Windows Camera Video glitch appears After Record is stopped


On a Windows 8 computer, consider the following scenario:

1.       The computer has a USB audio device and USB Camera device. Both of them are from one USB composite device.

2.       In the built-in Camera application, Start and Stop Record repeatedly at short internals like 3-5 seconds.

3.       Intermittently, after a Stop action, Camera Preview video shows some tearing/glitch.

More Information

The issue happens because when Camera stops recording, it cancels audio and video capture I/O calls on underlying USB devices. For Audio I/O, USBAUDIO aborts those ongoing recorded audio I/O transfers. Normally, USBAUDIO driver will not abort/cancel a transfer until a transfer’s frame is processed completely, so the cancel could take time and block video process shortly. As a result, we see video glitch after stop recording.

This is by design of how Camera and USBAUDIO driver handles audio I/O.

ID d'article : 2847615 - Dernière mise à jour : 21 mai 2013 - Révision : 1