diff --git a/Sources/SCScrollableWaveformView.h b/Sources/SCScrollableWaveformView.h
index 942ea63..775ab72 100644
--- a/Sources/SCScrollableWaveformView.h
+++ b/Sources/SCScrollableWaveformView.h
@@ -9,7 +9,7 @@
 #import <UIKit/UIKit.h>
 #import "SCWaveformView.h"
 
-@interface SCScrollableWaveformView : UIScrollView
+@interface SCScrollableWaveformView : UIScrollView<UIScrollViewDelegate>
 
 @property (readonly, nonatomic) SCWaveformView *waveformView;
 
diff --git a/Sources/SCScrollableWaveformView.m b/Sources/SCScrollableWaveformView.m
index 772ffd7..1e276a3 100644
--- a/Sources/SCScrollableWaveformView.m
+++ b/Sources/SCScrollableWaveformView.m
@@ -48,6 +48,30 @@ - (void)_commonInit {
     [self addSubview:_waveformView];
     
     [self addObserver:self forKeyPath:@"contentOffset" options:NSKeyValueObservingOptionNew context:ScrollableWaveformContentOffsetContext];
+    
+    self.delegate = self;
+}
+
+- (void)_setAutoNeedsDisplayedEnabled:(BOOL)enabled {
+    _waveformView.needsDisplayOnProgressTimeChange = enabled;
+}
+
+- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView {
+    [self _setAutoNeedsDisplayedEnabled:YES];
+}
+
+- (void)scrollViewDidEndScrollingAnimation:(UIScrollView *)scrollView {
+    [self _setAutoNeedsDisplayedEnabled:YES];
+}
+
+- (void)scrollViewWillBeginDragging:(UIScrollView *)scrollView {
+    [self _setAutoNeedsDisplayedEnabled:NO];
+}
+
+- (void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate {
+    if (!decelerate) {
+        [self _setAutoNeedsDisplayedEnabled:YES];
+    }
 }
 
 - (void)dealloc {
diff --git a/Sources/SCWaveformCache.m b/Sources/SCWaveformCache.m
index 64dd799..2f0c2e9 100644
--- a/Sources/SCWaveformCache.m
+++ b/Sources/SCWaveformCache.m
@@ -148,13 +148,13 @@ - (BOOL)readTimeRange:(CMTimeRange)timeRange width:(CGFloat)width error:(NSError
     }
     
     if (shouldReadAsset) {
-        NSDictionary *outputSettingsDict = [[NSDictionary alloc] initWithObjectsAndKeys:
-                                            [NSNumber numberWithInt:kAudioFormatLinearPCM], AVFormatIDKey,
-                                            [NSNumber numberWithInt:16], AVLinearPCMBitDepthKey,
-                                            [NSNumber numberWithBool:NO], AVLinearPCMIsBigEndianKey,
-                                            [NSNumber numberWithBool:NO], AVLinearPCMIsFloatKey,
-                                            [NSNumber numberWithBool:NO], AVLinearPCMIsNonInterleaved,
-                                            nil];
+        NSDictionary *outputSettingsDict = @{
+                                             AVFormatIDKey : [NSNumber numberWithInt:kAudioFormatLinearPCM],
+                                             AVLinearPCMBitDepthKey : @16,
+                                             AVLinearPCMIsBigEndianKey : @NO,
+                                             AVLinearPCMIsFloatKey : @NO,
+                                             AVLinearPCMIsNonInterleaved : @NO
+                                             };
         
         AVAssetReaderTrackOutput *output = [[AVAssetReaderTrackOutput alloc] initWithTrack:songTrack outputSettings:outputSettingsDict];
         output.alwaysCopiesSampleData = NO;
@@ -176,15 +176,14 @@ - (BOOL)readTimeRange:(CMTimeRange)timeRange width:(CGFloat)width error:(NSError
         NSUInteger bigSampleCount = 0;
         NSMutableData *data = [NSMutableData new];
         UInt32 bytesPerInputSample = 2 * channelCount;
-
-        CGFloat currentX = 0;
+        
         while (reader.status == AVAssetReaderStatusReading) {
             CMSampleBufferRef sampleBufferRef = [output copyNextSampleBuffer];
             
             if (sampleBufferRef) {
                 CMBlockBufferRef blockBufferRef = CMSampleBufferGetDataBuffer(sampleBufferRef);
                 size_t bufferLength = CMBlockBufferGetDataLength(blockBufferRef);
-       
+                
                 char *dataPointer;
                 CMBlockBufferGetDataPointer(blockBufferRef, 0, &bufferLength, nil, &dataPointer);
                 
@@ -207,7 +206,6 @@ - (BOOL)readTimeRange:(CMTimeRange)timeRange width:(CGFloat)width error:(NSError
                         
                         [data appendBytes:&averageSample length:(sizeof(float))];
                         
-                        currentX++;
                         bigSample = 0;
                         bigSampleCount  = 0;
                     }
diff --git a/Sources/SCWaveformView.h b/Sources/SCWaveformView.h
index 2cad45d..6d0ef3a 100644
--- a/Sources/SCWaveformView.h
+++ b/Sources/SCWaveformView.h
@@ -18,23 +18,8 @@
 @property (assign, nonatomic) CMTime progressTime;
 @property (assign, nonatomic) BOOL antialiasingEnabled;
 
+@property (assign, nonatomic) BOOL needsDisplayOnProgressTimeChange;
+
 @property (assign, nonatomic) CMTimeRange timeRange;
 
 @end
-
-
-//typedef enum : NSUInteger {
-//    /**
-//     The WaveformView draw manually in "drawRect:" method.
-//     This is the fastest way to render the waveform.
-//
-//     */
-//    SCWaveformViewRenderingModeDraw,
-//
-//    /**
-//     The WaveformView render the waveform in UIImage's.
-//     This is slower, however it will be.
-//
-//     */
-//    SCWaveformViewRenderingModeGenImages
-//} SCWaveformViewRenderingMode;
diff --git a/Sources/SCWaveformView.m b/Sources/SCWaveformView.m
index dcce984..3ed87b2 100644
--- a/Sources/SCWaveformView.m
+++ b/Sources/SCWaveformView.m
@@ -43,9 +43,11 @@ - (instancetype)initWithCoder:(NSCoder *)aDecoder {
 }
 
 - (void)commonInit {
+    _needsDisplayOnProgressTimeChange = YES;
     self.normalColor = [UIColor blueColor];
     self.progressColor = [UIColor redColor];
     _timeRange = CMTimeRangeMake(kCMTimeZero, kCMTimePositiveInfinity);
+    _progressTime = kCMTimeZero;
     
     _cache = [SCWaveformCache new];
 }
@@ -151,7 +153,10 @@ - (void)setAsset:(AVAsset *)asset {
 
 - (void)setProgressTime:(CMTime)progressTime {
     _progressTime = progressTime;
-    [self setNeedsDisplay];
+    
+    if (self.needsDisplayOnProgressTimeChange) {
+        [self setNeedsDisplay];
+    }
 }
 
 - (void)setAntialiasingEnabled:(BOOL)antialiasingEnabled {