ROHS SV-HVR2800 series User Manual page 20

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960H: About the same resolution as a DVD (960 x 480 for NTSC, or 960 x
576 for PAL).
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D1: About the same resolution as a DVD (704 x 480 for NTSC, or 704 x 576
for PAL). This is the default resolution for all channels, and we suggest
leaving this setting well alone.
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HD1: Literally, half of D1 (352 x 480 NTSC / 352 x 576 PAL) and about the
quality of a typical YouTube video. This won't save HDD space - the bitrate is
the important setting for determining how much space your recordings
require on the HDD.
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CIF: 1/4 of D1 (352 x 240 NTSC / 352 x 288 PAL), and about the same
resolution as a low-quality webcam. We can't think of a good reason to use
CIF as your resolution setting, unless you've some really cunning plan we
didn't think of. It won't save any HDD space - for that, you'll need to change
the bitrate.
Frame Rate: The number of frames per second (fps) that the DVR will record. The
default (and maximum) is referred to as "real-time" and is 30fps (NTSC) or 25fps (PAL).
Reducing the number of frames per second will either save hard drive space or improve
the data-rate per frame (depending how you set the bit-rate - see the next point).
Remember that your FPS count is the same as saying "take X photograph per second"
(where X is your FPS setting). If maintaining image clarity while reducing HDD
consumption is your priority, it makes sense to lower the frame rate. As with all settings
on this screen, some experimentation is encouraged to find the settings which will work
best for you!
Max. BitRate(Kbps): The actual amount of data that the DVR will use to record video.
The main-stream uses a variable bitrate to record video – the more movement occurs in
the video, the higher the bitrate will have to be. When there's little movement in view,
the DVR will automatically reduce the bitrate to conserve HDD space.
If the amount of movement in a recording would require a higher bitrate to accurately
record than you've selected as the maximum, the DVR will attempt to preserve as much
of the quality as possible by applying compression to the image. This compression will
take the form of irregular, fuzzy blocks over segments or all of the image. If you
encounter this, it indicates that you might need to increase the overall bitrate.
If you've set a high bitrate but a low frame rate, the DVR will still use all the data it can,
SV-HVR2800 Series DVR User Manual
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