修复视频转向方法中可能发生的内存泄漏问题

TZImagePickerController/TZImagePickerController/TZImageManager.m

@@ -835,29 +835,30 @@ static CGFloat TZScreenScale;
         NSArray *tracks = [videoAsset tracksWithMediaType:AVMediaTypeVideo];
         AVAssetTrack *videoTrack = [tracks objectAtIndex:0];
         
+        AVMutableVideoCompositionInstruction *roateInstruction = [AVMutableVideoCompositionInstruction videoCompositionInstruction];
+        roateInstruction.timeRange = CMTimeRangeMake(kCMTimeZero, [videoAsset duration]);
+        AVMutableVideoCompositionLayerInstruction *roateLayerInstruction = [AVMutableVideoCompositionLayerInstruction videoCompositionLayerInstructionWithAssetTrack:videoTrack];
+        
         if (degrees == 90) {
             // 顺时针旋转90°
             translateToCenter = CGAffineTransformMakeTranslation(videoTrack.naturalSize.height, 0.0);
             mixedTransform = CGAffineTransformRotate(translateToCenter,M_PI_2);
             videoComposition.renderSize = CGSizeMake(videoTrack.naturalSize.height,videoTrack.naturalSize.width);
+            [roateLayerInstruction setTransform:mixedTransform atTime:kCMTimeZero];
         } else if(degrees == 180){
             // 顺时针旋转180°
             translateToCenter = CGAffineTransformMakeTranslation(videoTrack.naturalSize.width, videoTrack.naturalSize.height);
             mixedTransform = CGAffineTransformRotate(translateToCenter,M_PI);
             videoComposition.renderSize = CGSizeMake(videoTrack.naturalSize.width,videoTrack.naturalSize.height);
+            [roateLayerInstruction setTransform:mixedTransform atTime:kCMTimeZero];
         } else if(degrees == 270){
             // 顺时针旋转270°
             translateToCenter = CGAffineTransformMakeTranslation(0.0, videoTrack.naturalSize.width);
             mixedTransform = CGAffineTransformRotate(translateToCenter,M_PI_2*3.0);
             videoComposition.renderSize = CGSizeMake(videoTrack.naturalSize.height,videoTrack.naturalSize.width);
+            [roateLayerInstruction setTransform:mixedTransform atTime:kCMTimeZero];
         }
         
-        AVMutableVideoCompositionInstruction *roateInstruction = [AVMutableVideoCompositionInstruction videoCompositionInstruction];
-        roateInstruction.timeRange = CMTimeRangeMake(kCMTimeZero, [videoAsset duration]);
-        AVMutableVideoCompositionLayerInstruction *roateLayerInstruction = [AVMutableVideoCompositionLayerInstruction videoCompositionLayerInstructionWithAssetTrack:videoTrack];
-        
-        [roateLayerInstruction setTransform:mixedTransform atTime:kCMTimeZero];
-        
         roateInstruction.layerInstructions = @[roateLayerInstruction];
         // 加入视频方向信息
         videoComposition.instructions = @[roateInstruction];