How to get the length of the current background music in seconds or milliseconds

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How to get the length of the current background music in seconds or milliseconds

(15 posts) (4 voices)

Started 2 years ago by CJ
Latest reply from andreh

Tags:

CJ
Moderator

Does anyone know how to get the duration of a sound file programatically?

I'd like to switch between different background music but I also want to display how much time remains on the currently playing song.

Thanks :)

Posted 2 years ago #
ob1
Member

If you use Denshion, probably something like

[[[[CDAudioManager] sharedManager] backgroundMusic] duration];

and

[[[[CDAudioManager] sharedManager] backgroundMusic] currentTime];

Posted 2 years ago #
Steve Oldmeadow
Administrator

Yes, ob1 is correct. Or using property notation:

[CDAudioManager sharedManager].backgroundMusic.duration
[CDAudioManager sharedManager].backgroundMusic.currentTime

note that currentTime can be set as well and is used to seek to a certain position within an audio file.

Posted 2 years ago #
CJ
Moderator

Works great! Thank you :)

Posted 2 years ago #
andreh
Member

Can anyone provide a more fleshed-out example of this in action?

[CDAudioManager sharedManager].backgroundMusic.currentTime

I'm having no luck...I keep getting this error when I try to get or set it (probably a syntax issue knowing my newbeeness): "request for member 'currentTime' in something not a structure or union"

A simple example that CCLOG's the current MP3 running time each frame would be incredibly helpful.

TIA,
André

Posted 2 years ago #
CJ
Moderator
try importing avfoundation framework
```
#import <AVFoundation/AVFoundation.h>
```
Posted 2 years ago #
andreh
Member
Thanks CJ...unfortunately that didn't solve the problem. I've already imported CDAudioManager.h (which itself imports AVFoundation/AVFoundation.h) and have successfully begun streaming an MP3 with:
```
[[CDAudioManager sharedManager] playBackgroundMusic:@"myMusic.mp3" loop:YES];
```
Still can't figure out a way to use the currentTime property to any extent.

André
Posted 2 years ago #
Steve Oldmeadow
Administrator

@andreh - try reading the source code. What is the return type of the backgroundMusic property? Does the returned class have a property called currentTime (No)? You may notice the code you are trying to use is from 8 months ago, things change:

http://www.cocos2d-iphone.org/wiki/doku.php/cocosdenshion:faq#i_m_upgrading_to_a_newer_version_of_cocosdenshion_and_now_i_get_errors

Posted 2 years ago #
andreh
Member
@Steve - Awesome, thanks...got it working with the following code:
```
[[CDAudioManager sharedManager] playBackgroundMusic:@"myTrack.mp3" loop:YES];
[[CDAudioManager sharedManager].backgroundMusic.audioSourcePlayer setCurrentTime: 1.5]; // <-appears to be time in seconds
CCLOG(@"%f",[CDAudioManager sharedManager].backgroundMusic.audioSourcePlayer.currentTime);
```
I had looked through the source code (trying not to be lazy here), but I'm still wrapping my head around Objective-C syntax. I'm sure I'll be asking more seemingly obvious questions here in the near future, and I appreciate your (and others') patience and your "teach a man to fish" approach to answering our Q's. ;)

André
Posted 2 years ago #
andreh
Member
Okay, so I've just done some testing on this and it appears currentTime is reflecting an inaccurate value once setCurrentTime is set.

In init function:
```
[[CDAudioManager sharedManager] playBackgroundMusic:@"myTrack.mp3" loop:YES];
[self schedule:@selector(nextFrame:)];
```
Elsewhere:
```
- (void) nextFrame:(ccTime)dt {
	float mxIndex = [CDAudioManager sharedManager].backgroundMusic.audioSourcePlayer.currentTime;
	CCLOG(@"%g", mxIndex);
	if (mxIndex >= 5){
		[[CDAudioManager sharedManager].backgroundMusic.audioSourcePlayer setCurrentTime: 0];
	}
}
```
With the setCurrentTime and mxIndex max times above, initially after five seconds the track will start over from the beginning, but the currentTime will reflect -5. Each successive restart of the music (which doesn't happen when 5 additional seconds of music have played but rather when the now incorrect currentTime value reads +5) will cause the currentTime value to jump back an additional 5 seconds (to -10, then to -15, then to -20) while the track itself actually starts over from the beginning each time.

Am I doing something wrong here (probably) or is this a bug?

André
Posted 2 years ago #
CJ
Moderator

What happens if you do rewind instead of setCurrentTime:0 ?

Posted 2 years ago #
Steve Oldmeadow
Administrator

@andreh - it sounds like a bug, are you testing on a device? Don't do any testing with background music in the simulator - the implementation of AVAudioPlayer is very poor in the simulator.

If you are on a device - what device and OS version?

Posted 2 years ago #
andreh
Member

@Steve - I'm currently testing on a 1G iPod Touch with OS 3.1.1 (will also be testing on a 2G OS 3.1.3 after I get Snow Leopard installed).

The problem occurs in Debug and Release builds 3.0 and 3.1 (Sim and Device) EXCEPT 3.0 Sim.

André

Posted 2 years ago #
Steve Oldmeadow
Administrator
I can confirm the bug occurs on a 3GS with 3.1.3. However, if I pause the background music before setting the currentTime everything seems to work okay. e.g something like
```
am.backgroundMusic.audioSourcePlayer.pause;
am.backgroundMusic.audioSourcePlayer.currentTime = 0.0f;
am.backgroundMusic.audioSourcePlayer.play;
```
Posted 2 years ago #
andreh
Member

Thanks Steve...your suggestion of pausing before using setCurrentTime seems to be solving the problem (except that I'm unable to resume playback after pausing and resetting...but I'm probably doing something wrong).

I'm working on a music game so achieving tight integration with playback is paramount. Your help (and from others) is greatly appreciated.

André

Posted 2 years ago #

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