Application Research Of Equalizer Algorithm Based On Android Platform

In recent years,with the continuous development of national economy and improvement of people's living standard,the smartphone manufacturing technology has developed rapidly which enriched people's daily entertainment activities and met people's pursuit of a better life.At present,among many entertainment activities,music is one of the activities that is deeply loved by people.In the music functions of smartphone support,audio equalizers are widely used because it can improve the tone color and make music playback effect consistent with their own listening habits.Through elaborate analysis of the source code for the audio equalizer of the Android system widely used by smartphones,this paper found that its native Audio Effect framework only supports 16-bit audio data processing,but lacked support for the 32-bit audio data.Therefore,improving the support of the framework for higher precision audio can improve the user experience and satisfy people's pursuit of music quality,so it attracts deep attention by researcher.According to the problems based on Android's native Audio Effect framework,this paper analyzed the development and social demand of the audio equalizer,and proposed two solutions that increased digit conversion module and used FFmpeg open source framework to customize a new Audio Effect framework.First,this paper elaborated analysis of the processing flow for the native Audio Effect framework in Android,to find the position for the bit conversion operations.According to the characteristics of digital audio encoding,this paper proposed to a convert the input audio data to 16-bit audio data solution,which shifted the input 32-bit audio data,and then forced the data to do make bit conversion operations.Because the solution can retain the more important data,and have some paper shows that it can control the distortion caused by bit conversion operations to about 0.00076%.Through experimental testing,the development solution can successfully make the Android system audio equalizer support 32-bit audio data processing.Secondly,since the custom new Audio Effect framework needs to migrate an audio equalizer algorithm,this paper adopted an algorithm from the FFmpeg open-source audio and video framework,because FFmpeg is excellent in present.Through elaborate analysis of the audio equalizer algorithm in FFmpeg,this paper adopted the Butterworth part of the high-order audio parametric multi band equalizer algorithm,and elaborated analysis the algorithm to verify the correctness of algorithm and ensure the effectiveness of development.Finally,according to the application solution of FFmpeg on the Android system,this paper proposed of two schemes for application layer development and bottom migration development.For the application layer development,this paper adopted the FFmpeg command line implementation model based on JNI development technology,its can greatly shorten the development difficulty and cycle.For the bottom migration development,this paper elaborated analysis of the source code characteristics of audio equalizer algorithm for Android native Audio Effect framework,and migrated the high-order audio parametric multi band equalizer algorithm based on the characteristics,it is also to lay the foundation for customizing the new Audio Effect framework.