VideoThumbnails

Using Media Foundation and GDI+ to create a thumbnail of any point of a video

This is a modified version of -Franky-'s VBC_MF_GDI+_VideoThumbnail project. He's a big fan of using DispCallFunc over typelib-defined interfaces, and I'm the opposite. This project shows converting the DispCallFunc calls into use of WinDevLib interfaces, and letting the APIs take over to easily also add 64bit compatibility. I've also made the thumbnail size selectable, displayed the video as Form-sized rather than thumbnail sized, and translated the string (with Google Translate, so apologies if inaccurate). Also simplified the propvariant use and time calculations by using tB's LongLong instead of Currency.

The project itself is great; it shows how to open a video with the Media Foundation interfaces, and use a horizontal scrollbar to advance it little by little, then grab a thumbnail (or full sized frame grab) of the current point in time, rather than just the first frame like normal thumbnails. GDI+ is then used to save it to a JPG.

Overall, a good intro to Media Foundation.

(Note: There's currently a bug in tB that prevents -Franky-'s original, unmodified version from working in tB. It does work in VB6).

Example:

            If Invoke(pIMFAttributes, SetUINT32, VarPtr(Str2Guid( _
                MF_SOURCE_READER_ENABLE_VIDEO_PROCESSING)), _
                API_True) = S_OK Then

easily becomes pIMFAttributes.SetUINT32 MF_SOURCE_READER_ENABLE_VIDEO_PROCESSING, API_True which I think is far more readable.

Thanks to -Franky- for his excellent work on the original project and for letting me post this update!