【作者】 史晋； 陈英； 焦健； 吕峰； 陈忱；

【Author】 SHI Jin1, CHEN Ying1, JIAO Jian1, LV Feng1, CHEN Chen2 1(Department of Computer Science & Technology, Beijing Institute of Technology, Beijing 100081, China) 2(Institute of Microelectronics, Tsinghua University, Beijing 100084, China)

【机构】 北京理工大学计算机科学技术学院； 清华大学微电子研究所；

【摘要】 码流生成器是验证解码器(decoder)正确性的工具。当前的码流生成方法需要大量的输入素材,或者使用第三方工具,甚至需要实现编码器(encoder),增加了解码器的测试成本。论文提出了利用解码器自身逻辑结构生成码流的方法,论证了将生成器看作解码器逆过程的解决方案。基于电影和电视工程师协会(SMPTE)和微软公司最新推出的VC-1码流规范,抽象出解码器的主要工作模型,利用XML技术存储规范中的语法和语义约束,通过解码器读取位到生成器写入位的变换算法完成正确码流的生成。同时,生成器的后端提供验证器保证码流是符合规范的。更多还原

【Abstract】 With the development of digital media, audio and video decoder plays an important role in the multi-media field. For assuring the quality of decoder, testing is one main path. The test cases of decoder are streams conforming to streaming media format. Bitstream generator is one tool for validating streaming decoder correctness, and it generates streams according to specified format. Till now, covering syntaxes and semantics of streaming format have been completed by traditional generating methods; however, they take high cost on test tools implementation, test cases design and test process time. After describes predominance and shortcoming of the methods based on encoder and using third-party tools, this paper presents bitstream generating ways based on decoder self-logic, and demonstrates that generating is a reverse process of decoding. According to VC-1 specification proposed by SMPTE and Microsoft, in this paper, summarizes main decoding process model, and analyzes layered framework of VC-1 format. Tree structure extracts from specification stands for syntaxes of different layers, and XML shows the same tree architecture as streaming format, and moreover Schema specifies the constraints on syntax nodes. By using XML-Schema technique to access syntaxes and semantics constraints of specification, it makes coding separate with saved data. Transform algorithm finishes reverse process conversion from getting bits to setting bits. The back-end of generator provides verification for generated bitstream. At the end of paper, it enumerates bitstream generating speed and coverage by different generating ways, and indicates future improvement of the method based on decoder.更多还原