Video transcoding has been a critical issue in order to make the multimedia contents available for different systems under various environments. In this paper, a dedicated transcoder from AVS to H.264/AVC with reduced...
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Video transcoding has been a critical issue in order to make the multimedia contents available for different systems under various environments. In this paper, a dedicated transcoder from AVS to H.264/AVC with reduced resolution is proposed, aiming to provide a fast and reliable solution for transcoding standard-definition videos to mobile contents. A multi-stage process is introduced for accurate motion and mode mapping. Through this process, huge computation time saving can be achieved with only negligible quality degradation.
In this paper, we propose an efficient motion estimation scheme for pixel domain downsizing homogeneous H.264 transcoding. We exploit the motion information from the original decoded frames to generate more accurate m...
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In this paper, we propose an efficient motion estimation scheme for pixel domain downsizing homogeneous H.264 transcoding. We exploit the motion information from the original decoded frames to generate more accurate motion vector (MV) candidates and make a fast selection of the best reference frame for current macroblock (MB) in the down-scaled frame, finally based on the chosen reference frame and MV candidates, perform the mode decision. Extensive experiment results show that the rate-distortion (RD) performance of the proposed scheme is very close to the benchmark full-search method (within 0.05 dB loss and 2% bit rate increase on average) while 68% computation time is saved.
Compressive sensing (CS) has recently attracted much attention due to its unique feature of directly and simultaneously acquiring compressed and encrypted data based on their sparse or compressible properties. To secu...
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Compressive sensing (CS) has recently attracted much attention due to its unique feature of directly and simultaneously acquiring compressed and encrypted data based on their sparse or compressible properties. To securely transmit compressively sensed multimedia data over networks, it is required to support transcoder to securely convert compressed multimedia into several different types for diverse receivers. In this paper, a secure transcoding scheme for compressive multimedia sensing is proposed. We focus on securely converting compressively sensed multimedia data (not data compressed via standard codec) with a certain number of measurements into other different numbers of measurements without resorting to reconstruct the original data. We show that the security can be achieved via transforming multimedia re-sensing process into another secure domain at the transcoder. We also show that the computational security can be achieved while transmitting compressively sensed data between the sender (or each receiver) and the transcoder over networks.
This paper presents a region-of-interest (ROI) segmentation technique to facilitate the video transcoding. In the low bit-rate transmission, ROI video coding can maintain better visual quality based on the properties ...
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This paper presents a region-of-interest (ROI) segmentation technique to facilitate the video transcoding. In the low bit-rate transmission, ROI video coding can maintain better visual quality based on the properties of the human visual system (HVS). In this paper, to aim this purpose, the Bayesian theorem is utilized to automatically determine the moving foreground objects by using motion intensity analysis and skin color information for inter coded frames. Experimental results show that the proposed method can extract ROI macroblocks (MBs) effectively.
MPEG-2 video compression standard is wildly used in traditional digital video, while H.264 is a new generation video compression standard, which has higher code efficiency. In this paper, we proposed a novel fast mode...
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ISBN:
(纸本)9781612844589
MPEG-2 video compression standard is wildly used in traditional digital video, while H.264 is a new generation video compression standard, which has higher code efficiency. In this paper, we proposed a novel fast mode selection algorithm for transcoding from MPEG-2 to H.264. Utilizing the CMT and DC factors obtained from MPEG-2 code stream, the proposed algorithm selects MacroBlcok model adaptively, and then finishes the progress of transcoding from MPEG-2 to H.264. The experimental study data shows the proposed fast mode selection algorithm has good performance for transcoding.
Scalable video coding (SVC) allows encoded bitstreams to be adapted. However, most bitstreams do not incorporate this scalability so bitstreams have to be adapted multiple times to accommodate for varying network cond...
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Scalable video coding (SVC) allows encoded bitstreams to be adapted. However, most bitstreams do not incorporate this scalability so bitstreams have to be adapted multiple times to accommodate for varying network conditions or end-user devices. Each adaptation incorporates an additional loss of quality due to transcoding. To overcome this issue, we propose a single transcoding step from H.264/AVC to SVC. Doing so, the resulting bitstream can be freely adapted without any additional quality reduction. Open-loop transcoding architectures can be used for H.264/AVC-to-SVC transcoding with a low complexity, although these architectures suffer from drift artifacts. Closed-loop transcoding, on the other hand, requires a higher complexity. To overcome the drawbacks of both systems, we propose combining both techniques.
In order to achieve good performances when temporally transcoded bitstream transmitted in the unreliable routines, an adaptive error-resilient scheme for temporal video transcoding is proposed. After all original fram...
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In order to achieve good performances when temporally transcoded bitstream transmitted in the unreliable routines, an adaptive error-resilient scheme for temporal video transcoding is proposed. After all original frames' motion intensity and error sensitivity values are calculated in the sliding window, every possible frame allocation's quality and error impact values due to the frame skipping are evaluated. Then, following the impact values, an optimum frame allocation selection approach based on the joint impact value is presented, which enables the dynamic balance between the coding efficiency and the error-resilient capability. Additionally, an effective intra refresh algorithm is advised to further enhance the robustness. Experiments prove that the re-decoded video's PSNR can be improved by the proposed scheme when transmitted unreliably.
This paper proposes an efficient motion re-estimation using enhanced predictive zonal search (EPZS) algorithm for H.264/AVC video downscaling transcoding to reduce computation cost while maintaining high coding perfor...
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This paper proposes an efficient motion re-estimation using enhanced predictive zonal search (EPZS) algorithm for H.264/AVC video downscaling transcoding to reduce computation cost while maintaining high coding performance. Three prediction motion vectors (PMV) using AAW, ABW and AWW approaches are defined based on CBP and MV information in original H.264/AVC coded videos. The proposed EPZS takes into account four MV predictors (including AAW, ABW and AWW predictors as well as median predictor defined in H.264/AVC). The experimental result reveals that the proposed EPZS algorithm achieves a significant reduction of 66% computation time while maintaining coding efficiency as good as fully decoding and re-encoding. The result also shows that the proposed algorithm outperforms the AWVM algorithm in all respects, including PSNR, bit-rate increment as well as computation saving.
In spite of the widespread attention to data and video, voice is still responsible for up to 75% of the revenue in wireless communications systems today. An unfortunate characteristic of 2 nd and 3 rd generation dig...
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In spite of the widespread attention to data and video, voice is still responsible for up to 75% of the revenue in wireless communications systems today. An unfortunate characteristic of 2 nd and 3 rd generation digital cellular systems has been the need to transcode at most network interfaces, since the voice codec at the other end of the call is usually unknown and cannot be negotiated. Fourth generation systems such as LTE also require transcoding when the call leaves the LTE network. transcoding at network interfaces adds complexity, degrades quality, and increases latency, all of which directly impact the quality and cost of voice communications. We investigate the issues in voice communications over tandem connections of wireline and wireless communications links using rate distortion theoretic results and speech coding studies and show that each transcoding operation can incur a 3-dB penalty in source coding performance, in addition to increased latency and complexity. Suggestions for addressing this performance loss are presented.
High Efficiency Video Coding (HEVC) is invented as new video coding standard for improvement of the H.264/AVC coding standard. HEVC currently used to enhance the video compression and quality of video. However, there ...
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ISBN:
(纸本)9781479960545
High Efficiency Video Coding (HEVC) is invented as new video coding standard for improvement of the H.264/AVC coding standard. HEVC currently used to enhance the video compression and quality of video. However, there are a lot of limitations in H.264/AVC encoded video. So the new efficient method is proposed for transcoding the H.264 encoded video into HEVC format. In this paper, different methods for video transcoding are explained which include mode mapping, machine learning, complexity scalable and background modeling.
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