我有一个基于上述问题的作业。问题中已知采样频率和每个样本的大小。我只需要了解所需的编码类型。
最佳答案
使用文件格式规范,例如 this one了解如何读取文件头、确定采样率、比特率等。
The canonical WAVE format starts with the RIFF header:
0 4 ChunkID Contains the letters "RIFF" in ASCII form
(0x52494646 big-endian form).
4 4 ChunkSize 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.
8 4 Format Contains the letters "WAVE"
(0x57415645 big-endian form).
The "WAVE" format consists of two subchunks: "fmt " and "data":
The "fmt " subchunk describes the sound data's format:
12 4 Subchunk1ID Contains the letters "fmt "
(0x666d7420 big-endian form).
16 4 Subchunk1Size 16 for PCM. This is the size of the
rest of the Subchunk which follows this number.
20 2 AudioFormat PCM = 1 (i.e. Linear quantization)
Values other than 1 indicate some
form of compression.
22 2 NumChannels Mono = 1, Stereo = 2, etc.
24 4 SampleRate 8000, 44100, etc.
28 4 ByteRate == SampleRate * NumChannels * BitsPerSample/8
32 2 BlockAlign == NumChannels * BitsPerSample/8
The number of bytes for one sample including
all channels. I wonder what happens when
this number isn't an integer?
34 2 BitsPerSample 8 bits = 8, 16 bits = 16, etc.
2 ExtraParamSize if PCM, then doesn't exist
X ExtraParams space for extra parameters
The "data" subchunk contains the size of the data and the actual sound:
36 4 Subchunk2ID Contains the letters "data"
(0x64617461 big-endian form).
40 4 Subchunk2Size == NumSamples * NumChannels * BitsPerSample/8
This is the number of bytes in the data.
You can also think of this as the size
of the read of the subchunk following this
number.
44 * Data The actual sound data.
之后,您将找到原始 pcm 数据,如交错
[sample 1 ][sample 2 ]
[s1,ch1][s1,ch2][s2,ch1][s2,ch2]
您可以以写入、二进制模式打开每个样本的文本文件,然后循环音频数据,读取单个样本/ channel 的字节,然后使用 fprintf
或 fwrite
将它们写入正确的文件。
关于c - 将 2 channel WAV 文件解交织为两个包含原始数据的文本文件,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/14748191/