An optical storage medium recording apparatus is provided a data preparing and ECC encoding circuit that both prepares the data by combining different categories of data into data sequences in accordance with a data layout on the optical storage medium and encodes the combined data. The encoded data is temporarily stored in a data buffer, and subsequently successively read out by a recording circuit for recording onto the optical storage medium according to the data layout. For a Blu-ray disc recording apparatus, the data preparing and ECC encoding circuit includes a LDC/BIS encoder for generating long distance error correction codes (LDC) and burst indicator subcodes (BIS) from the combined data to form LDC and BIS encoded data, which is temporarily stored in the data buffer. The recording circuit includes an interleave circuit for interleaving the LDC and BIS data to form physical clusters for recording on the disc.