在 iPhone 上合并音频文件
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【中文标题】在 iPhone 上合并音频文件【英文标题】：merge Audio files on iPhone 【发布时间】：2010-07-29 03:35:33 【问题描述】：我想在 iPhone 上将 .caf 文件和 .mp3 文件合并为 .mp3 文件，或者我可以将它们转换为 .aac 然后合并它们。我该怎么做？ （就像 Kala OK，我想把我的声音和音乐融合在一起）
【问题讨论】：
您所说的“合并”是指将它们混合在一起吗？还是在同一个文件中一个接一个地整理它们？ 就像 Kala OK，我想把我的声音和音乐融合在一起 【参考方案1】：您需要将这两个文件解码为 LPCM（普通的旧整数），将它们添加/混合在一起，然后重新编码。 iPhone SDK 不支持 MP3 编码，所以需要重新编码为 AAC。
Apple 示例代码 iPhoneExtAudioFileConvertTest 将是一个很好的起点。
【讨论】：
我将两个 LPCM 文件混合在一起，然后通过 sdk 将其编码为 aac。 您的问题解决了吗？我遇到了同样的问题。【参考方案2】：你可以用这个方法
- (BOOL) combineVoices1
NSError *error = nil;
BOOL ok = NO;
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
CMTime nextClipStartTime = kCMTimeZero;
//Create AVMutableComposition Object.This object will hold our multiple AVMutableCompositionTrack.
AVMutableComposition *composition = [[AVMutableComposition alloc] init];
AVMutableCompositionTrack *compositionAudioTrack = [composition addMutableTrackWithMediaType:AVMediaTypeAudio preferredTrackID:kCMPersistentTrackID_Invalid];
[compositionAudioTrack setPreferredVolume:0.8];
NSString *soundOne =[[NSBundle mainBundle]pathForResource:@"test1" ofType:@"caf"];
NSURL *url = [NSURL fileURLWithPath:soundOne];
AVAsset *avAsset = [AVURLAsset URLAssetWithURL:url options:nil];
NSArray *tracks = [avAsset tracksWithMediaType:AVMediaTypeAudio];
AVAssetTrack *clipAudioTrack = [[avAsset tracksWithMediaType:AVMediaTypeAudio] objectAtIndex:0];
[compositionAudioTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero, avAsset.duration) ofTrack:clipAudioTrack atTime:kCMTimeZero error:nil];
AVMutableCompositionTrack *compositionAudioTrack1 = [composition addMutableTrackWithMediaType:AVMediaTypeAudio preferredTrackID:kCMPersistentTrackID_Invalid];
[compositionAudioTrack setPreferredVolume:0.3];
NSString *soundOne1 =[[NSBundle mainBundle]pathForResource:@"test" ofType:@"caf"];
NSURL *url1 = [NSURL fileURLWithPath:soundOne1];
AVAsset *avAsset1 = [AVURLAsset URLAssetWithURL:url1 options:nil];
NSArray *tracks1 = [avAsset1 tracksWithMediaType:AVMediaTypeAudio];
AVAssetTrack *clipAudioTrack1 = [[avAsset1 tracksWithMediaType:AVMediaTypeAudio] objectAtIndex:0];
[compositionAudioTrack1 insertTimeRange:CMTimeRangeMake(kCMTimeZero, avAsset.duration) ofTrack:clipAudioTrack1 atTime:kCMTimeZero error:nil];
AVMutableCompositionTrack *compositionAudioTrack2 = [composition addMutableTrackWithMediaType:AVMediaTypeAudio preferredTrackID:kCMPersistentTrackID_Invalid];
[compositionAudioTrack2 setPreferredVolume:1.0];
NSString *soundOne2 =[[NSBundle mainBundle]pathForResource:@"song" ofType:@"caf"];
NSURL *url2 = [NSURL fileURLWithPath:soundOne2];
AVAsset *avAsset2 = [AVURLAsset URLAssetWithURL:url2 options:nil];
NSArray *tracks2 = [avAsset2 tracksWithMediaType:AVMediaTypeAudio];
AVAssetTrack *clipAudioTrack2 = [[avAsset2 tracksWithMediaType:AVMediaTypeAudio] objectAtIndex:0];
[compositionAudioTrack1 insertTimeRange:CMTimeRangeMake(kCMTimeZero, avAsset2.duration) ofTrack:clipAudioTrack2 atTime:kCMTimeZero error:nil];
AVAssetExportSession *exportSession = [AVAssetExportSession
exportSessionWithAsset:composition
presetName:AVAssetExportPresetAppleM4A];
if (nil == exportSession) return NO;
NSString *soundOneNew = [documentsDirectory stringByAppendingPathComponent:@"combined10.m4a"];
//NSLog(@"Output file path - %@",soundOneNew);
// configure export session output with all our parameters
exportSession.outputURL = [NSURL fileURLWithPath:soundOneNew]; // output path
exportSession.outputFileType = AVFileTypeAppleM4A; // output file type
// perform the export
[exportSession exportAsynchronouslyWithCompletionHandler:^
if (AVAssetExportSessionStatusCompleted == exportSession.status)
NSLog(@"AVAssetExportSessionStatusCompleted");
else if (AVAssetExportSessionStatusFailed == exportSession.status)
// a failure may happen because of an event out of your control
// for example, an interruption like a phone call comming in
// make sure and handle this case appropriately
NSLog(@"AVAssetExportSessionStatusFailed");
else
NSLog(@"Export Session Status: %d", exportSession.status);
];
return YES;
【讨论】：
【参考方案3】：您可以使用 SDAVAssetExportSession 和以下代码将许多文件导出到 AAC：
-(void)mergeAudioFiles
NSFileManager * fm = [[NSFileManager alloc] init];
NSError * error;
NSArray * filesNames = **NSArray of File Names;
NSString * filePath = @"Dest File Name";
NSString * pathToSave =[NSString stringWithFormat:@"%@%@",filePath,@".m4a"];
CMTime startTime = kCMTimeZero;
AVMutableComposition *composition = [AVMutableComposition composition];
AVMutableCompositionTrack *compositionAudioTrack =[AVMutableCompositionTrack alloc];
compositionAudioTrack = [composition addMutableTrackWithMediaType:AVMediaTypeAudio preferredTrackID:kCMPersistentTrackID_Invalid];
float audioEndTime=0;
for (NSString *fileName in filesNames)
NSURL *audioUrl = [NSURL fileURLWithPath:fileName];
AVURLAsset *audioasset = [[AVURLAsset alloc]initWithURL:audioUrl options:nil];
CMTimeRange timeRange = CMTimeRangeMake(kCMTimeZero, audioasset.duration);
AVAssetTrack *audioAssetTrack= [[audioasset tracksWithMediaType:AVMediaTypeAudio] lastObject];
[compositionAudioTrack insertTimeRange:timeRange ofTrack:audioAssetTrack atTime:startTime error:&error];
startTime = CMTimeAdd(startTime, timeRange.duration);
CMTime assetTime2 = [audioasset duration];
Float64 duration2 = CMTimeGetSeconds(assetTime2);
audioEndTime+=duration2;
NSURL *exportUrl = [NSURL fileURLWithPath:pathToSave];
float audiostartTime=0;
CMTime startTime1 = CMTimeMake((int)(floor(audioStartTime * 100)), 100);
CMTime stopTime = CMTimeMake((int)(ceil(audioEndTime * 100)), 100);
CMTimeRange exportTimeRange = CMTimeRangeFromTimeToTime(startTime1, stopTime);
SDAVAssetExportSession *encoder = [SDAVAssetExportSession.alloc initWithAsset:composition];
encoder.outputFileType = AVFileTypeAppleM4A;
encoder.outputURL = exportUrl;
encoder.audioSettings = @
AVFormatIDKey: @(kAudioFormatMPEG4AAC),
AVNumberOfChannelsKey: @2,
AVSampleRateKey: @44100,
AVEncoderBitRateKey: @128000,
;
encoder.timeRange = exportTimeRange;
dispatch_semaphore_t semaphore = dispatch_semaphore_create(0);
NSLog(@"Starting Audio Marge");
[encoder exportAsynchronouslyWithCompletionHandler:^
if (encoder.status == AVAssetExportSessionStatusCompleted)
NSLog(@"Audio Marge succeeded");
NSError * err = NULL;
BOOL result = [fm moveItemAtPath:pathToSave toPath:filePath error:&err];
if(!result)
NSLog(@"Error: %@", err);
NSLog(@"Audio Copied");
else if (encoder.status == AVAssetExportSessionStatusCancelled)
NSLog(@"Audio export cancelled");
else
NSLog(@"Audio export failed with error: %@ (%ld)", encoder.error.localizedDescription, encoder.error.code);
dispatch_semaphore_signal(semaphore);
];
NSLog(@"Audio Wait to Finish");
dispatch_semaphore_wait(semaphore, DISPATCH_TIME_FOREVER);
//cleanup
for (NSString *fileName in filesNames)
[fm removeItemAtPath:fileName error:&error];
NSLog(@"Audio Marge Finished");
【讨论】：
能否请您解释一下代码，因为这有助于在不逐行浏览的情况下了解代码【参考方案4】：合并两个音频文件代码
-(void)mergeTwoAudioFile
NSError * error;
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [[paths objectAtIndex:0] stringByAppendingPathComponent:@"Music_Directory"];
//first audio path
NSString *firstPath= [documentsDirectory stringByAppendingPathComponent:@"audio01.m4a"];
NSURL *audioUrl1 = [NSURL fileURLWithPath:firstPath];
AVMutableComposition *mixComposition = [AVMutableComposition composition];
AVMutableCompositionTrack *audioCompositionTrack1 =[[AVMutableCompositionTrack alloc]init];
AVURLAsset *audioasset1 = [[AVURLAsset alloc]initWithURL:audioUrl1 options:nil];
AVAssetTrack *audioAssetTrack1= [[audioasset1 tracksWithMediaType:AVMediaTypeAudio] lastObject];
audioCompositionTrack1 = [mixComposition addMutableTrackWithMediaType:AVMediaTypeAudio preferredTrackID:kCMPersistentTrackID_Invalid];
CMTime tempTime1= mixComposition.duration;
[audioCompositionTrack1 insertTimeRange:CMTimeRangeMake(kCMTimeZero, audioasset1.duration) ofTrack:audioAssetTrack1 atTime:tempTime1 error:&error];
//========second audio
NSString *secondPath= [documentsDirectory stringByAppendingPathComponent:@"audio02.m4a"];
NSURL *audioUrl2 = [NSURL fileURLWithPath:secondPath];
AVMutableCompositionTrack *audioCompositionTrack2 =[[AVMutableCompositionTrack alloc]init];
AVURLAsset *audioasset2 = [[AVURLAsset alloc]initWithURL:audioUrl2 options:nil];
AVAssetTrack *audioAssetTrack2= [[audioasset2 tracksWithMediaType:AVMediaTypeAudio] lastObject];
audioCompositionTrack2 = [mixComposition addMutableTrackWithMediaType:AVMediaTypeAudio preferredTrackID:kCMPersistentTrackID_Invalid];
CMTime tempTime2 = mixComposition.duration;
[audioCompositionTrack2 insertTimeRange:CMTimeRangeMake(kCMTimeZero, audioasset2.duration) ofTrack:audioAssetTrack2 atTime:tempTime2 error:&error];
NSString * pathToSave = [NSString stringWithFormat:@"finalTest.m4a"];
pathToSave =[documentsDirectory stringByAppendingPathComponent:pathToSave];
NSURL *movieUrl = [NSURL fileURLWithPath:pathToSave];
AVAssetExportSession *exporter =[[AVAssetExportSession alloc] initWithAsset:mixComposition presetName:AVAssetExportPresetAppleM4A];
exporter.shouldOptimizeForNetworkUse = YES;
exporter.outputURL = movieUrl;
exporter.outputFileType = AVFileTypeAppleM4A;
//====================================================================
float audioStartTime=0;
CMTime assetTime1 = [audioasset1 duration];
Float64 duration1 = CMTimeGetSeconds(assetTime1);
CMTime assetTime2 = [audioasset2 duration];
Float64 duration2 = CMTimeGetSeconds(assetTime2);
float audioEndTime=duration1+duration2;
CMTime startTime = CMTimeMake((int)(floor(audioStartTime * 100)), 100);
CMTime stopTime = CMTimeMake((int)(ceil(audioEndTime * 100)), 100);
CMTimeRange exportTimeRange = CMTimeRangeFromTimeToTime(startTime, stopTime);
exporter.timeRange =exportTimeRange;
//====================================================================
[exporter exportAsynchronouslyWithCompletionHandler:^(void)
NSString* message;
switch (exporter.status)
case AVAssetExportSessionStatusFailed:
message = [NSString stringWithFormat:@"Export failed. Error: %@", exporter.error.description];
NSLog(@"%@", message);
break;
case AVAssetExportSessionStatusCompleted:
message = [NSString stringWithFormat:@"Export completed"];
NSLog(@"%@", message);
break;
case AVAssetExportSessionStatusCancelled:
message = [NSString stringWithFormat:@"Export cancelled!"];
NSLog(@"%@", message);
break;
default:
NSLog(@"Export unhandled status: %ld", (long)exporter.status);
break;
];
【讨论】：
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