How can improve MPVolumeView performance?

Question

i'm working on a iOS project, related with video streamming. One of the controls in the UI is a MPVolumeView. The problem is that when i slide the control for change volume, it seems to use to much CPU. And in fact, the UI becomes slow while i use the slider. How can improve the performance?, maybe i'm doing something wrong?

Reference image for CPU Load from Instruments. In the left only streaming, the peaks in the right were streaming+volume slide.

Thanks.

EDIT:

This is how i'm adding the control to a view:

MPVolumeView *mpVolume = [[MPVolumeView alloc] initWithFrame:CGRectMake(32,
                                                                        56,
                                                                        160,
                                                                        9)];
[self addSubview:mpVolume];
[mpVolume release];

"self" is a custom view, inherits from UIView, but i'm not using xib and drawRect. I'm just adding all the controls in the "initWithFrame:frame" method.

In order for us to be able to answer your question, you need to add some more information. Right now there isn't enough detail included for anyone to do much more than guess :) — Dustin, Aug 02 '12 at 14:32
What is your `MPVolumeView`'s target action? There's a fair chance that the problem lies with changing the volume too often on a sensitive part of media playing code, rather than with the UI itself. — LodeRunner, Aug 02 '12 at 14:55
Hi @LodeRunner i'm not using MPVolumeView target action. It is my first time with this view, and i'm using it as simple as Apple doc explain. — LuisEspinoza, Aug 02 '12 at 15:05

score 0 · Answer 1 · answered Aug 02 '12 at 15:05

Watch how many times init with frame is called. Sometimes I have seen it get called more than once, and sometimes often, depending on the situation. You probably want to only Alloc the volume view when the view is first set up. It sounds like it might be setting up the volume view again and again.

One potential is to make the volume view a class property (private or public)

 @property (nonatomic, retain) MPVolumeView *mpVolume;

Then of course... @synthesize mpVolume = _mpVolume

Then in initWithFrame just check and see if it's nil, and then alloc

 if(_mpVolume == nil){
      _mpVolume = [[MPVolumeView alloc] initWithFrame:CGRectMake(32,56,160,9)];
      [self addSubview:_mpVolume];
 }

Then release mpVolume in dealloc

Ok... :-/ One other idea is that view checks for airplay devices and displays the airplay button if it's there. Have you tried doing the same CPU tests in airplane mode? I know using airplane mode is not a solution, but it would help you know if it's an airplay issue — Eric Welander, Aug 02 '12 at 15:30
Tested, but the problem continues.., it seems to be better, but not enough — LuisEspinoza, Aug 02 '12 at 16:59

How can improve MPVolumeView performance?

1 Answers1