Re: 2G Mic Question
Re: 2G Mic Question
- Subject: Re: 2G Mic Question
- From: Jeff Moore <email@hidden>
- Date: Tue, 04 Aug 2009 09:01:45 -0700
Two things come to mind:
1) Are you sure you are recording at the same rates? The original
iPhone only did audio input at 8k. The others can do input at higher
rates (like 44.1k). The difference in bandwidth can make the 8k stuff
sound funky by comparison.
2) Are you doing any echo cancellation? Without doing any AEC on the
mic, you are going to be at the mercy of any echos getting into the
mic, which can result in phase distortion and a "robotic" sound from
the short delays.
On Aug 4, 2009, at 2:58 AM, Angelica Grace Tanchico wrote:
Why is the captured data from built-in mic is not as clear as with
headset mic?
This question is specifically for iPhone 2G (since I have no problems
with iPod, iPhone 3G, and iPhone 3GS).
I asked this question since my application (voip) works when headset
is used.
But when the built in mic is used, the other party hears it like
robot.
Below are the details of the AudioStreamBasicDescription variable
used.
mDataFormat.mSampleRate = 8000
mDataFormat.mChannelsPerFrame = 1
mDataFormat.mFormatID = kAudioFormatLinearPCM
mDataFormat.mFormatFlags = 12
mDataFormat.mBitsPerChannel = 16
mDataFormat.mBytesPerPacket = 2
mDataFormat.mBytesPerFrame = 2
mDataFormat.mFramesPerPacket = 1
This was the size of the buffer when AudioQueueAllocateBuffer() was
called.
bufferbytes = 320
Please I really need help.
--
Jeff Moore
Core Audio
Apple
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| References: | |
| | >2G Mic Question (From: Angelica Grace Tanchico <email@hidden>) |