The present invention allows for display of an image generated from HDR video data on an LDR monitor in good condition. Applying a predetermined level-mapping curve to the input video data (HDR video data) in a first range of levels provides the video data for transmission (LDR video data) in a second range of levels narrower than the first range of levels. The video data for transmission is transmitted together with the auxiliary information used to convert the levels on the receiving end.