iOS: Audio Recording File Format

Question

I am implementing the Audio recording. It works fine with caf & wave format. But the problem is file size is too big.

So, can anyone h

Answer 1

NSMutableDictionary *settings = [[NSMutableDictionary alloc] initWithCapacity:0];

[settings setValue :[NSNumber numberWithInt:kAudioFormatMPEG4AAC] forKey:AVFormatIDKey];
[settings setValue:[NSNumber numberWithFloat:8000.0] forKey:AVSampleRateKey]; 
[settings setValue:[NSNumber numberWithInt: 1] forKey:AVNumberOfChannelsKey];
[settings setValue :[NSNumber numberWithInt:8] forKey:AVLinearPCMBitDepthKey];
[settings setValue :[NSNumber numberWithBool:NO] forKey:AVLinearPCMIsBigEndianKey];
[settings setValue :[NSNumber numberWithBool:NO] forKey:AVLinearPCMIsFloatKey];

//Encoder

[settings setValue :[NSNumber numberWithInt:12000] forKey:AVEncoderBitRateKey];
[settings setValue :[NSNumber numberWithInt:8] forKey:AVEncoderBitDepthHintKey];
[settings setValue :[NSNumber numberWithInt:8] forKey:AVEncoderBitRatePerChannelKey];
[settings setValue :AVAudioQualityMin           forKey:AVEncoderAudioQualityKey];