Broadcast Monitoring Audio Signal Processing Algorithm And Engineering Implementation

As one of the traditional radio applications,radio broadcasting station has the important mission of spreading the voices of the party and the country,and plays an irreplaceable role in promoting social and economic development and improving people's cultural life.This paper analyzes the basic tasks of China's broadcast monitoring,the development of automated broadcast monitoring systems at home and abroad,and some characteristics of broadcast audio.It is found that the main characteristics of broadcast audio are time delay,large dynamic range,and wide spectrum range.Different forms of random crosstalk.The shortcomings and deficiencies of traditional audio comparison methods based on audio feature parameters for broadcasting audio comparison are analyzed.In order to solve the problem of inaccurate audio comparison results caused by noise and delay in broadcast audio,an audio comparison algorithm with delayadaptive-aware is proposed.Aiming at the poor noise immunity of audio feature distance measurement in conventional algorithms,cepstrum is used to analyze the mixed signal of two audio to estimate delay adaptively and comparison,which has a strong ability to resolve equidistant frequency components in the power spectrum.And a method of short delay is proposed to obtain accurate similarity between two audios in different situations,which is added short delay in one of the audio.Then,the optimal short delay is selected according to the effect of adding different short delay,so as to improve the performance of the algorithm further.Finally,simulation experiments are conducted to evaluate the performance of the proposed algorithm,in which multiple audio clips of different broadcast programs are utilized,and under the condition of different SNR and additive white Gaussian noise,different delays are added to simulate a real transmission link.And the delay estimation results and audio similarity under different SNR are compared to verify the effectiveness of the algorithm.Experimental results show that the proposed algorithm outperforms existing algorithms and can achieve 90.36% audio comparison matching accuracy at low SNR(2d B),and the calculation speed can meet the requirement of real-time comparison.The Raspbian 3B + development board equipped with Raspbian system(based on Linux)and USB audio capture card are used,and the ALSA advanced Linux sound system is used as the audio driver library.An embedded system for real-time broadcast audio comparison is designed.The proposed scheme is also verified.The engineering practicability of the audio comparison algorithm in the application of broadcast audio monitoring implements real-time monitoring of broadcast audio,thereby ensuring the safety of broadcast transmission.