iOS Audio Trimming

Question

I searched a lot and couldn\'t find anything relevant... I am working on iOS audio files and here is what I want to do...

1. Record Audio and Save Clip (Checked,

Answer 1

// Swift 4.2

If anybody is still looking for answer in swift here it is.

//Audio Trimming

func trimAudio(asset: AVAsset, startTime: Double, stopTime: Double, finished:@escaping (URL) -> ())
{

        let compatiblePresets = AVAssetExportSession.exportPresets(compatibleWith:asset)

        if compatiblePresets.contains(AVAssetExportPresetMediumQuality) {

        guard let exportSession = AVAssetExportSession(asset: asset, 
        presetName: AVAssetExportPresetAppleM4A) else{return}

        // Creating new output File url and removing it if already exists.
        let furl = createUrlInAppDD("trimmedAudio.m4a") //Custom Function
        removeFileIfExists(fileURL: furl) //Custom Function

        exportSession.outputURL = furl
        exportSession.outputFileType = AVFileType.m4a

        let start: CMTime = CMTimeMakeWithSeconds(startTime, preferredTimescale: asset.duration.timescale)
        let stop: CMTime = CMTimeMakeWithSeconds(stopTime, preferredTimescale: asset.duration.timescale)
        let range: CMTimeRange = CMTimeRangeFromTimeToTime(start: start, end: stop)
        exportSession.timeRange = range

        exportSession.exportAsynchronously(completionHandler: {

            switch exportSession.status {
            case .failed:
                print("Export failed: \(exportSession.error!.localizedDescription)")
            case .cancelled:
                print("Export canceled")
            default:
                print("Successfully trimmed audio")
                DispatchQueue.main.async(execute: {
                    finished(furl)
                })
            }
        })
    }
}

You can use it for video trimming as well. For Video trimming replace the value of export session as bellow:

guard let exportSession = AVAssetExportSession(asset: asset, presetName: AVAssetExportPresetPassthrough) else{return}

and filetype to mp4

exportSession.outputFileType = AVFileType.mp4