利用可調式TILE邊界改善HEVC於影音串流上之負載平衡

Abstract

在影音串流中，高品質和低延遲一直是使用者們所在追求的，更不希望正在看的影片有感覺到延遲或定格的現象，而延遲時間由解碼和傳輸時間所影響。 於本論文中，我們使用高效率視頻編碼 (HEVC) 之中的工具，tile，來達到平行編解碼以及傳輸，並且提出動態決定tile切割位置的方法，來改善整個過程的負載平衡。 實驗結果顯示，在高位元率時，最多可降低22.03%（平均約13.83%）的延遲時間和41.2%（平均約13.92%）的掉幀率，在低位元率時，最多可降低17.04%（平均約4.66%）的延遲時間和14.3%（平均約5.03%）的掉幀率。

The high quality and low delay video streaming is desired for all users. Especially the playback delay is much more undesirable since it is easily perceived by human eyes, and it consists of decoding delay and transfer delay. In this thesis, we use High Efficiency Video Coding (HEVC) with tiles to achieve parallel encoding/transmission/decoding, and propose to use a novel adaptive tile boundary (ATB) method to further improve the load-balancing for the whole process. Experiment results show that the proposed method can decrease the delay times up to 22.03% (average 13.83%) and the frame drop rates up to 41.2% (average 13.92%) under high bit-rates; as well as reduce the delay time up to 17.04% (average 4.66%) and the frame drop rate up to 14.3% (average 5.03%) under low bit-rates, comparing with simple parallel processing scheme of using uniform tile partitioning.