blob: 9ab059bcaa24cdb8491b86791e954423dcd95cc6 [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 <memory>
#include <vector>
#include "webrtc/base/constructormagic.h"
#include "webrtc/modules/desktop_capture/desktop_region.h"
namespace webrtc {
// TODO(sergeyu): Simplify differ now that we are working with DesktopRegion.
// diff_info_ should no longer be needed, as we can put our data directly into
// the region that we are calculating.
// TODO(sergeyu): Rename this class to something more sensible, e.g.
// ScreenCaptureFrameDifferencer.
class Differ {
// Create a differ that operates on bitmaps with the specified width, height
// and bytes_per_pixel.
Differ(int width, int height, int bytes_per_pixel, int stride);
int width() { return width_; }
int height() { return height_; }
int bytes_per_pixel() { return bytes_per_pixel_; }
int bytes_per_row() { return bytes_per_row_; }
// Given the previous and current screen buffer, calculate the dirty region
// that encloses all of the changed pixels in the new screen.
void CalcDirtyRegion(const uint8_t* prev_buffer, const uint8_t* curr_buffer,
DesktopRegion* region);
// Allow tests to access our private parts.
friend class DifferTest;
// Identify all of the blocks that contain changed pixels.
void MarkDirtyBlocks(const uint8_t* prev_buffer, const uint8_t* curr_buffer);
// After the dirty blocks have been identified, this routine merges adjacent
// blocks into a region.
// The goal is to minimize the region that covers the dirty blocks.
void MergeBlocks(DesktopRegion* region);
// Checks whether the upper-left portions of the buffers are equal. The size
// of the portion to check is specified by the |width| and |height| values.
// Note that if we force the capturer to always return images whose width and
// height are multiples of kBlockSize, then this will never be called.
bool PartialBlocksEqual(const uint8_t* prev_buffer,
const uint8_t* curr_buffer,
int stride,
int width, int height);
// Dimensions of screen.
int width_;
int height_;
// Number of bytes for each pixel in source and dest bitmap.
// (Yes, they must match.)
int bytes_per_pixel_;
// Number of bytes in each row of the image (AKA: stride).
int bytes_per_row_;
// Diff information for each block in the image.
std::unique_ptr<bool[]> diff_info_;
// Dimensions and total size of diff info array.
int diff_info_width_;
int diff_info_height_;
int diff_info_size_;
} // namespace webrtc