Head-mountable display system

A video encoding method comprising:

• encoding, at a video server, video data representing panoramic video content in which the panoramic video content has a greater field of view than a displayable region at a client device, the encoding step comprising encoding spatial regions within the video content at different respective encoding qualities in dependence upon track data indicating, for temporal positions with respect to the panoramic video content, a preferred viewing region within the panoramic video content at those temporal positions, so that the preferred viewing region is encoded at a higher encoding quality than another region of the panoramic video content:,
• detecting an orientation of a head mounted display (HMD);
• and
• generating images for display by a display arrangement in dependence upon the detected current orientation, from panoramic video content sent to the HMD by the video server;
• and
• selecting, amongst a set of two or more representations of at least some of the panoramic video content, a representation according to a comparison of the detected orientation and metadata associated with the two or more representations.

A non-transitory, computer readable storage medium containing a computer program which, when executed by a computer, causes the computer to carry out actions, comprising:

• encoding, at a video server, video data representing panoramic video content in which the panoramic video content has a greater field of view than a displayable region at a client device, the encoding step comprising encoding spatial regions within the video content at different respective encoding qualities in dependence upon track data indicating, for temporal positions with respect to the panoramic video content, a preferred viewing region within the panoramic video content at those temporal positions, so that the preferred viewing region is encoded at a higher encoding quality than another region of the panoramic video content;
• detecting an orientation of a head mountable display (HMD);
• generating images for display by a display arrangement in dependence upon the detected current orientation, from panoramic video content sent to the HMD by the video server;
• and
• selecting, amongst a set of two or more representations of the panoramic video content, according to a comparison of the detected orientation and metadata associated with the two or more representations.