223 research outputs found
Inter-layer turbo coded unequal error protection for multi-layer video transmission
In layered video streaming, the enhancement layers (ELs) must be discarded by the video decoder, when the base layer (BL) is corrupted or lost due to channel impairments. This implies that the transmit power assigned to the ELs is wasted, when the BL is corrupted. To combat this effect, in this treatise we investigate the inter-layer turbo (IL-turbo) code, where the systematic bits of the BL are implanted into the systematic bits of the ELs at the transmitter. At the receiver, when the BL cannot be successfully decoded, the information of the ELs may be utilized by the IL-turbo decoder for the sake of assisting in decoding the BL. Moreover, for providing further insights into the IL technique the benefits of the IL-turbo scheme are analyzed using extrinsic information transfer (EXIT) charts in the scenario of unequal error protection (UEP) coded layered video transmission. Finally, our data partitioning based experiments show that the proposed scheme outperforms the traditional turbo code based UEP scheme by about an Eb/N0 of 1.1 dB at a peak signal-to-noise ratio (PSNR) of 36 dB or 3 dB of PSNR at an Eb/N0 of -5.5 dB at the cost of a complexity increase of 13%
Unequal Error Protected JPEG 2000 Broadcast Scheme with Progressive Fountain Codes
This paper proposes a novel scheme, based on progressive fountain codes, for
broadcasting JPEG 2000 multimedia. In such a broadcast scheme, progressive
resolution levels of images/video have been unequally protected when
transmitted using the proposed progressive fountain codes. With progressive
fountain codes applied in the broadcast scheme, the resolutions of images (JPEG
2000) or videos (MJPEG 2000) received by different users can be automatically
adaptive to their channel qualities, i.e. the users with good channel qualities
are possible to receive the high resolution images/vedio while the users with
bad channel qualities may receive low resolution images/vedio. Finally, the
performance of the proposed scheme is evaluated with the MJPEG 2000 broadcast
prototype
Rate-distortion optimization for stereoscopic video streaming with unequal error protection
We consider an error-resilient stereoscopic streaming system that uses an H.264-based multiview video codec and a rateless Raptor code for recovery from packet losses. One aim of the present work is to suggest a heuristic methodology for modeling the end-to-end rate-distortion (RD) characteristic of such a system. Another aim is to show how to make use of such a model to optimally select the parameters of the video codec and the Raptor code to minimize the overall distortion. Specifically, the proposed system models the RD curve of video encoder and performance of channel codec to jointly derive the optimal encoder bit rates and unequal error protection (UEP) rates specific to the layered stereoscopic video streaming. We define analytical RD curve modeling for each layer that includes the interdependency of these layers. A heuristic analytical model of the performance of Raptor codes is also defined. Furthermore, the distortion on the stereoscopic video quality caused by packet losses is estimated. Finally, analytical models and estimated single-packet loss distortions are used to minimize the end-to-end distortion and to obtain optimal encoder bit rates and UEP rates. The simulation results clearly demonstrate the significant quality gain against the nonoptimized schemes
Error resilient stereoscopic video streaming using model-based fountain codes
Ankara : The Department of Electrical and Electronics Engineering and the Institute of Engineering and Science of Bilkent University, 2009.Thesis (Ph.D.) -- Bilkent University, 2009.Includes bibliographical references leaves 101-110.Error resilient digital video streaming has been a challenging problem since
the introduction and deployment of early packet switched networks. One of
the most recent advances in video coding is observed on multi-view video coding
which suggests methods for the compression of correlated multiple image
sequences. The existing multi-view compression techniques increase the loss sensitivity
and necessitate the use of efficient loss recovery schemes. Forward Error
Correction (FEC) is an efficient, powerful and practical tool for the recovery of
lost data. A novel class of FEC codes is Fountain codes which are suitable to be
used with recent video codecs, such as H.264/AVC, and LT and Raptor codes are
practical examples of this class. Although there are many studies on monoscopic
video, transmission of multi-view video through lossy channels with FEC have
not been explored yet. Aiming at this deficiency, an H.264-based multi-view
video codec and a model-based Fountain code are combined to generate an effi-
cient error resilient stereoscopic streaming system. Three layers of stereoscopic
video with unequal importance are defined in order to exploit the benefits of Unequal
Error Protection (UEP) with FEC. Simply, these layers correspond to intra frames of left view, predicted frames of left view and predicted frames of right
view. The Rate-Distortion (RD) characteristics of these dependent layers are de-
fined by extending the RD characteristics of monoscopic video. The parameters
of the models are obtained with curve fitting using the RD samples of the video,
and satisfactory results are achieved where the average difference between the
analytical models and RD samples is between 1.00% and 9.19%. An heuristic
analytical model of the performance of Raptor codes is used to obtain the residual
number of lost packets for given channel bit rate, loss rate, and protection
rate. This residual number is multiplied with the estimated average distortion
of the loss of a single Network Abstraction Layer (NAL) unit to obtain the total
transmission distortion. All these models are combined to minimize the end-toend
distortion and obtain optimal encoder bit rates and UEP rates. When the
proposed system is used, the simulation results demonstrate up to 2dB increase
in quality compared to equal error protection and only left view error protection.
Furthermore, Fountain codes are analyzed in the finite length region, and
iterative performance models are derived without any assumptions or asymptotical
approximations. The performance model of the belief-propagation (BP)
decoder approximates either the behavior of a single simulation results or their
average depending on the parameters of the LT code. The performance model of
the maximum likelihood decoder approximates the average of simulation results
more accurately compared to the model of the BP decoder. Raptor codes are
modeled heuristically based on the exponential decay observed on the simulation
results, and the model parameters are obtained by line of best fit. The analytical
models of systematic and non-systematic Raptor codes accurately approximate
the experimental average performance.Tan, A SerdarPh.D
Historical information aware unequal error protection of scalable HEVC/H.265 streaming over free space optical channels
Free space optical (FSO) systems are capable of supporting high data rates between fixed points in the context of flawless video communications. Layered video coding facilitates the creation of different-resolution subset layers for variablethroughput transmission scenarios. In this paper, we propose Historical information Aware Unequal Error Protection (HAUEP) for the scalable high efficiency video codec (SHVC) used for streaming over FSO channels. Specifically, the objective function (OF) of the current video frame is designed based on historical information of its dependent frames. By optimizing this OF, specific subset layers may be selected in conjunction with carefully selected forward error correction (FEC) coding rates, where the expected video distortion is minimized and the required bitrate is reduced under the constraint of a specific throughput. Our simulation results show that the proposed system outperforms the traditional equal error protection (EEP) scheme by about 4.5 dB of Eb=N0 at a peak signal-to-noise ratio (PSNR) of 33 dB. From a throughput-oriented perspective, HA-UEP is capable of reducing the throughput to about 30% compared to that of the EEP benchmarker, while achieving an Eb=N0 gain of 4.5 dB
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