User Manual

Chapter 5 Custom settings and output formats 84
Stereo playback
Even with the popularity of 5.1 systems, you should always address stereo reproduction. There
are three basic ways to do this:
•
Prepare a new stereo mix from the original multitrack elements (using conventional stereo-
mixing sessions).
•
Prepare a studio-adjusted downmix from the multichannel mix. This method takes advantage
of the work that has gone into mixing the 5.1 version. It retains exibility in the exact
proportions of each channel represented in the nal stereo mix.
•
Let the decoder derive a stereo downmix, based on preset formulas in the decoder. Downmix
options and dynamic range control eects can be previewed and adjusted in the production
studio, and a range of adjustments are possible.
Always check the mix on an inexpensive surround system to evaluate how well it sounds on
modest playback systems.
Note: For more information about Dolby Digital Professional, visit the Dolby Laboratories Inc.
website at http://www.dolby.com.
MPEG-2 les
MPEG-2 overview
MPEG-2 is an internationally accepted compression standard developed by the Motion Picture
Experts Group (MPEG). MPEG-2 allows you to create broadcast-quality video les and was
designed to support high-resolution, high-bit-rate video. It’s the video compression format used
for high-quality video titles on DVD, high-denition (HD) broadcast, and home satellite dish
systems. All DVD players contain the hardware required for MPEG-2 playback.
The Compressor MPEG-2 encoder can create MPEG-2 video streams for the DVD-Video format.
To create DVD-Video discs, you can use a DVD authoring application in conjunction with
Compressor, or you can use the Create DVD job action, which is part of the Create DVD template.
For more information, see Post-transcoding actions overview on page 184 and Create a batch on
page 18.
Standard-denition (SD) MPEG-2
Standard MPEG-2 is full frame rate (23.98 to 29.97 fps) and full-screen resolution (720 x 480 for
NTSC and 720 x 576 for PAL). SD MPEG-2 has the following characteristics:
•
Support for interlaced video: MPEG-2 can support either interlaced or progressive video.
Because MPEG-2 streams are generally played from a local DVD drive rather than over a
network with variable bandwidth, video frame rate usually stays constant, and the video
normally looks completely smooth.
•
No streaming support: MPEG-2 is not suitable for streaming video les over the web because it
requires a high bit rate (2 to 9 Mbps) to maintain acceptable image quality.