Upmixing and downmixing two-channel stereo audio for consumer electronics

Abstract

In this comprehensive study, algorithms for upmixing, downmixing, and joint up/downmixing are examined. Two upmixing algorithms are employed to convert two-channel stereo signals to five-channel signals. For downmixing, methods ranging from mixing with simple gain adjustment to more sophisticated Read Related Transfer Function (HRTF) filtering and Crosstalk Cancellation System (CCS) are utilized to downmix the center channel and the surround channels into the available two frontal loudspeakers. For situations where only two-channel content and loudspeakers are available, a number of up/downmixing schemes are used to simulate a virtual surround environment Emphasis of comparison is placed on a dual-loudspeaker MP3 handset. Listening tests are conducted to compare the processing methods in terms of three levels of subjective indices. The results are processed by using the Multivariate ANalysis Of VArianee (MANOVA) to justify the statistical significance.