Method and apparatus for synchronously encoding audio signals with corresponding video frames

An audio signal encoder for coding an input audio signal corresponding to a video signal on the basis of specified data units to form coded audio data separated into coded blocks, comprising:

• coding means for blocking and coding said input audio signal in specified data units to form coded blocks separated into blocks and outputting the coded blocks as audio data;
• detection means for determining the phase difference between the frame or field boundaries in said video signal and said coded blocks in said audio data to detect the coded block corresponding to a particular frame or field boundary based on the phase difference;
• and
• memory means operative after the write of said audio data from said coding means for aligning, based on the results of detection by said detection means, the block leading position of the coded block with a corresponding frame or field boundary, and outputting an array of coded blocks in synchronism with the frames or fields of the video signal by reading said written audio data to arrange those coded blocks which follow the coded block the leading position of which has been aligned with the corresponding frame or field boundary in such a way that an integral number of coded blocks are filled in the period of time corresponding to one frame or field.

An audio signal coding and decoding method comprising

• audio signal coding steps including the steps of:
• blocking and coding an input audio signal corresponding to a video signal in specified data units to form coded blocks separated into blocks and writing the coded blocks to a first memory means;
• aligning the leading position of one of said coded blocks with a corresponding frame or field boundary in said video signal, and forming coded audio data in synchronism with the frames or fields of said video signal by reading data from said first memory means so as to arrange those coded blocks which follow the coded block the leading position of which has been aligned with said frame or field boundary in such a way that an integral number of said coded blocks are filled in the period of time corresponding to one frame or field;
• and
• adding to said coded audio data, information representing the phase difference between the frame or field boundary in said video signal and the coded block not subjected to alignment of the block leading position with the frame or field boundary, and
• coded audio data decoding steps including the steps of:
• writing said coded audio data to a second memory means;
• detecting relevant phase difference information from the coded audio data including said information on the phase difference;
• and
• reading data from said second memory means based on the detected phase difference information to recover the original phase relationship between said coded block and said video signal.

An audio signal encoder and decoder comprising an audio signal coding section including:

• coding means for blocking and coding an input audio signal corresponding to a video signal on the basis of specified data units to form coded blocks separated into blocks and outputting the coded blocks as audio data;
• detection means for determining the phase difference between the frame or field boundaries in said video signal and said coded blocks of said audio data to detect the coded block corresponding to a particular frame or field boundary based on the phase difference;
• first memory means operative after the write of said audio data from said coding means for aligning, based on the results of detection by said detection means, the block leading position of the coded block with a corresponding frame or field boundary, and outputting an array of coded audio blocks as coded audio data in synchronism with the frames or fields of the video signal by reading said written audio data to arrange those coded blocks which follow the coded block the leading position of which has been aligned with the corresponding frame or field boundary in such a way that an integral number of coded blocks are filled in the period of time corresponding to one frame or field;
• and
• phase difference addition means for adding the phase difference detected by said detection means to said coded block in said coded data output from said first memory means which is in synchronism with the frame or field, and
• a coded audio data decoding section including:
• phase difference information detection means for detecting said phase difference information from the coded audio data from said audio signal coding section;
• and
• second memory means operative after the write of the coded audio data from said audio signal coding section for reading the written coded audio data based on the phase difference information detected by said phase difference information detection means in order to recover the original phase relationship between said coded block and said video signal.