Dolby E Multichannel Distribution System User Manual | Common Dolby E Applications |
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2.2Commercial and Interstitial
Although current commercial and interstitial material is primarily two-channel stereo, this fast-growing broadcasting sector will almost certainly catch up to film practice, thereby ensuring smooth transitions between commercial and feature programs. See Section 2.1 - Film for the settings to use for two- and 5.1-channel material.
2.3News and Local Programming
News and local programming is either two-channel stereo or two-channel mono. The Dolby Srnd Mode metadata parameter should be set to Indicated. Programs that are Dolby Digital encoded at the DTV station, then decoded by the consumer result in mono programming directed to the Center channel, while stereo programming is mapped to the L, C, R channels. During Pro Logic decoding, dialogue emanates primarily from the Center channel in both cases. This channel placement most closely matches a 5.1- channel program and provides smooth transitions between mono, stereo, and 5.1-channel programming without operator intervention. Line Mode Pro and RF Mode Pro in both programs should be set to either Speech or Film Light depending on the type of program. Film Light is a good general purpose setting for programs with speech and music.
2.4Music
Film and DVD have introduced 5.1-channel music to the general public and these both require the 5.1 + 2 program configuration. The predominant music format, however, remains the two-channel compact disc; use the 2 + 2 program configuration. Since music is generally recorded at a much higher level than film audio, it may be necessary to increase the dialnorm value (i.e., closer to 0) to apply more attenuation at the Dolby Digital decoder. Line Mode Pro and RF Mode Pro should be set to either Music Standard or Music Light depending on the music. See Section 3.2.4 - Metadata Params.
2.5Live Events
Live events can require encoding techniques from each category mentioned in this chapter. The most distinguishing feature of a live event is that, although a VTR may record the event for later broadcast or storage, the tape cannot normally be stopped to alter encoding parameters and then restarted. This is not an issue for postproduction but is a serious concern for live events.
Using Presets is an excellent method of changing Program Configs during an encoding session to match the metadata to the source material being encoded. Pick the most appli- cable program configuration for a specific task and store it as a Preset. During the live event, simply recall the Presets as the encoding requirements change and all associated metadata parameters follow automatically.
See Section 3.2.3 - Presets, Using the Status Port to Select Presets on page 3-4and Using the Status Port to Select Voiceover and Switched Modes on page 4-4for more detailed information.
