# Video Error-Resilience Research Based on Error-Resilient Screen Content
## 3 Proposed Method
### Error-Resilient Coding  
To improve the robustness of video transmission, different error-resilient mechanisms are considered. The error-resilient code stream can be improved by providing additional code streams or information. During the encoding process, the information of the redundant frame count is included in the slice header. When a slice with a redundancy count is greater than 0, the slice is identified as a redundant slice, and a slice with a redundant frame count equal to 0 is identified as a primary slice. In the encoding process, the encoding of the current frame is divided into two phases: primary frame encoding and redundant frame encoding.  
By analyzing the code rate and distortion characteristics of the current frame, an adaptive redundant coding algorithm is implemented to optimize the reference end-to-end rate-distortion cost. At the same time, the redundant coding method is adaptively selected based on the ROI region, thus completing the security-based research on video error prevention mechanisms.  
The reconstructed value of the redundant pixels is made equal to the reconstructed value of the corresponding pixel in the original picture, which can reduce the error concealment bias. The embedding of redundancy can effectively enhance the error-resilient ability of the bit stream, but it also brings an increase in bit consumption. Therefore, it is necessary to strike a balance between coding efficiency and error prevention capability.  
Different from classical error-resilient coding algorithms, such as [20; 21; 22; 23], the proposed scheme in this paper provides an adaptive error prevention coding mechanism for frame level-based video transmission security. The total end-to-end rate-distortion cost can be optimized by adjusting the number of coded redundant frames. In order to further optimize the bit rate and redundancy allocation, the abrupt frames can be distinguished according to the characteristics of the screen content coding, and the region of interest can be considered as a redundant allocation. On the premise of secure transmission, it can better adapt to different network conditions and scenarios and ensure the rated performance.  
In the process of image processing, the region of interest (ROI) is an image region selected from the image. This region is the focus of image analysis and is circled for further processing. Circling the target with ROI can reduce the processing time and increase the precision. In addition, a video error-resilient scheme is proposed for error-resilient transmission of screen content coding (SCC) in this paper. More specifically, the primary slice will be encoded by the primary frame encoding in the proposed scheme. The ROI of the redundant slice will be divided, then the redundant slice will be encoded with the adaptive frame-level video error-resilient coding algorithm based on ROI. Taking the importance of the video frame ROI area into account in the co-encoding process contributes to realizing the security-based research on video error prevention mechanisms. Consequently, the redundancy insertion efficiency and the reliability are improved.