Retrospective: Historical Briefs From Past Issues

The April 2000 Journal published in: “Digital Audio Delivery to the Consumer” by Steve Lyman and Craig Todd: “Dolby Digital is a system for coding up to 5.1 channels of audio into a low bit rate data stream intended to deliver audio to the consumer … In order to satisfy practical requirements of an emissions coder, the syntax includes a number of features useful to broadcasters and consumers: loudness uniformity between program; dynamic range control; and broadcaster control of downmix coefficients … Included in the system are a number of unique features intended to be controlled by those who create the audio content: dialogue normalization, dynamic range control, and indication of the calibration of the audio mixing room. Proper generation (authoring) of the information to control these features will lead to increased consumer enjoyment … with its high-resolution spectral envelope coding and hybrid forward/backward adaptive bit allocation offers very high coding gain at modest complexity. Bit starvation is avoided during extreme signal demands by invoking the technique of coupling …” For the full article, see: https://tinyurl.com/mr33w46