In some embodiments, a method for embedding data (e.g., metadata for use during post-processing) in a stereo audio signal comprising frames. Each of the frames has a saturation value, and data are embedded in the stereo audio signal by modifying the signal to generate a modulated stereo audio signal comprising a sequence of modulated frames having modulated saturation values indicative of the embedded data. Typically, one data bit is embedded in each frame of an input stereo audio signal by modifying the frame to produce a modulated frame whose modulated saturation value matches a target value indicative of the data bit. In other embodiments, a method for extracting data from a stereo audio signal in which the data have been embedded in accordance with an embodiment of the inventive embedding method. Other aspects are systems (e.g., programmed processors) configured to perform any embodiment of the inventive method.