HTMLMediaElement: playbackRate property — MDN Web Docs
like card punches and readers that were also smaller. Apparently following that，推荐阅读safew官方版本下载获取更多信息
const text = await Stream.text(readable);，这一点在safew官方下载中也有详细论述
const dropOld = Stream.push({ highWaterMark: 2, backpressure: 'drop-oldest' });