QuickTime
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Note:
Only H.263 and the Developer Edition of the Sorenson Video codec support this
streaming option. H.263 calls this option Cycle Intra Macroblocks, and it is available through
its Options dialog in the Encode tab.
Lower refresh values result in shorter delays between when the viewer starts to see the image
and when the image is fully drawn. However, shorter refresh values generally produce lower
overall image quality because more refresh data must be included in the stream.
Generally, you should always use the Force Block Refresh option, especially on content that
mixes high-action and static material. Since high-action content automatically refreshes, there
is no wasted bandwidth on block refreshing. Static content, such as interviews or “talking
head” videos, benefits most from a block refresh because parts of the image may not change for
a long period of time.
A value of 2–5 seconds is often a good starting point with static material. We suggest you
experiment to determine the optimal settings for your material and personal preferences.
Note:
Force Block Refresh should never be used with local or progressive-download movies
because it wastes bandwidth.
Alternates
Alternate movies are primarily used to optimize the viewing experience for a wide range of
viewers. Alternates work with both progressive-streaming and realtime-streaming QuickTime,
as well as on the desktop with CD-ROM and DVD-ROM projects.
With alternates, you can create multiple versions of a movie and set criteria for which version
is played.
For example, you might make a movie that has a 56k modem version, an ISDN version and a
T1 version. Depending on the viewer’s connection speed, they are automatically shown the
version of the movie with the most appropriate data rate for their connection. This enables you
to present high-quality versions of movies to viewers with high-speed connections while
providing modem users with an acceptable experience at the same time.
Fallbacks
A fallback is the alternate movie or image displayed by the QuickTime Plug-in if it is not
capable of displaying any versions of the movie.
Alternates and Streaming
QuickTime enables you to intermix realtime streaming and progressive-streaming alternates
within the same alternate group to provide the optimal experience for a range of viewers.
Often, it works well to make the modem alternates of a progressive-streaming movie and the
higher-bandwidth alternates (ISDN and above) realtime streaming.
Содержание 64006-051108-9001 - Discreet Cleaner - Mac
Страница 1: ...from discreet November 2000 ...
Страница 8: ...Contents viii ...
Страница 16: ...Chapter 1 Introduction 8 ...
Страница 24: ...Chapter 2 Capture 16 ...
Страница 54: ...Chapter 4 Projects 46 ...
Страница 68: ...Chapter 5 Settings 60 ...
Страница 148: ...Chapter 7 Formats 140 ...
Страница 160: ...Chapter 8 Encoding 152 ...
Страница 220: ...Chapter 8 Encoding 212 ...
Страница 248: ...Chapter 11 Workflow 240 ...
Страница 254: ...Chapter 12 Troubleshooting 246 ...
Страница 284: ...Glossary 276 ...