ref: 422d7bc918386b81ce5487c13898b78db241cd06
parent: d56b3eb0cff6161413df9bf9ab259cf569d5dc3c
author: Paul Wilkins <paulwilkins@google.com>
date: Tue Oct 28 09:03:06 EDT 2014
Relax maximum Q for extreme overshoot. Added code to relax the active maximum Q in response to extreme local overshoot to reduce bandwidth peaks. The impact is small in metrics terms, but it this helps reduce bandwidth spikes and overall overshoot in a number of clips in our tests sets (especially the YT test set). In particular this should help prevent very big spikes where a clip is mainly easy but has a short hard section. In such a case a choice of maximum Q for the clip as a whole may allow us to hit the overall target rate but give some extreme spikes. The chunked encoding in YT mitigates this problem but it can show up where a longer clip is coded as a single chunk. Change-Id: I213d09950ccb8489d10adf00fda1e53235b39203