VBI Scope is a Direct Show filter which displays two lines of raw VBI sample data
from a WDM capture driver in realtime. The controls are very similar to a
traditional oscilloscope, and a typical display looks like:
The display above shows field 2 of line 20 on the upper display (a colorbar for video system calibration), while the bottom display shows closed caption data from
field1 of line 21.
The "VBI Line" control lets you select which VBI line to display. "F1"
and "F2" let you select field 1, field 2, or both fields.
Under "Timebase", you can control the zoom factor expressed as microseconds
per division, and the scroll bar along the bottom changes the starting point of
the display in microseconds. In the display above, roughly 53 microseconds
of VBI data has been captured per line, and the display shows 0 to 60 microseconds
horizontally.
Under "Format":
"BPL": is bytes of raw sampled data per line
"Str": is stride per line expressed in bytes
"28.636363" is the frequency of the sampled data expressed in MHz.
"NTSC M": shows the video standard in use
Download
Binary:
VBIScope.ax
Source:
VBIScope.zip
Installation
Copy vbiscope.ax
to your system directory
"regsvr32 vbiscope.ax"
Usage
In graphedt, insert "VBI Scope".
Here is a sample graph showing how to
hook it up.
DDK References
- KS_VBIINFOHEADER
- KS_DATAFORMAT_VBIINFOHEADER
- KS_DATARANGE_VIDEO_VBI
- KS_VBI_FRAME_INFO