1，添加字幕filter 2，修改合成视频 size

BFRecordScreenKit/Classes/BFRecordExport.swift

@@ -188,16 +188,17 @@ public class BFRecordExport {
         if voiceCount > 0 || videoStickers.count > 1 {
             let (audioMix, composition) = mergeAudio(videoStickers: videoStickers, audios: voiceList, synthesisAll: synthesisAll)
 
-            let filter = videoStickers.map { sticker in
-                PQMovieFilter(movieSticker: sticker)
+            var filters:[PQBaseFilter] =  Array.init()
+            for sticker in videoStickers {
+                filters.append(PQMovieFilter(movieSticker: sticker))
             }
-
-            exporter = PQCompositionExporter(asset: composition, videoComposition: nil, audioMix: audioMix, filters: filter, animationTool: nil, exportURL: outPutMP4URL)
-
-//            let asset = data?.first?.baseMaterial // 可能为空
-
-            let size = UIScreen.main.bounds.size // getVideoSize(asset: asset!)
-            var orgeBitRate = Int(size.width * size.height * 3)
+            let outputSize:CGSize = CGSize(width: 1080.0, height: 1080 * CGFloat(Int(UIScreen.main.bounds.size.height / UIScreen.main.bounds.size.width)))
+            BFLog(message: "输出视频大小:\(outputSize)")
+            filters.append(PQSubTitleFilter.init(st: titleStickers, inputSize: outputSize))
+            
+            exporter = PQCompositionExporter(asset: composition, videoComposition: nil, audioMix: audioMix, filters: filters, animationTool: nil, exportURL: outPutMP4URL)
+ 
+            var orgeBitRate = Int(outputSize.width * outputSize.height * 3)
 
             for stick in videoStickers {
                 if stick.type == StickerType.VIDEO.rawValue {
@@ -212,7 +213,7 @@ public class BFRecordExport {
 
             BFLog(message: "导出设置的码率为:\(orgeBitRate)")
 
-            if exporter!.prepare(videoSize: size, videoAverageBitRate: orgeBitRate) {
+            if exporter!.prepare(videoSize: outputSize, videoAverageBitRate: orgeBitRate) {
                 exporter!.start(playeTimeRange: CMTimeRange(start: CMTime.zero, end: synthesisAll ? CMTime(seconds: totalDuration, preferredTimescale: 100) : composition.duration))
             }
             exporter?.progressClosure = { [weak self] _, _, progress in