User Manual

DTC COMMUNICATIONS, INC.
14
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
only), PAL, NTSC, NTSC no pedestal, S-Video PAL, S-Video NTSC, S-Video
NTSC no pedestal.
MPEG Mode
MPEG mode selects the MPEG compression being used, options are: MPEG2
or MPEG4. MPEG4 mode has to be used when in the 1.25 MHz bandwidth
mode since this mode uses a nonstandard frame rate that is not supported
by MPEG2.
MPEG4 Encoding Mode
MPEG4 encoding mode selects the characteristics of the MPEG4 compres-
sion. Options are: low delay interlaced, standard delay interlaced, low delay progres-
sive, standard delay progressive, and SIF. 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 scan-
ning. SIF is a bandwidth-conserving camera scan mode that cuts resolution in half
in both the horizontal and vertical.
MPEG4 Frame Rate
MPEG4 frame rate selects the frame rate used in the MPEG4 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.
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. The video bit rate will also decrease as other
service options are activated such as audio and data channels. As a rule video
quality and latency improve as the bit rate is increased.
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 resolution of the camera in use.
Options are: 352, 480, 528, 704 pixels.