ios - 将音频片段以给定的偏移量插入原始音频文件中

Question

我正在开发一个具有录制功能的应用程序。现在，我需要在特定时间位置使用另一个剪辑对其进行编辑。即我有20秒的录制时间，现在想在10秒内用5秒的持续时间将其替换为另一个音频文件，所以我导出的音频文件将像前10秒是我录制的音频，第10-15秒是剪辑，我必须替换为原始文件，然后15秒-20秒再次成为我的录制文件。

请帮助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];
     });
 }];

}`

Answer 1

您必须先从特定偏移量修剪音频，否则此网址可能会对您有所帮助。

iOS Audio Trimming

之后，合并您的另一个音频。