Broadcast Quality Video Research Articles

Master Control in the Cloud: From Concept to Reality

If the revolution stays on pace, experts expect the year 2018 to usher in significant large-scale adoption of Internet Protocol (IP) infrastructure in the areas of routing, switching, live production, and playout. The one segment of the industry that will see their fortunes shift significantly are large-scale media companies tasked with delivering broadcast quality audio and video to multiple markets. Yet accomplishing that successfully—and under budget—is a significant challenge. Enter IP streaming over unmanaged IP networks.

802.11g packet-loss behavior at high sustained bit rates in the home

802.11g is a popular way to transmit data throughout homes wirelessly. However, common broadcast-quality video bitrates, up to 20 Megabits per second, represent difficult challenges for wireless networks in terms of latency, packet loss, and packet jitter. An in-home network was sampled between 0.5 and 2 Megabits per second (Mbps) and analyzed with respect to packet loss. Our experimental results indicate that the distribution of the number of consecutive error bursts is a combination of the classical Gilbert-Elliot model and a long-tail model.

An improved rate control algorithm based on a novel shot detection scheme for the H.264/AVC standard

H.264/AVC standard uses a variety of advanced signal processing/video coding techniques for broadcast quality video on half the bit rate required in MPEG-2. Despite being advanced, the current rate control algorithm of the standard does not exploit the fact that typical video sequences are composed of different shots. This paper argues that shot information can help us choose the size of the group of pictures (GOPs) more accurately, thus improving the performance of the rate control algorithm. We initially propose a novel MPEG-7 descriptor driven shot detection method with low computational cost for H.264/AVC. Then we exploit it to determine the initial quantization parameters for each shot based on modelling. These two steps can help us reduce the bit rate and PSNR fluctuation when video sequences have multiple shots. Our proposed scheme outperforms the rate control of the H.264/AVC significantly in terms of reducing the average bit rate fluctuation (variance) by 12.78–99.99% and the average PSNR fluctuation (variance) by 1.4–71% between shots. Experimental results also demonstrate that we can achieve similar or even better rate distortion (R-D) performance than the standard rate control algorithm. Our scheme is also applicable to computationally and memory restricted devices since it needs maximum two frames buffer space for MPEG-7 descriptor calculation, while the average amount of extra processing is only about 5.5% of the total CPU cycles.

Quad-Tree Motion Estimation in the Frequency Domain Using Gradient Correlation

We propose a new motion estimation scheme particularly suitable for broadcast-quality digital video applications due to its performance-complexity characteristics. The proposed scheme is based on the principle of gradient correlation and its computational efficiency is due to the fact that it operates in the frequency domain. The scheme involves the quad-tree decomposition of a frame thus providing a better level of adaptation to scene contents compared to fixed block size approaches. Quad-tree decompositions are obtained by using the motion compensated prediction error to control the partition of a parent block to four children quadrants. The partition criterion is applied iteratively until a target number of motion vectors or a target level of motion compensated prediction error is achieved or, ultimately, until no more than a single motion component can be identified. The partition criterion also guarantees a monotonic decrease of the motion compensated prediction error with an increasing number of iterations making our scheme suitable for progressive transmission and embedded coding applications. Our results show that our scheme outperforms fixed block size phase correlation as well as quad-tree motion estimation based on phase correlation in terms of rate-distortion characteristics yielding smoother motion vector fields as well as more compressible motion-compensated prediction residuals.

Highly accurate de-jittering scheme for broadcast quality video transmission

We propose a highly accurate jitter prevention method to provide broadcast quality video transmission over communication networks, such as ATM and IP, and describe some implementations and our eval...

Highly accurate de-jittering scheme for broadcast quality video transmission

We propose a highly accurate jitter prevention method to provide broadcast quality video transmission over communication networks, such as ATM and IP, and describe some implementations and our evaluation. This method measures network jitter using shared common clocks as a reference, and then restamping the program clock reference (PCR) values in the MPEG streams, to provide decoders with stable clock information. Common clocks were obtained from synchronized ATM network clocks, or from ISDN clocks for asynchronous IP networks. By implementing the proposed method in “MPEG-2 over ATM” and “MPEG-2 over IP” network adapters, the transmitted signals were compliant with MPEG-2 systems standard, such as PCR jitter, within a range of 0.5 μs, under a maximum packet delay variance of around 80 ms. The analog signal jitter of the decoded HDTV images was also suppressed to about 0.1 μs, which shows that highly stable video signal transmission can be achieved using this method. © 2006 Wiley Periodicals, Inc. Syst Comp Jpn, 37(10): 81–88, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.20464

Quality Relief of Broadcast-quality Video with Net-work Packet Losses

The impact of packet losses on broadcast-quality video transmission through an asynchronous network is discussed based on the quality of the video playback. The main requirements for broadcast-quality video transmission are quality, synchronization, and smooth failover. Therefore, video quality is also related to network quality in an asynchronous network. When video frames that contain network packet losses are decoded, noise-free video cannot be maintained for block noises caused in video playback. One of the most important features of real-time video data transmission through an asynchronous network is the ability to correct and conceal errors. Adding redundant bits to the source information, as in forward error correction and error correcting code, increases the data bandwidth. Adding redundancy, such as by interleaving, lengthens the latency of the video playback. The appropriate redundancy factor, therefore should ensure a real-time response, minimize latency, and maintain video playback quality. Therefore, when selecting an appropriate error correction/concealment code, it is necessary to clarify the impact of successive packet losses on the quality degradation of broadcast-quality video. To clarify the relationship between the broadcast-quality video quality and network packet losses, we analyzed data based on observation of an actual network with the loss window size as a parameter. Next, we discussed the characteristics of the block noises on the video playback using the Markov model. For this purpose, we made an 80, 000-km-long ATM path on the Japan Gigabit Network and examined the peak-signal to noise ratio of the SMPTE-314M.video playback that contained ATM cell losses.

Matching the faces of robbers captured on video

AbstractRecent research has shown that unfamiliar face matching from both high‐ and low‐quality closed circuit television video images to photographs is highly prone to error, even when viewpoint and expression are matched as closely as possible. The current experiments made use of a filmed, staged reconstruction of a bank raid that was captured on CCTV and on high‐quality broadcasting video. Experiment 1 tested the ability of members of the public to match actors captured on CCTV to photo‐spreads containing similar‐looking distractors. Further experiments, each testing different groups of subjects, investigated matching ability using both high‐quality photographs (Experiment 2) and broadcast‐quality video material (Experiment 3). Experiment 3 also investigated the effect of disguising hairstyle, and varied whether or not the target was present in the photo line‐up. The results of these experiments confirm those of previous work, that matching the identity of unfamiliar faces is highly fallible, even when high‐quality footage is used. Experiments 4 and 5 tested matching ability using two‐alternative forced‐choice and single‐item verification tasks. Performance remained highly error‐prone even with the simplest question asked. The legal implications of the results are discussed. Copyright © 2001 John Wiley & Sons, Ltd.

Broadcast quality video over IP

We consider the problem of designing systems for the transmission of video signals of the quality found in current television broadcasts, over high-speed segments of the public IP network. Our most important contribution is the definition of a network/coder interface for IP networks which gathers channel state information, and then sets parameters of the video coder to maximize the quality of the signal delivered to the receiver, while remaining fair to other data or video connections. This interface plays a role analogous to that of a Leaky Bucket controller, in that it specifies traffic shaping parameters which result in simultaneous good Quality-of-Service (QoS) for the source and good network performance. Since the network is not assumed to provide any form of QoS guarantee, fundamental to our construction is a hidden Markov model for the channel, based on which the interface solves a problem of optimal stochastic control, to decide how to configure the encoder. Other contributions are: a) modifications to the standard Internet transport protocol, to make it suitable for the transport of delay-constrained traffic and to gather channel state information, and b) the design of an error-resilient video coder. Experimental studies reveal that the proposed system is able to stream video signals of the quality of current TV-broadcasts, among hosts in wide-area networks connected to the experimental vBNS backbone.

An Interactive Telelecture System with Hybrid ATM/IP Networking

Currently, there is much debate whether ATM (Asynchronous Transfer Mode) or IP (Internet Protocol) is the better internetworking technology for multiparty multimedia applications. Proponents of ATM argue that only a connection-oriented network can satisfy the stringent timeliness requirements of high-quality audio and video data. Proponents of the Internet emphasize the scalability and flexibility of connectionless networking. In this paper a multiparty multimedia telelecture system, called Distance Learning Controller (DLC), is presented that uses both ATM and IP, thus, attempting to exploit the advantages of both technologies, without suffering the drawbacks of either technology. The DLC system uses ATM for transmission of broadcast-quality video and CD-quality audio, and IP-over-ATM for low-bandwidth applications and conference control functions. This paper describes the hardware and software components of the DLC system.

Remote Non-Linear Video Editing

Remote non-linear video editing (RNLE) is a natural progression to the next generation of video editing technology. A paradigm shift, editors are no longer chained to the edit suite. RNLE operates a medium or low-bitrate mirror copy of broadcast-quality video clips. With this approach a low-resolution rough cut is created on a PC in a simple cut-and-paste interface. Sometime later, the resulting edit decision list (EDL) is transferred back to the edit suite for the finish cut and committed at high resolution suitable for broadcast as film or HDTV.

A BiCMOS continuous-time filter for video signal processing applications

A fully integrated BiCMOS continuous-time filter for video signal processing applications is presented. It incorporates an input clamping circuit, a third-order equalizer, a fifth-order elliptic filter with sinx/x correction, and a 75-/spl Omega/ driver. The architectures of the input and output amplifiers as well as the filter and the equalizer are chosen based on the extensive study of circuit structures and Monte Carlo simulation to meet the linearity requirement for the broadcast-quality video system. The complete chip achieves a low-pass filter response with a 5.5-MHz cutoff frequency (f/sub cc/), 0.3-dB passband ripple, 20-ns group delay variation up to 0.9 f/sub c/, and 43-dB attenuation at 1.45 f/sub c/. With a nominal 2-Vpp signal at the output, measured results show 0.2% differential gain, 0.38/spl deg/ differential phase, and 1.7-mV rms noise demonstrating 10-bit linearity in a 1.5-/spl mu/m 4-GHz BiCMOS process technology. The filter active area is 8 mm/sup 2/ and it dissipates 350 mW in a single 5-V power supply.

System for conducting video communications over satellite communication link with aircraft having physically compact, effectively conformal, phased array antenna

A system architecture and communication methodology for significantly reducing the size of an aircraft antenna required to provide full broadcast quality video communications with an aircraft via a satellite communications link includes a combination of video bandwidth compression, spread spectrum waveform processing and an electronically steered, circular aperture phased array antenna, that is conformal with an airframe surface of the aircraft. The combination provides sufficient signal power to the aircraft, enables interference from other satellites to be rejected and maintains the power spectral density of the satellite's video transmission within FCC requirements. The polarization of the receive array is aligned with that of the incoming beam from the relay satellite by means of an error signal feed back path to control the steering weights of the array. Because the phased arrays are conformal, it is necessary to modify the phase shift settings produced by the antenna steering mechanism executed by the degree of departure of the conformal geometry of the array from a planar configuration. A coordinate transformation look-up table is coupled in the control feedback path from the antenna steering mechanism and the phase shift elements of the phased array.

Interactive Multimedia Services for Consumers and Businesses

The emergence of broadband networks for residential and business customers enables a wide range of new interactive services. For consumers, these new services might include movies on demand, networked multi-player video games, and interactive shopping via TV. Business applications might include broadcast-quality video teleconferencing, distance learning, and telecommuting. This paper presents the technical issues and infrastructure involved in delivering several of these services, along with some of the lessons learned and insights gained from AT&T's early interactive broadband services trials.

Transitioning desktops to set tops

Video provides the greatest realism in multimedia and also demands the most from computer systems. Innovations already enable conventional desktops, such as RISC workstations, to handle compressed audio and low-resolution video signals. Similarly, interactive, real-time, 3D animation graphics produce data processing and transmission challenges. Meeting these challenges will transition desktop systems to televisions with set-top boxes, linking broadcast quality video and audio to the interactivity of a computer.

Subjective Testing of Broadcast-Quality Compressed Video

This paper describes the analysis and subjective testing of broadcast-quality compressed video conducted by the Public Broadcasting Service (PBS) and the Communications Research Centre's (CRC's) Advanced Television Evaluation Laboratory (ATEL). To fulfill the program objectives, a novel approach to test preparation and conduct was adopted. New methodology was employed in the development of a reference model and in the selection of test material. The tests were conducted under controlled viewing conditions, using internationally recommended methods

MPEG coding for variable bit rate video transmission

For real-time transmission of broadcast-quality video on ATM-based B-ISDN, the intraframe to interframe ratio and the quantizer scale are two key parameters that can be used to control a video source in a network environment. Their impact on the traffic characteristics of the coder provides insights into the cell arrival process for an MPEG source. The authors obtain video source models for coders that utilize a standard algorithm that can be applied to a multitude of video services. The output stream of a video coder, which complies with the Motion Pictures Expert Group (MPEG) coding standard, is studied with an National Television Systems Committee (NTSC) quality video sequence as the input. Because the MPEG video coding algorithm has been proposed for a variety of applications, they also investigate the effect of changing the coding parameters on the statistics of interest. >

Conversations Over Video Conferences: An Evaluation of the Spoken Aspects of Video-Mediated Communication

Recent trends toward telecommuting, mobile work, and wider distribution of the work force, combined with reduced technology costs, have made video communications more attractive as a means of supporting informal remote interaction. In the past, however, video communications have never gained widespread acceptance. Here we identify possible reasons for this by examining how the spoken characteristics of video-mediated communication differ from face-to-face interaction, for a series of real meetings. We evaluate two wide-area systems. One uses readily available Integrated Services Digital Network (ISDN) lines but suffers the limitations of transmission lags, a half-duplex line, and poor quality video. The other uses optical transmission and video-switching technology with negligible delays, full duplex audio, and broadcast quality video. To analyze the effects of video systems on conversation, we begin with a series of conversational characteristics that have been shown to be important in face-to-face interaction. We identify properties of the communication channel in face-to-face interaction that are necessary to support these characteristics, namely, that it has low transmission lags, it is two way, and it uses multiple modalities. We compare these channel properties with those of the two video-conferencing systems and predict how their different channel properties will affect spoken conversation. As expected, when compared with face-to-face interaction, communication using the ISDN system was found to have longer conversational turns; fewer interruptions, overlaps, and backchannels; and increased formality when switching speakers. Communication over the system with broadcast quality audio and video was more similar to face-to-face meetings, although it did not replicate face-to-face interaction. Contrary to our expectations, formal techniques were still used to achieve speaker switching. We suggest that these may be necessary because of the absence of certain speaker-switching cues. The results imply that the advent of high-speed multimedia networking will improve but not remove all the problems of video conferencing as an interpersonal communications tool, and we describe possible solutions to the outstanding problems.

‘France Inter Active’: A Hypermedia Approach to Language Training

SUMMARY The development of optical storage media for powerful microcomputers capable of presenting broadcast quality video images combined with contemporary interactive hypermedia models of knowledge representation and the ‘communicative competence’ model of language acquisition make the development of effective multimedia computer‐assisted language learning a realistic possibility. This paper describes an interactive hypermedia approach to language training currently being developed by the Computer‐Assisted Language Study and Acquisition (CALSA) Unit at Teesside Polytechnic. The CALSA Unit was established with funding from the UK Training Agency (TEED) for the express purpose of exploiting current advances in microcomputing technology to develop a cost‐effective means of providing an opportunity for a wide variety of potential learners to acquire a second language. The object of this paper is to describe the aims and objectives of this project and its progress to date.

A new data structure for variable bit rate broadcast video transmission on ATM network

The asynchronous transfer mode (ATM) technique will probably increase the demand for sophisticated video services. The availability of wide bandwidth and fast rerouting at affordable rates will influence the design of new video codecs. Firstly, variable bit rate coding algorithms can efficiently be employed in order to achieve a uniform picture quality at the receiver. Secondly, the impairment due to cell loss that may occur in the ATM environment demands specialized error concealment strategy. In this paper the segmentation and reassembling of the bit stream generated by a hybrid DCT broadcast quality video codec is addressed. A VIDEO PACKET (V.P.), composed of a variable number of ATM cells, is associated to a defined portion of the television signal. Predefined patterns and layered protection included in the V.P. allow the detection of lost cells and consequently the application of a simple error concealment technique.