A video output apparatus comprising: a storage unit wherein an area of a first frame buffer and an area of a second frame buffer are reserved; a frame image data output unit configured to: output first frame image data stored in a first frame buffer to a conversion apparatus and to output second frame image data stored in a second frame buffer to the conversion apparatus; a blank signal output unit configured to output a first blank signal and a second blank signal to the conversion apparatus after the end of output of the first frame image data to the conversion apparatus; and a trigger signal output unit configured to output, to the conversion apparatus, a trigger signal to be converted into a vertical synchronization signal by the conversion apparatus, wherein the conversion apparatus is configured to convert the first frame image data in the first format into a second format and to output the first frame image data, wherein the first blank signal, the trigger signal and the second blank signal are sequentially output to the conversion apparatus after an end of output of the first frame image data to the conversion apparatus and before a start of output of second frame image data to the conversion apparatus, and wherein the trigger signal output unit is configured to output the trigger signal to the conversion apparatus in a period of time in which the first blank signal is output to the conversion apparatus, and at a timing at or after an end of writing of the second frame image data to the second frame buffer, and at a timing after an elapse of a first fixed period from a start of the output of the first blank signal, and at a timing a second fixed period before a timing of a start of the output of the second frame image data. a storage unit wherein an area of a first frame buffer and an area of a second frame buffer are reserved; a frame image data output unit configured to: output first frame image data stored in a first frame buffer to a conversion apparatus and to output second frame image data stored in a second frame buffer to the conversion apparatus; a blank signal output unit configured to output a first blank signal and a second blank signal to the conversion apparatus after the end of output of the first frame image data to the conversion apparatus; and a trigger signal output unit configured to output, to the conversion apparatus, a trigger signal to be converted into a vertical synchronization signal by the conversion apparatus, wherein the conversion apparatus is configured to convert the first frame image data in the first format into a second format and to output the first frame image data, wherein the first blank signal, the trigger signal and the second blank signal are sequentially output to the conversion apparatus after an end of output of the first frame image data to the conversion apparatus and before a start of output of second frame image data to the conversion apparatus, and wherein the trigger signal output unit is configured to output the trigger signal to the conversion apparatus in a period of time in which the first blank signal is output to the conversion apparatus, and at a timing at or after an end of writing of the second frame image data to the second frame buffer, and at a timing after an elapse of a first fixed period from a start of the output of the first blank signal, and at a timing a second fixed period before a timing of a start of the output of the second frame image data. a blank signal output unit configured to output a first blank signal and a second blank signal to the conversion apparatus after the end of output of the first frame image data to the conversion apparatus; and a trigger signal output unit configured to output, to the conversion apparatus, a trigger signal to be converted into a vertical synchronization signal by the conversion apparatus, wherein the conversion apparatus is configured to convert the first frame image data in the first format into a second format and to output the first frame image data, wherein the first blank signal, the trigger signal and the second blank signal are sequentially output to the conversion apparatus after an end of output of the first frame image data to the conversion apparatus and before a start of output of second frame image data to the conversion apparatus, and wherein the trigger signal output unit is configured to output the trigger signal to the conversion apparatus in a period of time in which the first blank signal is output to the conversion apparatus, and at a timing at or after an end of writing of the second frame image data to the second frame buffer, and at a timing after an elapse of a first fixed period from a start of the output of the first blank signal, and at a timing a second fixed period before a timing of a start of the output of the second frame image data.