Removing Silence from Audio Queue session recorded audio in ios

Question

I'm using Audio Queue to record audio from the iphone's mic and stop recording when silence detected (no audio input for 10seconds) but I want to discard the silence from audio file.

In AudioInputCallback function I am using following code to detect silence :

AudioQueueLevelMeterState meters[1];
UInt32 dlen = sizeof(meters);
OSStatus Status AudioQueueGetProperty(inAQ,kAudioQueueProperty_CurrentLevelMeterDB,meters,&dlen);
if(meters[0].mPeakPower < _threshold)
{ // NSLog(@"Silence detected");}

But how to remove these packets? Or Is there any better option?

Answer 1

Instead of removing the packets from the AudioQueue, you can delay the write up by writing it to a buffer first. The buffer can be easily defined by having it inside the inUserData.

When you finish recording, if the last 10 seconds is not silent, you write it back to whatever file you are going to write. Otherwise just free the buffer.

Answer 2

记录并关闭文件后，只需打开并截断您不感兴趣的示例数据（注意：您可以使用AudioFile / ExtAudioFile API正确更新任何相关的块/标头大小）。