First was that both Microsoft and Real were loudly proclaiming that their codecs were vastly superior to MPEG-1 and 2 at any given data rate. Second was that no one cared about 320x240 video anymore, at least at the 200KB/sec data rate where MPEG-1 was most comfortable. Most folks encoding for the desktop are thinking 640x480 or higher.
I also started wondering where MPEG-4 stood in terms of comparative quality with the troika of streaming heavyweights, Real, Microsoft, and Sorenson. By this time it was clear that I needed to take a good hard look at the respective quality offered by these codecs, and when it makes sense to consider using them.
Obviously there are some rules that we absolutely have to live by. For example, any video produced for DVD or SuperVideoCD must be MPEG-2, while video for VideoCD must be MPEG-1. In addition, if you're creating video for posting to a Web site or intranet, your codec selection may also be limited. For example, if your corporation uses Microsoft's Streaming Media Servers, you're excluded from selecting codecs from Real or Sorenson.
However, this leaves a vast array of potential digital video uses. For example, if you're creating video for integration into a PowerPoint presentation, what compression technology should you use? How about if you're creating a training video you want to send via CD-ROM to your branch offices? Beyond these you'll find a range of more traditional streaming functions like multicasting over a corporate network, or streaming over broadband connections.
Ultimately, we identified five data rates and video configurations to use for comparison purposes; these are shown in Table 1 [see page 4]. We then produced the files using encoding tools from each vendor.