Download Inverting dynamics compression with minimal side information Dynamics processing is a widespread technique, both at music production and diffusion stages. In particular, dynamic compression is often used in such a way that the “average” listener can best enjoy the music. However, this may lead to an excessive use of compression, especially with respect to listeners in quiet listening conditions. This paper presents estimates on the amount of extra data that is needed to invert the effects of such non-linear processing, using simple blind identification techniques. We present two simple test cases, first in the case when perfect reconstruction is needed, and second when the ancillary data rate is constrained, leading to an approximate reconstruction.
Download Detecting arrivals within room impulse responses using matching pursuit This paper proposes to use Matching Pursuit, in order to investigate some statistical foundations of Room Acoustics, such as the temporal distribution of arrivals, and the estimation of mixing time. As this has never been experimentally explored, this study is a first step towards a validation of the ergodic theory of reverberation. The use of Matching Pursuit is implicit, since correlation between the impulse response and the direct sound is assumed. The compensation for the energy decay is necessary to obtain stationnary signals. Methods for determining the best the temporal boundaries of the direct sound, for choosing an appropriate stopping criteria based on the similarity between acoustical indices of the original RIR and those of the synthesized signal, and for experimentally defining the mixing time constitute the scope of this study.