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RTP-based broadcast streaming of high definition H.264/AVC video: An error robustness evaluation
Hillestad Odd Inge, Jetlund Ola, Perkis Andrew
Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2006, 7(Supplement 1): 19-26.
https://doi.org/10.1631/jzus.2006.AS0019
In this work, we present an evaluation of the performance and error robustness of RTP-based broadcast streaming of high-quality high-definition (HD) H.264/AVC video. Using a fully controlled IP test bed (Hillestad et al., 2005), we broadcast high-definition video over RTP/UDP, and use an IP network emulator to introduce a varying amount of randomly distributed packet loss. A high-performance network interface monitoring card is used to capture the video packets into a trace file. Purpose-built software parses the trace file, analyzes the RTP stream and assembles the correctly received NAL units into an H.264/AVC Annex B byte stream file, which is subsequently decoded by JVT JM 10.1 reference software. The proposed measurement setup is a novel, practical and intuitive approach to perform error resilience testing of real-world H.264/AVC broadcast applications. Through a series of experiments, we evaluate some of the error resilience features of the H.264/AVC standard, and see how they perform at packet loss rates from 0.01% to 5%. The results confirmed that an appropriate slice partitioning scheme is essential to have a graceful degradation in received quality in the case of packet loss. While flexible macroblock ordering reduces the compression efficiency about 1 dB for our test material, reconstructed video quality is improved for loss rates above 0.25%.
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Content-adaptive robust error concealment for packet-lossy H.264 video streaming
Liao Ning, Yan Dan, Quan Zi-Yi, Men Ai-Dong
Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2006, 7(Supplement 1): 41-47.
https://doi.org/10.1631/jzus.2006.AS0041
In this paper, we present a spatio-temporal post-processing error concealment (EC) algorithm designed initially for a H.264 video-streaming scheme over packet-lossy networks. It aims at optimizing the subjective quality of the restored video under the constraints of low delay and computational complexity, which are critical to real-time applications and portable devices having limited resources. Specifically, it takes into consideration the physical property of motion field in order to achieve more meaningful perceptual video quality, in addition to the improved objective PSNR. Further, a simple bilinear spatial interpolation approach is combined with the improved boundary-match (B-M) based temporal EC approach according to texture and motion activity analysis. Finally, we propose a low complexity temporal EC method based on motion vector interpolation as a replacement of the B-M based approach in the scheme under low-computation requirement, or as a complement to further improve the scheme’s performance in applications having enough computation resources. Extensive experiments demonstrated that the proposal features not only better reconstruction, objectively and subjectively, than JM benchmark, but also robustness to different video sequences.
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Fast mode decision algorithm for spatial resolutions down-scaling transcoding to H.264
Bu Jia-Jun, Mo Lin-Jian, Chen Chun, Yang Zhi
Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2006, 7(Supplement 1): 70-75.
https://doi.org/10.1631/jzus.2006.AS0070
A fast mode decision algorithm is proposed in this paper to accelerate the process of transcoding videos into H.264 with arbitrary rate spatial resolution down-scaling. The proposed algorithm consists of three steps. First, an early-stop technique is introduced to determine the 16×16-mode blocks, which take up about 70% of all the macroblocks; then, a bottom-up merging process is performed to determine the mode of rest non-early-stopped blocks; and then, we adopt half-pixel motion estimation to further refine the acquired predictive motion vectors. In order to obtain the predictive motion vectors for early-stop and merging processes, we propose a motion vector composition scheme, which can reuse the information in the input pre-encoded videos to handle the spatial resolution down-scaling. Experimental results showed that our algorithm is about four times faster than the Cascaded-Decoder-Encoder method and has negligible PSNR drop and little bit rate increase.
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Resynchronization and remultiplexing for transcoding to H.264/AVC
Zhou Jin, Xiong Hong-Kai, Song Li, Yu Song-Yu
Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2006, 7(Supplement 1): 76-81.
https://doi.org/10.1631/jzus.2006.AS0076
H.264/MPEG-4 AVC standard appears highly competitive due to its high efficiency, flexibility and error resilience. In order to maintain universal multimedia access, statistical multiplexing, or adaptive video content delivery, etc., it induces an immense demand for converting a large volume of existing multimedia content from other formats into the H.264/AVC format and vice versa. In this work, we study the remultiplexing and resynchronization issue within system coding after transcoding, aiming to sustain the management and time information destroyed in transcoding and enable synchronized decoding of decoder buffers over a wide range of retrieval or receipt conditions. Given the common intention of multiplexing and synchronization mechanism in system coding of different standards, this paper takes the most widely used MPEG-2 transport stream (TS) as an example, and presents a software system and the key technologies to solve the time stamp mapping and relevant buffer management. The solution reuses previous information contained in the input streams to remultiplex and resynchronize the output information with the regulatory coding and composition structure. Experimental results showed that our solutions efficiently preserve the performance in multimedia presentation.
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Channel adaptive rate control for energy optimization
Blanch Carolina, Pollin Sofie, Lafruit Gauthier, Eberle Wolfgang
Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2006, 7(Supplement 1): 82-88.
https://doi.org/10.1631/jzus.2006.AS0082
Low energy consumption is one of the main challenges for wireless video transmission on battery limited devices. The energy invested at the lower layers of the protocol stack involved in data communication, such as link and physical layer, represent an important part of the total energy consumption. This communication energy highly depends on the channel conditions and on the transmission data rate. Traditionally, video coding is unaware of varying channel conditions. In this paper, we propose a cross-layer approach in which the rate control mechanism of the video codec becomes channel-aware and steers the instantaneous output rate according to the channel conditions to reduce the communication energy. Our results show that energy savings of up to 30% can be obtained with a reduction of barely 0.1 dB on the average video quality. The impact of feedback delays is shown to be small. In addition, this adaptive mechanism has low complexity, which makes it suitable for real-time applications.
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Improved fast intra prediction algorithm of H.264/AVC
Liu Qiong, Hu Rui-Min, Zhu Li, Zhang Xin-Chen, Han Zhen
Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2006, 7(Supplement 1): 101-105.
https://doi.org/10.1631/jzus.2006.AS0101
With advanced prediction modes of intra prediction, intra coding of H.264/AVC offers significant coding gains compared with previous video coding standards. It uses an important tool called Lagrangian rate-distortion optimization (RDO) technique to decide the best coding mode for a block, but the computational burden is extremely high. In this paper, we proposed an improved fast intra prediction algorithm including block type selection and mode decision algorithm based on analysis of edge feature of a block. Our algorithm filters out unlikely block type and candidate modes to reduce the RDO calculations. Experimental results showed that the proposed algorithm can reduce the computation complexity of intra prediction from 52.90% to 56.31%, with 0.04 dB PSNR degradation and 2% increase of bit rate.
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BulkTree: An overlay network architecture for live media streaming
Gong An, Ding Gui-Guang, Dai Qiong-Hai, Lin Chuang
Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2006, 7(Supplement 1): 125-130.
https://doi.org/10.1631/jzus.2006.AS0125
Peer-to-peer (P2P) systems are now very popular. Current P2P systems are broadly of two kinds, structured and unstructured. The tree structured P2P systems used technologies such as distributed hash tables (DHT) and hierarchical clustering can search the required target quickly, however, in a tree, the internal node has a higher load and its leave or crash often causes a large population of its offspring’s problems, so that in the highly dynamic Internet environment the tree structure may still suffer frequent breaks. On the other hand, most widely used unstructured P2P networks rely on central directory servers or massive message flooding, clearly not scalable. So, we consider both of the above systems’ advantages and disadvantages and realize that in the P2P systems one node may fail easily, but that when a number of nodes organized as a set, which we call “super node”, the set is robust. Super nodes can be created and updated aware of topology-aware, and used with simple protocol such as flooding or “servers” to exchange information. Furthermore the entire robust super node can be organized into exquisite tree structure. By using this overlay network architecture, P2P systems are robust, efficient, scalable and secure. The simulation results demonstrated that our architecture greatly reduces the alteration time of the structure while decreasing the average delay time, compared to the common tree structure.
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Experimental evaluation of an on-demand multipath routing protocol for video transmission in mobile ad hoc networks
Taniyama Kenta, Morii Takeshi, Koizumi Shinya, Noguchi Kazuhiro, Kotani Yukihiro, Katto Jiro
Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2006, 7(Supplement 1): 145-150.
https://doi.org/10.1631/jzus.2006.AS0145
We propose an on-demand multipath routing algorithm in a mobile ad hoc network for video transmission and evaluate its real world performance in video streaming application. There have been a number of multipath routing protocols extended from AODV which is a well-known single path routing protocol. Multipath routing protocols indicate good performance in the reduction of route discovery latency and unnecessary routing packets in simulations. We show that the route establishment using source route lists provided by us (Hu and Johnson, 2002) can reduce the route discovery latency, select stable routes automatically, and work well for live video streaming without limitation of the hop count based approaches. We evaluate this proposed method compared with the original AODV by using eight laptop PCs and demonstrate live streaming experiments.
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Multi-user Motion JPEG2000 over wireless LAN: Run-time performance-energy optimization with application-aware cross-layer scheduling
Ji Xin, Pollin Sofie, Lenoir Gregory, Lafruit Gauthier, Dejonghe Antoine, Catthoor Francky
Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2006, 7(Supplement 1): 151-158.
https://doi.org/10.1631/jzus.2006.AS0151
This paper introduces a video application-aware cross-layer framework for joint performance-energy optimization, considering the scenario of multiple users upstreaming real-time Motion JPEG2000 video streams to the access point of a WiFi wireless local area network and extends the PHY-MAC run-time cross-layer scheduling strategy that we introduced in (Mangharam et al., 2005; Pollin et al., in press) to also consider congested network situations where video packets have to be dropped. We show that an optimal solution at PHY-MAC level can be highly suboptimal at application level, and then show that making the cross-layer framework application-aware through a prioritized dropping policy capitalizing on the inherent scalability of Motion JPEG2000 video streams leads to drastic average video quality improvements and inter-user quality variation reductions of as much as 10 dB PSNR, without affecting the overall energy consumption requirements.
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26 articles
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