.wmv Seek by Frame

[WJD]

I am trying to grab frames (ISampleGrabber) from various formats, one of which is Windows Media Video (.wmv). As this uses variable bit rate encoding, then it is not possible to set the time format (IMediaSeeking->SetTimeFormat()) to TIME_FORMAT_FRAME.

I have been looking at the Directshow Editing Services (DES) as a possible solution, but it does say that IMediaDet->get_FrameRate() does not work with ASF files (of which .wmv is one).

Anyone have any ideas, or similar experiences?????

 

[WJD]

I have found the answer to my own question, as so invariably happens.

By using the Media 9 SDK, asf format files (in this case .wmv) can be re-indexed - therefore allowing the likes of DirectShow SampleGrabber to set frame accurate times. This does slightly increase the size of the file, as all the indexing data is added, but it does not alter the movie data.