JEITA  CP-3451 - 73 - 5.4.3   Channels The number of channels is either monaural or stereo (2 ch). 5.4.4   Compression Schemes The following three compressions schemes are specified here: ·  Uncompressed audio data: PCM , ·  Uncompressed audio data: m-Law PCM (conforming to ITU-T G.711), ·  Compressed data: IMA-ADPCM. 5.5  Basic Structure of Audio Data   Exif audio files are based on the RIFF WAVE Form Audio File format adopted as a Windows^™ standard audio file format, with the addition of various DSC attribute information as needed. Exif audio files are data-compatible with WAVE Form Audio files and can be played on accessories supplied with Windows^™. Of the general attribute information required by DSC applications, the common attributes are recorded on an INFO list, and the Exif-specific attributes are recorded in Exif chunks. The Exif chunks are provided to enable the addition of  information  as  necessary,  taking  advantage  of  chunk  extensibility.  The  method  of  recording  data  in  the Exif-specific chunks is patterned after that for the INFO list.   5.5.1   Basic Structure of WAVE Form Audio Files The  WAVE  Form  Audio  File  format  is  based  on  the  RIFF  (Resource  Interoperability  File  Format)  tagged  file structure. A RIFF file consists of basic data blocks called chunks. (1) Chunk Using C language syntax, a chunk may be defined as a structure, like that in Equation 1. The chunk structure may also be expressed in graphical form as in . typedef struct { unsigned long      ckID; // 4-character code unsigned long      ckSize; // Size of member <ckData>   unsigned char      ckData[ckSize]; // The data in the chunk } CK;                                                                                                                - - - [Equation 1] Address Offset   Meaning (Hex) +00 ckID (4 Bytes) +04 ckSize (4 Bytes) +08 ckData[ckSize] Figure 33 Chunk Structure