Can anyone please give pointers how we can add re verb effect to a recording in an iPhone app?
Vocal live free on app store is a pretty good example of how I would want to include reverb effect.
Core Audio Overview in iOS documentation references reverb as an audio unit.
Any help beyond this will be helpful.
Yoy can use ObjectAL library. See link below
https://github.com/kstenerud/ObjectAL-for-iPhone.
If you have access to the raw audio data, you can simply convolute it with corresponding reverberation finite impulse response (FIR) filter kernel.
Related
I'm trying to find a way to get the average power level for a channel, that comes out from the audio played in the embedded video. I'm using YouTube's iOS helper library for embedding the video https://developers.google.com/youtube/v3/guides/ios_youtube_helper
A lot of the answers I've found in StackOverflow refer to AVAudioPlayer, but that's not my case. I also looked in the docs of AudioKit framework to find something that can give the output level of the current audio, but I couldn't find anything related, maybe I missed something over there. I also looked in EZAudio framework even tough it's deprecated, and I also couldn't find something that relates to my case.
My direction of thinking was to find a way to get the actual level that's coming out from the device, but I found one answer in SO that's saying this is not allowed in iOS, although he didn't mention any source for this statement.
https://stackoverflow.com/a/12664340/4711172
So, any help would be much appreciated.
The iOS security sandbox blocks apps from seeing the device's digital audio output stream, or any other app's internal audio output (unless explicitly shared, e.g. inter-app audio, etc.) (when using Apple App store permitted public APIs.)
(Just a guess, but this was possibly and originally implemented in iOS to prevent apps from capturing samples of DRM'd music and/or recording phone call conversations.)
Might be a bit off/weird, but just in case -
Have you considered closing a loop? Meaning - record the incoming audio using 'AVAudioRecorder' and get the audio levels from there?.
See Apple's documentation for AVAudioRecorder (in the overview they're specifying: "Obtain input audio-level data that you can use to provide level metering")
AVAudioRecorder documentation
I have an app that uses AVAudioSession with AVAudioSessionCategoryPlayAndRecord to capture mic input. I'm looking to apply high pass (and possibly other) filters to the captured audio data, but cannot find any good documentation about this subject, especially with something that uses AVAudioSession for data capture. Any pointers appreciated.
I'm pretty sure this question is not actual for you 4 yeas later, but for future asking...
AudioSession is an intermediate between your application and iOS system media daemon, it does not record or play audio itself, it just sets up some audio preferences. For your purpose look at AudioUnit or AudioQueue. If all you need is just audio capturing, try high-level API like AVAudioRecord.
Hope it will help for someone.
guys.
I'm working on some audio services on iOS.
I trying to search any examples or tutorials about
how audio service or stream can read a existing audio file than
process something like filter, than write another file.
Is there any body who can help me?
Dirac3LE (by Stephan M. Bernsee) is a great library for this job.
There are examples and manual included in the download.
It is particulary inteded for time and pitch manipulation
but in your case you'll be interested in its EAFRead and EAFWrite
classes.
If you want to get familiar with the lower level library that you can also use for microphone input/sound output, and that you can get raw samples into and out of, I would suggest taking a look at Audio Queue Services.
I used it in my side project to get audio from the microphone, and I also wrote some code you might find useful to do fast vectorized, FFT based FIR filtering on input audio. You can find the code here https://github.com/jamescarlson/FreeAPRS
I need to implement a wavetable player in my app. For different notes (polyphony) a note on and note off feature is needed (including looping for relevant sounds).
The samples are available or can be converted by myself, the need is for a class that is capable of playing, looping and stopping the samples or waves.
I found some open source project like fluid synth but here the question is for some sample code available for iOS or openAL.
Thank you in advance for any hints or snippets,
regards, Koen.
You could take a look at the new Sampler audio unit in iOS5. This lets you play samples with pitch control at low latency.
There is some sample code from Apple.
Hi
I want to read and then want to perform some operations on raw audio. What is the best way to do this?
Audio File Services, Audio Converter Services, and Extended Audio File Services, all in Core Audio. AV Foundation + Core Media (specifically AVAssetReader) may also be an option, but it's really new, and therefore even less documented and less well understood than Core Audio at this point.
If you are looking for sample code, "Audio Graph" is a good starting point. The developer has provided a bit of his own documentation, that will help you quite a bit.
It will depend on the use for the audio. If latency is an issue, go for audio units. But if is not, a higher layer may be the one you require, such as AudioQueues.