H.264 Rate Control Based on Target Buffer Level and Target Bits

• Main Authors: Li-Chang Chiang, 姜禮彰
• Other Authors: Pao-Chi Chang
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/37204790725701737312

碩士 === 國立中央大學 === 通訊工程研究所碩士在職專班 === 98 === The development of networks and video coding techniques promote the applications of multimedia communication. The objective of the service of multimedia applications is not only to deliver videos with better quality but also to maintain the compressed bit stream to meet the requirements under various network situations. Therefore, the rate control mechanism plays an important role in a practical encoding system. The proposed methods can reflect the real status by utilizing the target buffer level and the target bits allocation. First, on the allocation of target buffer level, by using the ratio of remaining bits rather than linear decrease from JM, the proposed method can adjust dynamically to meet the actual buffer fullness. And then, on the allocation of target bits, by using the comparison of the actual available bit rate and the expected available bit rate rather than the average bit rate from JM, the proposed method allocates more suitable number of bits to reflect the actual bit rate and buffer fullness. The experiment results are compared with JM 15.1 reference software. It shows that the proposed methods fit the target rate more accurately, get more stable video quality, and reduce the occupancy of the virtual buffer to avoid buffer overflow or underflow problems.