Video transmission over a heterogeneous network suffers a condition that it has required to satisfy many different constraints because of the variety limitations of client equipments and preferences of each user. In this condition, the video stream should have the flexibility feature. Scalable video coding is one of the solutions to serve this condition. In order to provide a better flexibility on scalability feature, more than one combination with video spatial size, temporal frame rate, and visual quality resolution are utilized. It is difficult to adapt the appropriate relation between the various combinations and user preference. In this paper, we propose an objectivity-derived algorithm with soft decision scheme for serving scalable video adaptation. This method can be used in existing equipments without much computation overhead. This useful and simple solution is not only a practical way in scalable video adaptation design, but also an efficient scheme of achieving subjective satisfaction.