Rather than simply comparing two successive frames, this technique notices moving objects in a frame and predicts where they will be in the next frame. Then only the difference between the prediction and the actual location need be stored. Because temporal compression makes one frame depend on another, it makes editing of temporally compressed video difficult or impossible. Editing may require that video be decompressed and recompressed, often creating significant compression artifacts in the process. For this reason, temporal compression is best suited for final delivery.
Temporal compression can yield significant data reduction.
However, its effectiveness is reduced by common cinematic techniques such as pans, slow zooms or dollies, and the current rage, handheld camera work. Like spatial compression, it is sensitive to noise and grain. Choosing a Codec With all these differences, choosing the correct codec can be a difficult task. You need to choose the level of compression you need to meet your data rate limits, the level of quality you want and whether or not you need real-time compression. Next time we will sample some of the more popular codecs and look at their specific characteristics.