Cisco 3005 - VPN Concentrator - Gateway Operation Manual page 26

C I SCO SYSTEM S, IN C.
Mode
Choose CBR (Constant Bit Rate) or VBR (Variable Bit Rate) encoding. If the mode
is VBR, a parameter to specify Maximum Bit Rate in kb/sec will appear and the
Buffer Size parameter will be grayed.
Bit Rate
This setting indicates bits/sec in units of kb/sec. For example, a value of 1500 is
1.5Mbits/sec.
Key Frame Distance
This value (in milliseconds) sets the maximum distance between key frames. The
encoder may output key frames sooner than this interval (if it detects a scene
change, for example).
Buffer Size
The buffer size value (in milliseconds) sets the encoder buffer size. Two seconds
(2000 milliseconds) is a typical buffer size.
Interlace Encoding
Check this box if you want to perform interlaced based encoding. If not checked,
the encoder will process video as progressive. Interlace encoding is only available
for VC-1 Advanced Profile. VC-1 Main and Simple profiles do not support interlace
encoding. If you are not encoding as interlaced, then you should either choose to
de-interlace your video (for video content) or perform an inverse telecine (IVT) on
your video (for film based content). The Pre-Processing page is where these two
options are set.
ASF Streaming Mode
Choose between Broadcast and Web for the ASF streaming mode. If Web is
chosen, specify a value for Quality. The quality setting, from 0 to 100, is a tradeoff
between smoother video (Quality 0) and better quality video (Quality 100). A good
typical quality value is 80.
When Broadcast streaming is selected with Main Profile, the encoder emphasizes
smoother video over quality video, equivalent to Web streaming mode with Quality
0. In this mode, the encoder may drop (not encode) frames as needed. When
Broadcast streaming is selected with Advanced Profile, the encoder can encode
skip frames for frames the Main Profile encoder would drop. This allows for the
preservation of critical metadata, such as captioning and timecode.
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