使用 Objective C 在 iPhone 中合并两个 .wav 文件

Question

我想将两个 .wav 录音文件合并在一起。 任何人都可以帮助我弄清楚如何实现这一点。我尝试组合数据，但标题正在产生问题。 我们可以像合并波形文件一样进行合并吗？

这就是我做组合的方式，

NSMutableData *datas = [NSMutableData alloc];

NSData *data1 = [NSData dataWithContentsOfFile: [recordedTmpFile1 path]];

NSData *data2 = [NSData dataWithContentsOfFile: [recordedTmpFile2 path]];

 NSLog(@"file1 size : %d", [data1 length]);

 NSLog(@"file2 size : %d", [data2 length]);

[datas appendData:data1];

  [datas appendData:data2];

 NSLog(@"file3 size : %d", [datas length]);

            NSURL *combinedPath = [NSURL alloc];

combinedPath = [NSURL fileURLWithPath:[NSTemporaryDirectory() stringByAppendingPathComponent: 

[NSString stringWithFormat: @"1_20111215.%@",@"wav"]]];

            [[NSFileManager defaultManager] createFileAtPath:[combinedPath path] contents:datas attributes:nil];       

            NSFileManager * fm = [NSFileManager defaultManager];

[fm removeItemAtPath:[recordedTmpFile2 path] error:nil];  

Answer 1

我可以通过录制.wav扩展名的音频来实现两个文件的合并，代码如下，

NSURL *originalFileName = [NSURL alloc];    

NSURL *RecordingPath =[NSURL fileURLWithPath:[appDelegate.RecordingPath stringByAppendingPathComponent: 
                                              [NSString stringWithFormat:@"RecordingFile.wav"]]];  
NSLog(@"LocalRecoding Path :%@",RecordingPath);


originalFileName=RecordingPath;

NSURL *temporaryFileName = [NSURL alloc];
temporaryFileName = [NSURL fileURLWithPath:[appDelegate.RecordingPath  stringByAppendingPathComponent: 
                                            [NSString stringWithFormat: @"tempRecordingFile.%@", @"wav"]]];

long totalAudioLen = 0;
long totalDataLen = 0;
long longSampleRate = 11025.0;
int channels = 2;
long byteRate = 16 * 11025.0 * channels/8;    

NSData * wav1Data = [NSData dataWithContentsOfFile:[originalFileName path]];
NSData * wav2Data = [NSData dataWithContentsOfFile:[temporaryFileName path]];

if([wav1Data length]>0 && [wav2Data length] >0)
{
int wav1DataSize = [wav1Data length] - 44;  
NSLog(@"WAV I:%d",wav1DataSize);
int wav2DataSize = [wav2Data length] - 44;
NSLog(@"WAV II:%d",wav2DataSize);
NSData *Wave1= [NSMutableData dataWithData:[wav1Data subdataWithRange:NSMakeRange(44, wav1DataSize)]];
NSData *Wave2 =[NSMutableData dataWithData:[wav2Data subdataWithRange:NSMakeRange(44, wav2DataSize)]];

NSLog(@"WAV 1:%d",[Wave1 length]);

NSLog(@"WAV 2:%d",[Wave2 length]);


totalAudioLen=[Wave1 length]+[Wave2 length];

totalDataLen = totalAudioLen + 44;  

Byte *header = (Byte*)malloc(44);
header[0] = 'R';  // RIFF/WAVE header
header[1] = 'I';
header[2] = 'F';
header[3] = 'F';
header[4] = (Byte) (totalDataLen & 0xff);
header[5] = (Byte) ((totalDataLen >> 8) & 0xff);
header[6] = (Byte) ((totalDataLen >> 16) & 0xff);
header[7] = (Byte) ((totalDataLen >> 24) & 0xff);
header[8] = 'W';
header[9] = 'A';
header[10] = 'V';
header[11] = 'E';
header[12] = 'f';  // 'fmt ' chunk
header[13] = 'm';
header[14] = 't';
header[15] = ' ';
header[16] = 16;  // 4 bytes: size of 'fmt ' chunk
header[17] = 0;
header[18] = 0;
header[19] = 0;
header[20] = 1;  // format = 1
header[21] = 0;
header[22] = (Byte) channels;
header[23] = 0;
header[24] = (Byte) (longSampleRate & 0xff);
header[25] = (Byte) ((longSampleRate >> 8) & 0xff);
header[26] = (Byte) ((longSampleRate >> 16) & 0xff);
header[27] = (Byte) ((longSampleRate >> 24) & 0xff);
header[28] = (Byte) (byteRate & 0xff);
header[29] = (Byte) ((byteRate >> 8) & 0xff);
header[30] = (Byte) ((byteRate >> 16) & 0xff);
header[31] = (Byte) ((byteRate >> 24) & 0xff);
header[32] = (Byte) (2 * 8 / 8);  // block align
header[33] = 0;
header[34] = 16;  // bits per sample
header[35] = 0;
header[36] = 'd';
header[37] = 'a';
header[38] = 't';
header[39] = 'a';
header[40] = (Byte) (totalAudioLen & 0xff);
header[41] = (Byte) ((totalAudioLen >> 8) & 0xff);
header[42] = (Byte) ((totalAudioLen >> 16) & 0xff);
header[43] = (Byte) ((totalAudioLen >> 24) & 0xff);


NSData *headerData = [NSData dataWithBytes:header length:44];

//Merge the sound data of the original file with the temp file and create a new sound file with the 
//update header.
NSMutableData * soundFileData = [NSMutableData alloc];
[soundFileData appendData:[headerData subdataWithRange:NSMakeRange(0, 44)]];
[soundFileData appendData:Wave1];
[soundFileData appendData:Wave2];

//delete the original file
NSFileManager * fm = [NSFileManager defaultManager];
[fm removeItemAtPath:[originalFileName path] error:nil]; 

//create a new file with merged audio with the original file name.
NSURL *mergedFilePath = [NSURL alloc];

mergedFilePath = [NSURL fileURLWithPath:[appDelegate.RecordingPath  stringByAppendingPathComponent: 
                                         [NSString stringWithFormat:[originalFileName lastPathComponent]]]];   

[[NSFileManager defaultManager] createFileAtPath:[mergedFilePath path] contents:soundFileData attributes:nil];  

NSLog(@"COMBINED FILE PATH :%@",mergedFilePath);
}

Answer 2

此代码将剥离标头并仅返回 PCM 数据的 NSData。

- (NSData *)stripCAFHeader: (NSString *) path

    NSFileManager* fileMgr = [NSFileManager defaultManager];

    //Load the file in
    NSData* dataBuffer = [fileMgr contentsAtPath: path];
    //This is the data header
    NSData* searchString = [NSData dataWithBytes:"data" length:4];

    //Find where the header starts
    NSUInteger dataWordStart = [dataBuffer rangeOfData:searchString options:0 range:NSMakeRange(0,[dataBuffer length])].location;

    //Create the new range without the header
    //4 bytes for the DATA word, 8 bytes for the data length, and 4 bytes for the edit count
    NSRange dataRange = NSMakeRange(dataWordStart + 4 + 4 + 8, [dataBuffer length] - dataWordStart - 4 - 4 - 8);

    //Copy the new data
    NSData *data = [dataBuffer subdataWithRange:dataRange];
    return data;
}

Answer 3

我刚刚在我的项目中做到了这一点。我正在使用需要#import <AVFoundation/AVFoundation.h> 的AVMutableComposition 方法。我在应用程序的文档目录中有两个 .wav 文件，并将它们合并为一个新的 .wav 文件。

AVAsset *audio1 = [AVURLAsset URLAssetWithURL:audioFilePath options:nil];
AVAsset *audio2 = [AVURLAsset URLAssetWithURL:audioFilePath options:nil];

AVMutableComposition* composition = [[AVMutableComposition alloc] init];

AVMutableCompositionTrack *audioCombinedTrack = [composition addMutableTrackWithMediaType:AVMediaTypeAudio preferredTrackID:kCMPersistentTrackID_Invalid];
[audioCombinedTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero, [audio1 duration]) ofTrack:[audio1.tracks objectAtIndex:0] atTime:kCMTimeZero error:&error];
[audioCombinedTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero, [audio2 duration]) ofTrack:[audio2.tracks objectAtIndex:0] atTime:[audio1 duration] error:&error];

AVAssetExportSession *exportSession = [[AVAssetExportSession alloc] initWithAsset:composition presetName:AVAssetExportPresetPassthrough];

NSString *exportPath = [[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0] stringByAppendingPathComponent:@"Combined.wav"];
NSURL *exportURL = [NSURL fileURLWithPath:exportPath];

exportSession.outputURL = exportURL;
exportSession.outputFileType = AVFileTypeWAVE;

[exportSession exportAsynchronouslyWithCompletionHandler:^{
    NSLog (@"Exporting. status is %ld", (long)exportSession.status);
    switch (exportSession.status) {
        case AVAssetExportSessionStatusFailed:
        case AVAssetExportSessionStatusCompleted: {
            NSLog(@"export done");
            break;
        }
    };
}];