一種空域可分級的自適應(yīng)視頻碼流控制方法
A New Adaptive Rate Control Algorithm with Spatial Scalability for Video Coding
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摘要: 在傳統(tǒng)的CBR碼流控制中，為防止緩沖器上溢，通常采用跳幀的方法來保持碼率恒定。由于跳幀引起解碼端運動補(bǔ)償誤差增大，客觀上造成跳幀期間圖像PSNR降低，圖像失真度迅速增加，在主觀上造成圖像有跳躍感，畫面不流暢。針對以上缺陷，該文基于H.263+的TMN8幀級碼流控制算法，提出了一種空域可分級的自適應(yīng)碼流控制方法。該方法在編碼端對原跳幀方法中不編碼的幀進(jìn)行自適應(yīng)下采樣編碼，解碼端通過上采樣恢復(fù)。實驗結(jié)果證明，該文提出的碼流控制算法在低帶寬條件下，圖像質(zhì)量較跳幀方法有較大提高。在低碼率條件下,對于高運動圖像該方法的平均PSNR值比采用跳幀的碼流控制方法高0.3~0.8dB；比采用增大量化步長的方法高0.1~0.4dB，而對于跳幀階段PSNR值，該算法比傳統(tǒng)的跳幀方法高1~2dB左右。
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關(guān)鍵詞:
- 空域可分級;自適應(yīng)流控;固定比特率控制;可變比特率控制
Abstract: In the traditional CBR rate control algorithm, the skipping method is adopted to combat the overflow of video buffer , in which the motion compensation error and picture distortion are increased with the number of skipping frame. To deal with the disadvantage of traditional skipping method, a new adaptive rate control algorithm with spatial scalability for video coding is presented in this paper. In the method, the original skipped frame is adaptively sub-sampled at encoder and is up-sampled in decoder. Simulation results show that this scheme can highly improve the quality of reconstructed video and obtain a gain of about0.3~0.8dB and 0.1~0.4dB in PSNR respectively compared with the traditional skipping method and the method of increasing quantization step. -
Video codec test model, TMN8, ITU-T/SG15, 1997.[2]Test Mode 5, ISO/IEC JTC1/SC29/WG11, Sydney, Australia, 1993 .[3]Video Group, Text of ISO/IEC 14496-2 MPEG4 video VM-Version 8.0,ISO/IEC JTC1/SC29/WG11 Coding of Moving Pictures and Associated Audio MPEG97/W1796, Stockholm , Sweden July 1997.[4]Song Hwangjun, Jay Kuo C C. Rate control for low-bit-rate video via variable-encoding frame rates[J].IEEE Trans on Circuits and System for Video Technology.2001, 11(4):512-[5]牛建偉，李煒，胡建平. MPEG-2恒定碼率位率控制研究 .計算機(jī)研究與發(fā)展 2002, 21(12):1708～1713.[6]Li Jun, Zou Cairong, He Zhenya. A new algorithm on MPEG2 target bit-number allocation at scene changes[J].IEEE Trans on Circuits and System for Video Technology.1997, 7(5):815-[7]Aramvith S, Pao I M, Sun M T. IEEE Trans on Circuits and Systems for Video Technology, 2001, 11(5): 569.580.[8]Fung K T, Chan Y L, Siu W C. IEEE Trans on Image Processing, 2002, 11(8):886.900. -
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