A data generation device comprising: a generating circuit configured to generate video data according to an Advanced Video Coding, AVC, standard and a second opto-electrical transfer function, OETF; and a storage to store: video usability information, VUI, including a first value indicating a first OETF; and supplemental enhancement information, SEI, including a second value indicating the second OETF, wherein VUI and SEI are included in the video data; wherein the first OETF and the second OETF support a standard dynamic range, SDR, and a high dynamic range, HDR, respectively; the first value is to be referred to by a decoding device that does not support HDR, when the decoding device decodes the video data; and the second OETF has compatibility with the first OETF; wherein the first OETF is an OETF defined in one of BT. 709 and BT. 2020; and the SEI is in an IRAP NAL unit or an I-picture; wherein the video data covers a second luminance dynamic range of the HDR wider than a first luminance dynamic range of the SDR and has compatibility with the decoding device that does not support HDR such that the decoding device reproduces the video data based on SDR. a generating circuit configured to generate video data according to an Advanced Video Coding, AVC, standard and a second opto-electrical transfer function, OETF; and a storage to store: video usability information, VUI, including a first value indicating a first OETF; and supplemental enhancement information, SEI, including a second value indicating the second OETF, wherein VUI and SEI are included in the video data; wherein the first OETF and the second OETF support a standard dynamic range, SDR, and a high dynamic range, HDR, respectively; the first value is to be referred to by a decoding device that does not support HDR, when the decoding device decodes the video data; and the second OETF has compatibility with the first OETF; wherein the first OETF is an OETF defined in one of BT. 709 and BT. 2020; and the SEI is in an IRAP NAL unit or an I-picture; wherein the video data covers a second luminance dynamic range of the HDR wider than a first luminance dynamic range of the SDR and has compatibility with the decoding device that does not support HDR such that the decoding device reproduces the video data based on SDR. video usability information, VUI, including a first value indicating a first OETF; and supplemental enhancement information, SEI, including a second value indicating the second OETF, wherein VUI and SEI are included in the video data; wherein the first OETF and the second OETF support a standard dynamic range, SDR, and a high dynamic range, HDR, respectively; the first value is to be referred to by a decoding device that does not support HDR, when the decoding device decodes the video data; and the second OETF has compatibility with the first OETF; wherein the first OETF is an OETF defined in one of BT. 709 and BT. 2020; and the SEI is in an IRAP NAL unit or an I-picture; wherein the video data covers a second luminance dynamic range of the HDR wider than a first luminance dynamic range of the SDR and has compatibility with the decoding device that does not support HDR such that the decoding device reproduces the video data based on SDR.