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Chapter 17 Export
Video and Audio Parameters for DVD, VCD and SVCD
To modify a preset, select the Custom standard preset (or another) and then click Modify Preset.
Note that when you modify the preset parameters, they may fall outside the range of the format stan-
dards - for example, by exceeding the maximum bit rate.
Video parameters page 970
Audio parameters page 971
Video Parameters
Interlacing
Select interlaced (Top/Bottom field first), or else Progressive for full frame.
Bitrate and Bitrate Control (VBR/CBR)
According to its specifications, a DVD, or rather a DVD player can handle a data stream of max. 10.08
megabits per second (Mbps or Mbit/s) all inclusive (i.e. video plus audio plus subtitles plus reserve). Nat-
urally, the bit rate also depends on how much program you want to fit onto a disc, but using the Capacity
Indicator, you can easily determine the “bit budget” and optimally utilize the medium.
Avid Liquid offers two versions:
Constant (CBR)
A constant bit rate (CBR) ensures that each frame is handled with (almost) the same compression. This
has the advantage of allowing precise calculation, but it ignores the fact that some simple frame
sequences can be encoded just as well at a lower bit rate, meaning that you would be “wasting” band-
width. This is not so important, however, if you have a lot of free space available on the CD or DVD.
Constant (CBR) is recommended for formats that require a fixed bit rate (such as VCD).
If you select Constant, only the Peak meter counts. Set it to the desired video bit rate. Maximum value: 15
Mbps (ES); 8.5 Mbps (DVD image, VOB). The table below lists the approximate playing times for a 4.37
GB DVD:
3.0 Mbps > approx. 120 minutes
4.0 Mbps > approx. 100 minutes
6.0 Mbps > approx. 75 minutes
7.0 Mbps > approx. 65 minutes
7.5 Mbps > approx. 60 minutes
(with PCM audio)