如何解决iOS中的video定位问题
我正在使用一个应用程序，用户从照片中挑选video并将其上传到服务器。 由于我的服务器是.Net服务器，video被旋转。 我知道问题的原因可能是相同的情况下的形象（你可以参考我以前的回答https://stackoverflow.com/a/10601175/1030951 ），所以我GOOGLE了，并得到了一个代码来解决video方向 ，我从RayWenderlich.com获得了一个代码，并按照以下方式修改。 现在我的输出video工作正常，但video静音。 它播放，但不播放audio。 请帮助我，如果我失去了一些东西。
我传递信息字典-(void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info方法
- (void)fix:(NSDictionary*)pobjInfoDirectory withFileName:(NSString*)pstrOutputFileName { firstAsset = [AVAsset assetWithURL:[pobjInfoDirectory objectForKey:UIImagePickerControllerMediaURL]]; if(firstAsset !=nil) { //Create AVMutableComposition Object.This object will hold our multiple AVMutableCompositionTrack. AVMutableComposition* mixComposition = [[AVMutableComposition alloc] init]; //VIDEO TRACK AVMutableCompositionTrack *firstTrack = [mixComposition addMutableTrackWithMediaType:AVMediaTypeVideo preferredTrackID:kCMPersistentTrackID_Invalid]; [firstTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero, firstAsset.duration) ofTrack:[[firstAsset tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0] atTime:kCMTimeZero error:nil]; AVMutableVideoCompositionInstruction * MainInstruction = [AVMutableVideoCompositionInstruction videoCompositionInstruction]; MainInstruction.timeRange = CMTimeRangeMake(kCMTimeZero, firstAsset.duration); //FIXING ORIENTATION// AVMutableVideoCompositionLayerInstruction *FirstlayerInstruction = [AVMutableVideoCompositionLayerInstruction videoCompositionLayerInstructionWithAssetTrack:firstTrack]; AVAssetTrack *FirstAssetTrack = [[firstAsset tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0]; UIImageOrientation FirstAssetOrientation_ = UIImageOrientationUp; BOOL isFirstAssetPortrait_ = NO; CGAffineTransform firstTransform = FirstAssetTrack.preferredTransform; if(firstTransform.a == 0 && firstTransform.b == 1.0 && firstTransform.c == -1.0 && firstTransform.d == 0) { FirstAssetOrientation_= UIImageOrientationRight; isFirstAssetPortrait_ = YES; } if(firstTransform.a == 0 && firstTransform.b == -1.0 && firstTransform.c == 1.0 && firstTransform.d == 0) { FirstAssetOrientation_ = UIImageOrientationLeft; isFirstAssetPortrait_ = YES; } if(firstTransform.a == 1.0 && firstTransform.b == 0 && firstTransform.c == 0 && firstTransform.d == 1.0) { FirstAssetOrientation_ = UIImageOrientationUp; } if(firstTransform.a == -1.0 && firstTransform.b == 0 && firstTransform.c == 0 && firstTransform.d == -1.0) { FirstAssetOrientation_ = UIImageOrientationDown; } CGFloat FirstAssetScaleToFitRatio = 320.0/FirstAssetTrack.naturalSize.width; if(isFirstAssetPortrait_) { FirstAssetScaleToFitRatio = 320.0/FirstAssetTrack.naturalSize.height; CGAffineTransform FirstAssetScaleFactor = CGAffineTransformMakeScale(FirstAssetScaleToFitRatio,FirstAssetScaleToFitRatio); [FirstlayerInstruction setTransform:CGAffineTransformConcat(FirstAssetTrack.preferredTransform, FirstAssetScaleFactor) atTime:kCMTimeZero]; } else { CGAffineTransform FirstAssetScaleFactor = CGAffineTransformMakeScale(FirstAssetScaleToFitRatio,FirstAssetScaleToFitRatio); [FirstlayerInstruction setTransform:CGAffineTransformConcat(CGAffineTransformConcat(FirstAssetTrack.preferredTransform, FirstAssetScaleFactor),CGAffineTransformMakeTranslation(0, 160)) atTime:kCMTimeZero]; } [FirstlayerInstruction setOpacity:0.0 atTime:firstAsset.duration]; MainInstruction.layerInstructions = [NSArray arrayWithObjects:FirstlayerInstruction,nil];; AVMutableVideoComposition *MainCompositionInst = [AVMutableVideoComposition videoComposition]; MainCompositionInst.instructions = [NSArray arrayWithObject:MainInstruction]; MainCompositionInst.frameDuration = CMTimeMake(1, 30); MainCompositionInst.renderSize = CGSizeMake(320.0, 480.0); NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); NSString *documentsDirectory = [paths objectAtIndex:0]; NSString *myPathDocs = [documentsDirectory stringByAppendingPathComponent:[NSString stringWithFormat:@"mergeVideo-%d.mov",arc4random() % 1000]]; NSURL *url = [NSURL fileURLWithPath:myPathDocs]; AVAssetExportSession *exporter = [[AVAssetExportSession alloc] initWithAsset:mixComposition presetName:AVAssetExportPresetHighestQuality]; exporter.outputURL=url; exporter.outputFileType = AVFileTypeQuickTimeMovie; exporter.videoComposition = MainCompositionInst; exporter.shouldOptimizeForNetworkUse = YES; [exporter exportAsynchronouslyWithCompletionHandler:^ { dispatch_async(dispatch_get_main_queue(), ^{ [self exportDidFinish:exporter]; }); }]; } } - (void)exportDidFinish:(AVAssetExportSession*)session { if(session.status == AVAssetExportSessionStatusCompleted) { NSURL *outputURL = session.outputURL; ALAssetsLibrary *library = [[ALAssetsLibrary alloc] init]; if ([library videoAtPathIsCompatibleWithSavedPhotosAlbum:outputURL]) { if ([self.delegate respondsToSelector:@selector(videoExported)]) [self.delegate videoExported]; } } firstAsset = nil; }
在//VIDEO TRACK部分之后添加这个
//AUDIO TRACK AVMutableCompositionTrack *firstAudioTrack = [mixComposition addMutableTrackWithMediaType:AVMediaTypeAudio preferredTrackID:kCMPersistentTrackID_Invalid]; [firstAudioTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero, firstAsset.duration) ofTrack:[[firstAsset tracksWithMediaType:AVMediaTypeAudio] objectAtIndex:0] atTime:kCMTimeZero error:nil];
AVURLAsset* videoAsset = [[AVURLAsset alloc]initWithURL:@"your video url here..." options:nil];
添加AVMutableCompositionTrack之后。
set setPreferredTransform:在这里设置你想要以相同方向导出的源video。
// Grab the source track from AVURLAsset for example. AVAssetTrack *assetVideoTrack = [videoAsset tracksWithMediaType:AVMediaTypeVideo].lastObject; // Grab the composition video track from AVMutableComposition you already made. AVMutableCompositionTrack *compositionVideoTrack = [mixComposition tracksWithMediaType:AVMediaTypeVideo].lastObject; // Apply the original transform. if (assetVideoTrack && compositionVideoTrack) { [compositionVideoTrack setPreferredTransform:assetVideoTrack.preferredTransform]; }