问题
OK, so I'm trying to make a program that will manipulate .wav files, and I've seen this question/answers, but I'm not entirely sure as to what each piece of data in the header refers to. For example, what does a "chunk" refer to? Is that a specific number of bits/bytes?
If somebody could just tell me, at least in the format used in this question, what each datum being written to the .wav, aside from the constant String Literals and the 'data' array, refer to? In particular I'd especially like to know what a "chunk" is, and how Sample Rate, Byte Rate, Bytes per Sample, and Bytes per Sample for all Channels relate?(I suspect Byte Rate is Sample Rate * Bytes per Sample, but what about the 'for all channels' one?)
Any help is appreciated.
回答1:
It is against the board rules to just post a link, so here is the table I took from http://www.topherlee.com/software/pcm-tut-wavformat.html
Positions Sample Value Description
1 - 4 "RIFF" Marks the file as a riff file. Characters are each 1. byte long.
5 - 8 File size (integer) Size of the overall file - 8 bytes, in bytes (32-bit integer). Typically, you'd fill this in after creation.
9 -12 "WAVE" File Type Header. For our purposes, it always equals "WAVE".
13-16 "fmt " Format chunk marker. Includes trailing null
17-20 16 Length of format data as listed above
21-22 1 Type of format (1 is PCM) - 2 byte integer
23-24 2 Number of Channels - 2 byte integer
25-28 44100 Sample Rate - 32 bit integer. Common values are 44100 (CD), 48000 (DAT). Sample Rate = Number of Samples per second, or Hertz.
29-32 176400 (Sample Rate * BitsPerSample * Channels) / 8.
33-34 4 (BitsPerSample * Channels) / 8.1 - 8 bit mono2 - 8 bit stereo/16 bit mono4 - 16 bit stereo
35-36 16 Bits per sample
37-40 "data" "data" chunk header. Marks the beginning of the data section.
41-44 File size (data) Size of the data section, i.e. file size - 44 bytes header.
Sample values are given above for a 16-bit stereo source.
Update/Reminder
The header integers are all in Least significant byte order, so the two byte channel information 0x01 0x00 are actually 0x00001 e.g. mono.
来源：https://stackoverflow.com/questions/28137559/can-someone-explain-wavwave-file-headers