packet-buffering存在BUG

在开启packet-buffering后，并不是出现缓冲才按照100ms,1s,2s,4s,5s增长的，正常播放也是按照100ms,1s,2s,4s,5s增长，使得递增缓冲没有效果，这是不是个BUG？还是另有高明的用意？

Start by reproducing playback with packet-buffering enabled and compare normal playback with playback that actually encounters buffering. Trace where the 100ms, 1s, 2s, 4s, and 5s increments are applied; done means establishing whether this behavior is unintended and documenting or correcting the buffering policy accordingly.

Written by the indexing model from the issue text.