分散式視訊編解碼器的創新架構

A Novel Architecture of Distributed Video Codec

楊士毅(Shih-I Yang)

指導教授 ： 陳少傑

國立臺灣大學/電機資訊學院/電子工程學研究所/碩士(2017年)

https://doi.org/10.6342/NTU201702487

摘要

分散式視訊編碼 (DVC, Distributed Video Coding) 和傳統視訊架構的視訊編碼應用取向不同，它的特色是使用低運算複雜度的編碼器。我們提出一個創新的分散式視訊編解碼器架構，在極大碼率下獲得了比以往DVC更好的效能。我們在Intra-Frame的處理上採用JPEG 2000 處理Key Frame，並且在Wyner-Ziv Frame的處理上捨棄LDPCA (Low-Density Parity Check Accumulate Codes) 的使用，改用全部CAVLC (Context-based Adaptive Variable-Length Code) 的編解碼方式。在極大碼率的情況下，我們提出的架構，在高畫質需求的應用上獲得更好的效能。以解析度352 x 288的Highway視訊序列為例，碼率大於1.73 bbp (bit per pixel)之後的一定碼率下，我們獲得47.3 dB以上高於Hybrid DVC的PSNR (Peak Signal-to-Noise Ratio) 值。而且編碼時間和解碼時間皆有顯著減少，以執行解析度176 x 144的視訊序列Foreman為例，平均的編碼時間和解碼時間分別是Hybrid DVC的43.8%和8.2%。

關鍵字

分散式視訊編解碼 ； Wyner-Ziv編碼 ； JPEG 2000

並列摘要

Distributed Video Coding (DVC) was proposed to meet the need of low complexity encoder. The background knowledge of DVC is based on two theories, Slepain-Wolf Theory and Wyner-Ziv Theory. DISCOVER (Distributed Coding of Video service) and Hybrid DVC are two of the most popular DVC architectures in recent years. In this Thesis, we proposed a novel architecture of DVC. At extremely high bit rate, our DVC has a better video quality in high resolution and fast motion sequences than DISCOVER and Hybrid DVC. In the sequence of 352 x 288 Highway, when its bit rate is larger than 1.73 bpp (bit per pixel), the PSNR (Peak Signal to Noise Ratio) is getting higher than 47.3 dB, achieving a better quality than Hybrid DVC. Moreover, executing time of our work is less than DISCOVER and Hybrid DVC. As to the sequence of Foreman 176 x 144, its average encoding and decoding times are respectively 43.8% and 8.2%, compared to Hybrid DVC.

並列關鍵字

Distributed Video Coding ； Wyner-Ziv Codec ； Intra-Frame ； JPEG 2000

參考文獻

[1] D. Slepian and J.K. Wolf, “Noiseless Coding of Correlated Information Sources,” IEEE Transactions on Information Theory, vol. 19, no. 4, pp. 471-480, Jul. 1973.

[2] A.D. Wyner and J. Ziv, “The Rate-distortion Function for Source Coding with Side Information at the Decoder,” IEEE Transactions on Information Theory, vol. 22, no. 1, pp. 1-10, Jan. 1976.

[3] Y.-W. Huang, B.-Y. Hsieh, T.-C. Chen, and L.-G. Chen, “Analysis, Fast Algorithm, and VLSI Architecture Design for H.264/AVC Intra Frame Coder,” IEEE Transactions on Circuits System Video Technology, vol. 15, no. 3, pp. 378-401, Jul. 2005.

[5] C.-C. Chiu, S.-Y. Chien, C.-H. Lee, V.S. Somayazulu, and Y.-K. Chen, “Hybrid Distributed Video Coding with Frame Level Coding Mode Selection,” IEEE International Conference on Image Processing, pp. 1561-1564, Sep. 2012.

[6] H.-P. Yang, H.-C. Hsieh, S.-H. Chang, S.-J. Chen, “An Improved Distributed Video Coding with Low-Complexity Motion Estimation at Encoder,” The 28th IEEE International System-on-Chip Conference, pp. 163-172, Sep. 2015.