A transcoder reduces the processing amount when a coded stream to which at least intra prediction is applied is transcoded into a coded stream to which intra prediction and inter prediction are applied. The transcoder converts a first coded stream to at least part of which intra prediction is applied, into a second coded stream to which intra prediction and inter prediction are applied. The transcoder includes a decoding unit that decodes the first coded stream to generate decoded image data; a prediction mode obtaining unit that obtains a prediction mode of intra prediction applied in decoding; and a coding unit that codes the decoded image data by applying the intra prediction or inter prediction to generate the second coded stream. A control unit controls causes the coding unit to use the prediction mode obtained by the prediction mode obtaining unit when the coding unit applies intra prediction.