An adaptive error concealment mechanism for H. 264/AVC encoded low-resolution video streaming (original) (raw)

Error concealment aware streaming video system over packet-based mobile networks

IEEE Transactions on Consumer Electronics, 2008

A compressed video bitstream is extremely sensitive to errors when it is transmitted via networks with bursty packet loss such as 3G and mobile WiMAX. Error concealment techniques have been used to improve the recovered picture quality in cases in which parts of the coded picture are not available at the decoder for reconstruction. However, most conventional error concealment methods show low image reconstruction performance due to unavailable motion information about image blocks during burst packet loss, and require high energy consumption to find the best error concealment method in the receiver. The proposed error concealment aware error resilient streaming video system has an intelligent error concealment selector. The method recommends the best error concealment method per macroblock, by additionally transmitting its error concealment selection codes to the decoder. The streaming client conceals the corrupted MB via the chosen error concealment method, with low energy consumption, even when the frame loss is bursty. The experimental results show that the system is highly effective, in terms of the video quality and energy consumption, at the cost of a slight overhead for transmitted bit streams. 1

Extended Error Concealment Algorithm for Intra-frames in H. 264/AVC

The audiovisual and multimedia services are seen as important sources of data transmission within mobile networks these days. One of the limitations within the mobile networks is the low transmission bit rate which demands the reduction of the used video resolution and a high efficient video compression technique. Standard H.264/AVC, which is explained in this paper, is the newest codec of video compression, which provides a distinct improvement of quality in comparison with the previous video standards. Video stream transmission via wireless area results in data lost. It causes the emergence of the visual artefacts, and so the distinct fall of the picture quality. Since video stream transmission in real time is limited by transmission channel delay, it is not possible to transmit all faulty or lost packets. It is therefore inevitable to conceal these defects. In this paper, we analysed the error concealment algorithms, which are used in video transmission via wireless network, whic...

ERROR CONCEALMENT TECHNIQUES FOR ENCODED VIDEO STREAMS

In this paper we describe two error-recovery approaches for MPEG encoded video over ATM networks. The first approach aims at reconstructing each lost pixel by spatial interpolation from the nearest undamaged pixels. The second approach recovers lost macroblocks by minimizing intersample variations within each block and across its boundaries. Moreover, a new technique for packing ATM cells with compressed data is also proposed.

Second-generation error concealment for video transport over error prone channels

2002

Video transport over error-prone channels may result in loss or erroneous decoding of the video data. Error concealment is an effective mechanism to reconstruct the video data. In this paper, we review error-concealment methods and introduce a new framework, which we refer to as second-generation error concealment. All the error-concealment methods reconstruct the lost video data by making use of certain a priori knowledge about the video content. First-generation error concealment builds such a priori in a heuristic manner. The proposed second-generation error concealment builds the a priori by modeling the statistics of the video content explicitly, typically in the region of interest (ROI). Context-based models are trained with the correctly received video data and then used to replenish the lost video data. Trained models capture the statistics of the video content and thus reconstruct the lost video data better than reconstruction by heuristics. A new dynamic model 'updating principal components' (UPC) is proposed as a model for second-generation error concealment. UPC can be applied to pixel values to conceal loss of pixel data. In addition, UPC can be applied to motion vectors, which results in 'updating eigenflows' (U-Eigenflow), to conceal loss of motion vectors. With UPC applied to both pixel values and motion vectors, hybrid temporal/spatial error concealment can be achieved. The proposed second-generation error-concealment method provides superior performances to first-generation error-concealment methods.

Streaming Video with Transformation-Based Error Concealment and Reconstruction

1999

Real-time video streaming over the Internet requires robust delivery mechanisms with low overhead. Traditional error control schemes are not attractive because they either add redundant information that may worsen network traffic, or rely solely on the inadequate capability of the decoder to do error concealment. As sophisticated concealment techniques cannot be employed in a real-time software playback scheme, we propose in this paper a simple yet efficient transformation-based error concealment algorithm. The algorithm applies a linear transformation to the original video signals, with the objective of minimizing the mean squared error if missing information were restored by simple averaging at the destination. We also describe two strategies to cope with error propagations in temporal differentially coded frames. Experimental results show that our proposed transformation-based reconstruction algorithm performs well in real Internet tests.

Error concealment using a DVC approach for video streaming applications

2007

In this paper we consider an error resilience scheme, based on a Distributed Video Coding (DVC) paradigm, for the transmission of coded video over an error prone channel. In the proposed scheme, an auxiliary stream which contains generalized parity bits is generated for each coded frame. At the decoder side, error concealed decoded frames are used as side information to feed a Wyner-Ziv turbo decoder. We use an extended version of the Recursive Optimal per-Pixel Estimate (ROPE) algorithm to establish how many parity bits should be sent to the turbo decoder in order to correct the decoded and concealed frame. To validate the proposed scheme, tests with video sequences and realistic loss patterns are reported.

Temporal-spatial error concealment algorithm for intra-frames in H.264/AVC coded video

2010

Video communication through wireless channels is still a major problem due to the limitations in bandwidth and the presence of channel errors. The other limitations within the mobile networks is low transmission bit rate which demands the reduction of the used video resolution and a high efficient video compression technique. Video transmission in wireless environments is a challenging task calling for high-compression efficiency as well as a network-friendly design. The network-friendly design of H.264/AVC is addressed via the network abstraction layer that has been developed to transport the coded video data over any existing and future networks including wireless systems. Exploiting this feature, we present a modified temporal-spatial error concealment algorithm for H.264 coded video. Simulations were carried out in computing environment Matlab using the standard video-sequences.