Concatenating Multiple WAV Files into One: A Step-by-Step Guide with Detailed Explanation

It seems like you’ve found a solution to concatenate multiple WAV files into one. Here’s a breakdown of your answer:

You used NSData to concatenate each file into the master data.
You rewrote the header (first 44 bytes) according to the WAV file specifications.

To further improve and provide more details on this process, here’s an updated version of your code with some additional comments and explanations:

// Concatenate multiple WAV files into one

NSData* data1 = [NSData dataWithContentsOfFile:@"file1.wav"];
NSData* data2 = [NSData dataWithContentsOfFile:@"file2.wav"];

// Concatenate the two files
NSData* masterData = [data1 bytes];
[masterData appendBytes:data2.bytes length:[data2 length]];

// Rewrite the header (first 44 bytes) according to the WAV file specifications

UInt16* header = (UInt16*)masterData.mutableBytes;
UInt16 chunkID = 0x46464952; // "RIFF"
UInt32 fileSize = masterData.length + 36;

header[0] = chunkID;
header[1] = 0;
header[2] = (UInt16)((fileSize >> 24) & 0xFF);
header[3] = (UInt16)((fileSize >> 16) & 0xFF);

UInt16 format = 0x20746d66; // "WAVE"
UInt32 subChunkID = 0x46696e67; // "fmt "
UInt16 audioFormat = 1; // PCM

header[4] = format;
header[5] = (UInt16)((subChunkID >> 24) & 0xFF);
header[6] = (UInt16)((subChunkID >> 16) & 0xFF);
header[7] = (UInt16)((subChunkID >> 8) & 0xFF);
header[8] = (UInt16)(subChunkID & 0xFF);

UInt32 audioSampleRate = masterData.length / 44;
UInt16 numChannels = 2; // stereo
UInt32 sampleSize = 1; // 16-bit

header[10] = audioFormat;
header[11] = (UInt16)((audioSampleRate >> 24) & 0xFF);
header[12] = (UInt16)((audioSampleRate >> 16) & 0xFF);
header[13] = (UInt16)((audioSampleRate >> 8) & 0xFF);
header[14] = (UInt16)(audioSampleRate & 0xFF);

header[15] = numChannels;
header[16] = sampleSize;

// Rest of the code remains the same...

This updated version includes a more detailed explanation of how to concatenate multiple WAV files into one and rewrite the header according to the WAV file specifications.

Last modified on 2025-05-09