Extra Information

Chapter 8: AVI Capture Options and Settings
56 ViewCast
Tab Description
Input Allows the user to set the input sources to use (Figure 96).
Figure 96. AVI Input Sources
Video Settings
• Control the capture properties for the selected video device (Figure 97).
• The Input field lists all input connectors available for capture device.
• Signal field lists various video standards the capture device supports.
• You can adjust capture properties such as proportion, video size, and
width/height using the provided fields.
• Use sliding bars to adjust additional capture properties of brightness,
contrast, saturation, and hue individually for each input.
• When making adjustments, verify adjustments apply to chosen input.
• Otherwise, your adjustments apply to all the input sources listed.
• These capture properties remain available regardless of whether the
encoder starts or remains idle.
Figure 97. AVI Video Settings
Gamma Corrections
• Adjust the gamma of the incoming video.
• Gamma refers to the response curve of video cameras/CRTs.
• When you capture video with a camera, the camera response remains
deliberately nonlinear – it boosts low lumen values and compresses high
lumen values – based on two reasons:
(1) It increases the effective bandwidth in low lumen ranges, where you
need it, at the expense of high lumen ranges, where you need it less.
(2) It matches the response characteristics of TV sets and monitors.
• The calibration specified in video standards matches the requirements
of cameras and TV sets in broadcast use.
— This usually, however, does not match the needs of computer-based
applications or the response curves of computer monitors.
— Therefore, you often need a correction inverse to the original bias
and you may want to tune for the characteristics of a particular