AVAudioPlayer averagePowerForChannel
- (float)averagePowerForChannel:(NSUInteger)channelNumber
Parameters
channelNumber
The audio channel whose average power value you want to obtain. Channel numbers are zero-indexed. A monaural signal, or the left channel of a stereo signal, has channel number 0.
Return Value
A floating-point representation, in decibels, of a given audio channel’s current average power. A return value of 0 dB indicates full scale, or maximum power; a return value of -160 dB indicates minimum power (that is, near silence).
If the signal provided to the audio player exceeds ±full scale, then the return value may exceed 0 (that is, it may enter the positive range).
Discussion of [AVAudioPlayer averagePowerForChannel]
To obtain a current average power value, you must call the updateMeters method before calling this method.
AVAudioPlayer averagePowerForChannel example.
for (int currChan = 0; currChan < channels; currChan++) {
//Log the peak and average power
NSLog(@"%d %0.2f %0.2f", currChan, [audioPlayer peakPowerForChannel:currChan], [audioPlayer averagePowerForChannel:currChan]);
}
//Log the peak and average power
NSLog(@"%d %0.2f %0.2f", currChan, [audioPlayer peakPowerForChannel:currChan], [audioPlayer averagePowerForChannel:currChan]);
}
Example of [AVAudioPlayer averagePowerForChannel].
-(void) monitorAudioPlayer
{
[audioPlayer updateMeters];
for (int i=0; i<audioPlayer.numberOfChannels; i++)
{
//Log the peak and average power
NSLog(@"%d %0.2f %0.2f", i, [audioPlayer peakPowerForChannel:i],[audioPlayer averagePowerForChannel:i]);
}
}
- (void)audioPlayerDidFinishPlaying:(AVAudioPlayer *)player successfully:(BOOL)flag
{
NSLog (@"audioPlayerDidFinishPlaying:");
[playerTimer invalidate];
playerTimer = nil;
}
{
[audioPlayer updateMeters];
for (int i=0; i<audioPlayer.numberOfChannels; i++)
{
//Log the peak and average power
NSLog(@"%d %0.2f %0.2f", i, [audioPlayer peakPowerForChannel:i],[audioPlayer averagePowerForChannel:i]);
}
}
- (void)audioPlayerDidFinishPlaying:(AVAudioPlayer *)player successfully:(BOOL)flag
{
NSLog (@"audioPlayerDidFinishPlaying:");
[playerTimer invalidate];
playerTimer = nil;
}
AVAudioPlayer averagePowerForChannel example.
have used the AVAudioPlayer's peakPowerForChannel and averagePowerForChannel method for getting the decibles
AVAudioPlayer *avPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL:recordedTmpFile error:&error];
avPlayer.delegate = self;
avPlayer.meteringEnabled = YES;
[avPlayer prepareToPlay];
[avPlayer play];
NSTimer *levelTimer = [NSTimer scheduledTimerWithTimeInterval: 0.03 target: self selector: @selector(levelTimerCallback:) userInfo: nil repeats: YES];
This method is return the peakPowerForChannel and averagePowerForChannel
- (void)levelTimerCallback:(NSTimer *)timer {
[avPlayer updateMeters];
NSLog(@"Peak left: %f Avg right: %f", [avPlayer peakPowerForChannel:0],[avPlayer averagePowerForChannel:0]);
}
AVAudioPlayer *avPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL:recordedTmpFile error:&error];
avPlayer.delegate = self;
avPlayer.meteringEnabled = YES;
[avPlayer prepareToPlay];
[avPlayer play];
NSTimer *levelTimer = [NSTimer scheduledTimerWithTimeInterval: 0.03 target: self selector: @selector(levelTimerCallback:) userInfo: nil repeats: YES];
This method is return the peakPowerForChannel and averagePowerForChannel
- (void)levelTimerCallback:(NSTimer *)timer {
[avPlayer updateMeters];
NSLog(@"Peak left: %f Avg right: %f", [avPlayer peakPowerForChannel:0],[avPlayer averagePowerForChannel:0]);
}
