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The understanding of the video encoding/decoding processes is a key skill for students of computer science, engineering, or telecommunications, especially those specialized in multimedia. The special characteristics of the video signals, and how such features are leveraged to compress the video frames using coding theory, are hard to understand for engineering students. In this paper, we describe MPEG‐2 analyzer, an educational tool designed to provide a comprehensive and interactive way to understand MPEG‐2 video compression and encoding techniques. We have used our tool to evaluate its usefulness in reinforcing the knowledge about the MPEG‐2 video (de)coding process to Telecommunication Engineering students. Results show that the evaluation of the tool is very positive, and it has helped them to understand many of the complex concepts covered in the course. [ABSTRACT FROM AUTHOR]

During lossy video compression, a blocking artifact is introduced into a video. It can significantly reduce the quality of a compressed video, and consequently end-user Quality of Experience. Hence, it is very important to measure and monitor the quality of compressed videos delivered to the end-user, which can be performed only by using the no-reference (NR) approach, without the original video signal available. Many NR video quality assessment (VQA) metrics are based on measurements of different artifacts visibility, which are then used as an input for an objective NR VQA metric. Thus, reliable artifacts detection and their visibility estimation are the first step in a reliable VQA process. In this paper, a new algorithm for Real-Time NR Blocking Visibility Estimation (RT-BVE) in video frames is proposed. The performance of the proposed RT-BVE algorithm is compared to the performance of two freely available algorithms, i.e., BBT-BDA and MSU Blocking, using videos from the well-known databases (156 video sequences in total and more than 48,000 frames). While RT-BVE achieves performance comparable to BBT-BDA and MSU Blocking algorithms for MPEG-2 videos, it outperforms both algorithms for H.264 videos. The results show that the proposed RT-BVE algorithm can precisely estimate blocking visibility in video frames for videos compressed according to different compression standards by using a fixed set of algorithm parameter values. Additionally, RT-BVE is suitable for usage in real-time applications since it is capable of processing approximately 100 Full HD video frames per second on the current midrange × 86–64 platform. [ABSTRACT FROM AUTHOR]

To achieve robustness and imperceptibility, an adaptive compressed domain blind video watermarking method based on Discrete Wavelet Transform (DWT) is proposed in this research. In this technique, multiple binary images derived from a single watermark image are first embedded in a video sequence. The spatial spread spectrum watermark is directly incorporated in the compressed bit streams by modifying the four sets of discrete wavelet coefficients. Comprehensive simulation experiments demonstrate that the developed approach is efficient and also robust against spatial attacks such as scaling and frame averaging, noise attacks such as Gaussian and salt pepper noise, and temporal attacks like frame dropping and shifting. Moreover, the proposed approach can also withstand against rotation attacks of arbitrary angle. [ABSTRACT FROM AUTHOR]

This paper presents the design and implementation of TS over IP gateway system with FPGA based on MPEG-2 coding format. The system is a bridge between digital terrestrial television and internet protocol television networks. It is implemented on Xilinx Zynq-7020, MARVELL 88E1111 PHY chip is chosen as network interface, supporting 10M/100M1000M. In this system, there are multiple real-time Transport Stream (TS) from 256 sources need to be processed. To prevent PID conflict, self-defining the head structure of TS packet is proposed. Due to stream modifications performed during TS processing, Program Clock Reference (PCR) correction is implemented to guarantee receiver synchronization. The system works well and playout is quite satisfactory. [ABSTRACT FROM AUTHOR]

The program clock reference (PCR), which is carried by MPEG-2 transport streams, is commonly used for synchronizing different media types, in receivers. In summary, it is a snapshot of the transmitter's 27 MHz counter and is employed to adapt the local clock. However, the PCR may present inaccuracies on its time base information, known as jitter, given that the processing chain between transmitter and receiver often modifies relative distances among time stamps. In order to correct such a behavior, some authors have suggested PCR-jitter control schemes, which are able to compensate for new PCR positions, in streams. Nevertheless, as none of them takes into account the asynchronism among all elements involved in this procedure, there is often an increase in jitter. The present paper addresses this problem and introduces a methodology for joint rate adaptation and PCR correction, which has the potential to reduce the output jitter, when it is caused by stream modifications due to a rate adaptation module. Simulation results show that the proposed method is effective and outperforms traditional and more recent schemes presented in the literature, by keeping the output jitter level as close as possible to the one at the input and, consequently, avoiding large clock deviations. [ABSTRACT FROM AUTHOR]

This paper presents a reconfigurable architecture for two video coding standards, MPEG-2 and AVC/H.264. The proposed reconfigurable architecture dynamically configures the architecture to achieve multiple functions in variable length coding decoder and context-adaptive variable length coding decoder. By means of extracting the commonalities at the low-level dataflow, the designed reconfigurable architecture optimizes hardware resources and increases architectural flexibility through the reconfigurability in the adaptively constructing architecture. On the other hand, the proposed reconfigurable architecture combines several strategies in AVC/H.264 mode, and subsequently revises and integrates these mechanisms to achieve a high-throughput rate. As a consequence, the memory usage of the proposed reconfigurable architecture achieves 37.5 % memory bits saving and 46.7 % memory area reduction as compared to the individual implementation; moreover, in AVC/H.264 mode, this reconfigurable architecture requires only 50 cycles to decode one marcoblock on average. Due to the flexibility, the proposed reconfigurable architecture costs 10.8 K gates by using 0.18 μm CMOS technology at the 108 MHz clock rate, and supports variable length coding in MPEG-2 with 1920 × 1080@30fps and context-adaptive variable length coding in AVC/H.264 with 1920 × 1080@60fps. From the perspectives of architectural costs and supported functions, the proposed architecture surpasses the related works in the state of the art. [ABSTRACT FROM AUTHOR]

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The latest international video coding standard H.264/AVC significantly achieves better coding performance compared to prior video coding standards such as MPEG-2 and H.263, which have been widely used in today's digital video applications. To provide the interoperability between different coding standards, this paper proposes an efficient and general architecture for MPEG-2/H.263/H.264/AVC to H.264/AVC inter P frame transcoding, using the original information such as coded mode type (CMT), coded block pattern (CBP) and motion vector (MV). The experimental results conducted on H.264/AVC reference software JM12.2 reveal that average 93 % of computation (re-encoding) time can be saved (corresponding to a speed-up factor of 16), while still preserving good coding performance when compared with complex cascaded pixel domain transcoding (CCPDT). The results also indicate that the proposed algorithm significantly outperforms other distinct algorithms, in both rate-distortion performance and computation performance. [ABSTRACT FROM AUTHOR]

There is an inevitable requirement of transcoding from MPEG-2 to H.264/AVC in many video applications. Due to the use of variable block sizes and rate-distortion optimization techniques in H.264, there is extremely high computational complexity in the reference cascaded transcoder. To reduce the complexity, this paper presents a fast inter mode decision algorithm for P frames in MPEG-2 to H.264/AVC transcoding. Firstly, with the statistical analysis of the correlation between the MB's coding mode in MPEG-2 and the corresponding mode in H.264/AVC, the proposed algorithm directly determines the candidate modes for some special MBs based on the mode mapping rules. Then for other MBs, machine learning tools are used to exploit the correlation between the residual MB information in MPEG-2 and the coding mode in H.264/AVC, and the decision tree is derived to determine the candidate modes. The proposed algorithm efficiently reduces the number of candidate modes in H.264/AVC encoder. Experimental results show that the proposed algorithm can achieve 60 % of transcoding time saving on average with the less PSNR degradation and bitrate increase, comparing with the reference cascaded transcoder. [ABSTRACT FROM AUTHOR]

This paper presents an advanced video navigation concept for Personal Video Recording (PVR), based on jointly using the primary image and a Picture-in-Picture (PiP) image, featuring combined rendering of normal-play video fragments with audio and fast-search video. The hindering loss of audio during conventional fast-search trick play is eliminated, by adding the sound associated to the normal-play video fragments. The normalplay fragments provide detailed information, whereas the fastsearch signal simultaneously presents a coarse overview, where it will be shown that the audio enhances the overall navigation efficiency. This system setup requires a specific DTV decoding process, combining multiple, independent audiovisual information signals. Experiments revealed that it is possible to decode all signals by efficient signal processing, thereby re-using the standard DTV decoding platform for decoding, both the normal-play audiovisual fragments and associated fast-search information signal. By applying a decoding concept for the fast-search navigation signal that allows exchanging the navigation refresh rate against execution cycles, it is ensured that real-time performance is obtained on an embedded CPU, as typically deployed in DVT platforms for PVR. [ABSTRACT FROM PUBLISHER]

In this work, we have developed a file-size preserving algorithm to hide data directly in MPEG-2 bitstreams without violating the syntax. The approach is based on the realization that embedding of a bit directly in the bitstream can be achieved by creating an exception in the code space. An exception is created by inserting code words not occurring in the original content into the bitstream. Because the entropy-coded segment of MPEG-2 is fully used, every valid code word appears somewhere in the video. However, exceptions can still be created by recognizing that there are certain variable length codes (VLC) that never occur together in any video block. These are unused VLC pairs and although they vary from stream to stream, they always exist. It is then possible to embed one bit of data by forcing an unused pair in a block subject to a number of constraints, including transparency, file-size preservation and quality metric. The list of unused pairs constitutes a secure key that can be identified by pointer. This pointer can be efficiently encoded for sharing through a secure download. The content-dependence of the key allows a secure exchange of information because each key is valid only for the corresponding video. Because the cover video still uses standard VLCs, the marked bitstream is transparent to external observers. Application areas for the proposed approach are metadata binding and general data hiding when the size of the key is less important than the security and value of attaching data to content. Examples are surveillance video footage and medical applications. [ABSTRACT FROM AUTHOR]