| /* |
| * 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. |
| */ |
| |
| #ifndef WEBRTC_MODULES_DESKTOP_CAPTURE_DIFFER_H_ |
| #define WEBRTC_MODULES_DESKTOP_CAPTURE_DIFFER_H_ |
| |
| #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. |
| // http://crbug.com/92379 |
| // TODO(sergeyu): Rename this class to something more sensible, e.g. |
| // ScreenCaptureFrameDifferencer. |
| class Differ { |
| public: |
| // 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); |
| ~Differ(); |
| |
| 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); |
| |
| private: |
| // 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_; |
| |
| RTC_DISALLOW_COPY_AND_ASSIGN(Differ); |
| }; |
| |
| } // namespace webrtc |
| |
| #endif // WEBRTC_MODULES_DESKTOP_CAPTURE_DIFFER_H_ |