基于目标区域清晰显示的H.264编码策略

A Coding Strategy of H.264 Based on High-definition Display of Target Region

H.264是当前流行的视频编码标准,吸收了现有标准的优点,并采用了诸如帧内预测、整数余弦变换、多模式多参考帧运动估计、自适应熵编码等新技术,大大提高了视频编码的效率。在实时低速率传输的视频监控系统中,由于带宽有限,必须将码率控制在一定范围,以达到在给定码率的条件下,尽可能达到高质量的解码图像。文中采用帧间差与背景差相结合的运动目标检测跟踪及码率控制改进策略,保证目标区域(Target Region)的清晰度和平稳质量,并控制非TR质量波动在可接受范围内。该实时编码系统在DSP芯片TMS320DM642上实现。设计源于与中国航天时代电子公司的合作项目,设计成果将用于无人飞机无线实时视频编码传输系统,有着重要的实用意义。

H.264 is the latest video coding standard,and it adopts many new technologies such as intra prediction,integer cosine transform,multiple reference pictures for motion estimation,context adaptive entropy coding and so on,these methods largely improve the coding efficiency.Under real-time and low bit rate conditions,remote digital video monitoring system based on H.264 needs to be improved.In this paper,an inter-frame subtraction combining with background subtraction is used to detect the target region.To achieve the purpose of high-definition of target region under low bit rate,an optimized rate control scheme is proposed.The whole coding system is realized on TMS320DM642.The design originates from the co-operation project with some scientific research unit.The corresponding production will be used for wireless real-time video coding transmission system on unmanned aircraft.The research has important practical significance.