JVC VN-V25U User Manual

Page 41

JPEG

Quality/Size

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)]

MPEG4

Bitrate

For setting the MPEG4 encoding bit rate.
The rate control mode is applicable to both CBR and VBR.
[Setting range: 64 kbps - 8000 kbps]

Bitrate Control

For selecting whether to set the MPEG4 rate control mode to CBR (Constant
Bit Rate) or VBR (Variable Bit Rate).

CBR

: Encoding is performed at a fixed bit rate regardless of the condition

of the input video signals. Enables easy forecast of the bit rate.

VBR

: 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.

Frame Rate

For setting the MPEG4 frame rate.
[Setting range: 1 fps - 30 fps]

I Frame Interval

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]

Priority

For selecting whether to assign priority to the frame rate or picture quality
during MPEG4 encoding.

FPS

: Assigns priority to frame rate. Select this setting to enable

smooth monitoring of motion images.

Quality

: Assigns priority to picture quality.

VN-V25U_EN.book Page 41 Friday, November 2, 2007 11:26 PM