共查询到17条相似文献,搜索用时 109 毫秒
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由嵌入式设备所构建的视频会议系统终端,在会话建立后,需要对来自各方的媒体信息诸如语音进行混音处理。在信令集中、媒体流分布的系统中,媒体的混合没有独立出来放在Focus中,而是将与会的各终端发来的语音媒体流在会议参与者主机上实现端混合。在众多混音方案的比对中,这里介绍一种改进的符合语音信号特征的混音架构及溢出处理算法,并用语音信号的短时能量及短时过零率对混音过程进行动态修正。在嵌入式系统的实现验证中表明,该算法提高了混音溢出处理的效率,降低了噪音,具有较低的算法复杂度,并有良好的听觉舒适感。 相似文献
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视频会议中混音技术研究 总被引:1,自引:0,他引:1
在视频会议中,音频处理是基本的也是实时性要求最高的要素,而音频混音是音频处理中不可或缺的部分,也是音频处理中的一个难点。目前大部分视频会议系统都没有很好地解决这个难题,而且很多混音的研究工作都偏重于混音算法,而忽视了混音方案的研究。针对这个问题提出了集中式和分布式2种混音方案,并介绍混音中的一些关键技术,最后提供了一种按贡献加权算法来消除混音溢出问题。实验证明这种算法能有效地解决混音溢出问题。 相似文献
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针对现有双通道语音活动检测(Voice Activity Detection, VAD)算法依赖于固定阈值难以在多种噪声环境下准确地检测语音和噪声,应用于手机消噪系统会造成语音失真或噪声消除不好等问题,该文提出一种基于神经网络的VAD算法,该算法以分频带能量差和归一化互通道相关为特征,采用神经网络对语音和噪声进行分类。在此基础上,将神经网络VAD与基于互通道信号功率比值的VAD相结合,提出一种新的适用于手机消噪系统的语音和噪声活动检测算法分别对语音和噪声进行检测,并以此进行噪声抑制处理,减少了消噪系统因VAD误判而造成的性能下降。实验结果表明,该处理方法在抑制背景噪声和减少语音失真等方面优于现有的消噪算法,对于方向性语音干扰也有很好的抑制效果。 相似文献
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在多媒体会议房间中,鼓掌、咳嗽等非高斯干扰噪声常会严重影响语音处理系统的性能.为了有效地抑制非高斯干扰噪声,本文提出了一种基于线性预测残差域高阶统计量的语音VAD检测方法.该方法利用语音信号线性预测残差的归一化峰度表征语音和非语音信号在谐波数量上的差异,构造判别准则进行VAD检测,并通过预估高斯背景噪声的能量,削弱了背景噪声对VAD算法性能的影响.仿真实验结果表明,该方法能够有效地区分高斯背景噪声下的语音和非高斯噪声. 相似文献
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Software-Based Video/Audio Processing for Cellular Phones 总被引:1,自引:0,他引:1
Nowadays, most cellular phones are used beyond voice communication. Although the processing power of cellular phones is sufficient for most data applications, it is difficult to play video and audio contents in software because of their computational complexity and lack of basic tools for multimedia processing, so software-based multimedia processing on cellular phones is a challenging issue. Several transcoding methods are introduced to address this issue, but they are mainly of the DCT-domain conversion. Hence, they are only applicable to high-end cellular phones. To develop a solution for low-end and mid-tier cellular phones, we begin this paper by analyzing the complexity of existing video standards to see if it is possible to play them on cellular phones by software. Next, various coding profiles as combinations of subalgorithms are studied, and we select a profile that adapts its complexity to the processing power of cellular phones. Also, an efficient dithering algorithm called out-of-order dithering is developed. We implement the profile with out-of-order dithering in an actual cellular phone software environment and present the performance results. The performance results show that software based video/audio processing is indeed possible on low-end cellular phones. 相似文献
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With the development of cloudbased data centers and multimedia technologies , cloudbased multimedia service systems have been paid more and more attention. Audio highlights detection plays an important role in the cloudbased multimedia service system. In this paper, we proposed a novel highlight detection method to extract the audio highlight effects for the cloudbased multimedia service system using the unsupervised approach. In the proposed method, we first extract the audio features for each audio document. Then the spectral clustering scheme was used to decompose the audio document into several audio effects . Then, we introduce the TFIDF method to label the highlight effect. We design some experiments to evaluate the performance of the proposed method, and the experimental results show that our method can achieve satisfying results . 相似文献
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介绍了多媒体光纤传输电视会议控制系统的功能特点,视频,音频和控制信息的处理方法和技术,及系统软件的设计。 相似文献
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