Digital Audio Delivery to the Consumer
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. High quality is obtained with compression ratios approaching 12:1 for multichannel audio programs. The high-compression ratio is achieved by methods that do not increase decoder memory and, thus, cost. The methods employed include transmission of a high-frequency resolution spectral envelope and a novel forward/backward adaptive bit allocation algorithm. 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 programs; dynamic range control; and broadcaster control of downmix coefficients. Optimum application of the system involves the creation and delivery of metadata describing dialogue loudness and intended dynamic range.
- Print ISSN
- 0036-1682
- Published
- 2000-04
- Content type
- Original Research
- DOI
- 10.5594/J05366