{
  "slug": "dvd-ecc-block",
  "term": "DVD ECC block",
  "aliases": [
    "DVD error-correction block"
  ],
  "definition": "A DVD ECC block combines sixteen scrambled data frames with row and column Reed-Solomon parity before its rows are interleaved into recording frames.",
  "note": "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. [ecma267]\n\nThe 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. [ecma337]\n\nEight ECC blocks contain 1,664 rows: that is the window behind PI Sum8, not eight filesystem blocks or a count of unreadable files. [ecma267]",
  "status": "unknown",
  "advantages": [
    {
      "text": "Naming the format unit makes error-counter windows and coded-versus-payload byte counts explicit.",
      "citationIds": [
        "ecma267"
      ]
    }
  ],
  "limitations": [
    {
      "text": "Block geometry alone does not establish whether a drive recovered the data.",
      "citationIds": [
        "ecma337"
      ]
    }
  ],
  "related": [
    "dvd-pi-sum8"
  ],
  "supersedes": [],
  "supersededBy": [],
  "firstSeen": null,
  "lastSeen": null,
  "updated": "2026-10-29",
  "citations": [
    {
      "id": "ecma267",
      "title": "ECMA-267, third edition (April 2001), DVD-ROM, clauses 13.4.2 and 16-19: data frames, ECC blocks and recording frames.",
      "url": "https://ecma-international.org/wp-content/uploads/ECMA-267_3rd_edition_april_2001.pdf",
      "accessed": "2026-10-29"
    },
    {
      "id": "ecma337",
      "title": "ECMA-337, second edition (December 2003), DVD+RW, clauses 13.1-13.4 and 29.2: format geometry and error criteria.",
      "url": "https://www.ecma-international.org/wp-content/uploads/ECMA-337_2nd_edition_december_2003.pdf",
      "accessed": "2026-10-29"
    },
    {
      "id": "analysis",
      "title": "Hesela: optical error counters and the limits of DVD error masks.",
      "url": "https://hesela.com/analyses/optical-disc-rot-error-rate-signals/#pi-stages-heading",
      "accessed": "2026-10-29"
    }
  ],
  "provenance": [
    "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."
  ]
}