Digital Media Services

Media Encoding & Format Conversion

File Format Conversion &  Re-Encoding Services

Digital Media Services assists faculty and staff with file format conversion and encoding. We can convert video, audio and document formats for use on Sakai, the web, iTunes U, PowerPoint, Keynote, Word, CD, DVD and other digital distribution depending on your needs.  We have a VHS deck, DVCAM and HDV, and a special VHS deck that converts foreign formats like PAL or SECAM.

What is video encoding?

When you take a digital picture or record digital video you are, in essence, using a hardware encoding device. A digital still camera converts the analog world (whatever the camera is aimed at) into digital information which is encoded as a J-PEG, TIFF or RAW camera data.

The same is true when you are shooting digital video. Often, we record digital video on to magnetic tape using the miniDV format or simply DV (digital video). We then can say that we have used the camera to encode the DV format onto the tape.

The above form of encoding is automatic. However, what if we would like to use that digital video in some other context? On YouTube or  iTunes U? We then need to translate our DV information to the appropriate format for these destinations. Enter encoding, or more precisely transcoding. Transcoding is short for translation/encoding. It simply means converting information from one form to another. For example, after we have recorded information on a miniDV camcorder, we can download (capture or digitize) this information to a computer. In doing so, we create a computer file. Depending upon how this is accomplished we will have a working file that we can edit or transcode. To be more precise, we will consider specific destinations and the requirements of those destinations. Transcoding generally refers to the process of file format conversion, QuickTime to Windows Media for example.

The process of re-encoding video in the same format but at a lower bit rate is called transrating. A classic example is the QuickTime model where multiple .mov files are transrated for different audiences. (e.g. low bandwidth, high bandwidth)

Video Formats
You may be familiar with terms like QuickTime, Windows Media, Flash, and the like. These are families of video (and audio) formats. There are advantages and disadvantages to each format. Regardless, the decision to use a particular format is generally based on the set of tools you have at your disposal and the platform(s) you intend to target (Windows or Mac).

When choosing a file format for export consider the following:

  • User Platform (Windows vs. Mac)
  • User Bandwidth (dial-up, DSL, Cable Modem, Campus Backbone)
  • Media Player Access (QuickTime Player, Windows Media Player, Flash Player)
  • Video & Audio vs. Audio Only