Question

我目前正在查看WAV文件的以下信息，并且我遇到了其标题中包含的WAV文件的“ChunkSize”。但是，我无法理解如何计算ChunkSize的值。根据

http://tiny.systems/software/soundProgrammer/WavFormatDocs.pdf

    36 + SubChunk2Size, or more precisely: 
                           4 + (8 + SubChunk1Size) + (8 + SubChunk2Size) 
                           This is the size of the rest of the chunk  
                           following this number.  This is the size of the 
                           entire file in bytes minus 8 bytes for the 
                           two fields not included in this count: 
                           ChunkID and ChunkSize.

我现在已经看了大约40分钟了，我不明白数字的来源。例如，“4”来自哪里，“8”是哪个？

Answer 1

根据WavFormatDocs链接中的第一个图表，ChunkSize是Format，SubChunk1ID + SubChunk1Size + SubChunk1和SubChunk2ID + SubChunk2Size + SubChunk2字段中的总字节数：

Format:                              4 bytes
SubChunk1ID + SubChunk1Size: 4 + 4 = 8 bytes
SubChunk1:                           <SubChunk1Size> bytes
SubChunk2ID + SubChunk2Size: 4 + 4 = 8 bytes
SubChunk2:                           <SubChunk2Size> bytes
                                     ---------------------------------------------------
                                     4 + (8 + SubChunk1Size) + (8 + SubChunk2Size) bytes

fmt块是固定大小的：

SubChunk1ID:   4  bytes 
SubChunk1Size: 4  bytes 
SubChunk1:     16 bytes
               --------
               24 bytes

所以ChunkSize是：

Format:         4 bytes 
fmt chunk:     24 bytes 
SubChunk2ID:    4 bytes 
SubChunk2Size:  4 bytes
SubChunk2:     <SubChunk2Size> bytes
               ---------------------
               36 + <SubChunk2Size> bytes

WAV文件中的“ChunkSize”

1 个答案: