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Articles 1 - 11 of 11
Full-Text Articles in Physical Sciences and Mathematics
The Analysis Of Speech Codecs Using Psychoacoustic Measures, M. Raad, C. H. Ritz, I. Burnett, Alfred Mertins
The Analysis Of Speech Codecs Using Psychoacoustic Measures, M. Raad, C. H. Ritz, I. Burnett, Alfred Mertins
Dr Christian Ritz
This paper analyses two narrowband speech codecs, the 4.8 kbit/s FS1016 coder and the 8 kbit/s G729 coder, using objective psychoacoustic measures. Four measures are used: loudness, sharpness, roughness and tonality. The results show sharpness and roughness as the two major contributing factors to the subjective difference between the two coders.
Enhancing Interoperability Via Generic Multimedia Syntax Translation, Joseph Thomas-Kerr, I. Burnett, C. H. Ritz
Enhancing Interoperability Via Generic Multimedia Syntax Translation, Joseph Thomas-Kerr, I. Burnett, C. H. Ritz
Dr Christian Ritz
The Bitstream Binding Language (BBL) is a new technology developed by the authors and being standardized by MPEG, which describes how multimedia content and metadata can be mapped onto streaming formats. This paper describes how BBL can be used to enhance the interoperability of multimedia content by providing a generic mechanism for the translation of content between formats. As new content formats are developed, BBL can be used to describe how to translate the content into a form that existing devices are able to render. This consequently simplifies the adoption of new multimedia content forms because existing devices are able …
An Ambient Multimedia User Experience Feedback Framework Based On User Tagging And Eeg Biosignals, Eva Cheng, Stephen J. Davis, Ian Burnett, Christian H. Ritz
An Ambient Multimedia User Experience Feedback Framework Based On User Tagging And Eeg Biosignals, Eva Cheng, Stephen J. Davis, Ian Burnett, Christian H. Ritz
Dr Christian Ritz
Multimedia is increasingly accessed online and within social networks; however, users are typically limited to visual/auditory stimulus through media presented onscreen with accompanying audio over speakers. Whilst recent research studying additional ambient sensory multimedia effects recorded numerical scores of perceptual quality, the users’ time-varying emotional response to the ambient sensory feedback is not considered. This paper thus introduces a framework to evaluate user ambient quality of multimedia experience and discover users’ time-varying emotional responses through explicit user tagging and implicit EEG biosignal analysis. In the proposed framework, users interact with the media via discrete tagging activities whilst their EEG biosignal …
Is That A Fish In Your Ear? A Universal Metalanguage For Multimedia, Joseph Thomas-Kerr, I. Burnett, C. H. Ritz, S. Devillers, D. De Schrijever, R. Van De Walle
Is That A Fish In Your Ear? A Universal Metalanguage For Multimedia, Joseph Thomas-Kerr, I. Burnett, C. H. Ritz, S. Devillers, D. De Schrijever, R. Van De Walle
Dr Christian Ritz
Universal Multimedia Access promises to adaptively deliver multimedia content to users according to their needs?whether it's their device, context, or preferences. Central to UMA is the development of metadata standards for describing multimedia resources to allow their adaptation. In this article, the authors report on the development of the Bitstream Syntax Description Language (BSDL) and describe applications for scalable content adaptation, format independent streaming, and delivery and configurable media coding.
Low Bit Rate Wideband Wi Speech Coding, C. H. Ritz, I. Burnett, Jason Lukasiak
Low Bit Rate Wideband Wi Speech Coding, C. H. Ritz, I. Burnett, Jason Lukasiak
Dr Christian Ritz
This paper investigates waveform interpolation (WI) applied low bit rate wideband speech coding. An analysis of the evolutionary behaviour of wideband characteristic waveforms (CWs) shows that direct application of the classical WI algorithm may not be appropriate for wideband speech. We propose a modification whereby CW quantisation is performed using classical WI decomposition for the low frequency region and noise modelling for the high frequency region. Wideband WI coders incorporating this modification and operating at 4 kbps and 6 kbps are described. Subjective testing of these coders shows that WI is a promising approach to low bit rate wideband speech …
Very Low Rate Speech Coding Using Temporal Decomposition And Waveform Interpolation, C. H. Ritz, I. Burnett, J Lukasiak
Very Low Rate Speech Coding Using Temporal Decomposition And Waveform Interpolation, C. H. Ritz, I. Burnett, J Lukasiak
Dr Christian Ritz
In very low rate coding the aim is to accurately represent speech characteristics as efficiently as possible. High coding gains for the spectral features can be achieved through the use of temporal decomposition. Waveform interpolation coders accurately represent the excitation using characteristic waveforms (CWs) extracted at a constant rate. In this paper, the two approaches are combined into a very low rate coder operating at around 1 kbps. It is shown that the evolution of the excitation is related to the evolution of the speech spectrum. To minimise bit rates, the transmission of CWs is adapted to the spectral parameter …
Extending Waveform Interpolation To Wideband Speech Coding, C. H. Ritz, I. Burnett, Jason Lukasiak
Extending Waveform Interpolation To Wideband Speech Coding, C. H. Ritz, I. Burnett, Jason Lukasiak
Dr Christian Ritz
This paper investigates the extension of waveform interpolation (WI) to wideband speech coding. Included is an analysis of the evolutionary behaviour of wideband speech and the consequences for WI. We highlight problems associated with direct application of the classical WI algorithm applied to wideband speech.
Query Streaming For Multimedia Query By Content From Mobile Devices, Kevin Adistambha, S. J. Davis, Christian H. Ritz, I. Burnett
Query Streaming For Multimedia Query By Content From Mobile Devices, Kevin Adistambha, S. J. Davis, Christian H. Ritz, I. Burnett
Dr Christian Ritz
Formulating and processing of multimedia queries using mobile devices presents many challenges. This is due to the limitations of the devices themselves and the cost of the bandwidth involved in transmitting multimedia data between servers and devices. In this paper we propose a novel approach: “query streaming” which uses Reverse Polish Notation to perform multimedia query-by-example on a mobile device and server. An important advantage of query streaming is the ability to perform a query within the previous result set. To solve the problem of limited resources, the concept of result set examination using Fragment Request Units and Fragment Update …
Principles And Analysis Of The Squeezing Approach To Low Bit Rate Spatial Audio Coding, B. Cheng, C. H. Ritz, I. Burnett
Principles And Analysis Of The Squeezing Approach To Low Bit Rate Spatial Audio Coding, B. Cheng, C. H. Ritz, I. Burnett
Dr Christian Ritz
This paper presents a novel solution to multichannel spatial audio coding: spatial squeezing surround audio coding (S3AC). The S3AC scheme analyses a multichannel audio signal and downmixes it into a stereo signal pair containing both the monophonic properties of audio sources and their localization information; this avoids the need for side information. The approach uses time-frequency analysis of a spatial audio scene and exploits virtual sources and amplitude panning techniques to 'squeeze' 360deg of a horizontal soundfield to a 60deg stereo signal pair. In comparison with other spatial audio coding techniques, S3AC significantly advances in-band encoding of the localization information …
Temporal Decomposition For Low Rate Wideband Speech Compression, C. H. Ritz, I. Burnett
Temporal Decomposition For Low Rate Wideband Speech Compression, C. H. Ritz, I. Burnett
Dr Christian Ritz
An investigation into low bit rate wideband speech coding for applications such as unicast streaming is presented. Wideband spectral parameters are quantised below 1 kbit/s using temporal decomposition (TD) applied to the line spectral frequencies. Quantisation using TD performs significantly better than split vector quantisation at an equivalent bit rate.
Transcoding Of Narrowband To Wideband Speech, Christian H. Ritz, Nick Harders, Joseph Hermann, Matthew J. Baker
Transcoding Of Narrowband To Wideband Speech, Christian H. Ritz, Nick Harders, Joseph Hermann, Matthew J. Baker
Dr Christian Ritz
Transcoding is required to facilitate the communication of compressed speech between networks that have adopted opposing speech coding standards. The traditional transcoding technique of tandem conversion by decoding from the old standard and then re-encoding with the new standard suffers from unacceptable delay and complexity. For real time applications, delay and complexity can be reduced by performing transcoding in the bit stream domain. This paper describes techniques for transcoding between narrowband and wideband speech coding standards. In particular, an examination of the performance of bit stream mapping approaches to transcoding from the ITU-T G.729 narrowband speech coder to the ITU-T …