hesela.devDVD ECC block
A DVD ECC block combines sixteen scrambled data frames with row and column Reed-Solomon parity before its rows are interleaved into recording frames.
In the cited DVD-ROM layout, sixteen frames carry 32,768 bytes of main data. Including identification, control and detection fields, the input array is 192 x 172 = 33,024 bytes. Adding sixteen outer-parity rows and ten inner-parity bytes per row gives 208 x 182 = 37,856 coded bytes before modulation. [1]
The DVD+RW standard describes the same geometry. One outer-parity row is interleaved after each twelve input rows to form sixteen recording frames, each 13 x 182 bytes. These coded dimensions are not application capacity. [2]
Eight ECC blocks contain 1,664 rows: that is the window behind PI Sum8, not eight filesystem blocks or a count of unreadable files. [1]
Relations
- related
- DVD PI Sum8
Advantages
- Naming the format unit makes error-counter windows and coded-versus-payload byte counts explicit. [1]
Limitations
- Block geometry alone does not establish whether a drive recovered the data. [2]
Citations
- ECMA-267, third edition (April 2001), DVD-ROM, clauses 13.4.2 and 16-19: data frames, ECC blocks and recording frames.
- ECMA-337, second edition (December 2003), DVD+RW, clauses 13.1-13.4 and 29.2: format geometry and error criteria.
Further reading
Sources & caveats
- Byte totals are arithmetic from the cited format dimensions, not measured storage capacity or a new experiment.
- This record names the block used in the cited DVD-ROM and DVD+RW formats; it does not define every optical format or scanner counter.