Method and apparatus for compensating reproduced audio signals of an optical disc

Abstract

An apparatus and method for compensating audio signals to be recorded on an optical disc to optimize usage of memory in an audio decoding circuit, and to neutralize invalid audio data to produce good audio quality. A determination is made with regard to whether audio data signals contain normal data or invalid data. Invalid data is adjusted into normal audio data, and stored in the memory. The volume of the data stored in the memory is monitored to detect overflow and underflow conditions of the memory, a data transmitting stopping signal being sent during an overflow condition of the memory, a data transmitting requesting signal being sent during an underflow condition. The audio data reproduced from the memory is decoded, and the decoded audio data is output. Undesired errors are prevented by monitoring the reproduced audio data for invalid data and by adjusting invalid data into normal data when detected.

1. A method for controlling an audio memory of an audio decoding circuit included in a data decoding unit having a video decoding circuit, said method comprising:
 detecting an amount of data stored in said audio memory, and an address of a last audio data stored in said audio memory;   comparing the detected address of the last audio data stored in said audio memory with a reference address, which corresponds to a predetermined lower threshold for said amount of data stored in said audio memory, and determining whether said amount of data stored in said audio memory is less than said predetermined lower threshold based on the comparison of the detected address with the reference address; and   requesting additional audio data to be stored into said audio memory independently of processing in the video decoding circuit when said amount of data stored in said audio memory is less than said predetermined lower threshold.   
     
     
       2. The method recited by  claim 1 , further comprising:
 storing data that is representative of previously stored audio data when additional audio data is not available for storage into said audio memory while said amount of data stored in said audio memory is less than said predetermined lower threshold.   
     
     
       3. The method recited by  claim 1 , further comprising:
 storing dummy data into said audio memory while said amount of data stored in said audio memory is less than said predetermined lower threshold.   
     
     
       4. An apparatus for controlling an audio memory of an audio decoding circuit included in a data decoding unit having a video decoding circuit, said apparatus comprising:
 a volume detecting unit for detecting an amount of data stored in said audio memory, said volume detecting unit comprising a last address detecting unit for detecting an address of a last audio data stored in said audio memory;   a comparing unit for comparing the detected address of the last audio data stored in said audio memory with a reference address, which corresponds to a predetermined lower threshold for said amount of data stored in said audio memory, and determining whether said amount of data stored in said audio memory is less than said predetermined lower threshold based on the comparison of the detected address with the reference address; and   a controller including a signal generator, said signal generator generating a data transmission request signal requesting additional audio data to stored into said audio memory independently of processing in the video decoding circuit when said amount of data stored in said audio memory is less than said predetermined lower threshold.   
     
     
       5. The apparatus recited by  claim 4 , wherein said controller stores data that is representative of previously stored audio data when additional audio data is not available for storage into said audio memory while said amount of data stored in said audio memory is less than said predetermined lower threshold. 
     
     
       6. The apparatus recited by  claim 4 , wherein said controller further includes a dummy data generator for generating dummy data to be stored in said audio memory while said amount of data stored in said audio memory is less than said predetermined lower threshold. 
     
     
       7. A method for controlling an audio memory of an audio decoding included in a data decoding unit having a video decoding circuit, said method comprising:
 detecting an amount of data stored in said audio memory by detecting an address of a last audio data stored in said audio memory;   comparing the detected address of the last audio data stored in said audio memory with a reference address, which corresponds to a predetermined upper threshold for said amount of data stored in said audio memory, and determining whether said amount of data stored in said memory is greater than aid predetermined upper threshold based on the comparison of the detected address with the reference address; and   generating a data transmission stopping signal independently of processing in the video decoding circuit when said amount of data stored in said audio memory is greater than said predetermined upper threshold until said amount of data stored in said audio memory is less than or equal to said predetermined upper threshold.   
     
     
       8. The method recited by  claim 7 , further comprising:
 halting storage of additional audio data in said memory when said amount of data stored on said memory is greater than said predetermined upper threshold.   
     
     
       9. An apparatus for controlling an audio memory of an audio decoding circuit included in a data decoding unit having a video decoding circuit, said apparatus comprising:
 a volume detecting unit for detecting an amount of data stored in said audio memory, wherein said volume detecting unit comprising a last address detecting unit for detecting an address of a last audio data stored in said audio memory;   a comparing unit for comparing the detected address of the last audio data stored in said audio memory with a reference address, which corresponds to a predetermined upper threshold for said amount of data stored in said audio memory, and determining whether said amount of data stored in said audio memory is greater than said predetermined upper threshold based on the comparison of the detected address with the reference address; and   a controller including a signal generator, said generator generating a data transmission stopping signal independently of processing in the video decoding circuit when said amount of data stored in said audio memory is greater than said predetermined upper threshold until said amount of data stored in said audio memory is less than or equal to said predetermined upper threshold.   
     
     
       10. The apparatus recited by  claim 9 , wherein said controller halts storage of additional audio data in said memory when said amount of data stored on said memory is greater than said predetermined upper threshold. 
     
     
       11. A method for controlling an audio memory to produce a compensated audio data from an audio decoding circuit included in a data decoding unit having a video decoding circuit, the data decoding unit independently processing audio and video data, the method comprising:
 receiving the audio data including the compensated audio data, wherein compensating the audio data comprises:
 detecting an amount of audio data stored in the audio memory, the detecting comprising:
 determining a size of the audio data by detecting an address of a last audio data stored in the audio memory, 
 comparing the detected address of the last audio data stored in the audio memory with a reference address corresponding to a predetermined lower threshold for the amount of audio data stored in the audio memory, and 
 determining whether the amount of audio data stored in the audio memory is less than the predetermined lower threshold based on the comparison of the detected address with the reference address, 
 
 requesting additional audio data to be stored into the audio memory independently of processing in the video decoding circuit when the amount of audio data stored in the audio memory is less than the predetermined lower threshold, 
   detecting header data of a bitstream representing the audio data for determining a beginning of the audio data;   detecting invalid data based on count information associated with the audio data and the detecting of the header;   generating dummy data based on the detecting of the invalid data, the dummy data being repeatedly generated until the audio data reaches a predefined length of bytes;   storing the dummy data with the audio data in the audio memory to thereby produce the compensated audio data; and   decoding the compensated audio data output from the audio memory by processing the compensated audio data.    
     
     
       12. The method of claim 11, wherein the decoding includes an inverse discrete cosine converting transformation.  
     
     
       13. A data decoding apparatus for controlling an audio memory to produce a compensated audio data from an audio decoding circuit included in the data decoding apparatus having a video decoding circuit, the data decoding apparatus independently processing audio and video data, the data decoding apparatus comprising:
 an audio decoding unit included in the audio decoding circuit, the audio decoding unit comprising a control unit including a signal generator, and a volume detecting unit, the volume detecting unit comprising a comparing unit and a last address detecting unit; and   the audio memory included in the audio decoding circuit and coupled to the audio decoding unit, the audio decoding unit performing operations comprising:
 receiving the audio data including the compensated audio data, wherein compensating the audio data comprises:
 detecting, at the volume detecting unit, an amount of audio data stored in the audio memory, the detecting comprising:
 determining a size of the audio data by detecting, at the last address detecting unit, an address of a last audio data stored in the audio memory, 
 comparing, at the comparing unit, the detected address of the last audio data stored in the audio memory with a reference address corresponding to a predetermined lower threshold for the amount of audio data stored in the audio memory, and 
 determining, at the comparing unit, whether the amount of audio data stored in the audio memory is less than the predetermined lower threshold based on the comparison of the detected address with the reference address, 
 
 generating, at the signal generator, a data transmission request signal requesting additional audio data to be stored into the audio memory independently of processing in the video decoding circuit when the amount of audio data stored in the audio memory is less than the predetermined lower threshold, 
 
 detecting header data of a bitstream representing the audio data for determining a beginning of the audio data; 
 detecting invalid data based on count information associated with the audio data and the detecting of the header; 
 generating dummy data based on the detecting of the invalid data, the dummy data being repeatedly generated until the data reaches a predefined length of bytes; 
 storing the dummy data with the audio data in the audio memory to produce the compensated audio data; and 
 decoding the compensated audio data output from the audio memory by processing the compensated audio data.  
   
     
     
       14. The apparatus of claim 13, wherein the decoding includes an inverse discrete cosine converting transformation.