Method and device for decoding a scalable video stream

A device for decoding a scalable video stream, in which the images may be decoded by groups of several images, each group being constituted by at least three levels of image temporal hierarchy, the images of the lowest level having the lowest time frequency and the images of each following level having a time frequency at least twice that of the images of the preceding level, a temporal hierarchy level being formed by at least one predetermined time interval, a time interval separating two images in that temporal hierarchy level, comprising:

• a calculation unit configured to execute stored instructions;
• and
• a storage unit configured to store executable instructions for execution by the calculation unit;
• wherein the instructions stored by the storage unit cause the calculation unit to execute (a) an obtaining step, during the decoding of at least one temporal hierarchy level, of obtaining at least one item of information representing the motion in the images of the video stream over at least one time interval of said temporal hierarchy, wherein with respect to the item of information representing the motion of the images of the video stream, a parameter is calculated from the content of the images of the video stream over said one time interval, and (b) an ordering step to define an order in the decoding of the images of each group of images as a function of said information obtained.