The need to move. data among devices with different capabilities creates a need for transcoding. In this paper, an efficient transcoding algorithm from VC-1 to H.264 video with down/up sampling is discussed. Transcodi...
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ISBN:
(纸本)9781424417650
The need to move. data among devices with different capabilities creates a need for transcoding. In this paper, an efficient transcoding algorithm from VC-1 to H.264 video with down/up sampling is discussed. transcoding with resolution conversion usually results in lower video output quality. To address this problem an algorithm for quality enhancement with the use of irregular sampling is presented to use with transcoding. The quality enhancement module can also be used independently from the transcoding step. Experimental results show that the proposed algorithm can successfully remove artifacts and generate higher video quality. The main contribution of this paper is the use of irregular sampling techniques for video quality enhancement.
In this paper, we proposed an enhanced transform-domain intra prediction method for H.264/AVC. In the proposed scheme, H.264/AVC intra prediction can be described by generalized linear operation after defining both H-...
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In this paper, we proposed an enhanced transform-domain intra prediction method for H.264/AVC. In the proposed scheme, H.264/AVC intra prediction can be described by generalized linear operation after defining both H-filter and V-filter. Since intra prediction operation can be decomposed into some sparse matt-ices, we can reduce computational complexity for intra prediction. Our scheme can reduce the number of multiplication and addition operations more than Chen's by 22.4% and 21.6%, respectively, in each 4 x 4 block. Furthermore, we show that matrix multiplication can be simply processed using a look-up table which consists of 9 types of 4 x 4 constant matrices corresponding to 9 prediction modes in H.264. Consequently, we can insist that the proposed scheme in this paper can be used foe fast transform domain intra prediction in the area of transcoding MPEG-2 streams into H.264/AVC streams.
This paper presents a comparison between the scalable extension of H.264/AC (SVC) and transcoding, in terms of Rate-Distortion(RD) performance and computational complexity. Both bitrate and spatial resolution reductio...
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This paper presents a comparison between the scalable extension of H.264/AC (SVC) and transcoding, in terms of Rate-Distortion(RD) performance and computational complexity. Both bitrate and spatial resolution reduction cases are included. Simulation results show that, in the aspect of RD performance, SVC performs significantly better in bitrate reduction and slightly better in spatial resolution reduction. Meanwhile, SVC adaptation through bitstream extraction has negligible complexity compared with transcoding(1)..
Implementing MPEG-2 to H.264 transcoding schemes in the pixel domain introduces a high degree of computational complexity. In the transform domain, this transcoding is more computationally efficient, and several metho...
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Implementing MPEG-2 to H.264 transcoding schemes in the pixel domain introduces a high degree of computational complexity. In the transform domain, this transcoding is more computationally efficient, and several methods have been developed to address that approach. However, incompatibilities between the two standards, such as the mismatches between the MPEG-2 and H.264 motion compensation processes, cause several distortions that may affect the overall picture quality. In this study, we address the main distortions that result from requantization errors: luminance half-pixel and chrominance quarter/three-quarter interpolation errors. Then, we propose algorithms that compensate for these errors. The traditional requantization error compensation algorithm for DCT coefficients is updated so that it can be applied to the H.264 integer transform coefficients. Equations that compensate for the luminance half-pixel and chrominance quarter/three-quarter pixel interpolation errors are derived. To remove the interpolation errors, the previous H.264 frame is needed. Thus, the compensation scheme includes a closed-loop H.264 motion compensation process, which is implemented in the pixel domain. To evaluate the performance of the proposed compensation algorithms in terms of picture quality, our scheme is compared with two different cascaded pixel-domain transcoding structures. The first structure reuses the MPEG-2 motion vectors, and the other implements +/-2 pixels motion vector refinement, but each one has an H.264 deblocking filter. The experimental results show that the proposed compensation algorithms achieve 5-dB quality improvement over the open-loop transform-domain-based transcoding and almost the same picture quality (0.3-0.6 dB) as the cascaded structures. An additional advantage is the reduction in computational complexity that ranges from 13% to 69% compared with the two cascaded methods.
Existing and future media ecosystems need to cope with the ever-increasing heterogeneity of networks, devices, and user characteristics collectively referred to as (usage) context. The key to address this problem is m...
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Existing and future media ecosystems need to cope with the ever-increasing heterogeneity of networks, devices, and user characteristics collectively referred to as (usage) context. The key to address this problem is media adaptation to various and dynamically changing contexts in order to provide a service quality that is regarded as satisfactory by the end user. The adaptation can be performed in many ways and at different locations, e.g., at the edge and within the network resulting in a substantial number of issues to be integrated within a media ecosystem. This paper describes research challenges, key innovations, target research outcomes, and achievements so far for edge and in-network media adaptation by introducing the concept of Scalable Video Coding (SVC) tunneling.
In this article, we propose a hardware architecture for our fast Intra mode and direction prediction algorithm to accelerate the MPEG-2 to H.264/AVC transcoding devices. In order to eliminate the redundant operations ...
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In this article, we propose a hardware architecture for our fast Intra mode and direction prediction algorithm to accelerate the MPEG-2 to H.264/AVC transcoding devices. In order to eliminate the redundant operations in the transcoder, our implemented algorithm uses the DCT coefficients from the MPEG-2 decoder to predict the Intra mode and reconstruction direction for the H.264/AVC encoder. In addition, the Intra prediction process in the H.264/AVC part of the transcoder has been dramatically accelerated by using our full-search elimination technique. The empirical results show 92% reduction in the transcoding time while reducing the PSNR for less than 3.5%. The proposed architecture has achieved an operating frequency of 323MHz at a power consumption of 112 mW when implemented on Virtex-5 FPGA Development Board.
In this paper, we proposed a fast Intra prediction method for MPEG-2 to H.264/AVC transcoding. To reduce the computational complexity, we utilized the information of DCT coefficients in MPEG-2 decoder to measure the I...
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ISBN:
(纸本)9780769534718
In this paper, we proposed a fast Intra prediction method for MPEG-2 to H.264/AVC transcoding. To reduce the computational complexity, we utilized the information of DCT coefficients in MPEG-2 decoder to measure the Intra macroblock (AM) energy trend Base on the relationship between the energy trend and the Intra prediction direction, we can pre-determine the Intra prediction for both luminance (luma) and chrominance (chroma) components. The numbers of the Intra prediction candidates of luma Intra16x16 and chroma Intra8x8 can be reduced from original four to one or two, and the numbers of prediction candidates of luma Intra4x4 can be reduced from nine to four. With our proposed algorithm, the computational complexity of Intra prediction for MPEG-2 to H.264/AVC transcoding can be reduced about 60% compared with the conventional cascaded transcoding method at the negligible quality loss.
Leveraging the ubiquity of mobile devices, innovative social and cognitive applications are emerging. However, the gap between these social community services/applications and multicast transmission hinders their wide...
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ISBN:
(纸本)9781424420353
Leveraging the ubiquity of mobile devices, innovative social and cognitive applications are emerging. However, the gap between these social community services/applications and multicast transmission hinders their wide spread deployment and affect commercial viability. This leads us to rethink the existing broadcast/multicast transmission paradigm, especially group management features in mobile networks. We propose a hierarchal group management framework and shows how transcoding based groups can be managed. We discusses the network architecture and signaling interactions. Results are presented to highlight the resource usage for groups based in multiple codecs in an MMMS environment. This work is carried out as part of EU-IST project C-MOBILE (IST-2005-27423).
A new encryption strategy proposed in this paper, which based on duple permutation, is designed for transparent transcoding. Firstly the original image is divided into several macro blocks by certain size, and the seq...
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ISBN:
(纸本)9781424417230
A new encryption strategy proposed in this paper, which based on duple permutation, is designed for transparent transcoding. Firstly the original image is divided into several macro blocks by certain size, and the sequence of macro block rows is reordered Then, the macro blocks are permuted in rows. Theoretical analysis and experimental results indicate that the strategy proposed in this paper is transparent to transcoding, security and low computation complexity. It has little adverse impact on the compact ratio. All the attributes mentioned above make this strategy suitable to be the encryption approach for image transmission.
One objective in MPEG-2 to H.264 transcoding is to improve the H.264 compression ratio by using more accurate H.264 motion vectors. Motion re-estimation is by far the most time consuming process in video transcoding, ...
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ISBN:
(纸本)9781424414833
One objective in MPEG-2 to H.264 transcoding is to improve the H.264 compression ratio by using more accurate H.264 motion vectors. Motion re-estimation is by far the most time consuming process in video transcoding, and improving the searching speed is a challenging problem. We introduce a new transcoding scheme that uses the MPEG-2 DCT coefficients to predict the block size partitioning for H.264. Performance evaluations have shown that, for the same rate-distortion performance, our proposed scheme achieves an impressive reduction in the computational complexity of more than 82% compared to the full range motion estimation used by H.264.
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