Consider the following scenario:
You use an application to edit a .wmv file in Windows 8.1, Windows Server 2012 R2, Windows 8, or Windows Server 2012.
You import the source video and set a specific time for the first frame of the thumbnail.
You encode the video to generate a thumbnail.
When the encoded resolution is smaller than the displayed resolution in this scenario, the thumbnail in the output folder displays a black picture.
Note This issue occurs when the application uses a DirectShow decoder filter to seek the source video.
To resolve this issue, install update rollup 2975719 or update rollup 2975331. For more information about how to obtain these update rollup packages, click the following article number to view the article in the Microsoft Knowledge Base:
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
For more information about software update terminology, click the following article number to view the article in the Microsoft Knowledge Base:
824684 Description of the standard terminology that is used to describe Microsoft software updates