Adobe 38040165 - Visual Communicator - PC, Руководство пользователя

Страница: 135 / 156

4.
When you are satisfied with the custom video encoding settings, click OK to return to the
Video Publisher wizard, and continue following the wizard instructions.
The Video Publisher wizard lets you choose from three preset resolutions and frame rates
when creating Real video files, However, you can also specify custom encoding settings for
Real video size and quality.
To publish Real video and specify custom encoding settings:
1.
To start the Video Publisher wizard, click Publish, and select one of the publishing
methods for your video. For more information on the publishing methods, see
“Select the
publishing method” on page 123 .
2.
Select Publish a Real Video from the wizard.
3.
Select the Custom Size/Custom Quality checkbox, and click the Customize button to
display the Custom Encoding Settings dialog box.
The custom encoding settings are:
Constant Bit Rate
Lets you specify a constant bit rate video stream in kilobytes per
second (kbps). A constant bit rate video stream maintains the same data rate, providing a
consistent level of quality throughout playback. When you create a RealVideo clip, you
can choose constant bit rate (CBR) or variable bit rate (VBR) encoding. CBR encoding is
the more traditional method of encoding streaming video. It maintains a consistent bit
rate for the stream, such as a constant 34 Kbps when streaming to 56 Kbps modems. You
should generally use CBR video when streaming at bandwidths below 350 Kbps. At high
bandwidths, however, you can use CBR or VBR video.
Variable Bit Rate
(Default) lets you specify a variable bit rate video stream in kilobytes
per second (kbps). Variable bit rate (VBR) encoding generally provides superior video
quality to constant bit rate (CBR) encoding. It gives more bandwidth to scenes that are
hard to compress, making the most visible difference in videos that have fast moving,
high-action scenes.
You can specify a maximum bit rate, as well as an average bit rate that the Real video
encoder should strive to maintain. You can also determine the bandwidth of the variable
rate video stream by specifying the degree of video quality to maintain.
VBR encoding is suited for bandwidths of 350 Kbps or higher.
Audio Codec
A drop-down menu that lets you choose from several audio codecs, bit
rates, and sampling rates.