In this paper, we propose a quality-level selection method for adaptive video streaming with scalable video coding (SVC). The proposed method works on the client with the dynamic adaptive streaming over HTTP (DASH) with SVC. The proposed method consists of two components: introducing segment group and a buffer-aware layer selection algorithm. In general, quality of experience (QoE) performance degrades due to stalling (playback buffer underflow), low playback quality, frequent quality-level switching, and extreme-down quality switching. The proposed algorithm focuses on reducing the frequent quality-level switching, and extreme-down quality switching without increasing stalling and degrading playback quality. In the proposed method, a SVC-DASH client selects a layer every G segments, called a segment group to prevent frequent quality-level switching. In addition, the proposed method selects the quality of a layer based on a playback buffer in a layer selection algorithm for preventing extreme-down switching. We implement the proposed method on a real SVC-DASH system and evaluate its performance by subjective evaluations of multiple users. As a result, we confirm that the proposed algorithm can obtain better mean opinion score (MOS) value than a conventional SVC-DASH, and confirm that the proposed algorithm is effective to improve QoE performance in SVC-DASH.

Scalable Video Coding (SVC) is an extension of H.264/AVC, aiming to provide the ability to adapt to heterogeneous networks or requirements. It offers great flexibility for bitstream adaptation in multi-point applications such as videoconferencing. However, transcoding between SVC and AVC is necessary due to the existence of legacy AVC-based systems. The straightforward re-encoding method requires great computational cost, and delay-sensitive applications like videoconferencing require much faster transcoding scheme. This paper proposes a 3-stage fast SVC-to-AVC transcoder with medium-grain quality scalability (MGS) for videoconferencing applications. Hierarchical-P structured SVC bitstream is transcoded into IPPP structured AVC bitstream with multiple reference frames. In the first stage, mode decision is accelerated by proposed SVC-to-AVC mode mapping scheme. In the second stage, INTER motion estimation is accelerated by an optimized motion vector (MV) conjunction method to predict the MV with a reduced search range. In the last stage, hadamard-based all zero block (AZB) detection is utilized for early termination. Simulation results show that proposed transcoder achieves very similar coding efficiency to the optimal result, but with averagely 89.6% computational time saving.

As an extension of H.264/AVC, Scalable Video Coding (SVC) provides the ability to adapt to heterogeneous networks and user-end requirements, which offers great scalability in multi-point applications such as videoconferencing. However, transcoding between SVC and AVC becomes necessary due to the existence of legacy AVC-based systems. The straightforward full re-encoding method requires great computational cost, and the fast SVC-to-AVC spatial transcoding techniques have not been thoroughly investigated yet. This paper proposes a low-complexity hybrid-domain SVC-to-AVC spatial transcoder with drift compensation, which provides even better coding efficiency than the full re-encoding method. The macroblocks (MBs) of input SVC bitstream are divided into two types, and each type is suitable for pixel- or transform-domain processing respectively. In the pixel-domain transcoding, a fast re-encoding method is proposed based on mode mapping and motion vector (MV) refinement. In the transform-domain transcoding, the quantized transform coefficients together with other motion data are reused directly to avoid re-quantization loss. The drift problem caused by proposed transcoder is solved by compensation techniques for I frame and P frame respectively. Simulation results show that proposed transcoder achieves averagely 96.4% time reduction compared with the full re-encoding method, and outperforms the reference methods in coding efficiency.

Relay has been incorporated into standards of wireless access networks to improve the system capacity and coverage. However, the resource allocation problem to support scalable video coding (SVC) multicast for wireless relay networks is challenging due to the existence of relay stations (RSs). In this paper, we study the resource allocation problem for SVC multicast over multi-hop wireless relay networks to maximize the total utility of all users with a general non-negative, non-decreasing utility function. Since the problem is NP-hard, we simplify it with RS specification functions which specialize the relay station to receive data for each user, and convert the resource allocation problem with one RS specification function as finding a maximum spanning sub-tree of a directed graph under budget constraint. A heuristic algorithm is proposed to solve the problem with polynomial time complexity. The simulation results reveal that the proposed algorithm outperforms other algorithms under assumptions of two-hop wireless relay networks or separated transmission for relay and access links, and it keeps good approximation to the optimal results.

In this paper, we propose a novel layered scalable- multiple description coding (LS-MDC) which offers the benefits of both scalable video coding and multiple description coding for robust video transmission over packet lossy networks. In the proposed LS-MDC method, multiple descriptions including base layer, enhancement layers, and their corresponding FEC parity data are allocated into two network paths of a path diversity system. Unlike the conventional approaches, the source base/enhancement data and their own parities in the proposed method are not transmitted together but are transferred over different paths. Therefore, the effect of burst packet losses can be effectively reduced for the descriptions. Furthermore, in order to minimize the overall distortion for the LS-MDC system and exploit the benefits of path diversity, we also propose an optimal rate allocation scheme that can adaptively control the transmission rate as well as the channel coding rate for media senders. Experiments show that the proposed method provides much better peak signal-to-noise ratio (PSNR) than conventional MDC techniques.

In this paper, we propose a novel scheme for efficient video broadcasting over WLANs using the IEEE 802.11e HCCA MAC and H.264/SVC. We rearrange the outgoing sequence of H.264/SVC NAL units according to their dimension, temporal, and quality scalability. In addition, our proposed scheme broadcasts the NAL units at various data-rates by using the link adaptation function of IEEE 802.11 PHY. Our scheme is verified using NCTUns network simulator, and is evaluated in terms of throughput, delay, and quality of experience (QoE) using structural similarity (SSIM) rather than mean square error (MSE). We employee a real video clip to increase the reliability of the simulation in which the video clip is compressed as VBR with 24 scalable layers by JSVM reference codec of the H.264/SVC. In the simulation topology, a host broadcasts the video clip to 10 wireless stations which are within 150 meters from an AP. We present performance comparisons between our proposed scheme and the scheme provided by the IEEE 802.11e HCCA standard, which is to be referred to as the simple scheme in this paper. The proposed scheme noticeably enhances in the three performance metrics. All wireless stations by the proposed scheme receive more video data than the simple scheme around 2530% within a delay bound of 1 second. The proposed scheme controls the end-to-end delay to 510% under that of the simple scheme. As for the throughput and the delay performance, the proposed scheme enhances the video quality by up to 67% compared to the simple scheme in SSIM evaluation.

Scalable Video Coding (SVC) is an extension of H.264/AVC, aiming to provide the ability to adapt to heterogeneous networks or requirements. It offers great flexibility for bitstream adaptation in multi-point applications such as videoconferencing. However, transcoding between SVC and AVC is necessary due to the existence of legacy AVC-based systems. The straightforward re-encoding method requires great computational cost, and delay-sensitive applications like videoconferencing require much faster transcoding scheme. This paper proposes an ultra-low-delay SVC-to-AVC MGS (Medium-Grain quality Scalability) transcoder for videoconferencing applications. Transcoding is performed in pure frequency domain with partial decoding/encoding in order to achieve significant speed-up. Three fast transcoding methods in frequency domain are proposed for macroblocks with different coding modes in non-KEY pictures. KEY pictures are transcoded by reusing the base layer motion data, and error propagation is constrained between KEY pictures. Simulation results show that proposed transcoder achieves averagely 38.5 times speed-up compared with the re-encoding method, while introducing merely 0.71 dB BDPSNR coding quality loss for videoconferencing sequences as compared with the re-encoding algorithm.

MIMO-OFDM systems are widely used in next generation wireless communications due to their high data rates, spatial division multiplexing, and robustness against channel fading. Moreover, multimedia video service is developing very quickly, as are service demands. Consequently, in order to satisfy these demands, we use a MIMO-OFDM system with SDM characteristic to transmit Scalable Video Coding (SVC) signals; our approach maximizes throughput and greatly improves video quality. We propose an Unequal Antenna Power Allocation (UAPA) scheme to improve system performance by increasing the PSNR compared to that of conventional equal power transmission systems and to efficiently utilize the power. We evaluate the performance of the proposed scheme using simulations. The results show that the proposed system provides superior performance compared to conventional systems.

This paper proposes Burst Error Resilient coding (BRC) technology in mobile broadcasting network. The proposed method utilizes Scalable Video Coding (SVC) and Forward Error Correction (FEC) to overcome service outage due to burst loss in mobile network. The performance evaluation is performed by comparing PSNR of SVC and the proposed method under MBSFN simulation channel. The simulation result shows PSNR of SVC equal error protection (EEP), unequal error protection (UEP) and proposed BRC using Raptor FEC code.

Scalable video coding with different modulation and coding schemes (MCSs) applied to different video layers is very appropriate for wireless multicast services because it can provide different video quality to different users according to their channel conditions, and a promising solution to handle packet losses induced by fading wireless channels is the use of layered hybrid FEC/ARQ scheme according to light-weight feedback messages from users about how many packets they have received. It is important to choose an appropriate MCS for each layer, decide how many parity packets in one layer should be transmitted, and determine the resources allocated to multiple video sessions to apply scalable video coding to wireless multicast streaming. We prove that such resource allocation problem is NP-hard and propose an approximate optimal algorithm with a polynomial run time. The algorithm can get the optimal transmission configuration to maximize the expected utility for all users where the utility can be a generic non-negative, non-decreasing function of the received rate. The results from simulations revealed that our algorithm offer significant improvements to video quality over a nave algorithm, an optimal algorithm without feedback from users, and an algorithm with feedback from designated users, especially in scenarios with multiple video sessions and limited radio resources.

Scalable video coding offers efficient video transmission to a variety of display devices over heterogeneous and error-prone networks. Scalable video coding has been strenuously researched in recent years and state-of-the-art international coding with scalability has been standardized as SVC, which is an extension of H.264/AVC. This paper summarizes the recent advanced research that has been done for improving the quality and reducing the complexity of scalable video coding (including SVC), as well as for improving the quality assessment techniques. It is intended to give researchers a critical, technical overview of what is required to develop more efficient scalable video coding in the future.

Scalable Video Coding (SVC) was standardized as an extension of H.264/AVC with the intention to provide flexible adaptation to heterogeneous networks and different end-user requirements, which provides great scalability in multi-point applications such as video conferencing. However, due to the existence of H.264/AVC-based systems, transcoding between AVC and SVC becomes necessary. Most existing works focus on temporal transcoding, quality transcoding or SVC-to-AVC spatial transcoding while the straightforward re-encoding method requires high computational cost. This paper proposes a low-complexity AVC-to-SVC spatial transcoder based on coarse-level mode mapping for video conferencing scenes. First, to omit unnecessary motion estimations (ME) for layers with reduced resolution, an ME skipping scheme based on AVC mode distribution is proposed with an adaptive search range. Then a probability-profile based scheme is proposed for further mode skipping. After that 3 coarse-level mode-mapping methods are presented for fast mode decision and the adaptive usage of the 3 methods is discussed. Finally, motion vector (MV) refinement is introduced for further lower-layer time reduction. As for the top layer, direct encapsulation is proposed to preserve better quality and another scheme involving inter-layer predictions is also provided for bandwidth-crucial applications. Simulation results show that proposed transcoder achieves up to 92.6% time reduction without significant coding efficiency loss compared to re-encoding method.

Due to an increase in multimedia content and the acceleration of digital convergence, demand for next-generation IPTV service is rapidly growing. IPTV service seamlessly provides both real-time broadcasting and content sharing services on diverse terminals through complex networks. In this paper, a secure and scalable content sharing framework is proposed for next-generation IPTV service. The proposed framework has an advantage over conventional content protection techniques in producing scalable content with transcodable, adjustable, and perceptual security features. Moreover, it ensures end-to-end security over the entire service range based on a single security mechanism. The suitability of the proposed approach is demonstrated experimentally using a practical service scenario with real-world environments. The experiments show that the proposed approach can provide several different levels of content security, from a perceptual level to an almost unintelligible level, while keeping the additional time overhead low. Consequently, it is expected that use of this security technology alone can have a practical contribution in creating new business opportunities for IPTV services.

This paper proposes a new selective encryption scheme and a key management scheme for layered access control of H.264/SVC. This scheme encrypts three domains in hierarchical layers using different keys: intra prediction modes, motion vector difference values and sign bits of texture data. The proposed scheme offers low computational complexity, low bit-overhead, and format compliance by utilizing the H.264/SVC structure. It provides a high encryption efficiency by encrypting domains selectively, according to each layer type in the enhancement-layer. It also provides confidentiality and implicit authentication using keys derived in the proposed key management scheme for encryption. Simulation results show the effectiveness of the proposed scheme.

In this paper, we propose an Adaptation Decision-Taking Engine (ADTE) that targets the delivery of scalable video content in mobile usage environments. Our ADTE design relies on an objective perceptual quality metric in order to achieve video adaptation according to human visual perception, thus allowing to maximize the Quality of Service (QoS). To describe the characteristics of a particular usage environment, as well as the properties of the scalable video content, MPEG-21 Digital Item Adaptation (DIA) is used. Our experimental results show that the proposed ADTE design provides video content with a higher subjective quality than an ADTE using the conventional maximum-bit-allocation method.

This letter proposes a QoS control method for video streaming service over wireless networks. Based on statistical analysis, the time-varying MAC parameters highly related to channel condition are selected to predict available bitrate. Adaptive bitrate control of scalably-encoded video guarantees continuity in streaming service even if the channel condition changes abruptly.

The Fine Grain Scalability (FGS) technique used in SVC codec encodes and decodes the quantization error of QBL (quality base layer) along the cyclic scanning path. The FGS technique provides the scalability property to the compressed bit stream. However, the cyclic scanning procedure of FGS method may require a huge computing time. In this paper, we propose a fast FGS decoding scheme, which has a lower decoding complexity without sacrificing image quality.

A bit-depth scalability is proposed in an adaptive way based on modified inter-layer predictions of the spatial scalability. A simple prediction for high dynamic range (HDR) sequences is implemented to reduce the redundancy of the residual signals between the base layer which contains low dynamic range (LDR) sequences and the enhancement layer which contains HDR sequences by using scaling and offset values.

We propose a finite-capacity single-vacation model, with close-down/setup times and a Markovian arrival process (MAP), for SVC-based IP-over-ATM networks. This model considers the SVC processing overhead and the bursty nature of IP packet arrivals. Specifically, the setup time corresponds to the SVC setup time and the vacation time corresponds to the SVC release time, while the close-down time corresponds to the SVC timeout. The MAP is a versatile point process by which typical bursty arrival processes like the IPP (interrupted Poisson process) or the MMPP (Markov modulated Poisson process) is treated as a special case. The approach we take here is the supplementary variable technique. Compared with the embedded Markov chain approach, it is more straightforward to obtain the steady-state probabilities at an arbitrary instant and the practical performance measures such as packet loss probability, packet delay time, and SVC setup rate. For the purpose of optimal design of the SVC-based IP-over-ATM networks, we also propose and derive a new performance measure called the SVC utilization ratio. Numerical results show the sensitivity of these performance measures to the SVC timeout period as well as to the burstiness of the input process.

The emerging, ATM network will support permanent, semi-permanent and switched virtual channel connections (SVCC). A number of simulation studies have been carried out to study the performance of SVCCs using empirical data. The absence of an analytical model has prevented the study of SVCCs under known traffic distributions. In this paper, we develop a new delayed vacation model to facilitate the performance study of SVCCs with configurable inactivity timer in the ATM network interface card (NIC). Comparison with simulation results indicates that the proposed model is very accurate and can be effectively used to optimise the performance of SVCCs by selecting an appropriate inactivity timer.