A video processing method including: a multiplexing step of receiving plural pieces of digital coded audio and video data by multiplexing means; and a step of recording data output from the multiplexing means onto a recording medium, by data recording means; characterized in that: the multiplexing step includes: a step of further receiving an instruction signal indicating whether the plural pieces of digital coded audio and video data are to be multiplexed or not, from a user, a step of multiplexing the plural pieces of digital coded audio and video data, and outputting the multiplexed digital coded audio and video data and a flag indicating that the multiplexed digital coded audio and video data is multiplexed, to the recording means, when the instruction signal indicates the plural pieces of digital coded audio and video data are to be multiplexed, and a step of outputting the plural pieces of digital coded audio and video data and a flag indicating that the plural pieces of digital coded audio and video data are not multiplexed, to the recording means, when the instruction signal indicates the plural pieces of digital coded audio and video data are not to be multiplexed. a multiplexing step of receiving plural pieces of digital coded audio and video data by multiplexing means; and a step of recording data output from the multiplexing means onto a recording medium, by data recording means; characterized in that: the multiplexing step includes: a step of further receiving an instruction signal indicating whether the plural pieces of digital coded audio and video data are to be multiplexed or not, from a user, a step of multiplexing the plural pieces of digital coded audio and video data, and outputting the multiplexed digital coded audio and video data and a flag indicating that the multiplexed digital coded audio and video data is multiplexed, to the recording means, when the instruction signal indicates the plural pieces of digital coded audio and video data are to be multiplexed, and a step of outputting the plural pieces of digital coded audio and video data and a flag indicating that the plural pieces of digital coded audio and video data are not multiplexed, to the recording means, when the instruction signal indicates the plural pieces of digital coded audio and video data are not to be multiplexed. the multiplexing step includes: a step of further receiving an instruction signal indicating whether the plural pieces of digital coded audio and video data are to be multiplexed or not, from a user, a step of multiplexing the plural pieces of digital coded audio and video data, and outputting the multiplexed digital coded audio and video data and a flag indicating that the multiplexed digital coded audio and video data is multiplexed, to the recording means, when the instruction signal indicates the plural pieces of digital coded audio and video data are to be multiplexed, and a step of outputting the plural pieces of digital coded audio and video data and a flag indicating that the plural pieces of digital coded audio and video data are not multiplexed, to the recording means, when the instruction signal indicates the plural pieces of digital coded audio and video data are not to be multiplexed. a step of further receiving an instruction signal indicating whether the plural pieces of digital coded audio and video data are to be multiplexed or not, from a user, a step of multiplexing the plural pieces of digital coded audio and video data, and outputting the multiplexed digital coded audio and video data and a flag indicating that the multiplexed digital coded audio and video data is multiplexed, to the recording means, when the instruction signal indicates the plural pieces of digital coded audio and video data are to be multiplexed, and a step of outputting the plural pieces of digital coded audio and video data and a flag indicating that the plural pieces of digital coded audio and video data are not multiplexed, to the recording means, when the instruction signal indicates the plural pieces of digital coded audio and video data are not to be multiplexed.