Starting today, WMV playback on several software programs is incorrect. The bottom half of the WMV appears correctly, but the top half is black. This happens whether the WMV is scaled or not, and whether it is stretched or not.
The only thing different is Windows Updates were applied yesterday (9 Jul 2013).
Edit:
Playback using Windows Media Player seems unaffected. The bug occurs in the aforementioned software as well as, in my experience, Datastead TVideoGrabber 8.5.2.2.
Uninstalling Windows Update KB2803821 fixes the issue.
This update addresses a security vulnerability in WMV playback, but it appears in software such as Camtasia Studio, MoviePlusX6, and possibly others, this update is causing the half-black playback issue.
The flaw seems to be limited to decoding WMVs in directshow and using a sample grabber to readback the frames. The data received by the sample grabber in the graph is simply half blank and nothing else sticks out (media types, size and flags are all correct). My software can be configured to use the vmr9 filter with an allocator presenter to grab frames and that technique still works perfectly fine with the update.
it appears to work fine when configuring the samplegrabber by passing a AM_MEDIA_TYPE with subtype = MEDIASUBTYPE_RGB24 to ISampleGrabber.SetMediaType
a temporary workaround is to uninstall KB2834902 KB2834903 KB2834904 KB2834905 KB2845142 KB2803821 (depending on the windows media player version)
