A Guide to Audio for HDTV in Europe

Overview		Production		Distribution		Transmission		Set-Top Box Requirements

How do I produce multichannel audio content?

Many genres of programming are already being produced in HD with 5.1 audio, such as live awards shows and sports events, premium dramas, music, and movies. Production of original 5.1-channel audio for HD is straightforward and can be performed using a wide variety of mixing consoles and workstations.

A key consideration when producing 5.1 material is the setting of audio metadata. Metadata is additional data about the audio that is carried with the audio signals, ultimately allowing the sound to be presented in the best possible way in the home. For example, it controls how a 5.1 soundtrack is downmixed for presentation on systems with fewer speakers, and also controls dynamic range compression characteristics for small speakers or for late night listening.

Setting metadata during the mix gives you complete control over how the mix will sound in the home, whether it is being reproduced in mono, stereo, or over the full 5.1 channels. As it is likely that the 5.1 mix will be the only audio stream that is transmitted for HD services, you can use the metadata to ensure that anyone listening to the stereo or mono downmix gets precisely the mix you want them to have.

Whether your program is live or post-produced, the easiest way to deliver HD video and 5.1 audio to the broadcast center is using Dolby^® E. Dolby E allows up to eight discrete channels of audio, and associated metadata, to be carried on one AES channel pair of a tape, server, or link (see figure 1). This makes synchronization of material much simpler and means that there is no potential for misplacing associated tapes. The HD picture always has associated audio, and audio always has associated metadata. Dolby E is also widely used for carrying multichannel audio for 5.1 broadcasts on SD services.

Find out how you can get ready to produce thrilling Dolby 5.1 programming by contacting your local Dolby distributor.

View A Guide to Dolby Metadata.