The book type is a field of four bits at the start of every DVD (in the physical format information section of the control data block) that indicates what the physical format of the disc is. Many devices will use this "Book Type Field" to determine how the disc should be treated.
One common cause of compatibility problems is the failure of a device to recognize the book type of the disc, most likely because the device had been manufactured before that particular book type was defined; for example, most DVD playback devices made before mid-2004 cannot recognize the relatively new DVD+R DL Book Type. For DVD+R, DVD+RW, and DVD+R DL discs, it is possible to change the Book Type field value to the value associated with the DVD-ROM format (or in some rare and unorthodox cases, even the value associated with the DVD-R format - though only DVD+R can be changed to this) in order to fool older devices, which is a trick known as bitsetting.
These are the possible values of the Book Type Field:
| Value | Meaning |
|---|---|
| 0000 | DVD-ROM, either one or two layers |
| 0001 | DVD-RAM |
| 0010 | DVD-R or DVD-R DL, depending on the Part Version field |
| 0011 | DVD-RW |
| 1001 | DVD+RW |
| 1010 | DVD+R |
| 1101 | DVD+RW DL |
| 1110 | DVD+R DL |
Famous quotes containing the words book and/or type:
“We really learn only from those books that we cannot judge. The author of a book that we were able to judge would have to learn from us.”
—Johann Wolfgang Von Goethe (1749–1832)
“There is a limit to the application of democratic methods. You can inquire of all the passengers as to what type of car they like to ride in, but it is impossible to question them as to whether to apply the brakes when the train is at full speed and accident threatens.”
—Leon Trotsky (1879–1940)