BFRecordScreenKit/BFRecordScreenKit/Classes/BFVideoCompositionManager.swift

//
//  BFVideoCompositionManager.swift
//  BFRecordScreenKit
//
//  Created by 胡志强 on 2021/12/20.
//

import Foundation
import GPUImage
import BFCommonKit
import Photos

class BFVideoCompositionManager {
    var saveMovie = GPUImageMovie()
    var itemModels = [BFRecordItemModel]()
    var currItemModelIndex = 0
    
    var write : GPUImageMovieWriter?
   
    func getVideoSize(asset: AVURLAsset) -> CGSize {
        var size = CGSize.zero
        asset.tracks.forEach { track in
            if track.mediaType == .video {
                let realSize = __CGSizeApplyAffineTransform(track.naturalSize, track.preferredTransform)
                size = CGSize(width: ceil(abs(realSize.width)), height: ceil(abs(realSize.height)))
            }
        }

        return size
    }
    
    func export(avsss:AVURLAsset){
        let start = Date()
        saveMovie = GPUImageMovie(asset: avsss)
        let size = getVideoSize(asset: avsss)
        
        write = GPUImageMovieWriter(movieURL: URL(fileURLWithPath: exportVideosDirectory+"test.mov"), size: CGSize(width: 1080, height: 1920), fileType: "com.apple.quicktime-movie", outputSettings: [
                    AVVideoCodecKey: AVVideoCodecH264,
                    AVVideoWidthKey: 1080.0,
                    AVVideoHeightKey: size.height * 1080.0 / size.width ,
                    AVVideoCompressionPropertiesKey: [AVVideoAverageBitRateKey: 6*1024*1024 ]
                ] as [String : Any])
        
        if let saveWrite = write{
            let filter = GPUImageFilter()
            saveMovie.addTarget(filter)
//            saveWrite.shouldPassthroughAudio = false
            saveWrite.encodingLiveVideo = false
            filter.addTarget(saveWrite)
//            saveMovie.audioEncodingTarget = saveWrite;
            saveMovie.enableSynchronizedEncoding(using: saveWrite)
            saveMovie.startProcessing()
            saveWrite.startRecording()
//            DispatchQueue.global().asyncAfter(deadline: .now() + 2) { [weak self] in
//                saveWrite.finishRecording()
//                self?.saveMovie.endProcessing()
//            }
            saveWrite.completionBlock = {[weak self] in
                BFLog(1, message: "导出完毕：\(Date().timeIntervalSince(start))")
                self?.mix(date: start, index: 0)
            }
        }
    }
    
    func mix(date:Date, index:Double){
        guard let asset = itemModels[currItemModelIndex].videoAsset else {
            return
        }
        if 2*index > asset.duration.seconds {
            return
        }
        let comp = AVMutableComposition()
        let audio = comp.addMutableTrack(withMediaType: .audio, preferredTrackID: kCMPersistentTrackID_Invalid)
        let video = comp.addMutableTrack(withMediaType: .video, preferredTrackID: kCMPersistentTrackID_Invalid)
//    [AVURLAssetPreferPreciseDurationAndTimingKey:@YES]
        
        let bsset = AVURLAsset(url: URL(fileURLWithPath: exportVideosDirectory+"test.mov"))
        if let assetVideoTrack = bsset.tracks(withMediaType: .video).first {
            try? video?.insertTimeRange(CMTimeRange(start: CMTime(seconds: 2*index, preferredTimescale: 1000), end: CMTime(seconds: 2*index+2, preferredTimescale: 1000)), of: assetVideoTrack, at: .zero)
        }
        if let asset = itemModels[currItemModelIndex].videoAsset {
            if let assetAudioTrack = asset.tracks(withMediaType: .audio).first {
                try? audio?.insertTimeRange(CMTimeRange(start: .zero, end: bsset.duration), of: assetAudioTrack, at: .zero)
            }
        }
//        AVAssetExportSession *exporter = [[AVAssetExportSession alloc] initWithAsset:mixComposition
//                                                                              presetName:AVAssetExportPreset1280x720];
//            exporter.videoComposition = videoComp;
        try? FileManager.default.removeItem(at: URL(fileURLWithPath: exportVideosDirectory+"export.mov"))
        let export = AVAssetExportSession(asset: comp, presetName: AVAssetExportPreset1920x1080)
        export?.outputURL = URL(fileURLWithPath: exportVideosDirectory+"export.mov")
        export?.outputFileType = .mov
        export?.exportAsynchronously(completionHandler: {
            BFLog(1, message: "合成完毕：\(Date().timeIntervalSince(date))")
            
            PHPhotoLibrary.shared().performChanges {
                PHAssetChangeRequest.creationRequestForAssetFromVideo(atFileURL: URL(fileURLWithPath: exportVideosDirectory+"export.mov"))
            } completionHandler: {[weak self] isFinished, err in
                BFLog(1, message: "save \(Date().timeIntervalSince(date)) , \(err)")
            }

        })
    }
}