iPhone App Development - Audio Queue Recording - iphone

I am currently working on an App which needs to get some data from the microphone. I have read through some resources on the Internet and believe that Audio Queue is a good library to do it.
I only need to get an array which stores the microphone input data, and do not need to play it back.
Can anyone kindly give some hints on that? Greatly appreciated if a simple sample/essential code fragments can be given.

Speak Here App given by the Apple can give you some idea.You can get the link here http://developer.apple.com/iPhone/library/samplecode/SpeakHere/index.html

Related

How to record and play a captured video using AVAssertWriter and AVAssertReader in iphone sdk

I am displaying the camera data (video) on the preview layer.Now I want to record the video and store it in a local file and access it to play on the screen.
I had seen some websites that it is possible with AVAssertWriter and AVAssertReader. Its very difficult for me to understand. Can any one advice me in a clearcut manner or with any sample code.
Anyone's help will be much appreciated.
Thanks to all,
Monish.

iPhone SDK: Is it possible to process audio file from local library

Well, I will try best not to make it as a 'I just want the code' question...
I'm recently working on a project which requires some audio signal processing from local music files (e.g. iTunes Library). The whole work includes:
Get the PCM data of an audio file (normally from iTunes library); <--AudioQueue (?)
Write the PCM data to a new file (it seems that Apple does not allow direct modification on music tracks); <--CoreAudio(?)
Do some processing and modification, like filters, manipulators, etc. <-- Will be developed in C++
Play the processed track. <--RemoteIO
The problem is, after going through some blogs and discussions:
http://lists.apple.com/archives/coreaudio-api/2009/Aug/msg00100.html, http://atastypixel.com/blog/using-remoteio-audio-unit/
http://osdir.com/ml/coreaudio-api/2009-08/msg00093.html
as well as the official sample codes, I got a feeling that the CoreAudio SDK allow us to apply audio processing only on voice demos recorded from Mic.
My question is that:
Can I get raw data from iTunes library tracks instead of Mic input?
If the first question is 'No', is there a way to 'fool' the SDK to let it think it is getting data from Mic input, not from iTunes? (I have done some similar 'hacking' stuff in C# before XD)
If the whole processing just doesn't work, can anyone provide some alternative ideas?
Any help will be appreciated. Thank you very much :-)
Thanks.
Just found something really cool yesterday.
From iPhone Media Library to PCM Samples in Dozens of Confounding, Potentially Lossy Steps
(http://www.subfurther.com/blog/?p=1103
And also a class library by MIT:
TSLibraryImport: Objective-C class + sample code for importing files from user's iPod Library in iOS4.
(http://bitbucket.org/artgillespie/tslibraryimport/changeset/a81838f8c78a
Hope they help!
Cheers,
Manca
1) No. Apple does not allow direct access to PCM data of songs. Otherwise you could create music-sharing apps, which is not in Apple's interests.
2) No. Hacking and getting approved is impossible due to Apple's code approval mechanism.
3) The only alternative I could think of is that you have to do the processing part on PC/Mac and then transfer it to the iPhone. Or you would have to store the files in your own applications folder - you should be able to load and process these via CoreAudio.
I know this thread is old but... did this work for you, Manca? And did this app get approved?
EDIT: just discovered the AVAssetReader class, introduced since iOS 4.1, should help

Streaming a video on iPhone and then storing it on the device

I've been told that some apps have video streaming which streams initially and when completely downloaded the video is stored to the user's device for quick and internet-free subsequent viewing.
Firstly, is this possible? Secondly, could you point me towards resources demonstrating how it could be done, or possibly offer some insight to get me started?
Thanks friends.
good tutorial on how to stream video:
http://buildmobilesoftware.com/2010/08/09/how-to-stream-videos-on-the-iphone-or-ipad/

Is there a way to render IPhone mic input directly into memory without working with files?

I see that the IPhone core audio does not include audioDevice objects to render audio input directly into RAM. I hear people talking about using files to do this(like speak here) but I am thinking there must be a way to do this otherwise. Your thoughts would be appreciated.
Check out the aurioTouch sample in the iPhone Developer site.

Best way to stream MP3 from an iPhone app?

I am working on an application that will stream music from a server of mine from an iPhone application.
This is my first iPhone app so I am a bit confused :
What would be the best way to do
this?
Is there something already built in
that I could use, like a MP3 player
that I just need to point toward the
correct server?
Do I need a streaming server to do
so?
I'm relatively new to Objective-C/Cocoa (touch), but I have read an article on the cocoawithlove site titled "Streaming and playing an MP3 stream" and tested the sample code on my iPhone and it works perfectly. I don't know about the licensing or anything, if you would be able to use it, but I'm sure someone or even you can figure that out.
Sorry again for not being able to provide any more information or even a link. This is my first answer on SO and cannot post hyperlinks :(
(edit: Here's the link: Streaming and playing an MP3 stream)