer_id];
// Maybe the previous and current screens can't be differenced.
if ((current.size != prev.size) ||
(current.bytes_per_pixel != prev.bytes_per_pixel) ||
(current.bytes_per_row != prev.bytes_per_row)) {
InvalidateFullScreen(current.size.width(), current.size.height());
return;
}
// Make sure the differencer is set up correctly for these previous and
// current screens.
if (!differ_.get() ||
(differ_->width() != current.size.width()) ||
(differ_->height() != current.size.height()) ||
(differ_->bytes_per_pixel() != current.bytes_per_pixel) ||
(differ_->bytes_per_row() != current.bytes_per_row)) {
differ_.reset(new Differ(current.size.width(), current.size.height(),
current.bytes_per_pixel, current.bytes_per_row));
}
InvalidRects rects;
differ_->CalcDirtyRects(prev.data, current.data, &rects);
InvalidateRects(rects);
}
void CapturerGdi::CaptureRects(const InvalidRects& rects,
CaptureCompletedCallback* callback) {
const VideoFrameBuffer& buffer = buffers_[current_buffer_];
DataPlanes planes;
planes.data[0] = static_cast<uint8*>(buffer.data);
planes.strides[0] = buffer.bytes_per_row;
scoped_refptr<CaptureData> data(new CaptureData(planes,
buffer.size.width(),
buffer.size.height(),
pixel_format_));
data->mutable_dirty_rects() = rects;
FinishCapture(data, callback);
}
void CapturerGdi::CaptureImage() {
// Make sure the structures we use to capture the image have the correct size.
UpdateBufferCapture(GetScreenSize());
// Select the target bitmap into the memory dc.
SelectObject(memory_dc_, target_bitmap_[current_buffer_]);
// And then copy the rect from desktop to memory.
BitBlt(memory_dc_, 0, 0, buffers_[current_buffer_].size.width(),
buffers_[current_buffer_].size.height(), desktop_dc_, 0, 0,
SRCCOPY | CAPTUREBLT);
}
gfx::Size CapturerGdi::GetScreenSize() {
return gfx::Size(GetSystemMetrics(SM_CXSCREEN),
GetSystemMetrics(SM_CYSCREEN));
}
// static
Capturer* Capturer::Create(MessageLoop* message_loop) {
return new CapturerGdi(message_loop);
}
} // namespace remoting
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