• Open Menu Close Menu
  • Apple
  • Shopping Bag
  • Apple
  • Mac
  • iPad
  • iPhone
  • Watch
  • TV
  • Music
  • Support
  • Search apple.com
  • Shopping Bag

Lists

Open Menu Close Menu
  • Terms and Conditions
  • Lists hosted on this site
  • Email the Postmaster
  • Tips for posting to public mailing lists
Re: [iOS]More on recording
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [iOS]More on recording

  • Subject: Re: [iOS]More on recording
  • From: Aran Mulholland <email@hidden>
  • Date: Fri, 12 Nov 2010 09:42:48 +1100
I think you have some misconceptions. An AUGraph is a network of audio connections. The application that you describe sounds like a typical drum pad. If we had a drum pad with 16 pads you could set up the AUGraph as follows

Inputs 1-16 --> Mixer --> Output.

The AUGraph is a pull model, in the above example when the graph is started the Output would ask the Mixer for samples. The mixer would then ask each of its inputs for samples using a callback function. When this callback is fired (and it would fire once for each of the inputs, so 16 times in total) you are presented with a buffer that you copy samples into. At this point if the loop was playing you would copy samples across, otherwise you zero out the buffers. Because you decide what samples to copy into those buffers you can change the loop that you are playing, or stop and start the loop, at run time. If you can decide before the program starts as to how many possible pads you want you set up the AUGraph for them and there is never a need to change the graph at run time.

Because the nodes in the graph can be hardwired or connected via callbacks you can get access to the audio data at any node of the graph which means you can be writing the samples that are played to disk at any point, so recording is easy.

Aran

On Fri, Nov 12, 2010 at 8:24 AM, Development <email@hidden> wrote:
No ideas?

Is what i am trying to do even possible? How do other applications make audio files out of sequenced sounds?

I went over sooperlooper and basically it didn't make any sense, mostly because c++ isn't one of my stronger languages.
Is there no way using AVFoundation or something to capture the audio context like you do with images or capture the output stream?



On Nov 9, 2010, at 7:23 PM, Development wrote:

> I'll study it to see how it is doing what it is doing.  Maybe it'll be the answer. Thanks for the info :)
>
> However I'm still wondering if there is a way to Use AVFoundation to do this?
>
> On Nov 9, 2010, at 3:34 PM, Paul Davis wrote:
>
>> On Tue, Nov 9, 2010 at 5:22 PM, Development <email@hidden> wrote:
>>> Ok, I've been pouring over Audio Units, Audio Toolbox and Openal... I've also been looking at AVFoundation.
>>>
>>>
>>> Using an AUGraph to do what I want to do does not seem like it will work... So let me explain
>>>
>>> I have a board. You can press buttons to play sound loops. Loops are played in real time. Going on and off as the user determines. Often they will loop continuously.
>>> If I understand things, AUGraphs must be constructed ahead of time, then played. If I am wrong is the an expample of how to do them in real time because there is sample code on how to capture the AuGraph.
>>
>> sounds a lot like sooperlooper, which is an AU plugin written without
>> AUGraph and without most of the CoreAudio API except for the bits
>> needed to be a plugin.
>>
>> http://sonosaurus.com/sooperlooper/
>>
>> sooperlooper is open source, so please don't abuse this. its an
>> awesome tool used by quite a few live looping performers in
>> combination with a variety of MIDI controllers.
>>
>> --p
>
> _______________________________________________
> Do not post admin requests to the list. They will be ignored.
> Coreaudio-api mailing list      (email@hidden)
> Help/Unsubscribe/Update your Subscription:
>
> This email sent to email@hidden

 _______________________________________________
Do not post admin requests to the list. They will be ignored.
Coreaudio-api mailing list      (email@hidden)
Help/Unsubscribe/Update your Subscription:

This email sent to email@hidden

 _______________________________________________
Do not post admin requests to the list. They will be ignored.
Coreaudio-api mailing list      (email@hidden)
Help/Unsubscribe/Update your Subscription:

This email sent to email@hidden
References: 
 >[iOS]More on recording (From: Development <email@hidden>)
 >Re: [iOS]More on recording (From: Paul Davis <email@hidden>)
 >Re: [iOS]More on recording (From: Development <email@hidden>)
 >Re: [iOS]More on recording (From: Development <email@hidden>)

  • Prev by Date: Re: [iOS]More on recording
  • Next by Date: Re: Percussive attack on iPhone 4
  • Previous by thread: Re: [iOS]More on recording
  • Next by thread: Bouncing a graph to a file offline.
  • Index(es):
    • Date
    • Thread