blob: 35ac8e2475525b71899e9d14538a8889aac88908 [file] [log] [blame]
* Copyright (c) 2013 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 <stdint.h>
#include <memory>
#include <vector>
#include "modules/desktop_capture/desktop_geometry.h"
#include "modules/desktop_capture/desktop_region.h"
#include "modules/desktop_capture/shared_memory.h"
#include "rtc_base/system/rtc_export.h"
namespace webrtc {
const float kStandardDPI = 96.0f;
// DesktopFrame represents a video frame captured from the screen.
class RTC_EXPORT DesktopFrame {
// DesktopFrame objects always hold BGRA data.
static const int kBytesPerPixel = 4;
virtual ~DesktopFrame();
DesktopFrame(const DesktopFrame&) = delete;
DesktopFrame& operator=(const DesktopFrame&) = delete;
// Returns the rectangle in full desktop coordinates to indicate it covers
// the area of top_left() to top_letf() + size() / scale_factor().
DesktopRect rect() const;
// Returns the scale factor from DIPs to physical pixels of the frame.
// Assumes same scale in both X and Y directions at present.
float scale_factor() const;
// Size of the frame. In physical coordinates, mapping directly from the
// underlying buffer.
const DesktopSize& size() const { return size_; }
// The top-left of the frame in full desktop coordinates. E.g. the top left
// monitor should start from (0, 0). The desktop coordinates may be scaled by
// OS, but this is always consistent with the MouseCursorMonitor.
const DesktopVector& top_left() const { return top_left_; }
void set_top_left(const DesktopVector& top_left) { top_left_ = top_left; }
// Distance in the buffer between two neighboring rows in bytes.
int stride() const { return stride_; }
// Data buffer used for the frame.
uint8_t* data() const { return data_; }
// SharedMemory used for the buffer or NULL if memory is allocated on the
// heap. The result is guaranteed to be deleted only after the frame is
// deleted (classes that inherit from DesktopFrame must ensure it).
SharedMemory* shared_memory() const { return shared_memory_; }
// Indicates region of the screen that has changed since the previous frame.
const DesktopRegion& updated_region() const { return updated_region_; }
DesktopRegion* mutable_updated_region() { return &updated_region_; }
// DPI of the screen being captured. May be set to zero, e.g. if DPI is
// unknown.
const DesktopVector& dpi() const { return dpi_; }
void set_dpi(const DesktopVector& dpi) { dpi_ = dpi; }
// Indicates if this frame may have the mouse cursor in it. Capturers that
// support cursor capture may set this to true. If the cursor was
// outside of the captured area, this may be true even though the cursor is
// not in the image.
bool may_contain_cursor() const { return may_contain_cursor_; }
void set_may_contain_cursor(bool may_contain_cursor) {
may_contain_cursor_ = may_contain_cursor;
// Time taken to capture the frame in milliseconds.
int64_t capture_time_ms() const { return capture_time_ms_; }
void set_capture_time_ms(int64_t time_ms) { capture_time_ms_ = time_ms; }
// Copies pixels from a buffer or another frame. `dest_rect` rect must lay
// within bounds of this frame.
void CopyPixelsFrom(const uint8_t* src_buffer,
int src_stride,
const DesktopRect& dest_rect);
void CopyPixelsFrom(const DesktopFrame& src_frame,
const DesktopVector& src_pos,
const DesktopRect& dest_rect);
// Copies pixels from another frame, with the copied & overwritten regions
// representing the intersection between the two frames. Returns true if
// pixels were copied, or false if there's no intersection. The scale factors
// represent the ratios between pixel space & offset coordinate space (e.g.
// 2.0 would indicate the frames are scaled down by 50% for display, so any
// offset between their origins should be doubled).
bool CopyIntersectingPixelsFrom(const DesktopFrame& src_frame,
double horizontal_scale,
double vertical_scale);
// A helper to return the data pointer of a frame at the specified position.
uint8_t* GetFrameDataAtPos(const DesktopVector& pos) const;
// The DesktopCapturer implementation which generates current DesktopFrame.
// Not all DesktopCapturer implementations set this field; it's set to
// kUnknown by default.
uint32_t capturer_id() const { return capturer_id_; }
void set_capturer_id(uint32_t capturer_id) { capturer_id_ = capturer_id; }
// Copies various information from `other`. Anything initialized in
// constructor are not copied.
// This function is usually used when sharing a source DesktopFrame with
// several clients: the original DesktopFrame should be kept unchanged. For
// example, BasicDesktopFrame::CopyOf() and SharedDesktopFrame::Share().
void CopyFrameInfoFrom(const DesktopFrame& other);
// Copies various information from `other`. Anything initialized in
// constructor are not copied. Not like CopyFrameInfoFrom() function, this
// function uses swap or move constructor to avoid data copy. It won't break
// the `other`, but some of its information may be missing after this
// operation. E.g. other->updated_region_;
// This function is usually used when wrapping a DesktopFrame: the wrapper
// instance takes the ownership of `other`, so other components cannot access
// `other` anymore. For example, CroppedDesktopFrame and
// DesktopFrameWithCursor.
void MoveFrameInfoFrom(DesktopFrame* other);
// Set and get the ICC profile of the frame data pixels. Useful to build the
// a ColorSpace object from clients of webrtc library like chromium. The
// format of an ICC profile is defined in the following specification
const std::vector<uint8_t>& icc_profile() const { return icc_profile_; }
void set_icc_profile(const std::vector<uint8_t>& icc_profile) {
icc_profile_ = icc_profile;
// Sets all pixel values in the data buffer to zero.
void SetFrameDataToBlack();
// Returns true if all pixel values in the data buffer are zero or false
// otherwise. Also returns false if the frame is empty.
bool FrameDataIsBlack() const;
DesktopFrame(DesktopSize size,
int stride,
uint8_t* data,
SharedMemory* shared_memory);
// Ownership of the buffers is defined by the classes that inherit from this
// class. They must guarantee that the buffer is not deleted before the frame
// is deleted.
uint8_t* const data_;
SharedMemory* const shared_memory_;
const DesktopSize size_;
const int stride_;
DesktopRegion updated_region_;
DesktopVector top_left_;
DesktopVector dpi_;
bool may_contain_cursor_ = false;
int64_t capture_time_ms_;
uint32_t capturer_id_;
std::vector<uint8_t> icc_profile_;
// A DesktopFrame that stores data in the heap.
class RTC_EXPORT BasicDesktopFrame : public DesktopFrame {
// The entire data buffer used for the frame is initialized with zeros.
explicit BasicDesktopFrame(DesktopSize size);
~BasicDesktopFrame() override;
BasicDesktopFrame(const BasicDesktopFrame&) = delete;
BasicDesktopFrame& operator=(const BasicDesktopFrame&) = delete;
// Creates a BasicDesktopFrame that contains copy of `frame`.
// TODO(zijiehe): Return std::unique_ptr<DesktopFrame>
static DesktopFrame* CopyOf(const DesktopFrame& frame);
// A DesktopFrame that stores data in shared memory.
class RTC_EXPORT SharedMemoryDesktopFrame : public DesktopFrame {
// May return nullptr if `shared_memory_factory` failed to create a
// SharedMemory instance.
// `shared_memory_factory` should not be nullptr.
static std::unique_ptr<DesktopFrame> Create(
DesktopSize size,
SharedMemoryFactory* shared_memory_factory);
// Takes ownership of `shared_memory`.
// Deprecated, use the next constructor.
SharedMemoryDesktopFrame(DesktopSize size,
int stride,
SharedMemory* shared_memory);
// Preferred.
SharedMemoryDesktopFrame(DesktopSize size,
int stride,
std::unique_ptr<SharedMemory> shared_memory);
~SharedMemoryDesktopFrame() override;
SharedMemoryDesktopFrame(const SharedMemoryDesktopFrame&) = delete;
SharedMemoryDesktopFrame& operator=(const SharedMemoryDesktopFrame&) = delete;
// Avoid unexpected order of parameter evaluation.
// Executing both std::unique_ptr<T>::operator->() and
// std::unique_ptr<T>::release() in the member initializer list is not safe.
// Depends on the order of parameter evaluation,
// std::unique_ptr<T>::operator->() may trigger assertion failure if it has
// been evaluated after std::unique_ptr<T>::release(). By using this
// constructor, std::unique_ptr<T>::operator->() won't be involved anymore.
SharedMemoryDesktopFrame(DesktopRect rect,
int stride,
SharedMemory* shared_memory);
} // namespace webrtc