Microsoft KB Archive/111974

Microsoft Knowledge Base

Video: Vertical Sync Error When Capturing Audio and Video

Last reviewed: November 22, 1994
Article ID: Q111974

The information in this article applies to:

• Microsoft Video for Windows, versions 1.0, 1.1

SUMMARY

The VidCap utility that is provided with Video for Windows may give you the following error message when you attempt to capture video and audio:

   No frames were captured; confirm that vertical sync
   interrupts are configured and enabled.

MORE INFORMATION

All existing capture drivers use the Vertical Sync (VSYNC) as an interrupt to determine when to capture a frame. (The Intel ActionMedia II card uses an interrupt on the i750 to trigger frame processing, so the motherboard does not see the interrupt directly; however, the outcome is basically the same). Therefore, if there is no VSYNC, no frames will be captured.

Below is a potential list of problems that can generate the Vertical Sync error:

1. A jumper on the capture card may need to be installed to enable interrupts.
2. The software interrupt setting (set by choosing Drivers from Control Panel and choosing Setup) does not match the hardware jumper setting.
3. The selected interrupt may be in use by another device.
4. The capture card may have difficulty generating internal video timing signals (VSYNC) if no video source is connected.
5. The driver is out of date.
6. The hardware is defective.

KBCategory: kbmm kbdisplay kbprb kberrmsg KBSubcategory: vfw Additional reference words: 1.0 1.1 video THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY. Last reviewed: November 22, 1994 ©1997 Microsoft Corporation. All rights reserved. Legal Notices.