create with mp4+mp4+uielement

[akerdi]

I need to create with
mp4-》filter↘️
mp4 —》alphaBlend ↘️
GPUImageUIElement -》alphaBlend -》GPUImageView
a thought from this one trace
`
self.movieFile = [[THImageMovie alloc]initWithURL:self.movieFileURL];//PlayerItem:playItem];
self.movieFile.runBenchmark = YES;
self.movieFile.playAtActualSpeed = YES;
self.filter = [[GPUImageToonFilter alloc] init];

            GPUImageAlphaBlendFilter *alphaBlendFilter = [[GPUImageAlphaBlendFilter alloc]init];
            [alphaBlendFilter setMix:0.5];
            
            self.secondMovie = [[THImageMovie alloc]initWithURL:[NSURL fileURLWithPath:[[NSBundle mainBundle] pathForResource:@"Yh1" ofType:@"mp4"]]];
            self.secondMovie.runBenchmark = YES;
            self.secondMovie.playAtActualSpeed = YES;
            
            UIView *contentView = [self uielementView];
            self.uiElementInput = [[GPUImageUIElement alloc]initWithView:contentView];
            //输入
            [self.movieFile addTarget:self.filter];
            @weakify(self);
            
            //输过程
            [self.filter addTarget:alphaBlendFilter];
            //                [self.uiElementInput addTarget:alphaBlendFilter];
            [self.secondMovie addTarget:alphaBlendFilter];
            
            GPUImageTwoInputFilter *twoInputFilter = [[GPUImageTwoInputFilter alloc]init];
            [self.uiElementInput addTarget:twoInputFilter];
            [alphaBlendFilter addTarget:twoInputFilter];
            
            [self.filter setFrameProcessingCompletionBlock:^(GPUImageOutput *output, CMTime frameTime) {
                LxDBAnyVar(frameTime);
            }];
            
            NSArray *thMovies = @[self.movieFile,self.secondMovie];
            // In addition to displaying to the screen, write out a processed version of the movie to disk
            NSString *pathToMovie = [self movieSavedPath];
            unlink([pathToMovie UTF8String]); // If a file already exists, AVAssetWriter won't let you record new frames, so delete the old movie
            NSURL *movieURL = [NSURL fileURLWithPath:pathToMovie];
            LxDBAnyVar(self.mutableVideoComposition.renderSize);
            self.movieWriter = [[THImageMovieWriter alloc] initWithMovieURL:movieURL size:self.mutableVideoComposition.renderSize movies:thMovies];
            
            GPUImageView *filterView = self.movieImageView;
            [twoInputFilter addTarget:filterView];
            [twoInputFilter addTarget:self.movieWriter];
            
            // Configure this for video from the movie file, where we want to preserve all video frames and audio samples
            //渲染
            [self.movieFile startProcessing];
            [self.secondMovie startProcessing];
            [self.movieWriter startRecording];
            
            [self.movieWriter setCompletionBlock:^{
                @strongify(self);
                LxDBAnyVar(@"record complete");
                [self.filter removeTarget:self.movieWriter];
                [self.movieFile endProcessing];
                [self.secondMovie endProcessing];
                [self.movieWriter finishRecording];
                
                [movieURL saveToCameraRollWithCompletion:^(NSString * _Nullable path, NSError * _Nullable error) {
                    LxDBAnyVar(@"save complete");
                    LxDBAnyVar(error);
                }];
                [subscriber sendNext:nil];
                [subscriber sendCompleted];
            }];`

but it can't work out.
I've try mp4+mp4 ,it works well,and mp4+ uielement too.
can someone help with this,vary vary thanks.
By the way ,the THImageMovie is a class that subclass GPUImageMovie which help with write the audioTrack.