在给定偏移量处将音频剪辑插入原始音频文件

Posted 2023-02-25

【中文标题】在给定偏移量处将音频剪辑插入原始音频文件

【英文标题】：Insert audio clip in original audio file at given offset

【发布时间】：2017-02-06 10:07:35

【问题描述】：

我正在开发一个具有录音功能的应用程序。现在我需要在特定时间位置用另一个剪辑对其进行编辑。即我录制了 20 秒，现在想在第 10 秒用另一个持续时间为 5 秒的音频文件替换它，所以我导出的音频文件就像前 10 秒是我录制的音频，第 10 - 15 秒是剪辑我必须用原来的替换，然后第 15 - 20 秒又是我录制的文件。

请帮我找到附近的解决方案

提前致谢。

这是我的代码` -(void)mergeAndSaveWithVideoURLAtFirstOffset:(CMTime)offset1 和SecondOffset:(CMTime)offset2

NSURL *video_url = [NSURL fileURLWithPath:[[NSBundle mainBundle] pathForResource:@"Source" ofType:@"mp4"]];

AVMutableComposition* mixComposition = [AVMutableComposition composition];

NSURL *source_audio_url=[NSURL fileURLWithPath:[[NSBundle mainBundle] pathForResource:@"Source" ofType:@"mp3"]];

NSURL *audio_url=[NSURL fileURLWithPath:[[NSBundle mainBundle] pathForResource:@"Asteroid_Sound" ofType:@"mp3"]];

audioAsset = [[AVURLAsset alloc]initWithURL:audio_url options:nil];

source_audioAsset = [[AVURLAsset alloc]initWithURL:source_audio_url options:nil];

CMTimeRange audio_timeRange = CMTimeRangeMake(kCMTimeZero, source_audioAsset.duration);

AVMutableCompositionTrack *b_compositionAudioTrack = [mixComposition addMutableTrackWithMediaType:AVMediaTypeAudio preferredTrackID:kCMPersistentTrackID_Invalid];

[b_compositionAudioTrack insertTimeRange:audio_timeRange ofTrack:[[source_audioAsset tracksWithMediaType:AVMediaTypeAudio] objectAtIndex:0] atTime:kCMTimeZero error:nil];

audio_timeRange = CMTimeRangeMake(kCMTimeZero, audioAsset.duration);

[b_compositionAudioTrack insertTimeRange:audio_timeRange ofTrack:[[audioAsset tracksWithMediaType:AVMediaTypeAudio] objectAtIndex:0] atTime:offset1 error:nil];

[b_compositionAudioTrack insertTimeRange:audio_timeRange ofTrack:[[audioAsset tracksWithMediaType:AVMediaTypeAudio] objectAtIndex:0] atTime:offset2 error:nil];

videoAsset = [[AVURLAsset alloc]initWithURL:video_url options:nil];

CMTimeRange video_timeRange = CMTimeRangeMake(kCMTimeZero,videoAsset.duration);

AVMutableCompositionTrack *a_compositionVideoTrack = [mixComposition addMutableTrackWithMediaType:AVMediaTypeVideo preferredTrackID:kCMPersistentTrackID_Invalid];

[a_compositionVideoTrack insertTimeRange:video_timeRange ofTrack:[[videoAsset tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0] atTime:kCMTimeZero error:nil];

NSArray *dirPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *docsDir = [dirPaths objectAtIndex:0];
NSString *outputFilePath = [docsDir stringByAppendingPathComponent:[NSString stringWithFormat:@"FinalVideo.mov"]];
NSURL *outputFileUrl = [NSURL fileURLWithPath:outputFilePath];
if ([[NSFileManager defaultManager] fileExistsAtPath:outputFilePath])
    [[NSFileManager defaultManager] removeItemAtPath:outputFilePath error:nil];

AVAssetExportSession* _assetExport = [[AVAssetExportSession alloc] initWithAsset:mixComposition presetName:AVAssetExportPresetHighestQuality];
_assetExport.outputFileType = @"com.apple.quicktime-movie";
_assetExport.outputURL = outputFileUrl;

[_assetExport exportAsynchronouslyWithCompletionHandler:
 ^(void ) 
     dispatch_async(dispatch_get_main_queue(), ^
         [self exportDidFinish:_assetExport];
     );
 ];

`

【问题讨论】：

您能否详细说明您为自己解决问题所做的具体工作以及预期结果与实际结果有何不同？仅通过一些折腾的代码真的很难分辨。

【参考方案1】：

您必须先从特定偏移量修剪音频，这可能会对您有所帮助。

ios Audio Trimming

然后合并您的另一个音频。