音頻處理工具SSRC能提供轉換采樣率、采樣位數、音量等功能。
一、下載地址
https://github.com/shibatch/SSRC
二、SSRC介紹
SSRC —— A fast and high quality sampling rate converter written by Naoki Shibata
Homepage : http://shibatch.sourceforge.net/ e-mail : shibatch@users.sourceforge.net
This program converts sampling rates of PCM wav files. This program also has a function to apply dither to its output and extend perceived dynamic range.
Sampling rates of 44.1kHz and 48kHz are populary used, but the ratio between these two frequencies is 147:160, which are not small numbers. As a result, sampling rate conversion without degradation of sound quality requires filter with very large order, and it is difficult to have both quality and speed. This program quickly converts between these sampling frequencies without audible degradation.
三、總結
一款命令行轉換工具，可以轉換采樣率、音量、保存位數等，轉換效果很好。比取平均值的方案效果好多了。
對於一個音頻應用的開發人員來說，感覺質量很高，效果也是夠用，唯一的不足就是效率較慢。
此外，有人基於Java重寫了一套，鏈接：https://github.com/umjammer/vavi-sound/tree/67db9c098c079a356b42627310e9c622342fde43/src/main/java/vavi/sound/pcm/resampling/ssrc，有興趣的可以了解一下。