Ligang Lu, Shu Xiao, J. Kouloheris et al. · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2002
We present a low cost high performance scheme for video transcoding. Our scheme includes the information look-ahead structure and the transcoding algorithm. It is this look-ahead mechanism that greatly facilitates the use of information embedded in the bitstream for informative and intelligent transcoding. Furthermore, our transcoding algorithm has four new features: 1) picture complexity look-ahead for efficient rate allocation and control; 2) dynamic bit allocation weighting on picture types based on the scene complexity and bit rate; 3) adaptive nonlinear rate control on macroblocks based on complexity distribution in the picture; 4) Intra frame requantization adjustment to reduce the transcoding distortion. The software simulation results have proven that the performance of our transcoding scheme is significantly better than the reencoding scheme and comparable to the direct encoding scheme.
Cited by 5
Seung S. Yang, Javed Khan · IGI Global eBooks · 2011
This chapter provides a comprehensive awareness and understanding of research efforts in the field of extreme rate-distributed video transcoding. The basic concepts and theories of rate control methods such as requantization, temporal resolution reduction, spatial resolution reduction, and object-based transcoding are introduced. We will identify each rate control scheme’s strengths and weaknesses and provide a distributed video transcoding system architecture that uses multiple transcoding techniques in the creation of an extreme rate video. Experimental results show that the appropriate use of multiple transcoding schemes retains a better quality video in an extreme rate control. At the end of this chapter, we will identify unsolved problems and related issues and will offer suggestions for future research directions. Request access from your librarian to read this chapter's full text.
Cited by 0
Jens Brandt, Lars Wolf, Paal Halvorsen · ACM SIGMultimedia Records · 2009
The prominence of digital video on the Internet is rising constantly. Faster Internet connections and more powerful devices make video streaming over the Internet more and more popular. With mobile devices, however, the usability of digital videos that are streamed over a wireless network connection is still limited by the available resources. Mobile devices are often not capable of receiving and decoding high quality video streams from the Internet because of their limited resources as well as due to the limitations of a wireless network connection. The presentation, for instance, of a video stream with 1920x1080 pixels on a screen with a resolution of only 320x240 pixels is not possible without a high amount of processing power at the receiving device. The transmission of such a high quality video stream over a wireless link may additionally consume a large part of the available network capacity, which then may interfere active network connections of other devices. A limited network capacity may additionally prevent the device from decoding and displaying the video stream at all. One solution of these problems is to perform an adaptation of the video stream to the requirements of mobile devices during the transmission of the stream to the client.
Cited by 10
Artur Janicki, Wojciech Mazurczyk, Krzysztof Szczypiorski · Journal of Homeland Security and Emergency Management · 2014
Abstract Nowadays cyber criminalists’ interest in incorporation of steganography into armory of rogue hackers is on the rise and information hiding techniques are becoming the new black among Black Hats. In this paper we focus on analyzing the efficiency of the recently proposed IP telephony information hiding method called transcoding steganography (TranSteg) that enables hidden communication with a high steganographic bandwidth while retaining good voice quality. Specifically, we focus on analyzing which voice codecs would be the most favourable for TranSteg to minimize the negative influence on voice quality while maximizing the obtained steganographic bandwidth and limiting the risk of detection.
Cited by 3
LONETTI, FRANCESCA · Electronic Theses and Dissertations Repository (University of Pisa) · 2010
La tesi analizza il problema della transcodifica temporale per la trasmissione del video in tempo reale su reti mobili. Viene proposta un’architettura di transcodifica temporale e un nuovo algoritmo di ricalcolo dei vettori di moto per il transcoder temporale H.264. Per fronteggiare il problema della riduzione costante della banda del canale wireless nelle reti infrastrutturate, vengono proposte diverse politiche di frame skipping basate sul dimensionamento del buffer del transcoder per garantire una comunicazione in tempo reale. Il moto di un frame e il numero di frames consecutivi scartati vengono inoltre considerati per migliorare la qualità del video transcodificato. E’ stato inoltre proposto e studiato un sistema di trasmissione video per reti veicolari con protocollo IEEE 802.11, basato su transcodifica temporale. Questo sistema permette di scartare quei frames il cui tempo di trasmissione supera un massimo ritardo ammisssibile al di sopra del quale tali frames non verrebbero comunque visualizzati. Il sistema proposto permette un notevole risparmio di banda e migliora la qualità del video evitando che molti frames consecutivi vengano scartati a causa della congestione.
Cited by 0Open access
Peter Schojer, Hermann Hellwagner · 2004
Due to the increasing availability of audio/visual data on the Internet, proxy caching is gaining on importance as a per-formance factor. This increase is accompanied by a diversi-fication in the end terminals, which calls for media gateways and filters. An adaptive proxy is presented which performs (1) caching, (2) filtering and (3) media gateway functionality in one. The proxy can perform media adaptation – using transcoding – on its own. A cost model is presented which incorporates user requirements, terminal capabilities and video variations in one formula. Based on this model, the proxy acts as a general broker of different user requirements and of different video variations. This is a first step towardsWhat You Need is What You Get (WYNIWYG) video services, which deliver videos to users in exactly that quality what they need and what they want to pay for. The MPEG-7 and MPEG-21 standards enables this in an interoperable way. A detailed evaluation based on a series of measurements is provided.
Cited by 0
Fung, Kai-tat · PolyU Institutional Research Archive (Hong Kong Polytechnic University) · 2011
Cited by 0
Thomas, Nithin · OpenGrey (Institut de l'Information Scientifique et Technique) · 2009
In order to service heterogenous, variable bandwidth networks, low complexity transcoding architectures have been developed to allow modification of video bitrate. SVC, the scalable extension to H.264, was also developed for this purpose. When encrypted video is transmitted, it cannot be modified prior to decryption. Any decryption carried out at a transcoder would use security weaknesses in the network. In the above context, there is a need to develop transparent encryption techniques that allow bitrate reduction without decryption. For SVC bitstreams, an architecture called SVE is presented in this thesis to allow the full range of scalabilities to be supported without compromising quality or security. This approach is shown to outperform all existing techniques presented in the literature and shows significant potential for commercial deployment.
Cited by 0
Soam Acharya, Brian Smith · 2008
Current video compression formats optimize for either compression or editing. For example, motion-JPEG (MJPEG) provides excellent random access and moderate overall compression, while MPEG optimizes for compression at the expense of random access. Converting from one format to another, a process called transcoding, is often desirable over the life of a video segment. This paper shows how to transcode MPEG-1 video to motion-JPEG without fully decompressing the MPEG-1 source. The described technique for compressed domain transcoding differs from previous work because it uses a new approximation approach that is optimized for software implementations. This new approach is 1.5 to 3 times faster than spatial domain transcoders and offers an additional degree of freedom: higher transcoding speeds can be obtained at the price of lower picture quality. This speed/quality trade-off is useful in many real-time applications such as off-line editing and video gateways. 1.
Cited by 0
Haeggström, Johan · Aaltodoc (Aalto University) · 1997
Cited by 0
John R. Bowen · ELH · 1996
Performing Business, Training Ghosts: Transcoding Nickleby John Bowen In August, 1860, Dickens writes to a friend: My mother, who was also left to me when my father died (I never had anything left to me but relations), is in the strangest state of mind from senile decay; and the impossibility of getting her to understand what is the matter, combined with the desire to be got up in sables like a female Hamlet, illumines the dreary scene with a ghastly absurdity that is the chief relief I can find in it. 1 A passage about domestic irritability and high tragedy, about inheritance of wealth and obligation, about desire and forbidden desires in families and fictions; about Shakespeare and Dickens, parent and child, darkness and death; the costuming of revenge in the apparition of a figure which implicates and undoes theatricality and domesticity, tragedy and comedy, sexuality and madness; which is male and female, mother and son, author and character; a spectacle of horror and despair, the melancholy site of a grotesque, black laughter. In November, Dickens reports that his mother is “much better than I supposed” as “the instant she saw me, she plucked up a spirit, and asked for a pound.” 2 The next five lines of the letter have been removed by Georgina Hogarth, Dickens’s sister-in-law, executor and first editor of the letters. Plucking up spirit and money in writing and excision; the strangest state of mind, and the impossibility of getting him to understand what is the matter; family business. I Nancy Armstrong in her Desire and Domestic Fiction has argued that a profound shift occurs in the history of the novel in the course of the nineteenth century, a change that grants an unprecedented centrality to the figure of the domestic woman. Through the elaboration of a set of norms and fictional understandings of desire and the self, a deeply de-politicized conception of middle-class life emerges. Novels, particularly from the 1830s, she argues, enclose political conflict within the domestic sphere and detach the household from politics to provide the “complement and antidote to it.” The household thus becomes “the [End Page 153] ‘counter-image’ of the modern marketplace, an apolitical realm of culture within the culture as a whole.” 3 I want to try to revise that account by looking at the work of Dickens, in particular the novel Nicholas Nickleby. At first, Nickleby seems a useful illustration of the main lines of Armstrong’s argument. It values the domestic virtues to excess, and its central characters move through difficulties and dangers to a happy resolution of multiple marriages and return to the family home. Women in the book are valued for their virtue, domesticity and silence, devalued for interference and excessive talk. Against male aristocratic immorality, the virtues of the industrious, home-loving bourgeoisie are victorious. Yet such an account abstracts the domestic issues both from the dense economic and political forces within which Dickens embeds them and the specific fictional form and strengths of the novel. Characters are constantly impelled by economic motives in the book, but Dickens is not concerned simply with the depiction of a multiplicity of human agents whose economic situation and motives are constantly in play; he also attempts to depict economic forces that are not reducible to individual intentions. Families in the book—the Mantalinis, the Cheerybles, the Crummleses, the Squeerses, the Nicklebys—are also family businesses, where the claims of the domestic and economic are intimately bound together. They have the force of institutions—a school, a mercantile house, an acting troupe—which extend and transform the social relations both of their members and those for and upon whom they work. Much of the comedy stems from this, as in the mixture of domestic affection and economic self-interest in Vincent Crummles’s fostering of the Infant Phenomenon or the older Wackford’s feeding of the younger, but the serious point is made too: that the family is not, cannot be, free of economic determinants, or the violence and conflict of the wider society. Indeed the family often provides a particular focus for such conflict, tragically in the brutalization and death of Smike...
Cited by 4
Li‐Wei Kang, Chih‐Yang Lin, Hung-Wei Chen et al. · 2011
Compressive sensing (CS) has recently attracted much attention due to its unique feature of directly and simultaneously acquiring compressed and encrypted data based on their sparse or compressible properties. To securely transmit compressively sensed multimedia data over networks, it is required to support transcoder to securely convert compressed multimedia into several different types for diverse receivers. In this paper, a secure transcoding scheme for compressive multimedia sensing is proposed. We focus on securely converting compressively sensed multimedia data (not data compressed via standard codec) with a certain number of measurements into other different numbers of measurements without resorting to reconstruct the original data. We show that the security can be achieved via transforming multimedia re-sensing process into another secure domain at the transcoder. We also show that the computational security can be achieved while transmitting compressively sensed data between the sender (or each receiver) and the transcoder over networks.
Cited by 5
Keqiu Li, Hong Shen, Keishi Tajima · Lecture notes in computer science · 2004
Cited by 7Open access
H-s Vetro, A. Hata, T. Kuwahara et al. · 2005
This paper presents a newly developed region-on-interest (ROI) transcoding method for JPEG 2000 images, which can be used for many progressive image/video streaming applications. The proposed method takes advantage of the empty packet property provided by JPEG 2000 standard to elevate the priority of the ROI. Baased on the user specified ROI information and progressive parameters, the developed transcoder extracts the selected ROI and background packets with the desired quality and suppresses the unselected packets to the low quality. Since the transcoder only performs re-organizing the packets in the original coded bitstream, it does not involve any re-encoding operation. Compared to other ROI coding schemes in the literature, the proposed method has the advantages of lower complexity and faster processing. Therefore, it is very suitable for real-time application.
Cited by 0
Lujun Yuan, Huifang Sun, Wen Gao · 2008
In this paper a system level MPEG transcoding scheme is proposed. The MPEG-2 system standard specifies two kinds of streams: transport stream (TS) and program stream (PS). Each is optimized for a different set of applications. The transcoding between TS and PS has an important application, which can be applied to convert the digital television (DTV) broadcasting bitstreams to the bitstreams for digital video disc (DVD) application. An important technical issue for transcoding between PS and TS is the rate control algorithm. Usually, for DVD application, the video is encoded by variable bit rate (VBR) in order to provide constant quality over whole sequence, while for DTV application due to buffer requirement the video should be encoded by constant bit rate (CBR). In this paper, a novel VBR rate control algorithm is proposed for the on-line video transcoding process. In this algorithm, the bit allocation strategy at picture level, which is based on a bit producing model and hyperbolic R-Q function, is first discussed. Then, the rate control algorithm at macroblock level with R-D optimization is proposed. Experiment results show that the proposed VBR transcoding algorithm achieved the better image quality compared with CBR transcoding at the same bit rate. 1.
Cited by 0
Björn Knutsson · 2003
Introduction Many web site designers face a dilemma: they must balance the richness of the user experience against the limited bandwidth and user interfaces of many Web clients. Media content create particular problems: for example, large images increase download times, and may be hard to display on small screens. The Internet is seeing growth not just in users with wideband access, but also in people using portable narrowband clients with small displays. To avoid discouraging the latter users, site designers often employ fewer, smaller, or lower-quality images than they would otherwise prefer. Even so, many users encounter sites with excessive image complexity, either because a thoughtful site designer was unwilling to unduly compromise the experience of well-connected users, or because a thoughtless site designer failed to consider the impact of image size. To cope with this mismatch between content and capabilities, content can be adapted to fit the capabilities of individual dev
Cited by 0
Simon Harper, Sean Bechhofer, Darren Lunn · 2008
Visually impaired users are hindered in their efforts to access the World Wide Web (Web) because their information and presentation requirements are different from those of a sighted user. These requirements can become problems as the Web becomes ever more visually centric with regard to presentation and information order / layout, this can (and does) hinder users who need presentationagnostic access to information. Finding semantic information already encoded directly into pages can help to alleviate these problems and support users who wish to understand the meaning as opposed to the presentation and order of the information. Our solution, Structural-Semantics for Accessibility and Device Independence (SADIe) involves building ontologies of Cascading Sytle-Sheets (CSS) and using those ontologies to transform Web pages.
Cited by 0
Lonetti F., Martelli F. · ISTI Open Portal · 2007
Cited by 0
Journal of International Crisis and Risk Communication Research · 2009
In this paper, we present a unified architecture that can perform Discrete Cosine Tran form (DCT), Inverse Discrete Cosine Transform (IDCT), DCT domain motion estimation and compensation (DCT-ME/MC). Our proposed architecture is a Wavefront Array-based Processor with a highly modular structure consisting of 8x8 Processing Elements (PEs). By utilizing statistical properties and arithmetic operations, it can be used as a high performance hardware accelerator for video transcoding applications. We show how different core algorithms can be mapped onto the same hardware fabric and can be executed through the pre-defined PEs. In addition to the simplified design process of the proposed architecture and savings of the hardware resources, we also demonstrate that high throughput rate can be achieved for IDCT and DCT-MC by fully utilizing the sparseness property of DCT coefficient matrix.
Cited by 0Open access
Marcelo Atenas, Alejandro Cánovas, Miguel García et al. · 2010
IP Television (IPTV) is a new service that is growing up very quick in recent years. Its implementation is performed as a Triple-Play service, being the integration of voice, high-speed data and television. Moreover, the network traffic has been increased due to the use of VoIP, video or P2P. It is also creating congestion problems to the network provider and has high impact on the quality of IPTV. For this reason, it is necessary to provide tools in order to reduce the congestion and provide the maximum Quality of Experience to the customers. In this paper we analyze the bandwidth used by a movie and we propose a video transcoder as a tool to control the congestion in IPTV networks. The results obtained are similar to the traffic shaping. The measurements obtained in our test bench shows that a video transcoder can be used to guarantee a certain QoE, in the presence of congestion.
Cited by 11