Hi, now that i have released libburn and cdrskin with CD-TEXT features, i want to contribute to the libcdio docs about that topic.
Are there files to read and update, other than these ? doc/glossary.texi item "CD Text" doc/libcdio.texi node "CD Text" --------------------------------------------------------------------------- doc/glossary.texi: Consider to add a pointer which refers to libburn's doc/cdtext.txt. http://libburnia-project.org/browser/libburn/trunk/doc/cdtext.txt or http://libburnia-project.org/browser/libburn/trunk/doc/cdtext.txt?format=txt (The latter triggers on my elderly browser download rather than viewing.) --------------------------------------------------------------------------- doc/libcdio.texi: Some of its aspects go beyond my own CD knowledge. Nevertheless, i have to question some statements: > The first place the information can be recorded is in the R-W sub > codes in the lead in area of the CD giving a data capacity of about > 5,000 ASCII characters (or 2,500 Kanji or Unicode characters). How was the payload of 5,000 bytes computed ? The highest lead-in start for recordable CD media in my list is 97m 49s 00f which means LBA -9975. Lead-in reaches up to LBA -150. Each sector can take 4 text packs of 12 bytes payload = 471,600 bytes. MMC command READ TOC/PMA/ATIP could retrieve 65,534 bytes from lead-in. A CD-TEXT block can have only 253 payload packs of 12 bytes each. There can be 8 blocks at most. 253 * 12 * 8 = 24,288 bytes. A single block (i.e. one language) can have 253 * 12 = 3036 bytes. > The second place the information can be recorded is in the R-W sub > codes in the program area of the CD giving a data capacity of roughly > 31MB. This information is stored in a format that follows the > Interactive Text Transmission System (ITTS) which is the same data > transmission standard used by such things as Digital Audio > Broadcasting (DAB), and virtually the same as the data standard for > the MiniDisc. Traditionally the R-W sub codes have been used for text > and graphics in applications such as CD+G Shouldn't the statement about the format be separated in an own paragraph ? "This information is stored in a format [...] the MiniDisc." Afaik, the format is the same in lead-in and in program area. Is the statement about CD+G particularly about program area or does it apply to lead-in too ? > In the case of ATAPI drives, the > SFF8020 spec covers the reading of the RW subcodes. This is covered by MMC meanwhile. Reading from lead-in is done by command 43h READP TOC/PMA/ATIP, Format 0101b. Reading from program area is supposed to be done by BEh READ CD. (I did not explore the latter yet.) Are any non-MMC drives still worth to be mentioned ? How much degree of detail from http://libburnia-project.org/browser/libburn/trunk/doc/cdtext.txt would be appropriate for doc/libcdio.texi resp. other libcdio documentation ? You are of course invited to simply copy the whole thing. But near the end it contains some libburn specifics. (Proff-reading would be appreciated, too.) Have a nice day :) Thomas
