字幕信息有助于观众对音视频内容进行理解,在音视频文件中起着不可或缺的作用.针对自动字幕生成系统的要求,提出了一种灵活、高效的语音端点检测算法,可以在复杂背景噪声的情况下,从连续的音频信号中提取语音端点.将短时能量、短时过零率、短时信息熵这3种基本音频参数进行结合,形成新的音频特征参数:短时能零熵(EZE-feature),在结合了音频信号时域特征和频域特征优点的同时,规避了它们各自的不足.在此基础上,还提出了一种环境自适应的语音端点判定算法,在端点检测过程中对背景噪声进行实时分析,并根据背景噪声的变化对短时能零熵参数进行调整.该语音端点检测算法已被成功应用于自动字幕生成系统中.

With the development of multimedia technology, the use of video has increased in many fields, and captions are frequently inserted into video images to aid the understanding of audience. This paper proposes a robust endpoint detection algorithm for continuous speech in noisy environment, and it can be used in automatic video caption generation systems. In the proposed algorithm, we integrate the widely used energy, zero crossing and entropy to form a new feature, EZE-feature, which possesses advantages while compensating the drawbacks of each individual. Moreover, an adaptive endpoint detection method is proposed which makes the EZE-feature modify its environment parameters by adapting to the strength of background noise. The proposed algorithm has been used in an automatic video caption generation system, and the performance of the algorithm is very well.

Supported by the National Natural Science Foundation of China under Grant No.90612013 (国家自然科学基金); the National High -Tech Research and Development Plan of China under Grant No.2006AA01Z304 (国家高技术研究发展计划(863)); the Cosponsored Project of Beijing Committee of Education of China under Grant No.SYS100130422, the 111 Project of China under Grant No.B08004