1，处理导出视频时音乐拼接

BFFramework/Classes/Stuckpoint/Controller/PQStuckPointPublicController.swift

@@ -57,6 +57,11 @@ class PQStuckPointPublicController: PQBaseViewController {
     
     //add by ak 是否是再创作模式
     var isReCreate:Bool = false
+    
+    //最终使用的音频时长,用于拼接音乐使用
+    var finallyUserAudioTime:Float = 0.0
+    //拼接音乐的开始和结束位置
+    var clipAudioRange: CMTimeRange = CMTimeRange.zero
     // 预览大小
     private var preViewSize: CGSize {
         switch aspectRatio {
@@ -632,7 +637,12 @@ extension PQStuckPointPublicController {
         BFLog(message: "导出视频地址 \(outPutMP4URL)")
         let inputAsset = AVURLAsset(url: URL(fileURLWithPath: documensDirectory + (audioMixModel?.localPath ?? "")), options: nil)
         // 每次初始化的时候设置初始值 为 nIl
-        exporter = PQCompositionExporter(asset: inputAsset, videoComposition: nil, audioMix: nil, filters: nil, stickers: mStickers, animationTool: nil, exportURL: outPutMP4URL)
+        var audioMix: AVMutableAudioMix?
+        var composition: AVMutableComposition?
+        if(finallyUserAudioTime != 0){
+            (audioMix, composition) = PQPlayerViewModel.setupAudioMix(originAsset: inputAsset, bgmData:nil, videoStickers: nil,originMusicDuration:finallyUserAudioTime,clipAudioRange: clipAudioRange)
+        }
+        exporter = PQCompositionExporter(asset: inputAsset, videoComposition: nil, audioMix: audioMix, filters: nil, stickers: mStickers, animationTool: nil, exportURL: outPutMP4URL)
 
         var orgeBitRate = (editProjectModel?.sData?.videoMetaData?.videoWidth ?? 0) * (editProjectModel?.sData?.videoMetaData?.videoHeight ?? 0) * 3