Download Fast perceptual convolution for the room reverberation
The FIR-based reverberators, which convolve the input sequence with an impulse response modelling the concert hall, have better quality compared to the IIR-based approach. However, the high computational complexity of the FIR-based reverberators limits the applicability to most cost-oriented system. This paper introduces a method that uses perceptual criterion to reduce the complexity of convolution methods for reverberation. Also, an objective measurement criterion is introduced to check the perceptual difference from the reduction. The result has shown that the length of impulse response can be cut off by 60% without affecting the perceptual reverberation quality. The method is well integrated into the existing FFT-based approach is have around 30% speed-up.
Download A comparison of music similarity measures for a P2P application
In this paper we compare different methods to compute music similarity between songs. The presented approaches have been reported by other authors in the field and we implemented minor improvements of them. We evaluated the different methods on a common database of MP3 encoded songs covering different genres, albums and artists. We used the best approach of the evaluation in a P2P scenario to compute song profiles and recommendations for similar songs. We will describe this integration in the second part of the paper.
Download Metabolic emergent auditory effects by means of physical particle modeling: the example of musical sand
In the context of Computer Music, physical modeling is usually dedicated to the modeling of sound sources or physical instruments. This paper presents an innovative use of physical modeling in order to model and synthesize complex auditory effects such as collective acoustic phenomena producing metabolic emergent auditory organizations. As a case study, we chose the ‘dune effect’, which in open nature leads both to visual and auditory effects. The article introduces two particle physical models, able to collaborate. The first is dedicated the synthesis of spatial (or visual) dynamics effects of moving sand dunes. The second i s dedicated to the rendering of acoustical dynamics of “sounding sands”. Altogether, they lead to a multisensorial simulation of sand in dune. Keywords: auditory effects, metabolic effects, emergence, sonification process, sounding sands,
Download Bit allocation for advanced audio coding using bandwidth-proportional noise-shaping criterion
The bandwidth-proportional noise-shaping criterion has been proposed to be the optimum bit allocation criterion in the sense of minimizing segmental masking-to-noise ratio [1]. A single loop bit allocation has been developed for ISO/IEC MPEG1layer 3 (MP3) [2] to reduce the complexity over the existing two nested loop method for MP3 encoder. Also, the allocation method also leads to the better compression quality. This paper extends the allocation method to the ISO/IEC MPEG-2/4 Advanced Audio Coding (AAC) [3] [4]. This paper derives the perceptual bandwidth for the scale factor bands, provides the bit consumption trade-off to transmit the bits for the scale factors, and illustrates an efficient sectioning method on the Huffman codebook. All these methods jointly integrate with the bit allocation method to improve the quality and the computing complexity of the widely used AAC reference encoder, FAAC [5].
Download A real-time audio rendering system for the Internet (iARS), embedded in an electronic music library (IAEM)
The internet Audio Rendering System (iARS) is an Internet browser extension extending the browser’s capabilities with real-time signal processing. The proposed system allows to receive audio streams from the Internet and apply various audio algorithms with no additional computational power needed from the server. iARS is part of the Internet Archive of Electronic Music (IAEM) project which is also presented in this paper.The IAEM is intended to be a platform to access an extensive and distributed archive of electronic music. It combines collaborative tools, real time signal processing on the client side and the content of the archive to a powerful teaching, research and publishing tool.
Download Analysis of transient musical sounds by auto-regressive modeling
This paper gives an example of an auto-regressive (AR) spectral analysis on transient musical sounds. The attack part of many musical sounds is mostly too short to be analysed by a short-time Fourier analysis, whereas this short period of time is long enough for several AR-methods. The AR-spectra obtained from short segments of signals with attack transients have a sufficiently high frequency resolution. These spectra contain more information about the evolution of a sound than a fast Fourier transform made over a small amount of samples.
Download Matching live sources with physical models
This paper investigates the use of a physical model template database as the parameter basis for a MPEG-4 Structured Audio (MP4-SA) codec. During analysis, the codec attempts to match the closest corresponding instrument in the database. In this paper, we emphasize the mechanism enabling this match. We give an overview of the final front end, including the pitch detection stage, and remaining problems are discussed. A draft implementation, written in the Python language is described.
Download A hierarchical approach to automatic musical genre classification
A system for the automatic classification of audio signals according to audio category is presented. The signals are recognized as speech, background noise and one of 13 musical genres. A large number of audio features are evaluated for their suitability in such a classification task, including well-known physical and perceptual features, audio descriptors defined in the MPEG-7 standard, as well as new features proposed in this work. These are selected with regard to their ability to distinguish between a given set of audio types and to their robustness to noise and bandwidth changes. In contrast to previous systems, the feature selection and the classification process itself are carried out in a hierarchical way. This is motivated by the numerous advantages of such a tree-like structure, which include easy expansion capabilities, flexibility in the design of genre-dependent features and the ability to reduce the probability of costly errors. The resulting application is evaluated with respect to classification accuracy and computational costs.
Download MOSIEVIUS: Feature driven interactive audio mosaicing
The process of creating an audio mosaic consists of the concatenation of segments of sound. Segments are chosen to correspond best with a description of a target sound specified by the desired features of the final mosaic. Current audio mosaicing techniques take advantage of the description of future target units in order to make more intelligent decisions when choosing individual segments. In this paper, we investigate ways to expand mosaicing techniques in order to use the mosaicing process as an interactive means of musical expression in real time. In our system, the user can interactively choose the specification of the target as well as the source signals from which the mosaic is composed. These means of control are incorporated into MoSievius, a framework intended for the rapid implementation of different interactive mosaicing techniques. Its integral means of control, the Sound Sieve, provides real-time control over the source selection process when creating an audio mosaic. We discuss a number of new real-time effects that can be achieved through use of the Sound Sieve.
Download Hierarchical Gaussian tree with inertia ratio maximization for the classification of large musical instrument databases