remoting/host/capturer_linux.cc - chromium/src - Git at Google

 // 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_linux.h"

 #include <X11/Xlib.h>
 #include <X11/Xutil.h>
 #include <X11/extensions/Xdamage.h>

 #include <set>

 #include "remoting/base/types.h"

 namespace remoting {

 static int IndexOfLowestBit(unsigned int mask) {
   int i = 0;

   // Extra-special do-while premature optimization, just to make dmaclach@
   // happy.
   do {
     if (mask & 1) {
       return i;
     }
     mask >>= 1;
     ++i;
   } while (mask);

   NOTREACHED() << "mask should never be 0.";
   return 0;
 }

 static bool IsRgb32(XImage* image) {
   return (IndexOfLowestBit(image->red_mask) == 16) &&
          (IndexOfLowestBit(image->green_mask) == 8) &&
          (IndexOfLowestBit(image->blue_mask) == 0);
 }

 static uint32_t* GetRowStart(uint8* buffer_start, int stride, int cur_row) {
   return reinterpret_cast<uint32_t*>(buffer_start + (cur_row * stride));
 }

 // Private Implementation pattern to avoid leaking the X11 types into the header
 // file.
 class CapturerLinuxPimpl {
  public:
   explicit CapturerLinuxPimpl(CapturerLinux* capturer);
   ~CapturerLinuxPimpl();

   bool Init();  // TODO(ajwong): Do we really want this to be synchronous?
   void CalculateInvalidRects();
   void CaptureRects(const InvalidRects& rects,
                     Capturer::CaptureCompletedCallback* callback);

  private:
   void DeinitXlib();
   // We expose two forms of blitting to handle variations in the pixel format.
   // In FastBlit, the operation is effectively a memcpy.
   void FastBlit(XImage* image, int dest_x, int dest_y,
                 CaptureData* capture_data);
   void SlowBlit(XImage* image, int dest_x, int dest_y,
                 CaptureData* capture_data);

   static const int kBytesPerPixel = 4;

   // Reference to containing class so we can access friend functions.
   // Not owned.
   CapturerLinux* capturer_;

   // X11 graphics context.
   Display* display_;
   GC gc_;
   Window root_window_;

   // XDamage information.
   Damage damage_handle_;
   int damage_event_base_;
   int damage_error_base_;

   // Capture state.
   uint8* buffers_[CapturerLinux::kNumBuffers];
   int stride_;
   bool capture_fullscreen_;
 };

 CapturerLinux::CapturerLinux(MessageLoop* message_loop)
     : Capturer(message_loop),
       pimpl_(new CapturerLinuxPimpl(this)) {
   // TODO(ajwong): This should be moved into an Init() method on Capturer
   // itself.  Then we can remove the CHECK.
   CHECK(pimpl_->Init());
 }

 CapturerLinux::~CapturerLinux() {
 }

 void CapturerLinux::ScreenConfigurationChanged() {
   // TODO(ajwong): Support resolution changes.
   NOTIMPLEMENTED();
 }

 void CapturerLinux::CalculateInvalidRects() {
   pimpl_->CalculateInvalidRects();
 }

 void CapturerLinux::CaptureRects(const InvalidRects& rects,
                                  CaptureCompletedCallback* callback) {
   pimpl_->CaptureRects(rects, callback);
 }

 CapturerLinuxPimpl::CapturerLinuxPimpl(CapturerLinux* capturer)
     : capturer_(capturer),
       display_(NULL),
       gc_(NULL),
       root_window_(BadValue),
       damage_handle_(BadValue),
       damage_event_base_(-1),
       damage_error_base_(-1),
       stride_(0),
       capture_fullscreen_(true) {
   for (int i = 0; i < CapturerLinux::kNumBuffers; i++) {
     buffers_[i] = NULL;
   }
 }

 CapturerLinuxPimpl::~CapturerLinuxPimpl() {
   DeinitXlib();

   for (int i = 0; i < CapturerLinux::kNumBuffers; i++) {
     delete [] buffers_[i];
     buffers_[i] = NULL;
   }
 }

 bool CapturerLinuxPimpl::Init() {
   // TODO(ajwong): We should specify the display string we are attaching to
   // in the constructor.
   display_ = XOpenDisplay(NULL);
   if (!display_) {
     LOG(ERROR) << "Unable to open display";
     return false;
   }

   root_window_ = RootWindow(display_, DefaultScreen(display_));
   if (root_window_ == BadValue) {
     LOG(ERROR) << "Unable to get the root window";
     DeinitXlib();
     return false;
   }

   gc_ = XCreateGC(display_, root_window_, 0, NULL);
   if (gc_ == NULL) {
     LOG(ERROR) << "Unable to get graphics context";
     DeinitXlib();
     return false;
   }

   // Setup XDamage to report changes in the damage window.  Mark the whole
   // window as invalid.
   if (!XDamageQueryExtension(display_, &damage_event_base_,
                              &damage_error_base_)) {
     LOG(ERROR) << "Server does not support XDamage.";
     DeinitXlib();
     return false;
   }
   damage_handle_ = XDamageCreate(display_, root_window_,
                                  XDamageReportDeltaRectangles);
   if (damage_handle_ == BadValue) {
     LOG(ERROR) << "Unable to create damage handle.";
     DeinitXlib();
     return false;
   }

   // TODO(ajwong): We should be able to replace this with a XDamageAdd().
   capture_fullscreen_ = true;

   // Set up the dimensions of the catpure framebuffer.
   XWindowAttributes root_attr;
   XGetWindowAttributes(display_, root_window_, &root_attr);
   capturer_->width_ = root_attr.width;
   capturer_->height_ = root_attr.height;
   stride_ = capturer_->width() * kBytesPerPixel;
   VLOG(1) << "Initialized with Geometry: " << capturer_->width()
           << "x" << capturer_->height();

   // Allocate the screen buffers.
   for (int i = 0; i < CapturerLinux::kNumBuffers; i++) {
     buffers_[i] =
         new uint8[capturer_->width() * capturer_->height() * kBytesPerPixel];
   }

   return true;
 }

 void CapturerLinuxPimpl::CalculateInvalidRects() {
   // TODO(ajwong): The capture_fullscreen_ logic here is very ugly. Refactor.

   // Find the number of events that are outstanding "now."  We don't just loop
   // on XPending because we want to guarantee this terminates.
   int events_to_process = XPending(display_);
   XEvent e;
   InvalidRects invalid_rects;
   for (int i = 0; i < events_to_process; i++) {
     XNextEvent(display_, &e);
     if (e.type == damage_event_base_ + XDamageNotify) {
       // If we're doing a full screen capture, we should just drain the events.
       if (!capture_fullscreen_) {
         XDamageNotifyEvent *event = reinterpret_cast<XDamageNotifyEvent*>(&e);
         gfx::Rect damage_rect(event->area.x, event->area.y, event->area.width,
                               event->area.height);
         invalid_rects.insert(damage_rect);
         VLOG(3) << "Damage receved for rect at ("
                 << damage_rect.x() << "," << damage_rect.y() << ") size ("
                 << damage_rect.width() << "," << damage_rect.height() << ")";
       }
     } else {
       LOG(WARNING) << "Got unknown event type: " << e.type;
     }
   }

   if (capture_fullscreen_) {
     capturer_->InvalidateFullScreen();
     capture_fullscreen_ = false;
   } else {
     capturer_->InvalidateRects(invalid_rects);
   }
 }

 void CapturerLinuxPimpl::CaptureRects(
     const InvalidRects& rects,
     Capturer::CaptureCompletedCallback* callback) {
   uint8* buffer = buffers_[capturer_->current_buffer_];
   DataPlanes planes;
   planes.data[0] = buffer;
   planes.strides[0] = stride_;

   scoped_refptr<CaptureData> capture_data(
       new CaptureData(planes, capturer_->width(), capturer_->height(),
                       media::VideoFrame::RGB32));

   for (InvalidRects::const_iterator it = rects.begin();
        it != rects.end();
        ++it) {
     XImage* image = XGetImage(display_, root_window_, it->x(), it->y(),
                               it->width(), it->height(), AllPlanes, ZPixmap);

     // Check if we can fastpath the blit.
     if ((image->depth == 24 || image->depth == 32) &&
         image->bits_per_pixel == 32 &&
         IsRgb32(image)) {
       VLOG(3) << "Fast blitting";
       FastBlit(image, it->x(), it->y(), capture_data);
     } else {
       VLOG(3) << "Slow blitting";
       SlowBlit(image, it->x(), it->y(), capture_data);
     }

     XDestroyImage(image);
   }

   // TODO(ajwong): We should only repair the rects that were copied!
   XDamageSubtract(display_, damage_handle_, None, None);

   capture_data->mutable_dirty_rects() = rects;
   // TODO(ajwong): These completion signals back to the upper class are very
   // strange.  Fix it.
   capturer_->FinishCapture(capture_data, callback);
 }

 void CapturerLinuxPimpl::DeinitXlib() {
   if (gc_) {
     XFreeGC(display_, gc_);
     gc_ = NULL;
   }

   if (display_) {
     XCloseDisplay(display_);
     display_ = NULL;
   }
 }

 void CapturerLinuxPimpl::FastBlit(XImage* image, int dest_x, int dest_y,
                                   CaptureData* capture_data) {
   uint8* src_pos = reinterpret_cast<uint8*>(image->data);

   DataPlanes planes = capture_data->data_planes();
   uint8* dst_buffer = planes.data[0];

   const int dst_stride = planes.strides[0];
   const int src_stride = image->bytes_per_line;

   // TODO(ajwong): I think this can never happen anyways due to the way we size
   // the buffer. Check to be certain and possibly remove check.
   CHECK((dst_stride - dest_x) >= src_stride);

   // Flip the coordinate system to match the client.
   for (int y = image->height - 1; y >= 0; y--) {
     uint32_t* dst_pos = GetRowStart(dst_buffer, dst_stride, y + dest_y);
     dst_pos += dest_x;

     memcpy(dst_pos, src_pos, src_stride);

     src_pos += src_stride;
   }
 }

 void CapturerLinuxPimpl::SlowBlit(XImage* image, int dest_x, int dest_y,
                                   CaptureData* capture_data) {
   DataPlanes planes = capture_data->data_planes();
   uint8* dst_buffer = planes.data[0];
   const int dst_stride = planes.strides[0];

   unsigned int red_shift = IndexOfLowestBit(image->red_mask);
   unsigned int blue_shift = IndexOfLowestBit(image->blue_mask);
   unsigned int green_shift = IndexOfLowestBit(image->green_mask);

   unsigned int max_red = image->red_mask >> red_shift;
   unsigned int max_blue = image->blue_mask >> blue_shift;
   unsigned int max_green = image->green_mask >> green_shift;

   for (int y = 0; y < image->height; y++) {
     // Flip the coordinate system to match the client.
     int dst_row = image->height - y - 1;
     uint32_t* dst_pos = GetRowStart(dst_buffer, dst_stride, dst_row + dest_y);
     dst_pos += dest_x;
     for (int x = 0; x < image->width; x++) {
       unsigned long pixel = XGetPixel(image, x, y);
       uint32_t r = (((pixel & image->red_mask) >> red_shift) * max_red) / 255;
       uint32_t g =
           (((pixel & image->green_mask) >> green_shift) * max_blue) / 255;
       uint32_t b =
           (((pixel & image->blue_mask) >> blue_shift) * max_green) / 255;

       // Write as 32-bit RGB.
       *dst_pos = r << 16 | g << 8 | b;
       dst_pos++;
     }
   }
 }

 // static
 Capturer* Capturer::Create(MessageLoop* message_loop) {
   return new CapturerLinux(message_loop);
 }

 }  // namespace remoting
	// 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_linux.h"

	#include <X11/Xlib.h>
	#include <X11/Xutil.h>
	#include <X11/extensions/Xdamage.h>

	#include <set>

	#include "remoting/base/types.h"

	namespace remoting {

	static int IndexOfLowestBit(unsigned int mask) {
	int i = 0;

	// Extra-special do-while premature optimization, just to make dmaclach@
	// happy.
	do {
	if (mask & 1) {
	return i;
	}
	mask >>= 1;
	++i;
	} while (mask);

	NOTREACHED() << "mask should never be 0.";
	return 0;
	}

	static bool IsRgb32(XImage* image) {
	return (IndexOfLowestBit(image->red_mask) == 16) &&
	(IndexOfLowestBit(image->green_mask) == 8) &&
	(IndexOfLowestBit(image->blue_mask) == 0);
	}

	static uint32_t* GetRowStart(uint8* buffer_start, int stride, int cur_row) {
	return reinterpret_cast<uint32_t>(buffer_start + (cur_row stride));
	}

	// Private Implementation pattern to avoid leaking the X11 types into the header
	// file.
	class CapturerLinuxPimpl {
	public:
	explicit CapturerLinuxPimpl(CapturerLinux* capturer);
	~CapturerLinuxPimpl();

	bool Init(); // TODO(ajwong): Do we really want this to be synchronous?
	void CalculateInvalidRects();
	void CaptureRects(const InvalidRects& rects,
	Capturer::CaptureCompletedCallback* callback);

	private:
	void DeinitXlib();
	// We expose two forms of blitting to handle variations in the pixel format.
	// In FastBlit, the operation is effectively a memcpy.
	void FastBlit(XImage* image, int dest_x, int dest_y,
	CaptureData* capture_data);
	void SlowBlit(XImage* image, int dest_x, int dest_y,
	CaptureData* capture_data);

	static const int kBytesPerPixel = 4;

	// Reference to containing class so we can access friend functions.
	// Not owned.
	CapturerLinux* capturer_;

	// X11 graphics context.
	Display* display_;
	GC gc_;
	Window root_window_;

	// XDamage information.
	Damage damage_handle_;
	int damage_event_base_;
	int damage_error_base_;

	// Capture state.
	uint8* buffers_[CapturerLinux::kNumBuffers];
	int stride_;
	bool capture_fullscreen_;
	};

	CapturerLinux::CapturerLinux(MessageLoop* message_loop)
	: Capturer(message_loop),
	pimpl_(new CapturerLinuxPimpl(this)) {
	// TODO(ajwong): This should be moved into an Init() method on Capturer
	// itself. Then we can remove the CHECK.
	CHECK(pimpl_->Init());
	}

	CapturerLinux::~CapturerLinux() {
	}

	void CapturerLinux::ScreenConfigurationChanged() {
	// TODO(ajwong): Support resolution changes.
	NOTIMPLEMENTED();
	}

	void CapturerLinux::CalculateInvalidRects() {
	pimpl_->CalculateInvalidRects();
	}

	void CapturerLinux::CaptureRects(const InvalidRects& rects,
	CaptureCompletedCallback* callback) {
	pimpl_->CaptureRects(rects, callback);
	}

	CapturerLinuxPimpl::CapturerLinuxPimpl(CapturerLinux* capturer)
	: capturer_(capturer),
	display_(NULL),
	gc_(NULL),
	root_window_(BadValue),
	damage_handle_(BadValue),
	damage_event_base_(-1),
	damage_error_base_(-1),
	stride_(0),
	capture_fullscreen_(true) {
	for (int i = 0; i < CapturerLinux::kNumBuffers; i++) {
	buffers_[i] = NULL;
	}
	}

	CapturerLinuxPimpl::~CapturerLinuxPimpl() {
	DeinitXlib();

	for (int i = 0; i < CapturerLinux::kNumBuffers; i++) {
	delete [] buffers_[i];
	buffers_[i] = NULL;
	}
	}

	bool CapturerLinuxPimpl::Init() {
	// TODO(ajwong): We should specify the display string we are attaching to
	// in the constructor.
	display_ = XOpenDisplay(NULL);
	if (!display_) {
	LOG(ERROR) << "Unable to open display";
	return false;
	}

	root_window_ = RootWindow(display_, DefaultScreen(display_));
	if (root_window_ == BadValue) {
	LOG(ERROR) << "Unable to get the root window";
	DeinitXlib();
	return false;
	}

	gc_ = XCreateGC(display_, root_window_, 0, NULL);
	if (gc_ == NULL) {
	LOG(ERROR) << "Unable to get graphics context";
	DeinitXlib();
	return false;
	}

	// Setup XDamage to report changes in the damage window. Mark the whole
	// window as invalid.
	if (!XDamageQueryExtension(display_, &damage_event_base_,
	&damage_error_base_)) {
	LOG(ERROR) << "Server does not support XDamage.";
	DeinitXlib();
	return false;
	}
	damage_handle_ = XDamageCreate(display_, root_window_,
	XDamageReportDeltaRectangles);
	if (damage_handle_ == BadValue) {
	LOG(ERROR) << "Unable to create damage handle.";
	DeinitXlib();
	return false;
	}

	// TODO(ajwong): We should be able to replace this with a XDamageAdd().
	capture_fullscreen_ = true;

	// Set up the dimensions of the catpure framebuffer.
	XWindowAttributes root_attr;
	XGetWindowAttributes(display_, root_window_, &root_attr);
	capturer_->width_ = root_attr.width;
	capturer_->height_ = root_attr.height;
	stride_ = capturer_->width() * kBytesPerPixel;
	VLOG(1) << "Initialized with Geometry: " << capturer_->width()
	<< "x" << capturer_->height();

	// Allocate the screen buffers.
	for (int i = 0; i < CapturerLinux::kNumBuffers; i++) {
	buffers_[i] =
	new uint8[capturer_->width() * capturer_->height() * kBytesPerPixel];
	}

	return true;
	}

	void CapturerLinuxPimpl::CalculateInvalidRects() {
	// TODO(ajwong): The capture_fullscreen_ logic here is very ugly. Refactor.

	// Find the number of events that are outstanding "now." We don't just loop
	// on XPending because we want to guarantee this terminates.
	int events_to_process = XPending(display_);
	XEvent e;
	InvalidRects invalid_rects;
	for (int i = 0; i < events_to_process; i++) {
	XNextEvent(display_, &e);
	if (e.type == damage_event_base_ + XDamageNotify) {
	// If we're doing a full screen capture, we should just drain the events.
	if (!capture_fullscreen_) {
	XDamageNotifyEvent event = reinterpret_cast<XDamageNotifyEvent>(&e);
	gfx::Rect damage_rect(event->area.x, event->area.y, event->area.width,
	event->area.height);
	invalid_rects.insert(damage_rect);
	VLOG(3) << "Damage receved for rect at ("
	<< damage_rect.x() << "," << damage_rect.y() << ") size ("
	<< damage_rect.width() << "," << damage_rect.height() << ")";
	}
	} else {
	LOG(WARNING) << "Got unknown event type: " << e.type;
	}
	}

	if (capture_fullscreen_) {
	capturer_->InvalidateFullScreen();
	capture_fullscreen_ = false;
	} else {
	capturer_->InvalidateRects(invalid_rects);
	}
	}

	void CapturerLinuxPimpl::CaptureRects(
	const InvalidRects& rects,
	Capturer::CaptureCompletedCallback* callback) {
	uint8* buffer = buffers_[capturer_->current_buffer_];
	DataPlanes planes;
	planes.data[0] = buffer;
	planes.strides[0] = stride_;

	scoped_refptr<CaptureData> capture_data(
	new CaptureData(planes, capturer_->width(), capturer_->height(),
	media::VideoFrame::RGB32));

	for (InvalidRects::const_iterator it = rects.begin();
	it != rects.end();
	++it) {
	XImage* image = XGetImage(display_, root_window_, it->x(), it->y(),
	it->width(), it->height(), AllPlanes, ZPixmap);

	// Check if we can fastpath the blit.
	if ((image->depth == 24 \|\| image->depth == 32) &&
	image->bits_per_pixel == 32 &&
	IsRgb32(image)) {
	VLOG(3) << "Fast blitting";
	FastBlit(image, it->x(), it->y(), capture_data);
	} else {
	VLOG(3) << "Slow blitting";
	SlowBlit(image, it->x(), it->y(), capture_data);
	}

	XDestroyImage(image);
	}

	// TODO(ajwong): We should only repair the rects that were copied!
	XDamageSubtract(display_, damage_handle_, None, None);

	capture_data->mutable_dirty_rects() = rects;
	// TODO(ajwong): These completion signals back to the upper class are very
	// strange. Fix it.
	capturer_->FinishCapture(capture_data, callback);
	}

	void CapturerLinuxPimpl::DeinitXlib() {
	if (gc_) {
	XFreeGC(display_, gc_);
	gc_ = NULL;
	}

	if (display_) {
	XCloseDisplay(display_);
	display_ = NULL;
	}
	}

	void CapturerLinuxPimpl::FastBlit(XImage* image, int dest_x, int dest_y,
	CaptureData* capture_data) {
	uint8* src_pos = reinterpret_cast<uint8*>(image->data);

	DataPlanes planes = capture_data->data_planes();
	uint8* dst_buffer = planes.data[0];

	const int dst_stride = planes.strides[0];
	const int src_stride = image->bytes_per_line;

	// TODO(ajwong): I think this can never happen anyways due to the way we size
	// the buffer. Check to be certain and possibly remove check.
	CHECK((dst_stride - dest_x) >= src_stride);

	// Flip the coordinate system to match the client.
	for (int y = image->height - 1; y >= 0; y--) {
	uint32_t* dst_pos = GetRowStart(dst_buffer, dst_stride, y + dest_y);
	dst_pos += dest_x;

	memcpy(dst_pos, src_pos, src_stride);

	src_pos += src_stride;
	}
	}

	void CapturerLinuxPimpl::SlowBlit(XImage* image, int dest_x, int dest_y,
	CaptureData* capture_data) {
	DataPlanes planes = capture_data->data_planes();
	uint8* dst_buffer = planes.data[0];
	const int dst_stride = planes.strides[0];

	unsigned int red_shift = IndexOfLowestBit(image->red_mask);
	unsigned int blue_shift = IndexOfLowestBit(image->blue_mask);
	unsigned int green_shift = IndexOfLowestBit(image->green_mask);

	unsigned int max_red = image->red_mask >> red_shift;
	unsigned int max_blue = image->blue_mask >> blue_shift;
	unsigned int max_green = image->green_mask >> green_shift;

	for (int y = 0; y < image->height; y++) {
	// Flip the coordinate system to match the client.
	int dst_row = image->height - y - 1;
	uint32_t* dst_pos = GetRowStart(dst_buffer, dst_stride, dst_row + dest_y);
	dst_pos += dest_x;
	for (int x = 0; x < image->width; x++) {
	unsigned long pixel = XGetPixel(image, x, y);
	uint32_t r = (((pixel & image->red_mask) >> red_shift) * max_red) / 255;
	uint32_t g =
	(((pixel & image->green_mask) >> green_shift) * max_blue) / 255;
	uint32_t b =
	(((pixel & image->blue_mask) >> blue_shift) * max_green) / 255;

	// Write as 32-bit RGB.
	*dst_pos = r << 16 \| g << 8 \| b;
	dst_pos++;
	}
	}
	}

	// static
	Capturer* Capturer::Create(MessageLoop* message_loop) {
	return new CapturerLinux(message_loop);
	}

	} // namespace remoting