PRB: Every other line is black in still captured from videoconferencing output

Document ID: Q101021

This article applies to the following:
Product(s): Second Opinion
Hardware: Tandberg video conferencing unit or other non-interlaced video source, Integral FlashPoint 128 or FlashBus video capture card.
Last Revised On: April 24, 2001

Summary

When capturing images from non-interlaced video sources, such as the video output from a Tandberg videoconferencing system, captured frames appear with alternating black lines. Windows and menus that are opened on top of the video preview window also leave behind a ghosted image of themselves when they are closed. 

You can confirm the problem by capturing a still frame from the video source, saving it, then opening the saved document and zooming it. You will see that every other line is black.

Discussion

Tandberg videoconferencing system and some other video sources output a non-interlaced video signal. The Integral FlashPoint and FlashBus video capture cards are designed to work with NTSC and PAL video formats, which are normally interlaced. To resolve this problem, you must change the video output of the device to interlaced or use a different video output.

See Also

Q101015 - PRB: Black lines in video capture using Integral Technologies FlashBus