AVMutableComposizione Creazione di video Numero

Question

Sto creando video utilizzando AVMutableComposition ed esportandolo utilizzando AVAssetExportSession dandogli il valore predefinito AVAssetExportPresetHighestQuality.

Il video viene creato correttamente quando le dimensioni del video sono ridotte. Ma quando la dimensione del video è grande, ad es. (1280 × 1920), il video non viene creato correttamente. Una sovrapposizione verde si aggiunge al video come di seguito immagine:

Ma quando io uso AVAssetExportPresetPassthrough invece AVAssetExportPresetHighestQuality, il video è stato creato bene.

Qualche idea del motivo?

Grazie in anticipo !!

Answer 1

provare questo codice:

-(void)convertVideo:(NSString *)videoPath{ 
     AVURLAsset *firstAsset=[[AVURLAsset alloc]initWithURL:[NSURL URLWithString: [NSString stringWithFormat:@"%@", videoPath]] options:nil]; 
     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); 

     CMTime audioTime = kCMTimeIndefinite; 
     CMTimeRange audio_timeRange = CMTimeRangeMake(kCMTimeZero, firstAsset.duration); 

     AVAudioSession *audioSession = [AVAudioSession sharedInstance]; 
     [audioSession setCategory:AVAudioSessionCategoryPlayAndRecord error:nil]; 
     [audioSession setActive:YES error:nil]; 

     if (OS_VERSION>=7) { 
      if (firstAsset!=NULL) { 
       AVMutableCompositionTrack *compositionCommentaryTrack = [mixComposition addMutableTrackWithMediaType:AVMediaTypeAudio preferredTrackID:kCMPersistentTrackID_Invalid]; 

       [compositionCommentaryTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero, firstAsset.duration) ofTrack:[[firstAsset tracksWithMediaType:AVMediaTypeAudio] objectAtIndex:0] atTime:kCMTimeZero error:nil]; 
      } 
     } 
     else{ 
      AVMutableCompositionTrack *b_compositionAudioTrack = [mixComposition addMutableTrackWithMediaType:AVMediaTypeAudio preferredTrackID:kCMPersistentTrackID_Invalid]; 
      [b_compositionAudioTrack insertTimeRange:audio_timeRange ofTrack:[[firstAsset tracksWithMediaType:AVMediaTypeAudio] objectAtIndex:0] atTime:audioTime error:nil]; 
     } 

     //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; 
     } 

     [FirstlayerInstruction setOpacity:0.0 atTime:firstAsset.duration]; 

     CGFloat FirstAssetScaleToFitRatio = 0; 


     MainInstruction.layerInstructions = [NSArray arrayWithObjects:FirstlayerInstruction,nil]; 

     AVMutableVideoComposition *MainCompositionInst = [AVMutableVideoComposition videoComposition]; 
     MainCompositionInst.instructions = [NSArray arrayWithObject:MainInstruction]; 
     MainCompositionInst.frameDuration = CMTimeMake(1, 30); 

     /*if(isFirstAssetPortrait_){ 
      FirstAssetScaleToFitRatio = 0.67; 
      CGAffineTransform FirstAssetScaleFactor = CGAffineTransformMakeScale(FirstAssetScaleToFitRatio,FirstAssetScaleToFitRatio); 
      [FirstlayerInstruction setTransform:CGAffineTransformConcat(FirstAssetTrack.preferredTransform, FirstAssetScaleFactor) atTime:kCMTimeZero]; 
      naturalSizeFirst = CGSizeMake(FirstAssetTrack.naturalSize.height, FirstAssetTrack.naturalSize.width); 
      }else{ 

       naturalSizeFirst = FirstAssetTrack.naturalSize; 
     } 
     */ 

     CGSize naturalSizeFirst; 
     if(isFirstAssetPortrait_){ 
      FirstAssetScaleToFitRatio = FirstAssetTrack.naturalSize.width/FirstAssetTrack.naturalSize.height; 
      CGAffineTransform FirstAssetScaleFactor = CGAffineTransformMakeScale(FirstAssetScaleToFitRatio,FirstAssetScaleToFitRatio); 
      [FirstlayerInstruction setTransform:CGAffineTransformConcat(FirstAssetTrack.preferredTransform, FirstAssetScaleFactor) atTime:kCMTimeZero]; 
      naturalSizeFirst = CGSizeMake(FirstAssetTrack.naturalSize.height, FirstAssetTrack.naturalSize.width); 

     }else { 
      naturalSizeFirst = FirstAssetTrack.naturalSize; 
     } 

     MainCompositionInst.renderSize = CGSizeMake(naturalSizeFirst.width, naturalSizeFirst.height); 

     NSString *tmpDirectory = NSTemporaryDirectory(); 
     NSString *fname = [NSString stringWithFormat:@"mergeVideo-%d.mov",arc4random() % 1000]; 
     NSString *tmpFile = [tmpDirectory stringByAppendingPathComponent:fname]; 

     NSURL *url = [NSURL fileURLWithPath:tmpFile]; 

     AVAssetExportSession *exporter = [[AVAssetExportSession alloc] initWithAsset:mixComposition presetName:AVAssetExportPresetHighestQuality]; 
     exporter.outputURL=url; 
     exporter.outputFileType = AVFileTypeQuickTimeMovie; 
     exporter.videoComposition = MainCompositionInst; 
     exporter.shouldOptimizeForNetworkUse = YES; 

     [exporter exportAsynchronouslyWithCompletionHandler:^{ 

      if (AVAssetExportSessionStatusCompleted == exporter.status) { 
       [self.progressStatus setText:@"Converted..."]; 

       selectedVideo = selectedVideo+1; 
      } else if (AVAssetExportSessionStatusFailed == exporter.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 
       //ALog(@"AVAssetExportSessionStatusFailed %@",exporter.error); 

      } else { 
       //ALog(@"Export Session Status: %d", exporter.status); 
      } 
     }]; 
    } 
}