I want to give an input file, output a reverberation effects of files, but renderOffline:toBuffer always AVAudioEngineManualRenderingStatusError

Question

I want to give an input file, output a reverberation effects of files, but renderOffline: always AVAudioEngineManualRenderingStatusError toBuffer method return status, how can I write to achieve effect, thank you very much

Here's how I wrote it

• (BOOL)renderAudioFileWithReverb:(NSString *)inputFilePath outputFilePath:(NSString *)outputFilePath error:(NSError **)errorPtr {

    [[AVAudioSession sharedInstance] setCategory:AVAudioSessionCategoryPlayAndRecord withOptions:AVAudioSessionCategoryOptionAllowBluetoothA2DP error:nil];
    [[AVAudioSession sharedInstance] setActive:YES error:nil];
  
    NSURL *fileURL = [NSURL fileURLWithPath:inputFilePath];
    AVAudioFile *audioFile = [[AVAudioFile alloc] initForReading:fileURL error:errorPtr];
    if (!audioFile) return NO;
  

// [self.engine stop];

    AVAudioEngine *engine = [[AVAudioEngine alloc] init];
    AVAudioPlayerNode *playerNode = [[AVAudioPlayerNode alloc] init];
    AVAudioUnitReverb *reverbNode = [[AVAudioUnitReverb alloc] init];

    
    AVAudioFormat *format = audioFile.processingFormat;
    
    [engine attachNode:playerNode];
    [engine attachNode:reverbNode];
    [reverbNode loadFactoryPreset:AVAudioUnitReverbPresetMediumHall];
    reverbNode.wetDryMix = 50;
    [engine connect:playerNode to:reverbNode format:format];
    [engine connect:reverbNode to:engine.mainMixerNode format:format];
    
    [playerNode scheduleFile:audioFile atTime:nil completionHandler:nil];
    AVAudioFrameCount maxFrames = 4096;
    NSError *error;
    [engine enableManualRenderingMode:AVAudioEngineManualRenderingModeOffline format:format maximumFrameCount:maxFrames error:&error];

    [engine startAndReturnError:&error];
    [playerNode play];
    
    AVAudioPCMBuffer *buffer = [[AVAudioPCMBuffer alloc]initWithPCMFormat:engine.manualRenderingFormat frameCapacity:engine.manualRenderingMaximumFrameCount];

    AVAudioFile *outputFile = [[AVAudioFile alloc] initForWriting: [NSURL fileURLWithPath:outputFilePath] settings:audioFile.fileFormat.settings error:&error];
    
    while (engine.manualRenderingSampleTime < audioFile.length) {

      AVAudioFrameCount frameCount = audioFile.length - engine.manualRenderingSampleTime;
        AVAudioEngineManualRenderingStatus statu = [engine renderOffline:frameCount toBuffer:buffer error:&error];
        switch (statu) {
            case AVAudioEngineManualRenderingStatusSuccess:
            {
                BOOL result =  [outputFile writeFromBuffer:buffer error:&error];
                NSLog(@"1");
            }
                break;
            case AVAudioEngineManualRenderingStatusError:
            {
             
            }
                break;
                
            default:
                break;
        }
    }
    
    return YES;
}

I tried installTapOnBus and I couldn't output a normal file, so I wanted to pass in a file and output a file with reverberation, and I didn't need to play it，thank you very much。