Method and apparatus for embedding data in and extracting data from voice code

A data embedding/extracting method in a system having a voice encoding apparatus for encoding voice according to a prescribed voice encoding scheme and embedding optional data in voice code thus obtained, and a voice reproducing apparatus for extracting embedded data from voice code and reproducing voice from this voice code, comprising the steps of:

• defining beforehand a first element code and a threshold value used to determine whether data has been embedded or not, and a second element code in which data will be embedded based upon the result of the determination;
• when data is to be embedded, determining whether data embedding conditions are satisfied using the first element code and the threshold value, and embedding optional data in the voice code by replacing the second element code with the optional data if the data embedding condition is satisfied;
• and
• when data is to be extracted, determining whether data embedding condition is satisfied using the first element code and the threshold value, determining that optional data has been embedded in the second element code portion of the voice code if the data embedding condition is satisfied, and extracting the embedded data.

A data extracting apparatus for extracting data embedded in voice code that has been encoded according to a prescribed voice encoding scheme, comprising:

• a demultiplexer for demultiplexing element codes constituting the voice code;
• an embedding decision unit for determining whether data embedding condition is satisfied using a first element code from among the element codes and a threshold value;
• and
• an embedded-data extracting unit for determining that optional data has been embedded in a second element code portion of the voice code if the data embedding condition is satisfied, and extracting the embedded data.

A voice encoding/decoding system for encoding voice according to a prescribed voice encoding scheme and embedding optional data in voice code thus obtained, and for extracting embedded data from the voice code and reproducing voice from this voice code, comprising:

• a voice encoding apparatus for embedding optional data in voice code obtained by encoding voice according to a prescribed voice encoding scheme;
• and
• a voice decoding apparatus for reproducing voice by applying decoding processing to voice code that has been encoded by a prescribed voice encoding scheme, and extracting data that has been embedded in this voice code;
• said voice encoding apparatus including:
• an encoder for encoding voice according to a prescribed voice encoding scheme;
• an embedding decision unit for determining whether data embedding condition is satisfied using a first element code from among element codes constituting the voice code, and a threshold value;
• and
• a data embedding unit for embedding optional data in the voice code by replacing a second element code with the optional data if the data embedding condition is satisfied;
• and
• said voice decoding apparatus includes:
• a demultiplexer for demultiplexing voice code into element codes;
• an embedding decision unit for determining whether data embedding condition is satisfied using a first element code from among element codes constituting received voice code, and a threshold value;
• an embedded-data extracting unit for determining that optional data has been embedded in a second element code portion of the voice code if the data embedding condition is satisfied, and extracting the embedded data;
• and
• a decoder for decoding the received voice code and reproducing voice;
• wherein the first element code and threshold value used to determine whether data has been embedded or not, and the second element code in which data will be embedded based upon the result of the determination, are defined beforehand in said voice encoding apparatus and said voice decoding apparatus.