NCast PR-HD - Manual (Page 35)

NCast Presentation Recorder Reference Manual
5.6.2. Frame-rate
The video frame-rate represents the number of frame (visual image) grabs per second the system will
attempt to achieve. The range of this setting is 1-30 frames per second. For NTSC video encoding a full 30
frames/second is achieved.
At HD720 resolutions, dropping the frame rate to lower values (5 frames/second, for example) allows a
broader range of lower performance PCs to successfully decode the received presentations. It also reduces
the required network bandwidth. At these rates, however, cursor movements look somewhat jerky and
embedded video clips do not play well. One tradeoff might be to send a lower resolution (SVGA, 800x600)
image at a higher frame-rate.
At settings of 10 frames/second cursor movement and drop-down menus look natural, but video still suffers.
At 15 frames/second video playback starts to become acceptable, but high-motion imagery has detectable
artifacts. At the higher rates of 20 frames/second and up both the video and graphics performance look
natural. These high frame-rates deliver smooth animation and video playback that most viewers will find
acceptable.
5.6.3. Bit Rate
The video bit-rate in kilobits-per-second defines the maximum bit-rate that the encoders may utilize in
creating the media stream. For static images the bit-rate may decrease from this peak level.
The following table lists the absolute minimum recommended bit-rates for high frame-rates:
NCast Corporation Revision 2.2
Page 35