纯前端解码、播放、录音、编码 AMR 音频，无须服务器支持，基于 amr.js 和 RecorderJs。 注意：由于使用了 amr.js 做编码和解码，因此 js 文件（压缩后，未 gzip）接近 500 KB，使用前请考虑。

Note: This package targets the latest versions of Chrome, Firefox, and Safari. Returns a Promise that resolves when all the downloads have started. Note that there's a delay of 1 second between each ...