Why You Can’t Skip Around in Some WMV Files [Windows Media]

Here another one from the RTFM files:

There are a few different reasons why you wouldn’t be able to skip around, fast forward, or rewind in WMV (windows media video) files. One reason has to do with what codec (remember, a file’s codec and container can be different) the file was encoded with, and another could be a problem with the player. Another reason is key frames, or lack thereof.

My problem was I thought I was being smart… I was recording a live event with audio and video last week using Windows Media Encoder (WME). In the options in WME, I turned off the “Index File” option for the archived file (Windows Media Encoder has the ability to broadcast an event while arching that broadcast to file). The index file option inserts key frames every X number of seconds (8 by default), so I thought that I wouldn’t need key frames in the archived file; it would only increase the size of the file, right?

Wrong.

Without index frames, the file is treated like a live stream and you’re unable to skip, fast forward, or rewind.

So… you might want to leave that “Index File” option on in Windows Media Encoder.

Oh and before someone says something: I’m only talking about WMV files, and only one obscure reason why. If you’re trying to play something other than WMV in Windows Media Player, you might be able to blame not having the correct codec.