Frequency Domain Techniques for Stereo to Multichannel Upmix
In this paper we propose a series of upmixing techniques for generating multichannel audio from stereo recordings. The techniques use a common analysis framework based on the comparison between the Short-Time Fourier Transforms of the left and right stereo signals. An inter-channel coherence measure is used to identify time-frequency regions consisting mostly of ambience components, which can then be weighed via a non-linear mapping function, and extracted to synthesize ambience signals. A similarity measure is used to identify the panning coefficients of the various sources in the mix in the time-frequency plane, and different mapping functions are applied to unmix (extract) one or more sources, and/or to re-pan the signals into an arbitrary number of channels. We illustrate the application of the various techniques in the design of a two-to-five channel upmix system.
Click to purchase paper or login as an AES member. If your company or school subscribes to the E-Library then switch to the institutional version. If you are not an AES member and would like to subscribe to the E-Library then Join the AES!
This paper costs $33 for non-members, $5 for AES members and is free for E-Library subscribers.