Imagine NEO DVR-3901, Installation And Operation Manual

Page: 77 / 111

DVR-3901 Installation and Operation Manual 61
Chapter 5: Functions and Controls
phase on the AES output. Note that the DARS must be locked to the
reference video, which could be a reference video input or an SDI input,
depending on the RefVid setting. Otherwise, the
DARSLocked status
will show “Not locked” and the AES output will be in the wrong
format.
Audio Video Delay
Use PlyAVDelay to adjust the audio delay in the range of [-1 to +1]
video frame if there is a need to compensate for lip sync errors present
downstream during playback.
Time Code
The DVR-3901 supports LTC input and output. For video standard 525,
use
DropMode to select drop frame or non-drop frame for time code
generation. The use of time code differs in different operation modes.
See
“Online Operation Modes” on page 65 for details.
Video Compression
The DVR-3901 uses the ndustry standard M-JPEG (baseline) as its
video compression method. You can find out the compression ratio
from the
CompRatio parameter. It can range roughly from 4:1 to 10:1.
For the D1-525 system, the video lines 17 to 262 of each field are
compressed using M-JPEG and stored; for D1-625, the lines are 23 to
310. Closed captions and other VBI lines are retained with the
compressed video.
You can adjust the compressed video bit rate at any time using the
VidBitRate parameter, which ranges from 17 Mbps to 42 Mbps. If the
bit rate is changed during recording, the change takes effect in the next
recording. During playback, video is decompressed seamlessly from
clip to clip with various bit rate settings.