Information recording method and apparatus and information recording medium

In an information recording device, variable-speed reproduction by software control is to be enabled. To this end, the information recording device has an HDD for recording an audio/visual digital data stream with a logical sector as an accessing unit, and an AV micro-computer system 10. This AV micro-computer system 10 has, as a recording data unit, a fixed length of the audio/visual digital data stream corresponding to an integer number multiple of a frame length. The AV micro-computer system 10 allocates the recording data unit to a minimum number of the logical sectors that can record the recording data unit in its entirety, while stuffing dummy data in the remaining portion of a logical sector of the digital data stream.