Methods and apparatus to perform windowed sliding transforms

Abstract

Methods and apparatus to perform windowed sliding transforms are disclosed. An example apparatus includes a coding format identifier to identify, from a received first audio signal representing a decompressed second audio signal, an audio compression configuration used to compress a third audio signal to form the second audio signal, a source identifier to identify a source of the second audio signal based on the identified audio compression configuration, a windowed sliding transformer to perform a first time-frequency analysis of a first block of the first audio signal according to a first trial compression configuration, and perform a second time-frequency analysis of the first block of the first audio signal according to a second trial compression configuration, wherein the windowed sliding transformer includes a multiplier to multiply a vector including a first frequency-domain representation and a matrix including a third frequency-domain representation, an artifact computer to determine a first compression artifact resulting from the first time-frequency analysis, and determine a second compression artifact resulting from the second time-frequency analysis; and a controller to select between the first trial compression configuration and the second trial compression configuration as the audio compression configuration based on the first compression artifact and the second compression artifact.