NI 5431 Composite Video Generator
Intermediate Create Composite Signal from BMP Image

This intermediate VI example is equivalent to Basic Create Composite Signal from the BMP Image, except that you can modify an arbitrary number of video attributes and insert digital synchronization patterns into your video data.

You can access this VI example in the LabVIEW palette by selecting Functions»Video Generation»Generator Examples»Intermediate create composite signal from BMP image.

Video attributes, which are parameters of your video signal, can be modified. In this VI, the Attribute list control is an array of clusters. Each element in the array corresponds to an attribute that can be modified. The clusters contain two simple controls on the front panel of the VI.

To modify the video attributes, follow these steps:

1. After selecting the example VI icon in the LabVIEW palette, click the LabVIEW diagram to place the icon there. Double-click the VI example icon to open it in LabVIEW.

Note  You can also access this VI from the installation drive by double-clicking the Composite Video Generator Examples.llb library. The File Dialog box appears. Click the Intermediate create composite signal from BMP image.vi, then click OK. The VI opens in LabVIEW.

2. Make sure theDevice ID control value matches the device number assigned in MAX during device configuration. Refer to the NI Signal Sources Getting Started Guide for information about device configuration.
3. On the front panel of the VI, using the LabVIEW palette operator tool and the up and down arrows on the Video type control, select the appropriate video format.
4. In the Attribute list data array control, click any one of the three Attribute controls that you want to modify, and choose the attribute by name. If you need to change more than three attributes, scroll down the array using the Index control on the left side of the Attribute list data array control.
5. In the Attribute list data array control, input the attribute values in the Value control. This example VI shows three default cases:
   • Synchronization amplitude (Sync amplitude (IRE)) set to the value 40 IRE (the default for PAL/SECAM = 43; the default for NTSC = 40)
   • Synchronization pulses duration (Sync duration (us)) set to the value 4.7 µs (the default value for all video standards)
   • Contrast factor (Contrast) set to the value 1.00 (the default value for all video standards)

   When you select enable on the Digital sync control, the VI inserts four digital synchronization signals in order-composite sync (Csync), horizontal sync (Hsync), vertical sync (Vsync), and field identification (Field ID)-into the four least significant bits of your video data. The video data is created and/or saved as 16-bit data, but only 12 of these bits are used to generate the analog video signal. When you create the four digital synchronization signals, it does not affect your analog signal quality.

   The four signals can be accessed as standard TTL signals on the digital output connector of your NI 5431.

Note  To generate these signals, enable both the computation and the digital output of your NI 5431.

6. Run the VI. An Input BMP file ? dialog box appears, prompting you to select a bitmap image file.
7. Double-click the BMPs shortcut to browse for the appropriate bitmap image file according to the video format you chose in step 3.
8. Double-click the appropriate subdirectory, then double-click a .bmp file.

Note  To avoid being prompted for the file, type the bitmap image file path in the Input BMP file path control before running the VI.

After a few seconds, a video signal with the modified attributes should start generating.