Recording?

[zoul]

Recording?

[zoul]

You mean that you want to record a sound and then play it back with Finch? That should be easy. Just record the sound using AVFoundation, use the raw sound data to create an FISample and then you can use the sample to create an FISound.

[jsplashindia]

Not exactly, I want to do the kinda opposite. Whatever I played with finch, I need to export them as a single sound file. it can be a series of sounds played using Finch.

[zoul]

Ah, sorry. I don’t know how to do that. Are you after the pitch changes?

[jsplashindia]

Basically, I've made an instrument that uses Finch to playback sounds. Now, I need to support recording in my instrument. So, after I start recording, I need to be able to capture whatever is played using Finch and then once recording is stopped, export them as a sound file.

[zoul]

In that case you could use Finch just to play the sounds and use another trick to record. As an example, you could just mark the time and the name of the sample to play during the recording:

- (void) playSample: (NSString*) sampleName
{
    FISound *sound = [self sampleForName:sampleName];
    [sound play];
    if (recording) {
        [currentRecording addSample:sampleName atTime:currentTime];
    }
}

Or something like that, you get the idea. When the user later selects to export the recording, you can stitch the samples together using AVFoundation and export.

[jsplashindia]

That sounds like a very good idea. Are you sure we can stitch the samples using AVFoundation? Can you point to some resources on how this can be done?

[zoul]

I’ve done it before, so I’m sure it works. You create a mutable AV composition (see API docs for AVMutableComposition) and there you can insert given assets (see AVURLAsset) created from the samples. In the end you create and configure an AVAssetExportSession and export the mutable composition into a file.

[jsplashindia]

Thanks for the suggestion. I'll try that out.