In this paper, a novel rate control scheme with sliding window basic unit is proposed to achieve consistent or smooth visual quality for H.264/AVC based video streaming. A sliding window consists of a group of successive frames and moves forward by one frame each time. To make the sliding window scheme possible for real-time video streaming, the initial encoder delay inherently in a video streaming system is utilized to generate all the bits of a window in advance, so that these bits for transmission are ready before their due time. The use of initial encoder delay does not introduce any additional delay in video streaming but benefits visual quality as compared to traditional one-pass rate control algorithms of H.264/AVC. Then, a Sliding Window Buffer Checking (SWBC) algorithm is proposed for buffer control at sliding window level and it accords with traditional buffer measurement of H.264/AVC. Extensive experimental results exhibit that higher coding performance, consistent visual quality and compliant buffer constraint can be achieved by the proposed algorithm. © 2012 Elsevier B.V.
Bibliographical noteThe work was partially supported by a grant for the Research Grants Council of the Hong Kong (Project CITYU115109), the Major State Basic Research Development Program of China (973 Program) under Grant 2009CB320905, the Shanghai Pujiang Program under Grant 11PJ1409400, the National Natural Science Foundation of China under Grants 61202242, 61102059, the Fundamental Research Funds for the Central Universities under Grant 0800219158.
- Consistent/smooth visual quality
- Rate control
- Sliding window
- Video coding
- Video streaming