【移動(dòng)應(yīng)用開(kāi)發(fā)技術(shù)】iOS中如何給視頻添加背景音樂(lè)同時(shí)保留原音

【移動(dòng)應(yīng)用開(kāi)發(fā)技術(shù)】iOS中如何給視頻添加背景音樂(lè)同時(shí)保留原音

代碼：//抽取原視頻的音頻與需要的音樂(lè)混合

-(void)addmusic:(id)sender

{

[MBProgressHUDshowHUDAddedTo:self.viewanimated:YES];

AVMutableComposition

*composition

=[AVMutableCompositioncomposition];

audioMixParams

=[[NSMutableArrayalloc]initWithObjects:nil];

//錄制的視頻

NSURL

*video_inputFileUrl

=[NSURLfileURLWithPath:self.videoPath];

AVURLAsset

*songAsset

=[AVURLAssetURLAssetWithURL:video_inputFileUrloptions:nil];

CMTime

startTime

=CMTimeMakeWithSeconds(0,songAsset.duration.timescale);

CMTime

trackDuration

=songAsset.duration;

//獲取視頻中的音頻素材

[selfsetUpAndAddAudioAtPath:video_inputFileUrltoComposition:compositionstart:startTimedura:trackDurationoffset:CMTimeMake(14*44100,44100)];

//本地要插入的音樂(lè)

NSString

*bundleDirectory

=[[NSBundlemainBundle]bundlePath];

NSString

*path

=

[bundleDirectorystringByAppendingPathComponent:@"30secs.mp3"];

NSURL

*assetURL2

=[NSURLfileURLWithPath:path];

//獲取設(shè)置完的本地音樂(lè)素材

[selfsetUpAndAddAudioAtPath:assetURL2toComposition:compositionstart:startTimedura:trackDurationoffset:CMTimeMake(0,44100)];

//創(chuàng)建一個(gè)可變的音頻混合

AVMutableAudioMix

*audioMix

=[AVMutableAudioMixaudioMix];

audioMix.inputParameters

=[NSArrayarrayWithArray:audioMixParams];//從數(shù)組里取出處理后的音頻軌道參數(shù)

//創(chuàng)建一個(gè)輸出

AVAssetExportSession

*exporter

=[[AVAssetExportSessionalloc]

initWithAsset:composition

presetName:AVAssetExportPresetAppleM4A];

exporter.audioMix

=

audioMix;

exporter.outputFileType=@"com.apple.m4a-audio";

NSString*

fileName

=[NSStringstringWithFormat:@"%@.mov",@"overMix"];

//輸出路徑

NSString

*exportFile

=[NSStringstringWithFormat:@"%@/%@",[selfgetLibarayPath],

fileName];

if([[NSFileManagerdefaultManager]fileExistsAtPath:exportFile])

{

[[NSFileManagerdefaultManager]removeItemAtPath:exportFileerror:nil];

}

NSLog(@"是否在主線程1%d",[NSThreadisMainThread]);

NSLog(@"輸出路徑===%@",exportFile);

NSURL

*exportURL

=[NSURLfileURLWithPath:exportFile];

exporter.outputURL

=

exportURL;

self.mixURL

=exportURL;

[exporterexportAsynchronouslyWithCompletionHandler:^{

int

exportStatus

=(int)exporter.status;

switch

(exportStatus){

caseAVAssetExportSessionStatusFailed:{

NSError

*exportError

=exporter.error;

NSLog(@"錯(cuò)誤，信息:

%@",

exportError);

[MBProgressHUDhideHUDForView:self.viewanimated:YES];

break;

}

caseAVAssetExportSessionStatusCompleted:{

NSLog(@"是否在主線程2%d",[NSThreadisMainThread]);

NSLog(@"成功");

//最終混合

[selftheVideoWithMixMusic];

break;

}

}

}];

}

//最終音頻和視頻混合

-(void)theVideoWithMixMusic

{

NSError

*error

=nil;

NSFileManager

*fileMgr

=[NSFileManagerdefaultManager];

NSString

*documentsDirectory

=[NSHomeDirectory()

stringByAppendingPathComponent:@"Documents"];

NSString

*videoOutputPath

=[documentsDirectorystringByAppendingPathComponent:@"test_output.mp4"];

if

([fileMgrremoveItemAtPath:videoOutputPatherror:&error]!=YES)

{

NSLog(@"無(wú)法刪除文件，錯(cuò)誤信息：%@",[error

localizedDescription]);

}

//聲音來(lái)源路徑（最終混合的音頻）

NSURL

*audio_inputFileUrl

=self.mixURL;

//視頻來(lái)源路徑

NSURL

*video_inputFileUrl

=

[NSURLfileURLWithPath:self.videoPath];

//最終合成輸出路徑

NSString

*outputFilePath

=[documentsDirectorystringByAppendingPathComponent:@"final_video.mp4"];

NSURL

*outputFileUrl

=

[NSURLfileURLWithPath:outputFilePath];

if([[NSFileManagerdefaultManager]fileExistsAtPath:outputFilePath])

[[NSFileManagerdefaultManager]removeItemAtPath:outputFilePatherror:nil];

CMTime

nextClipStartTime

=kCMTimeZero;

//創(chuàng)建可變的音頻視頻組合

AVMutableComposition*

mixComposition

=[AVMutableCompositioncomposition];

//視頻采集

AVURLAsset*

videoAsset

=[[AVURLAssetalloc]initWithURL:video_inputFileUrloptions:nil];

CMTimeRange

video_timeRange

=CMTimeRangeMake(kCMTimeZero,videoAsset.duration);

AVMutableCompositionTrack*a_compositionVideoTrack

=

[mixCompositionaddMutableTrackWithMediaType:AVMediaTypeVideopreferredTrackID:kCMPersistentTrackID_Invalid];

[a_compositionVideoTrackinsertTimeRange:video_timeRangeofTrack:[[videoAssettracksWithMediaType:AVMediaTypeVideo]objectAtIndex:0]atTime:nextClipStartTimeerror:nil];

//聲音采集

AVURLAsset*

audioAsset

=[[AVURLAssetalloc]initWithURL:audio_inputFileUrloptions:nil];

CMTimeRange

audio_timeRange

=CMTimeRangeMake(kCMTimeZero,videoAsset.duration);//聲音長(zhǎng)度截取范圍==視頻長(zhǎng)度

AVMutableCompositionTrack*b_compositionAudioTrack

=

[mixCompositionaddMutableTrackWithMediaType:AVMediaTypeAudiopreferredTrackID:kCMPersistentTrackID_Invalid];

[b_compositionAudioTrackinsertTimeRange:audio_timeRangeofTrack:[[audioAssettracksWithMediaType:AVMediaTypeAudio]objectAtIndex:0]atTime:nextClipStartTimeerror:nil];

//創(chuàng)建一個(gè)輸出

AVAssetExportSession*

_assetExport

=[[AVAssetExportSessionalloc]initWithAsset:mixCompositionpresetName:AVAssetExportPresetMediumQuality];

_assetExport.outputFileType

=AVFileTypeQuickTimeMovie;

_assetExport.outputURL

=outputFileUrl;

_assetExport.shouldOptimizeForNetworkUse=YES;

self.theEndVideoURL=outputFileUrl;

[_assetExportexportAsynchronouslyWithCompletionHandler:

^(void

)

{

[MBProgressHUDhideHUDForView:self.viewanimated:YES];

//播放

NSURL*url

=

[NSURLfileURLWithPath:outputFilePath];

MPMoviePlayerViewController

*theMovie

=[[MPMoviePlayerViewControlleralloc]initWithContentURL:url];

[selfpresentMoviePlayerViewControllerAnimated:theMovie];

theMovie.moviePlayer.movieSourceType=MPMovieSourceTypeFile;

[theMovie.moviePlayerplay];

}

];

NSLog(@"完成！輸出路徑==%@",outputFilePath);

}

//通過(guò)文件路徑建立和添加音頻素材

-

(void)setUpAndAddAudioAtPath:(NSURL*)assetURLtoComposition:(AVMutableComposition*)composition

start:(CMTime)startdura:(CMTime)duraoffset:(CMTime)offset{

AVURLAsset

*songAsset

=[AVURLAssetURLAssetWithURL:assetURLoptions:nil];

AVMutableCompositionTrack

*track

=[compositionaddMutableTrackWithMediaType:AVMediaTypeAudiopreferredTrackID:kCMPersistentTrackID_Invalid];

AVAssetTrack

*sourceAudioTrack

=[[songAssettracksWithMediaType:AVMediaTypeAudio]objectAtIndex:0];

NSError

*error

=nil;

BOOL

ok

=NO;

CMTime

startTime

=

start;

CMTime

trackDuration

=

dura;

CMTimeRange

tRange

=CMTimeRangeMake(startTime,trackDuration);

//設(shè)置音量

//AVMutableAudioMixInputParameters（輸入?yún)?shù)可變的音頻混合）

//audioMixInputParametersWithTrack（音頻混音輸入?yún)?shù)與軌道）

AVMutableAudioMixInputParameters

*trackMix

=[AVMutableAudioMixInputParametersaudioMixInputParametersWithTrack:track];

[trackMix