JEITA  CP-3451 - 75 - An illustration of the RIFF chunk is given in Figure 34. Address Offset Code Meaning (Hex) (Hex) +00 52 +01 49 +02 46 +03 46 "RIFF" (ckID) +04 ckSize (4 Bytes) +08 formType (4 Bytes) +0C Subchunk 1 :   Subchunk 2 : : : : RIFF chunk ckData [ckSize] Figure 34 RIFF Chunk Structure Note−Representative form types are given in Table 21. These are written in all upper-case letters because they are registered form types.   Table 21 Representative Form Types Form Type Name PAL Palette file form RDIB RIFF DIB (Device Independent Bitmap) form RMID RIFF MIDI form RMMP RIFF multimedia movie form   WAVE WAVE Form Audio File format (3) WAVE Form Audio File Format The WAVE Form is one kind of RIFF form. It is a file for handling digitized sound data. The form type is WAVE, in upper-case letters. The file extension for a WAVE Form Audio File is ".WAV". The data structure of the WAVE Form Audio File format is shown in Figure 35. As is evident from Figure 35, the chunk data (ckData [ckSize]) of a RIFF chunk generally consists of    the formType ("WAVE"), fmt-ck (format chunk), fact-ck (fact chunk), and data-ck (data chunk). fmt-ck and data-ck are mandatory chunks, but  fact-ck may be mandatory or not, depending on the format type (audio coding format) of the WAVE Form. In  addition  to  these,  optional  sub-chunks  may  be  recorded  and  may  store  various  attribute  information.  These optional sub-chunks are not shown in Figure 35.