The invention relates to a system for encoding video data and/or a system for decoding video data. The system for encoding video data includes a first encoding unit, a second encoding unit, and a header information generating unit. The first encoding unit encodes input video data according to a predetermined syntax and generates a first bitstream. The second encoding unit encodes input video data according to other syntax that is different from the predetermined syntax and generates a second bitstream. The header information generating unit receives the first bitstream or the second bitstream and adds header information including syntax type information that indicates which syntax is used to encode the first bitstream or the second bitstream to the first bitstream or the second bitstream.