Phytec pciGrabber4x4, Руководство по оборудованию

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Programming Manual
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PHYTEC Messtechnik GmbH 2008 L-720e_0
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Dropping fields/frames in a video Signal
void TemporalDect(WORD nDevNo,
WORD nDecField,
WORD nFldAlign,
WORD nDecRat);
nDecField: 0 = drop frame(s)
1 = drop field(s)
nAlign: 0 = odd field will be dropped first
1 = even field will be dropped first
nDecRat: number of the fields / frames to be dropped out of 50 (PAL)
or 60 (NTSC)
The pciGrabber-4x4 allows for continuous digitization to select the
number of images digitized per second. Default are 50 or 60 (NTSC)
digitized images per second (video-standard).
With the help of this function it can be determined how many images
of the 50 or 60 images are
dropped during digitization.
The other two parameters give instructions of the kind of omissions:
The parameter
nAlign aligns the start of the decimation with an even
or odd field.
The parameter
TDecField defines whether decimation is by fields or
frames.
Example (PAL/SECAM):
nD e cField =0, nDecRate =2
The reduction refers to frames. From 50 images two are omitted.
The images 1-24 are produced as usually, then an image is omitted.
Images 26-49 are produced and then again one image is omitted.
nDecField
=1,
nDecRate
=25
In this case 25 fields are omitted of 50. The result will be, that each
second image will be produced, so always the same field type will
be omitted. Which field will be omitted first, depends on nAlign.