iPhone - show audio record feedback using AVAudioRecorder

Question

Hi

I am using the AVAudioRecorder class to record to a wav file. I would like to implement a recording feedback (like the SpeakHere example) which shows the recording level.

I did go through the SpeakHere sample but could not understand how the recording level was changed. Can someone please guide me as to what needs to be done?

Thanks.

Answer 1

If you are using AVAudioRecorder, you might want to just use the following to get the power levels:

- (float)peakPowerForChannel:(NSUInteger)channelNumber
- (void)updateMeters

Those give you the values to graph. There are simpler ways to graph those values, but to see how the SpeakHere sample does it, see their README:

AQLevelMeter.h
AQLevelMeter.mm

The AQLevelMeter class defines the level meter view for the applcation, displaying the metering data from an AudioQueue object

LevelMeter.h
LevelMeter.m

LevelMeter is a base metering class, providing simple functionality for displaying level data

GLLevelMeter.h
GLLevelMeter.m

GLLevelMeter is a subclass of LevelMeter that uses OpenGL for drawing

AQRecorder.h
AQRecorder.m