This section will guide you through the steps of compressing video using the basic settings. You will also be introduced to some of the concepts used in modern codecs (such as DivX) so that you are better equipped to configure those to your needs. We will also touch on the issues of interoperability we mentioned earlier, but this time on a lower and more specific level.
The public interface that the operating system exposes to applications like VirtualDub is Video for Windows. This offers a simplistic way of defining the codec options before you encode a video. That is, it allows you to specify:
A quality factor (0 to 100)
The data rate in kilobytes/sec
The maximum interval that the stream will not contain a key-frame
There are two important points to note here:
1. The data rate is specified in kilobytes instead of kilobits; kilobits are a measure commonly used in the world of lossy compression.
2. The key-frame interval is very important as it will define how precisely you will...