针对高效率视频编码(High Efficiency Video Coding,HEVC)在编码过程中的帧层比特分配未考虑视频内容特性与缓冲区的状态而导致帧层比特分配不合理及编码性能低等问题,本文提出一种基于R-λ模型的帧层码率控制优化算法。首先,通过计算...针对高效率视频编码(High Efficiency Video Coding,HEVC)在编码过程中的帧层比特分配未考虑视频内容特性与缓冲区的状态而导致帧层比特分配不合理及编码性能低等问题,本文提出一种基于R-λ模型的帧层码率控制优化算法。首先,通过计算得到一种度量帧层图像复杂度的综合因子,并作为新帧层比特分配权重;其次,根据目标缓冲级与缓冲区剩余比特计算出缓冲区反馈比特;最后,根据计算获得的新帧层比特分配权重和缓冲区反馈比特对帧层进行比特分配。本文算法在HM16.0上进行了实现和性能测试,结果表明,与HEVC原始的码率控制算法相比,优化算法的码率控制误差平均下降了2.008%,峰值信噪比平均提高了0.21dB。展开更多
It is proved that there exists a formula of first-order logic with only one non-logical symbol, a binary function symbol Ap signifying application, which uniformly defines inclusion in all BF(E)-models Some definabili...It is proved that there exists a formula of first-order logic with only one non-logical symbol, a binary function symbol Ap signifying application, which uniformly defines inclusion in all BF(E)-models Some definability results give an isomorphism between the group of bi-stable Ap -automorphisms of A and the group of permutations of A; it also implies that each BF(E)-model is determined, up to isomorphism, by the cardinal of its set of atoms.展开更多
An extension of the simply-typed lambda calculus with constructs for expressing a notion calledunderdeterminism is studied. This allows us to interpret notions of stub and skeleton used in top-down program development...An extension of the simply-typed lambda calculus with constructs for expressing a notion calledunderdeterminism is studied. This allows us to interpret notions of stub and skeleton used in top-down program development. We axiomatise a simple notion of program refinement, and give a semantics, for which the calculus is proved sound and complete.展开更多
文摘针对高效率视频编码(High Efficiency Video Coding,HEVC)在编码过程中的帧层比特分配未考虑视频内容特性与缓冲区的状态而导致帧层比特分配不合理及编码性能低等问题,本文提出一种基于R-λ模型的帧层码率控制优化算法。首先,通过计算得到一种度量帧层图像复杂度的综合因子,并作为新帧层比特分配权重;其次,根据目标缓冲级与缓冲区剩余比特计算出缓冲区反馈比特;最后,根据计算获得的新帧层比特分配权重和缓冲区反馈比特对帧层进行比特分配。本文算法在HM16.0上进行了实现和性能测试,结果表明,与HEVC原始的码率控制算法相比,优化算法的码率控制误差平均下降了2.008%,峰值信噪比平均提高了0.21dB。
基金Project partially supported by a post-doctor grant of the Chinese Academy of Sciences.
文摘It is proved that there exists a formula of first-order logic with only one non-logical symbol, a binary function symbol Ap signifying application, which uniformly defines inclusion in all BF(E)-models Some definability results give an isomorphism between the group of bi-stable Ap -automorphisms of A and the group of permutations of A; it also implies that each BF(E)-model is determined, up to isomorphism, by the cardinal of its set of atoms.
文摘An extension of the simply-typed lambda calculus with constructs for expressing a notion calledunderdeterminism is studied. This allows us to interpret notions of stub and skeleton used in top-down program development. We axiomatise a simple notion of program refinement, and give a semantics, for which the calculus is proved sound and complete.
