How to add playable(such as wav,wmv) header with PCM data/buffer in iOS?

Question

I am trying to add a wav header on top of raw PCM data to make it playable via AVAudioPlayer. But i couldn\'t find any solution or source code to do that on iOS using Object

Answer 1

Very helpful question and answer, thank you very much.

This swift version is for those in need:

static func createWAV(from pcmFilePath: String, to wavFilePath: String) -> Bool {

    // Make sure that the path does not contain non-ascii characters
    guard let fout = fopen(wavFilePath.cString(using: .ascii), "w") else { return false }

    guard let pcmData = try? Data(contentsOf: URL(fileURLWithPath: pcmFilePath)) else { return false }

    var numChannels: CShort = 1
    let numChannelsInt: CInt = 1
    var bitsPerSample: CShort = 16
    let bitsPerSampleInt: CInt = 16
    var samplingRate: CInt = 16000
    let numOfSamples = CInt(pcmData.count)
    var byteRate = numChannelsInt * bitsPerSampleInt * samplingRate / 8
    var blockAlign = numChannelsInt * bitsPerSampleInt / 8
    var dataSize = numChannelsInt * numOfSamples * bitsPerSampleInt / 8
    var chunkSize: CInt = 16
    var totalSize = 46 + dataSize
    var audioFormat: CShort = 1

    fwrite("RIFF".cString(using: .ascii), MemoryLayout.size, 4, fout)
    fwrite(&totalSize, MemoryLayout.size, 1, fout)
    fwrite("WAVE".cString(using: .ascii), MemoryLayout.size, 4, fout);
    fwrite("fmt ".cString(using: .ascii), MemoryLayout.size, 4, fout);
    fwrite(&chunkSize, MemoryLayout.size,1,fout);
    fwrite(&audioFormat, MemoryLayout.size, 1, fout);
    fwrite(&numChannels, MemoryLayout.size,1,fout);
    fwrite(&samplingRate, MemoryLayout.size, 1, fout);
    fwrite(&byteRate, MemoryLayout.size, 1, fout);
    fwrite(&blockAlign, MemoryLayout.size, 1, fout);
    fwrite(&bitsPerSample, MemoryLayout.size, 1, fout);
    fwrite("data".cString(using: .ascii), MemoryLayout.size, 4, fout);
    fwrite(&dataSize, MemoryLayout.size, 1, fout);
    fclose(fout);

    guard let handle = FileHandle(forUpdatingAtPath: wavFilePath) else { return false }

    handle.seekToEndOfFile()
    handle.write(pcmData)
    handle.closeFile()

    return true
}