Braille books get online outlet
Braille books get online outlet
Library of Congress delivers FTP files via the Web, is working on digital audio
By William Jackson
|Judith Dixon says braille files are about 30 percent smaller than ASCII files and easier for Library of Congress patrons to download.|
The Library of Congress is developing new ways to deliver books to the blind and visually impaired via a Web site for braille books and through digital audio.
The site uses File Transfer Protocol to upload files to a Web server from which people can download to a braille embosser, or they can read the files on an electronic braille display.
'We ftp'd the files to a site and added some security,' said Judith Dixon, consumer relations officer at the National Library Service for the Blind and Physically Handicapped. 'This is 1994 Web activity.'
The braille files, which the library already had in its inventory, are about 30 percent smaller than ASCII text files, making them easier to download and store.
Delivering a digital audio book is no simple task, however. A digital audio file is about 6,000 times as big as a comparable text file, creating hurdles for both delivery and storage. But digital recordings have better quality and flexibility than the analog audiocassettes now in use. Furthermore, the cassette's days are numbered, said Michael Moodie, a research and development officer at the library.
'We know the analog cassette is going to die,' Moodie said. 'Analog recording equipment already is getting harder to buy.'
Moodie said analog cassettes have another five, maybe 10, years of life. By that time, convenient technology for handling large files should be available, he said.Shortcut codes
The National Library Service for the Blind and Physically Handicapped launched the service, called Web-Braille and accessed from www.loc.gov/nls
, in October. Since 1992, NLS has kept extra disks of the code it uses to print books in Grade 2 braille, a short-form version of the system of raised dots in which symbols and abbreviations stand for letter combinations or entire words. Files from the disks are loaded on an IBM RS/6000 server.
A braille embosser can print out the downloaded files, or users can read them from a refreshable braille display, which raises and lowers a pin array to make a line of braille characters. Access to the copyrighted books is restricted by password to registered users.
The Web-Braille site opened with about 2,700 titles. New books are being added at a rate of about 40 a week.
'As our quality assurance section approves a book for shipment, they put the book on the server,' Dixon said.
About 1G worth of books resides on the server now, ranging from cookbooks to John Grisham novels. Although there were only about 400 users after two months, 'the people who use it are ecstatic,' Dixon said.
The number of people using the library's books-on-tape service is much greater. Moodie said 500,000 to 600,000 special cassette players are in use, playing unabridged books on six-hour analog cassette tapes. An average book runs about 12 hours, Moodie said. Accommodating so many listeners in the switch to digital audio will require small, robust, high-capacity digital players that have not yet been developed.
'We are at the stage of defining the standards for the file format,' Moodie said.
The standards being considered are Web-based, such as the popular MP3 format, but the Web is unlikely to be the immediate delivery vehicle. Using common sampling ratios, an average book takes up about 3.8G. Even with 15-fold compression, a digital audio book would occupy about 250M.
'That's a very big file' that would take about 10 hours to download with a 56-Kbps modem, Moodie said. 'That's not feasible.'
Although Moodie said he is convinced that digital audio books eventually will be available online, last-mile bandwidth for convenient downloads of such size will not be available to enough users soon enough to make the Web a likely vehicle in the near future. At least one generation of physical players is needed.
'We really like the idea of solid-state storage,' Moodie said. Although companies are beginning to produce digital players, no one has yet come up with the ruggedness, ease of use and capacity the library wants.
'We think they're going to be there in the time frame in which we'll need them,' Moodie said. But, he added, moving to digital in less than five years would be tough.