如何获得avplayer的averagePowerForChannel

Question

如何从AVPlayer获取averagePowerForChannel。 这是我的AVAudioPlayer代码，但我想从AVPlayer获取averagePowerForChannel，如下所示：

.h
@property (nonatomic, strong) AVAudioPlayer *player;

.m
- (void)updateMeters
{
    normalizedValue = [self _normalizedPowerLevelFromDecibels:[self.Player averagePowerForChannel:0]];

}