I am developing an app where the user can record their voice, and then alter it in some way. I have implemented OpenAL, and I am able to adjust the pitch to speed up and slow down the audio file. The thing is, I want to add filters like echo, reverb, etc.. I have scoured the internet for hours and have found nothing to help me. I came across a OpenAL called FreeSL, which has a bunch of filters built in, but I cannot get it compile in xcode.
I have also looked into Dirac3, but again all I am seeing is basic pitch/time controls; no echos or anything.
Can anyone point me in the direction a good framework or explain how OpenAL can handle filters like this?
Thanks!
I found a library that is exactly what I am looking for, FMOD:
http://www.fmod.org/index.php/fmod
Related
I'm very new to audio programming, but I know this must be possible. (This is an iOS/iPhone related question).
How would I go about changing the tempo of a loaded audio file without changing the pitch, and then playing it back?
I think I need to delve into the CoreAudio framework, but I'm not sure where to begin.
If anyone could let me know what classes I need to look at, or the general process involved, that would help me get started and I'd really appreciate it!
Cheers!
This question is highly related: it relates to pitch shifting, rather than time shifting, but I'd check out the comments and links.
Real-time Pitch Shifting on the iPhone
What you are looking for is a time-pitch modification library. Core Audio on iOS currently does not contain such, but there appear to be some 3rd party libraries available (commercially). There are also time pitch tutorials on the web, such as at dspdimention, which require a large amount of DSP development to get working.
I have to develop an iPhone app which is a DJ app. It includes everything right from playing song to scratching the audio.
Is there a way I can scratch the audio? Are there any good frameworks which you can suggest? Which are best possible options?
I have referred to this links below but didn't help my cause
http://blog.glowinteractive.com/2011/01/vinyl-scratch-emulation-on-iphone/
Scratching Audio
I'd start with reading Kjetil Falkenberg Hansen's recent PhD thesis: The Acoustics and Performance of DJ Scratching to get to grips with the nature of the problem. This should provide you with some effective parameters for your program.
I imagine you'll want to buffer a certain amount of the audio to be 'scratched' and simply advance through said buffer at varying speeds both forward and backwards.
Consider this link (and similar ones) for how to build a buffer.
If the iphone API doesn't provide a useful way to advance through the buffer at different speeds you might consider making your own temporary buffer, then using this to populate the buffer used by the iPhone based on some interpolating function.
BTW - the first link you posted looks very useful indeed! What's it missing?
I am trying to write an iPhone App that should monitor the any incoming sound. I am not sure how can I get the sound recorded by iPhone's Microphone and detect its frequency. If same frequency sound repeated couple of times then I need to take some action. Could anyone please help me here. I went through the How to detect sound frequency / pitch on an iPhone? but I couldn't understood how to use them.
Any documentation or example would be really useful.
Thanks.
You'll appreciate reading this, on how to get the sound "without having to drop down to C", by using AVAudioRecorder...
Then, begin researching FFT...
Checkout this post about FFT for iPhone, which mentions various options, including the possibility of using Apple's Accelerate framework (in which you will need to drop to C) to apparently get "Apple-written FFT functions".
This is probably what you really want to read.
I'm new to programming in Objective-c and the iPhone but I am working on an app to teach myself. I have been trying to figure out how to record sounds on the iPhone. Apple provides excellent documentation for recording from the microphone with AVAudioRecorder but I want to record sounds made by my app, or even just record sounds when buttons are pressed (button is pressed, certain audio gets recorded).
I have no clue how to do this and can't seem to find anything that would help me along this path, only microphone stuff.
Can anyone share ideas or code that would make this possible?
Thanks
Once you move beyond the convenience classes like AVAudioRecorder, you've got a lot of studying to do.
I would start with:
Getting Started with Audio and Video
Multimedia Programming Guide:Audio
Core Audio Overview
Audio programming is a very large and complex subject. If you want to customize, be prepared to spend some time learning it.
I've made a sample app that records sounds/audio and has a playback. Hope this helps! https://github.com/casspangell/AudioMic
In my application i have done to record the voice and playing in the device.
Now i want to find the audio frequency of that recorded voice(While recording). How can i find?.I dont have any idea. I have downloaded "aurio Touch" program.But its too difficult to understand me. So is there any tutorials are avilable(in iPhone)?. How can i achieve this?
Please guide me.
Thanks.
This involves math. If that scares you, you should probably get/buy a library to do the analysis for you. If not, Fourier transform is a good place to start to see what's involved. When I did this, I started by poking around Audacity's source code to get an idea of what's involved.