M. Ghanbari. Two-layer coding of video signals for vbr networks. IEEE JSAC, vol. 7, June 1989.  Home/Search   Document Not in Database   Summary   Related Articles   Check

....more monitoring functionalities. In [18] Wang and Zhu made a detailed overview of error control and concealment techniques. These techniques can be characterized as follows: 1) Layered coding with transport prioritization, i.e. a combination of scalability layers and error correction codes [2, 12, 21]; 2) Multiple description coding [16, 17] 3) Joint source and channel coding [1] 4) Robust waveform coding, i.e. redundancy in the waveform coding stage [6] 5) Robust entropy coding, which places redundancy in the entropy coding stage [11, 13] 6) Postprocessing at the decoder, which ....

M. Ghanbari, "Two-layer coding of video signals for VBR networks," IEEE J. Select. Areas Comm., Vol. 7, pp. 801806, June 1989.

....in Section 3.5. Finally, a frame rate scalable extension to SVIP is presented in Section 3.6 followed by a conclusion. 3. 2 Error Resilience Bandwidth scalable video compression schemes are often designed with transport prioritization in mind and produce packets that are highly inter dependent [47, 28, 45, 134, 124, 135]. In particular, it has been shown [47, 28, 45] that by separating the source material into a base layer and an enhancement layer and by applying priority queuing [28, 45] or di#erent loss probabilities [47] results superior to the one layer approach are obtained for statistically multiplexed ....

....SVIP is presented in Section 3.6 followed by a conclusion. 3. 2 Error Resilience Bandwidth scalable video compression schemes are often designed with transport prioritization in mind and produce packets that are highly inter dependent [47, 28, 45, 134, 124, 135] In particular, it has been shown [47, 28, 45] that by separating the source material into a base layer and an enhancement layer and by applying priority queuing [28, 45] or di#erent loss probabilities [47] results superior to the one layer approach are obtained for statistically multiplexed networks. However, due to the lack of prioritized ....

[Article contains additional citation context not shown here]

M. Ghanbari. Two-layer coding of video signals for VBR networks. IEEE J. Selected Area Comm., 7(5), pp. 771--81, June 1989.

....discussion on how to build a layered encoder based on these proposed coding schemes. In addition, since SPIHT exploits cross band correlation in the wavelet domain, it is not easy to separate the generated bit stream into resolution or spatial layers. Layered coding was first proposed by Ghanbari [7] and has since then become one of the most promising techniques to facilitate video streaming or delivery over heterogeneous networks. Recently, layered coding is adopted as a means to enable video distribution over networks that consist of both high and low capacity links [8, 9, 12, 2] Layered ....

M. Ghanbari, "Two-layer coding of video signals for VBR networks", IEEE JSAC, vol. 7, pp. 771-781, June 1989.

....evidence of combined source channel coding technique exists in [28] which discusses its usage for images. More recently, works presented in [8,22,35] discussed the usage of such techniques for real time services. Particular emphasis is given to scalable coding for VBR video over ATM networks in [9,12]. Data loss is a major problem for transmitting video over wireless networks. Bit error rates of around 10 to 10 may arise for long periods of time (approximately hundreds of milliseconds) especially in mobile environments. Data loss can be prevented if we used sufficient error correction ....

M Ghanbari. Two-layer coding of video signals for vbr networks. IEEE Journal on Selected Areas in Communications, 7(5):771--781, June 1989.

....computational complexity of at least O(N3 M ) DW72] which raises the need for good approximations with polynomial complexity. The hierarchical encoding technique enables us to use the resources more eciently. This encoding method has received a lot of attention from the networking community [Gha89] [KV89] 1 and is still an active research area. Hierarchical encoding is a layered way of encoding the kind of information that can appear in di erent quality levels such as audio and video data. In hierarchical encoding, the information of a session is divided into an enumerated set of levels, ....

M. Ghanbari. Two-layer coding of video signals for VBR networks. IEEE Journal on Selected Areas on Communications, 7(5):771-781, 1989.

....traf c classes with di erent QoS in terms of loss and delay. One possible approach to exploit such diversity of QoS is to transcode the MPEG video into alternative formats that can be easily mapped to the di erent QoS parameters. For instance, transcoding MPEG video into a layered representation [1, 2] would allow natural mapping of layers to trac classes with increasing loss rates. In particular, the ability of some scalable compression techniques to produce more than two layers [3] further increases the level of achievable trac di erentiation. However, this transcoding approach su ers from ....

....the entire video. This alternative formulation allows maximization of reception quality for a given cost. 3 Related Work The idea of providing di erential treatment to di erent parts of compressed digital video with di erent error sensitivity is not new. In particular, it has been shown in [1, 4] that by separating the source material into a base layer and an enhancement layer, and by applying priority queuing [4] or di erent loss probabilities [1] results superior to the one layer approach can be obtained. In terms of MPEG, it has also been shown that two layer scalable MPEG outperforms ....

[Article contains additional citation context not shown here]

M. Ghanbari, \Two-layer coding of video signals for VBR networks," IEEE J. Selected Area Comm., vol. 7, no. 5, pp. 771-81, June 1989.

.... implementable congestion control schemes, including connection admission control (CAC) and usage parameter control (UPC) To minimize the impact of delay and loss, the video community has focused on developing good error concealment algorithms and designing efficient two layer coding algorithms [1,2] for use in combination with the dual priority transport provided by ATM networks. For example, while one layer MPEG 2 [3] produces generally unacceptable video quality with a cell loss ratio of 10 3 , losses at this rate with SNR scalability (one of the four standardized layered coding ....

M. Ghanbari, "Two-layer coding of video signals for VBR networks," IEEE J. Select. Areas Commun., vol. 7, p771-781, June 1989.

.... and implementable congestion control schemes, including connection admission control (CAC) and usage parameter control (UPC) To minimizethe impact of delay and loss, the video community has focused on developing good error concealment algorithms and designing efficient two layer coding algorithms [1,2] for use in combination with the dual priority transport provided by ATM networks. For example, while one layer MPEG 2 [3] produces generally unacceptable video quality with a cell loss ratio of 10 3 , losses at this rate with SNR scalability (one of the four standardized layered coding ....

....deviation s i . The modified covariance method [26] is used to evaluate the autoregressive parameters. We explored the general p th order ARP, and determined using the Akaike information criterion [26] that the optimal order was p = 1 for this data. The ARP parameters are given by a = c rr [1, 0] c rr [1, 1] 4a) and s 2 = c rr (0, 0) a c rr (0, 1) 4b) where c rr ( j, k) 1 N 1 N 1 n=1 S r(n j) r(n k) 5) is the modified covariance function and N represents the number of samples over which the covariance function is evaluated. Next, we test the hypothesis that ....

[Article contains additional citation context not shown here]

M. Ghanbari, "Two-layer coding of video signals for VBR networks," IEEE J. Select. Areas Commun. , vol. 7, p771-781, June 1989.

....# # ## # # ### # # # ### in this case. We assume that receiving a portion of the packets of a layer improves the reception quality as compared to receiving no packet of the layer. This assumption is realistic as packet loss causes a graceful degradation in signal quality in many coding schemes[6]. For example, in [6] signal exhibits a reasonable enhancement in quality above the lowest layer for ### packet loss in the next higher layer. This transition is gradual up until #### packet loss in the next higher layer. Real time transmission in internet uses these coding schemes, because packet ....

....# # ### in this case. We assume that receiving a portion of the packets of a layer improves the reception quality as compared to receiving no packet of the layer. This assumption is realistic as packet loss causes a graceful degradation in signal quality in many coding schemes[6] For example, in [6] signal exhibits a reasonable enhancement in quality above the lowest layer for ### packet loss in the next higher layer. This transition is gradual up until #### packet loss in the next higher layer. Real time transmission in internet uses these coding schemes, because packet losses are frequent. ....

M. Ghanbari. Two-Layer Coding of Video Signals for VBR Networks. IEEE Journal on Selected Areas in Communications, VOL. #. No. #. June ####

....the VBR video bit stream transmitted by the source so that it conforms to the specified UPC contract and buffer constraints, while keeping picture quality degradations within acceptable levels. This approach is known as source rate control [5, 6] and also employs DP at the source. In earlier work [9, 10, 11], DP was based on splitting the DCT coefficients at some predetermined point resulting in two partitions of the bit streams, but in recent works, adaptive DP algorithms have been proposed. Luo and El Zarki [6] designed an adaptive DP scheme within the MPEG framework, which has the capability of ....

M. Ghanbari, "Two-Layer Coding of Video Signals for VBR Networks", IEEE J. on Sel. Areas in Commun., Vol. 7, Jun. 1989.

....(ADP) Scheme. ADP splits the MPEG 2 video bitstream into two sub bitstreams. This split is done by taking into account the relevance of the different pieces of information of the original MPEG 2 encoded bitstream. ADP offers advantages over similar hierarchical schemes proposed in the past [9][10] 13] Under this scheme, low frequency coefficients together with other relevant information, are transmitted at a high priority level, also denominated base layer. High frequency coefficients and other less important information are then transmitted at a lower priority level, also denominated ....

M. Ghanbari "Two-Layer Coding of Video Signals for VBR Networks" IEEE Journal on Selected Areas in Communications, Vol. 7, No. 5, June 1989, pp. 771-781.

....to achieve better results. I. INTRODUCTION N ETWORKED multimedia services, such as teleconferencing, video on demand, and distance learning are emerging. In these applications, it is often needed to adapt the bitrate of the coded video bit streams to the available bandwidth of various channels [1] [5] In a heterogeneous network, the bitrate adaptation allows different end users with different subnetworks to have different quality of service (QoS) based on their available network bandwidths. For some real time video coding applications, the adaptation of the bitrates can be achieved ....

M. Ghanbari, "Two-layer coding of video signals for VBR networks," IEEE J. Select. Areas Commun., vol. 7, pp. 771--781, June 1989.

.... the previous frame and interpolations from the adjacent blocks of the current frame [22] A second approach divides the discrete cosine transform (DCT) coefficients of a frame into layers so that in overload situations the lower layers can be discarded, resulting in an image of a lower quality [5, 11]. The third technique involves sending adjacent pixels in different packets, so that lost packets do not imply localized pixel loss, and each lost pixel usually has undamaged neighbors [19, 20] l PB FF Rew Figure 1: Model of a user watching a video 3 QoS Metrics This section describes the ....

GHANBARI, M. Two-Layer Coding of Video Signals for VBR Networks. IEEE Journal on Selected Areas in Communications 7, 5 (June 1989), 771--781.

....For example, video using interframe compression produces much lower information rates when there is little motion or change between frames, but generates very high bit rate peaks when there are scene changes or fast motion. Peak to mean bit rate ratio for VBR codecs is usually very high. In [Ghanbari89] the value 4.7 is reported for one particular codec. The use of VBR coding is based on the capability of packet switching networks to use statistical multiplexing for efficient utilization of network resources. One can then economize on resources when the information content of the signal is low ....

....important in the future. Hierarchically coded media transmission is ideally positioned to take advantage of these developments. 3. Hierarchical Coding Hierarchical coding techniques (also referred to as component, layered, or sub band coding) split signals into components of varying importance [Ghanbari89, Karlsson89]. The aggregation of these components reconstructs the original data, but subsets of them can also provide various degrees of approximation to the original signal. For example, a simple form of hierarchical coding could decompose a video frame into two sub frames: 1) a low resolution component ....

[Article contains additional citation context not shown here]

M. Ghanbari, "Two-Layer Coding of Video Signals for VBR Networks," IEEE Journal on Selected Areas in Communications Vol. 7(5), pp. 771-781 (June 1989).

....and produce heavy volumes of bursty network traffic. In addition, interactive real time applications, e.g. teleconferencing, introduce strict delay constraints. Hierarchical Coding (HC) also referred to as layered coding, techniques split signals into components of varying importance [1] [2]. The aggregation of these components reconstructs the original data, but subsets of the components can also provide various degrees of approximation to the original signal. HC is very important for the efficient use of high speed packet switching networks such as the emerging Broadband Integrated ....

....with Fig. 2(c) V. Networking Applications of HJPEG The advantages of hierarchical coding for various applications, e.g. congestion control in high speed networks, accommodation for heterogeneous end devices, and error resiliency in network transmission have been presented in many papers [2], 12] 6] In this section, some potential applications of HJPEG are discussed. A. Multimedia Database Browsing As multimedia databases, dealing mostly with images, are widely used, content based information retrieval [16] has gained attention in the database community. This trend of treating ....

M. Ghanbari, "Two-Layer Coding of Video Signals for VBR Networks," IEEE Journal on Selected Areas in Communications, Vol 7, No. 5, pp. 771-781, June 1989.

.... Layered encoding is founded on the notion that the output of a source coder can be partitioned into an essential layer (which is critical for conveying basic information content of the image) and enhancement layers (which when added to the the essential layer recreate the signal more fully) [3, 4, 5, 6, 7, 11]. Consequently, transport protocols that employ layered encoding techniques arrange the contents of the essential and enhancement layers into packets of high and low priority, respectively, and then ensure that all the high priority packets are timely delivered to each of the client sites. Since ....

M. Ghanbari. Two-Layer Coding of Video Signals for VBR Networks. IEEE Journal on Selected Areas in Communications, 7(5):771--781, June 1989.

....evidence of combined source channel coding technique exists in [24] which discusses its usage for images. More recently, works presented in [7,18,31] discussed the usage of such techniques for real time services. Particular emphasis is given to scalable coding for VBR video over ATM networks in [8,11]. Data loss is a major problem for transmitting video over wireless networks. Bit error rates of around 10 Gamma3 to 10 Gamma2 may arise for long periods of time (approximately hundreds of milliseconds) especially in mobile environments. Data loss can be prevented if we used sufficient ....

M Ghanbari. Two-layer coding of video signals for vbr networks. IEEE Journal on Selected Areas in Communications, 7(5):771--781, June 1989.

....produced by the coding scheme, but instead, an effort is made to produce constant quality signal at a given average bit rate (or level of quality) by using Variable Bit Rate (VBR) schemes. Peak to mean bit rate ratios for VBR codecs is usually high; a 4. 7 value is reported for one particular codec [2]. 2 HAN POLYZOS The use of VBR coding is based on the capability of packet switching networks to use statistical multiplexing for efficient utilization of network resources. One can then economize on resources when the information content of the signal is low and expend them at a higher rate ....

.... many facets of image and video transmission [5] 6] 7] LC with a variable spatial resolution [8] has received less attention than LC with a fixed resolution, despite its adoption in some popular coding standards [9] 10] 11] Two layer coding has been mostly considered in the literature [2], 5] 7] 12] 13] with the first, coarse or low frequency, subsignal usually referred to as the base layer, and the second, higher resolution, subsignal termed the enhancement layer. We use the term Multi resolution Layered Coding (MLC) to refer to LC with more than two layers of spatial ....

M. Ghanbari, "Two-layer coding of video signals for VBR networks, " IEEE Journal on Selected Areas in Communications, Vol. 7, No. 5, pp. 771-781, June 1989.

....modes in H.263, independent segment decoding, and dynamic reference picture selection [14, 79] These schemes can only limit adverse effects of error propagation due to prediction coding. Layered coding (LC) has been an area of active research in the past decade in the context of ATM [3, 23, 48, 85] and wireless networks [30, 32, 84] Layered coding partitions data into a base layer and a few enhancement layers. The base layer contains visually important video data that can be used to produce output of acceptable quality, whereas the enhancement layers contain complementary information that ....

M. Ghanbari. Two-layer coding of video signals for VBR networks. IEEE journal on Selected Areas in Communications, 7:801-806, June 1989.

No context found.

M. Ghanbari. Two-layer coding of video signals for vbr networks. IEEE JSAC, vol. 7, June 1989.

No context found.

M. Ghanbari. Two-layer coding of video signals for VBR networks. IEEE Journal on Selected Areas in Communications, 7(5):771--781, June 1989.

No context found.

M. Ghanbari, "Two-layer coding of video signals for VBR networks," IEEE J. Select. Areas Commun., vol. 7, pp. 801-806, June 1989.

No context found.

M. Ghanbari, "Two-layer coding of video signals for VBR networks," IEEE Journal on Selected Areas in Communications, vol. 7, pp. 771--781, June 1989.

No context found.

M.Ghanbari. Two-Layer Coding of Video Signals for VBR Networks. IEEE Trans. Selected Areas in Commun., Vol. 7, No. 5, June 1989.

No context found.

M. Ghanbari, Two-layer coding of video signals for VBR networks, IEEE JSAC, 1989

First 50 documents  Next 50

Online articles have much greater impact   More about CiteSeer.IST   Add search form to your site   Submit documents   Feedback  

CiteSeer.IST - Copyright Penn State and NEC