ZLHistogramAudioPlot 0.0.1

ZLHistogramAudioPlot 0.0.1

LangLanguage Obj-CObjective C
License MIT
ReleasedLast Release Dec 2014

Maintained by Zhixuan Lai.

  • By
  • Zhixuan Lai

A hardware-accelerated audio visualization view using EZAudio, inspired by AudioCopy.



preview buffer


preview rolling


Checkout the demo app for an example.

Customizable attributes:

/// The upper bound of the frequency range the audio plot will process. Default: 10000Hz
@property (nonatomic) float maxFrequency;

/// The lower bound of the frequency range the audio plot will process. Default: 1200Hz
@property (nonatomic) float minFrequency;

/// The number of bins in the audio plot. Default: 30
@property (nonatomic) NSUInteger numOfBins;

/// The padding of the bins in percent. Default: 0.1
@property (nonatomic) CGFloat padding;

/// The gain applied to the heights of bins. Default: 10
@property (nonatomic) CGFloat gain;

/// A float that specifies the vertical gravitational acceleration applied to bins in the audio plot. Default: 10 pixel/s^2
@property (nonatomic) float gravity;

/// The color of bins in the audio plot
@property (strong,nonatomic) UIColor *color;

/// An array of color objects defining the color of each bin in the audio plot. If not set, the color attribute will be used instead. Currently not supported by Buffer type.
@property (strong,nonatomic) NSArray *colors;


  • ZLHistogramAudioPlot is a subclass of EZAudioPlot. It requires EZAudio.
  • It also requires Accelerate framework for hardware acceleration.


ZLHistogramAudioPlot uses the following interface provided by EZAudio to get audio data:

- (void)updateBuffer:(float *)buffer withBufferSize:(UInt32)bufferSize;

It can be easily modified to work with Audio Unit and Core Audio.


  • iOS 6 or higher.
  • Automatic Reference Counting (ARC).


ZLHistogramAudioPlot is available under the MIT license. See the LICENSE file for more info.