An example apparatus is caused to receive a video sequence of a plurality of frames, and activate one of a plurality of available decoding processes based on a comparison of a size of the frames to a predefined threshold. The apparatus is also caused to select some but not all of the frames of the video sequence as potential key frames of the video sequence. The selected frames are located at or close to predefined positions along a length of the video sequence. The apparatus is also caused to decode the potential key frames according to the activated decoding process, and cause output of at least some of the potential key frames as key frames of the video sequence. The apparatus may be caused to discard from the potential key frames, one or more plain frames and/or a frame identified as being similar to other potential key frames.