User's Manual

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PROGRAMMING
Video Input
Video input selects the video format going into the MPEG video compressor. Options are: OFF (no video input
typically used when link is used for data or audio only), PAL, NTSC, NTSC no pedestal, SDI PAL, SDI NTSC.
Horizontal Resolution
Horizontal resolution determines the maximum number of horizontal Pixels that can be sampled by the video
encoder. For optimal performance this setting should be set to the first value that exceeds the horizontal resolu-
tion of the camera in use. Options are: 352, 480, 528, 720 pixels.
Video Sharpness
Video sharpness is a filter that may be switched in to smooth out blockiness in the video.
MPEG Mode
MPEG mode selects the MPEG compression being used, options are: MPEG2 or MPEG-4 (Part 2 ASP). MPEG-4
mode has to be used when in the 1.25 MHz bandwidth mode since this mode can use a nonstandard frame rate
that is not supported by MPEG-2. MPEG-4 is not available in DVB-T mode.
Video Profile
Selects the chroma format; 4:2:0 or 4:2:2. Note that 4:2:2 is not useful in narrowband modulations due to the
degree of compression used.
GOP Length
Selects the Group Of Pictures (GOP) size; min. 0, max. 100. Note that system latency increases with GOP length,
while reducing the video bit rate. The specified latency of 54 ms for this product applies only for a GOP length of
0. A GOP length of 15 for NTSC video (12 for PAL) will result in a latency of approximately 1/2 a second.
Video Bitrate (status only)
Video bitrate is a status window that will display the video transport data rate. This varies with bandwidth,
modulation, FEC rate and guard interval. The rate will increase with bandwidth and higher levels of modulation,
it will go down as the FEC rate and guard interval are increased and other services are active such as data and
audio. The video bit rate will also decrease as other service options are activated such as audio and data chan-
nels. As a rule video quality and latency improve as the bit rate is increased.
MPEG-4 Encoding Mode
MPEG4 encoding mode selects the characteristics of the MPEG4 compression. Options are: low delay interlaced,
standard delay interlaced, low delay progressive, and standard delay progressive. Interlaced scanning is what is
used in conventional over-the-air video. Progressive scan is available on some cameras and involves scanning an
entire frame in one pass rather than two in interlaced scanning.
MPEG-4 Frame Rate
MPEG-4 frame rate selects the frame rate used in the MPEG-4 mode, full frame rate is 30 fps for NTSC and 25
fps for PAL a frame rate of 1/2 or less has to be used in 1.25 MHz bandwidth mode. Options are: Full, 1/2, 1/4,
1/8. or 1/24.