JVC VN-V25U VN-V26U ユーザーズマニュアル

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B
For specifying the rate control mode and target file size for JPEG.
When 
AVFS1B to AVFS7B is selected, the quantization table during JPEG 
encoding will be maintained and the file size will increase/decrease 
according to the input signals. Stipulated values will be displayed in the Size 
field. When recording JPEG data to a recorder with a limited storage 
capacity, note that the maximum recording time may vary as the file size 
fluctuates under this setting.
When 
AAFSB is selected, encoding is performed such that the target file size 
is the average size of multiple JPEG images. You can enter the target size in 
the Size field.
[Quality field set values: VFS1 - VFS7, AFS]
[Size field setting range for VGA: 10kB - 100kB (only when AFS is 
specified)]
[Size field setting range for QVGA: 3kB - 33kB (only when AFS is 
specified)]
C
For setting the MPEG4 encoding bit rate.
[Setting range: 64 kbps - 8000 kbps]
D
For selecting whether to set the MPEG4 rate control mode to CBR (Constant 
Bit Rate) or VBR (Variable Bit Rate).
: Encoding is performed at a fixed bit rate regardless of the condition 
of the input video signals. Enables easy forecast of the bit rate.
: Changes the bit rate according to the condition of the input video 
signals. Picture quality is stable, but forecast of the bit rate is 
difficult.
E
For setting the MPEG4 frame rate.
[Setting range: 1 fps - 30 fps]
F
For setting the I-frame interval. MPEG4 starts encoding from the I-frame. 
Shortening the interval stabilizes the picture quality even when there are 
rapid changes in the video image. However, the picture quality for images 
with little change will deteriorate. In addition, when multicast packet loss 
occurs, the time interval required to restore the image is shorter.
[Set values: 30, 60, 90, 120, 150]
G
For selecting whether to assign priority to the frame rate or picture quality 
during MPEG4 encoding.
: Assigns priority to frame rate. Select this setting to enable 
smooth monitoring of motion images.
: Assigns priority to picture quality.
VN-V25U_26U_EN.book  Page 45  Friday, January 18, 2008  2:56 PM