Video Test Reference Architecture: Digital Video Analysis and Stream to Disk
PrintOverview
The Example programs demonstrates a simple digital video pixel test with the data being streamed to disk as it is tested. This works well due to the high speed of the PXIe bus.
Downloads
Filename: digvid_pixlt_stream.vi
Requirements: View
Digital Video Pixel Test and Stream to Disk
There are two main operations in the code. One in each while loop.
The stream to disk loop is the same as in all of our other data acquisition and streaming examples. The key being to use the win32 file API library. This turns off windows caching. This allows for the data to be streamed into the RAID array at a much higher rate than using the traditional LabVIEW file I/O functions.
The upper acquisition loop is written to acquire the digital data. Then using the LabVIEW Vision Module image acquisition VIs displays the image and performs a pixel test on it. Currently the test is a comparison of the current frame with an image from file. This test image could also be acquired from the board before hand, or from another device with minor modification to the code.
In this example the analysis being done is simple enough that the data acquisition is being called often enough to avoid buffering problems. If the image analysis become more complicated it would be better split this loop into two parallel loops one for data acquisition. The other for image processing and analysis. This would take advantage of LabVIEW's inherent parrallelism.
Requirements
Filename: digvid_pixlt_stream.vi
Software Requirements
Application Software: LabVIEW Professional Development System 8.5.1
Toolkits and Add-Ons: Vision Development Module 8.5
Language(s): LabVIEW
Hardware Requirements
Hardware Group: High-Speed Digital I/O
Hardware Model: PXIe-6537
Driver: NI-DAQmx 8.7.1
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This example program (this "program") was developed by a National Instruments ("NI") Applications Engineer. Although technical support of this program may be made available by National Instruments, this program may not be completely tested and verified, and NI does not guarantee its quality in any way or that NI will continue to support this program with each new revision of related products and drivers. THIS EXAMPLE PROGRAM IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND AND SUBJECT TO CERTAIN RESTRICTIONS AS MORE SPECIFICALLY SET FORTH IN NI.COM'S TERMS OF USE (http://ni.com/legal/termsofuse/unitedstates/us/).