An Auto-Equalization System Based on DirectShow Technology and Its Application in Audio Broadcast System of Radio Station

How to ensure the output volume absolutely consistent has been a very important problem the audio broadcast system faced. An auto-equalization system based on DirectShow technology is proposed in this paper. In this system, it processes the audio file with equalize analysis processing. In this process, it compares the average loudness level of the input audio with the standard target loudness level which is defined in a SMPTE standard, and then obtains the difference between the two and save the result in the audio file itself before play with a simple watermarking algorithm. And then it can adjust the output volume by this result saved in the audio file itself when playback. In this way, it can ensure the output volume absolutely consistent perfectly.