音频信号AGC及响度控制算法的研究

发布时间：2018-05-09 01:07

本文选题：音频 + AGC　；参考：《南京大学》2014年硕士论文

【摘要】：音频响度控制是保证广播电视节目质量的重要技术手段,也一直是广播电视领域重要的研究内容之一。一般来说,音频标准、传输条件、人为失误等因素都可能使得音频信号之间出现声音突变或者响度不一致的情况,这时就需要对音频信号放大或缩小以避免让人感到不适。针对上述问题,可以采用限幅处理或音频增益控制以改善语音质量,实现方式包括硬件方式和软件算法。在本课题中,我们主要研究音频信号自动增益控制算法,并对其改进使算法能够符合响度一致的要求。本文主要创新点在于融合了AGc和NLMS算法,把均方能量作为响度特征值引入控制算法,尝试性的提出了一种音频响度控制的算法。这种新的控制算法在后来的测试中运行良好,它使得原先忽大忽小的音频信号变得平稳而不失原有的特性。本课题主要针对WAV格式的音频文件进行读写和控制,研究响度控制算法,首先会在MATLAB平台上进行算法的仿真模拟,对处理后的音频信号进行比较、分析和探讨,得到最优的参数和结果；接着在Linux平台下利用ALSA音频驱动来实现一个简易的响度控制播放程序。
[Abstract]:Audio loudness control is an important technical means to ensure the quality of radio and television programs, and has been one of the important research contents in the field of radio and television. Generally speaking, audio standards, transmission conditions, human errors and other factors may make audio signals sound mutation or noise inconsistency between the situation, the audio signal needs to be amplified or reduced to avoid discomfort. In order to improve the speech quality, the amplitude limiting processing or the audio gain control can be used to improve the speech quality, including hardware and software algorithms. In this thesis, we mainly study the automatic gain control algorithm of audio signal and improve it to meet the requirement of uniform loudness. The main innovation of this paper lies in the fusion of AGc and NLMS algorithms. The mean square energy is introduced into the control algorithm as the loudness eigenvalue, and an audio loudness control algorithm is proposed in this paper. The new control algorithm works well in later tests, which makes the original audio signal steady without losing its original characteristics. This paper mainly aims at reading, writing and controlling the audio files in WAV format, studies the loudness control algorithm. First, the simulation of the algorithm will be carried out on the MATLAB platform, and the processed audio signals will be compared, analyzed and discussed. The optimal parameters and results are obtained, and then a simple loudness control program is realized by using ALSA audio driver in Linux platform.
【学位授予单位】：南京大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN948.1;TN912.3

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