Method of transmitting audio information and additional information in digital form
First Claim
1. A method of transmitting digital audio information representing samples of an analog audio signal with additional digital information comprising:
- generating a plurality of multibit digital words from said samples of an analog signal;
selecting a number of lower order bits in said digital words to be replaced with bits of data from said additional digital information when the amplitude of said analog signal represented by each digital word exceeds a first level;
replacing said lower order data bits of every nth word with bits of the additional digital information, whereby every nth word contains a number of bits of said additional digital information depending upon the size of said analog sample; and
,transmitting each of said digital words to a receiving apparatus.
1 Assignment
0 Petitions
Accused Products
Abstract
The invention relates to a method of transmitting audio information in digital form, in which for the transmission of additional information in digital form data bits of said additional information replace one or a plurality of least significant bits in every nth code word of the audio information. For this purpose one or a plurality of least significant bits of the audio information in every nth code word is/are replaced in predetermined manner by additional information bits, the number of bits being replaced depending on the value of the instantaneous code word of the audio information. This dependence is such that for larger values of the audio information more bits are replaced than for smaller values.
-
Citations
7 Claims
-
1. A method of transmitting digital audio information representing samples of an analog audio signal with additional digital information comprising:
-
generating a plurality of multibit digital words from said samples of an analog signal; selecting a number of lower order bits in said digital words to be replaced with bits of data from said additional digital information when the amplitude of said analog signal represented by each digital word exceeds a first level; replacing said lower order data bits of every nth word with bits of the additional digital information, whereby every nth word contains a number of bits of said additional digital information depending upon the size of said analog sample; and
,transmitting each of said digital words to a receiving apparatus. - View Dependent Claims (2, 3, 4, 5)
-
-
6. A method of transmitting audio information in digital form, in which a predetermined number of code words each representing a sample of an analog audio signal, together with block synchronizing information, sub-code information and error-code information are combined to form blocks of fixed predetermined length, and which provides for the transmission of additional information of digital form by replacing one or a plurality of least significant bits in each nth code of the digital audio information, n being a positive integer, with said additional information, comprising the following steps:
-
a. dividing the successive code words in a block into a plurality of sequential identical code-word groups comprising code words, b. dividing each code word group into reference data words whose information content is invariable and into variable mixed code words, the reference data words constituting the beginning of a code-word group, c. replacing a number of least significant bits of the mixed code words by bits of suitably encoded additional information which number of bits to be replaced may be either a predetermined number, or a number which depends on the value of the digital audio information, so that more bits are replaced in the case of larger values of said mixed code words, d. detecting the temporal position of the reference code words and the mixed code words of the code word groups by means of the block synchronization information, e. separating the bits representing the additional information from the mixed code words and filling the vacated bit positions with bits of suitable significance from a substitution auxiliary-signal source, and f. decoding reconstructed digital code words of the original audio information and of the additional information recovered from the mixed code words. - View Dependent Claims (7)
-
Specification