Signal processing method and apparatus, signal reproducing method and apparatus, and recording medium

1. A signal processing method comprising:

forming data packs by dividing main data to be processed into constant size data packs;

forming a data block including data sectors, the data packs being multiplexed/arranged in two data sectors;

adding an error correction code to the data block to constitute an error correction coded block;

replacing a predetermined sector of the error correction coded block with specific data; and

outputting the error correction coded block after replacing the predetermined sector with the specific data to a transmission medium or a recording medium.

2. The method according to claim 1 , wherein the error correction code is a product code.

3. The method according to claim 1 , wherein the replacing comprises replacing data in rows of the error correction coded block with the specific data.

4. The method according to claim 1 , wherein the replacing comprises replacing data in columns of the error correction coded block with the specific data.

5. The method according to claim 1 , wherein the specific data includes an error correction code.

6. The method according to claim 1 , wherein the part of the error correction coded block which is replaced with the specific data is predetermined.

7. The method according to claim 1 , wherein the replacing comprises replacing data in every other row of the error correction coded block with the specific data.

8. A signal processing method for processing an error correction coded block transmitted through a transmission medium or reproduced from a recording medium, the error correction coded block being obtained by forming data packs by dividing main data to be processed into constant size data packs, forming a data block including data sectors, the data packs being multiplexed/arranged in two data sectors, adding an error correction code to the data block to constitute the error correction coded block; replacing a predetermined sector of the error correction coded block with specific data; and outputting the error correction coded block after replacing the predetermined sector with the specific data to the transmission medium or the recording medium, the method comprising:

reproducing an original error correction coded block before replacing the specific data by copying to the predetermined sector of the error correction coded block data of another sector in which data of the predetermined sector is arranged; and

performing an error detection/correction processing with respect to the original error correction coded block.

9. The method according to claim 8 , wherein the error correction code is a product code.

10. The method according to claim 8 , wherein the replacing comprises replacing data in rows of the error correction coded block with the specific data.

11. The method according to claim 8 , wherein the replacing comprises replacing data in every other row of the error correction coded block with the specific data.

12. The method according to claim 8 , wherein the replacing comprises replacing data in columns of the error correction coded block with the specific data.

13. The method according to claim 8 , wherein the specific data includes an error correction code.

14. The method according to claim 8 , wherein the part of the error correction coded block which is replaced with the specific data is predetermined.

15. A signal processing apparatus comprising:

a data pack forming unit configured to form data packs by dividing main data to be processed into constant size data packs;

a data block forming unit configured to form a data block including data sectors, the data packs being multiplexed/arranged in two data sectors;

an adder configured to add an error correction code to the data block to constitute an error correction coded block;

a data replacing circuit configured to replace a predetermined sector of the error correction coded block with specific data; and

an output circuit configured to output the error correction coded block, after the predetermined sector is replaced, with the specific data to a transmission medium or a recording medium.

16. The apparatus according to claim 15 , wherein the data sector includes identification information indicating an address, other control information, and main data, and the main data is multiplexed/arranged in two data sectors.

17. The apparatus according to claim 15 , wherein the error correction code is a product code including inner-code parities relating to a row and outer-code parities relating to a column.

18. The apparatus according to claim 15 , wherein the specific data includes an error correction code.

19. The apparatus according to claim 15 , wherein the block of the main data and the specific data are processed by the same error correction apparatus.

20. The apparatus according to claim 15 , wherein the part of the error correction coded block which is replaced with the specific data is predetermined.

21. The signal processing apparatus according to claim 15 , further comprising:

a reproducing circuit configured to receive the error correction coded block output from the output circuit and configured to reproduce an original error correction coded block before replacing the specific data by copying to the predetermined sector of the error correction coded block data of another sector in which data of the predetermined sector is arranged; and

an error correction circuit configured to perform an error detection/correction processing with respect to the original error correction coded block.

22. The apparatus according to claim 15 , wherein the data replacing circuit is configured to replace data in rows of the error correction coded block with the specific data.

23. The apparatus according to claim 15 , wherein the data replacing circuit is configured to replace data in every other row of the error correction coded block with the specific data.

24. The apparatus according to claim 15 , wherein the data replacing circuit is configured to replace data in columns of the error correction coded block with the specific data.