A data output apparatus comprising: a decoder that decodes a video stream to generate a first video signal with a first luminance range; an acquisition unit that acquires first metadata regarding a luminance range of the first video signal; an interpreter that interprets the first metadata to acquire characteristic data indicating the luminance range of the first video signal; a control information generator that converts the characteristic data into control information according to a predetermined transmission protocol; and an output unit that outputs the control information in accordance with the predetermined transmission protocol; wherein the interpreter further interprets the first metadata to acquire conversion auxiliary data for converting the luminance range of the first video signal, the data output apparatus further comprises a converter that converts the luminance range of the first video signal based on the conversion auxiliary data to generate a second video signal with a second luminance range narrower than the first luminance range, and the output unit further outputs at least one of the first video signal and the second video signal in accordance with the predetermined transmission protocol, wherein when a display apparatus connected to the data output apparatus supports video output with the luminance range of the first video signal, the output unit outputs the first video signal and the control information to the display apparatus and, if the display apparatus fails to support the first video signal, the output unit outputs the second video signal and the control information to the display apparatus; and wherein the output unit determines whether the display apparatus supports video output with the luminance range of the first video signal in initialization processing of the predetermined transmission protocol and wherein, if it is determined that conversion processing is not necessary, the first video signal obtained by the decoder is input into the output unit without passing through the converter. a decoder that decodes a video stream to generate a first video signal with a first luminance range; an acquisition unit that acquires first metadata regarding a luminance range of the first video signal; an interpreter that interprets the first metadata to acquire characteristic data indicating the luminance range of the first video signal; a control information generator that converts the characteristic data into control information according to a predetermined transmission protocol; and an output unit that outputs the control information in accordance with the predetermined transmission protocol; wherein the interpreter further interprets the first metadata to acquire conversion auxiliary data for converting the luminance range of the first video signal, the data output apparatus further comprises a converter that converts the luminance range of the first video signal based on the conversion auxiliary data to generate a second video signal with a second luminance range narrower than the first luminance range, and the output unit further outputs at least one of the first video signal and the second video signal in accordance with the predetermined transmission protocol, wherein when a display apparatus connected to the data output apparatus supports video output with the luminance range of the first video signal, the output unit outputs the first video signal and the control information to the display apparatus and, if the display apparatus fails to support the first video signal, the output unit outputs the second video signal and the control information to the display apparatus; and wherein the output unit determines whether the display apparatus supports video output with the luminance range of the first video signal in initialization processing of the predetermined transmission protocol and wherein, if it is determined that conversion processing is not necessary, the first video signal obtained by the decoder is input into the output unit without passing through the converter.