OC (已验证)

//
//  WAVWriter.h
//  NUIdemo
//  Created by JoyTim on 2024/6/5
//  Copyright © 2024 skydrui.regular. All rights reserved.
//
    

#import <Foundation/Foundation.h>

NS_ASSUME_NONNULL_BEGIN

@interface WAVWriter : NSObject
- (void)appendBuffer:(NSData *)buffer;
- (void)closeFile;
- (instancetype)initWithSampleRate:(int)sampleRate
                           bitDepth:(int)bitDepth
                           channels:(int)channels
                        outputFile:(NSString *)outputFile;
@end

NS_ASSUME_NONNULL_END

#import <Foundation/Foundation.h>

@interface WAVWriter : NSObject

- (void)appendBuffer:(NSData *)buffer;
- (void)closeFile;

@end
@implementation WAVWriter {
    NSFileHandle *_fileHandle;
    uint32_t _dataSize;
    int _sampleRate;
    int _bitDepth;
    int _channels;
}

- (instancetype)initWithSampleRate:(int)sampleRate
                           bitDepth:(int)bitDepth
                           channels:(int)channels
                         outputFile:(NSString *)outputFile {
    if (self) {
        _sampleRate = sampleRate;
        _bitDepth = bitDepth;
        _channels = channels;
        _dataSize = 0;
        
        // 创建文件并写入文件头部信息
        [[NSFileManager defaultManager] createFileAtPath:outputFile contents:nil attributes:nil];
        _fileHandle = [NSFileHandle fileHandleForWritingAtPath:outputFile];
        [self writeWAVHeaderWithDataSize:0];
    }
    return self;
}

- (void)appendBuffer:(NSData *)buffer {
    // 更新文件头部中的数据长度信息
    _dataSize += (uint32_t)buffer.length;
    [self updateWAVHeaderWithDataSize:_dataSize];
    
    // 追加 buffer 到文件末尾
    [_fileHandle seekToEndOfFile];
    [_fileHandle writeData:buffer];
}

- (void)closeFile {
    [_fileHandle closeFile];
}

- (void)writeWAVHeaderWithDataSize:(uint32_t)dataSize {
    NSMutableData *headerData = [NSMutableData data];
    uint32_t chunkSize = 36 + dataSize;
    uint16_t audioFormat = 1;
    uint16_t blockAlign = _channels * _bitDepth / 8;
    uint32_t byteRate = _sampleRate * _channels * _bitDepth / 8;
    
    [headerData appendBytes:"RIFF" length:4];
    [headerData appendBytes:&chunkSize length:4];
    [headerData appendBytes:"WAVE" length:4];
    [headerData appendBytes:"fmt " length:4];
    uint32_t subchunk1Size = 16;
    [headerData appendBytes:&subchunk1Size length:4];
    [headerData appendBytes:&audioFormat length:2];
    [headerData appendBytes:&_channels length:2];
    [headerData appendBytes:&_sampleRate length:4];
    [headerData appendBytes:&byteRate length:4];
    [headerData appendBytes:&blockAlign length:2];
    [headerData appendBytes:&_bitDepth length:2];
    [headerData appendBytes:"data" length:4];
    [headerData appendBytes:&dataSize length:4];
    
    [_fileHandle seekToFileOffset:0];
    [_fileHandle writeData:headerData];
}

- (void)updateWAVHeaderWithDataSize:(uint32_t)dataSize {
    [_fileHandle seekToFileOffset:4];
    uint32_t chunkSize = 36 + dataSize;
    [_fileHandle writeData:[NSData dataWithBytes:&chunkSize length:4]];
    
    [_fileHandle seekToFileOffset:40];
    [_fileHandle writeData:[NSData dataWithBytes:&dataSize length:4]];
}

@end

swift 代码 （未测试）

import Foundation

class WAVWriter {
    private let fileHandle: FileHandle
    private var dataSize: UInt32 = 0
    private let sampleRate: Int
    private let bitDepth: Int
    private let channels: Int
    
    init(sampleRate: Int, bitDepth: Int, channels: Int, outputFile: String) {
        self.sampleRate = sampleRate
        self.bitDepth = bitDepth
        self.channels = channels
        
        // 创建文件并写入文件头部信息
        FileManager.default.createFile(atPath: outputFile, contents: nil, attributes: nil)
        fileHandle = FileHandle(forWritingAtPath: outputFile)!
        writeWAVHeader(dataSize: 0)
    }
    
    func appendBuffer(_ buffer: Data) {
        // 更新文件头部中的数据长度信息
        dataSize += UInt32(buffer.count)
        updateWAVHeader(dataSize: dataSize)
        
        // 追加 buffer 到文件末尾
        fileHandle.seekToEndOfFile()
        fileHandle.write(buffer)
    }
    
    func closeFile() {
        fileHandle.closeFile()
    }
    
    private func writeWAVHeader(dataSize: UInt32) {
        var headerData = Data()
        let chunkSize = 36 + dataSize
        let audioFormat: UInt16 = 1
        let blockAlign = UInt16(channels * bitDepth / 8)
        let byteRate = UInt32(sampleRate * channels * bitDepth / 8)
        
        headerData.append("RIFF".data(using: .ascii)!)
        headerData.append(chunkSize.littleEndian.data)
        headerData.append("WAVE".data(using: .ascii)!)
        headerData.append("fmt ".data(using: .ascii)!)
        let subchunk1Size: UInt32 = 16
        headerData.append(subchunk1Size.littleEndian.data)
        headerData.append(audioFormat.littleEndian.data)
        headerData.append(UInt16(channels).littleEndian.data)
        headerData.append(UInt32(sampleRate).littleEndian.data)
        headerData.append(byteRate.littleEndian.data)
        headerData.append(blockAlign.littleEndian.data)
        headerData.append(UInt16(bitDepth).littleEndian.data)
        headerData.append("data".data(using: .ascii)!)
        headerData.append(dataSize.littleEndian.data)
        
        fileHandle.seek(toFileOffset: 0)
        fileHandle.write(headerData)
    }
    
    private func updateWAVHeader(dataSize: UInt32) {
        fileHandle.seek(toFileOffset: 4)
        let chunkSize = 36 + dataSize
        fileHandle.write(chunkSize.littleEndian.data)
        
        fileHandle.seek(toFileOffset: 40)
        fileHandle.write(dataSize.littleEndian.data)
    }
}

extension UInt16 {
    var data: Data {
        var value = self.littleEndian
        return Data(bytes: &value, count: MemoryLayout.size(ofValue: value))
    }
}

extension UInt32 {
    var data: Data {
        var value = self.littleEndian
        return Data(bytes: &value, count: MemoryLayout.size(ofValue: value))
    }
}