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Asymmetric stereoscopic coding can save bitrate and maintain the overall visual quality of stereoscopic perception, so it is an alternative for wireless environment in which the bandwidth is limited. In asymmetric stereoscopic coding, the right-view images are down-sampled to half resolution before coding, while the direction of sampling influences the rate-distortion performance of the asymmetric...
Bitrate adaptation and higher compression ratio are the major issues in world of Video compression. H.264 is the latest standard for video compression with high flexibility in compression ratio, quality of video and rate adaptation. This paper explores the possibility of bitrate reduction and proposes an algorithm to calculate the cost of each 8x8 subMacroblocks. Based on the threshold and the cost...
Side information generation is a critical step in distributed video coding systems. This is performed by using motion compensated temporal interpolation between two or more key frames (KFs). However, when the temporal distance between key frames increases (i.e. when the GOP size becomes large), the linear interpolation becomes less effective. In a previous work we showed that this problem can be mitigated...
This paper focuses on recent research on unequal error protection random linear coding (UEP RLC) for applications in network coded (NC) multimedia communications. We define a class of UEP RLC called expanding window random linear coding (EW-RLC) and provide exact decoding probability analysis for different importance classes of the source data assuming the Gaussian Elimination (GE) decoder applied...
High definition video over IP based networks (IPTV) has become a mainstay in today's consumer environment. In most applications, encoders conforming to the H.264/AVC standard are used. But even within one standard, often a wide range of coding tools are available that can deliver a vastly different visual quality. Therefore we evaluate in this contribution different coding technologies, using different...
With the rapid development of multimedia technology, video transmission over error prone channels is widely used. Using predictive video coding can lead to temporal and spatial propagation of channel errors, which consequently results in high degradation in the quality of the received video. In order to address this problem different error resilient methods have been proposed. In this paper, a number...
This paper proposes a fast inter prediction mode decision method for H.264. Motion compensation residuals of macroblock are used to analyze motion characteristics of each portion, and reduce the candidate inter modes to a small subset. Compared with the exhaustive mode search, the proposed method achieves an average 63% reduction in computation time with negligible degradation in visual quality. Compared...
This paper focuses on the rate-distortion optimization of low-delay 3D video communications based on the latest H.264/MVC video coding standard. The first part of the work proposes a new low-complexity model for distortion estimation suitable for low-delay stereoscopic video communication scenarios such as 3D videoconferencing. The distortion introduced by the loss of a given frame is investigated...
In wireless multimedia communications, optimizing the quality of user experience is a major design goal, which is often quantified by the end-to-end distortion between the actual multimedia source at the encoder and its reconstructed version at the decoder. Joint source-channel coding (JSCC) techniques aim to optimize codec and radio system parameters in order to minimize end-to-end distortion and...
Different data hiding methods would be required in different operating environments. To improve the quality of videos embedded by data, this paper will apply the differences of matching blocks in the H.264 encoder during the inter prediction stage and enforce the size of the matching blocks to implement data hiding. Bit rate increases after being embedded by data, to resolve the problem, this paper...
Medium Grain Scalable (MGS) coding is widely used as the quality scalable video coding (SVC) method. In this paper, we study bitstream extractor for MGS-based bitstream. In MGS, the coded data corresponding to a quantization step size can be fragmented into at most 15 sub-layers, which is called MGS slices. The contribution of each slice to the video quality is evaluated by our proposed algorithm,...
Video streaming is challenging in wireless networks due to the high loss rate and limited bandwidth. In video sequences, different part has different importance for reconstruction. Based on H.264 error resilient tool of datapartitioning, we apply UEP (Unequal Error Protection) to different data partitions. RS (Reed Solomon) coding is used for data partition A, whereas simple repeat-packet coding for...
With the rapid development of video streaming era, multipath video streaming comes as a promising solution. However, dividing the video into different sub-streams is still considered as an important challenge for researchers. In this paper, we propose an approach for generating multiple complementary descriptions of the video flow, then to couple these descriptions with the path diversity provided...
A fast mode decision algorithm is proposed to solve the computation complexity for enhancement hierarchical-B pictures with adaptive inter-layer prediction in H.264/AVC scalable extension, scalable video coding. This method exploits the evaluated modes of the co-located reference macroblocks, which include the best and other abandoned modes, to compose a new candidate group for the current macroblock...
The technique of variable block-size motion estimation is employed in the H.264 international video coding standard to obtain better compression performance. However, this technique brings about a lot of increase in the computational complexity and thus is very time-consuming. For this reason, a new fast motion estimation mode decision algorithm is proposed in this paper to reduce the computational...
Intra-frame plays a significant role in controlling video quality for H.264/AVC rate control. In this paper, we present an adaptive current buffer fullness ratio-based intra-frame rate control for H.264/AVC. The proposed algorithm adaptively adjusts the quantization step (QP) of the intra-frame by taking current buffer fullness ratio and scene change into consideration. Experimental results show that...
H.264 rate control is an interesting problem that has motivated numerous possible solutions. The challenge lies in determining a quantization parameter Qp that will be used for both the rate-distortion (R-D) optimization process and the quantization of transform coefficients. In this work, we attempt to achieve effective rate control with a different approach. By modelling the relationships of distortion,...
Asymmetric stereoscopic video coding can save the bitrate and maintain the overall visual quality of three dimensional perception. But for mobile three-dimensional television, the original full resolution restoring is complex for the decoder. In this paper, a decoding and up-sampling optimization scheme for asymmetric stereoscopic video coding is proposed, in which macroblocks encoded with SKIP mode...
This paper analyzes a joint error resilience and error concealment method (J-ER-EC) for video sequences. The method is based on a spatial-domain error concealment approach plus some redundant information, providing an edge-based sketch-description of the whole frame. The technique has its origin in well-known ideas concerning the use of side information to help video concealment: in J-ER-EC the redundant...
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