[Bug] Xamarin.iOS delegate AVAudioSinkNodeReceiverHandler gives strange reference to AudioBuffers

[jfversluis]

---

Issue moved from xamarin/Xamarin.Forms#15694

• Please respond to @Grubleren.

---

From @Grubleren on Thursday, February 16, 2023 11:05:32 AM

I am trying to use the iOS sink node as in the following example
Visual Studio 2022 17.4.4
Remote connection to Mac

using System;
using System.Runtime.InteropServices;
using System.Threading;
using Foundation;
using AudioToolbox;
using AVFoundation;
using UIKit;

void SomeFunc()
        {
           var  engine = new AVAudioEngine();
            var inputNode = engine.InputNode;
            var inputFormat = inputNode.GetBusOutputFormat(0);
            var handler = new AVAudioSinkNodeReceiverHandler(SinkHandler);   
            var sinkNode = new AVAudioSinkNode(handler); 
            engine.AttachNode(sinkNode);
            engine.Connect(inputNode, sinkNode, inputFormat);
            NSError error;
            engine.StartAndReturnError(out error);
        }

 int SinkHandler(AudioTimeStamp ts, uint n, ref AudioBuffers buffers)
        {
                    int nCh = buffers.Count;
                    for (int i = 0; i < nCh; i++)
                    {
                        var f = buffers[i].Data;
                        Marshal.Copy(f, data, 0, (int)n);
                    }

            return 0;
        }

The program crash since buffers is not a valid reference to AudioBuffers. Also it is strange to use a ref parameter in the delegate
AVAudioSinkNodeReceiverHandler. I cannot find a way to make it work

[ghost]

Hi @jfversluis. We have added the "need-repro" label to this issue, which indicates that we require steps and sample code to reproduce the issue before we can take further action. Please try to create a minimal sample project/solution or code samples which reproduce the issue, ideally as a GitHub repo that we can clone. See more details about creating repros here: https://github.com/xamarin/xamarin-macios/blob/main/docs/bug-repro.md

This issue will be closed automatically in 7 days if we do not hear back from you by then - please feel free to re-open it if you come back to this issue after that time.

[ghost]

Hi @jfversluis. Due to inactivity, we will be closing this issue. Please feel free to re-open this issue if the issue persists. For enhanced visibility, if over 7 days have passed, please open a new issue and link this issue there. Thank you.

[Grubleren]

I have made the repository https://github.com/Grubleren/TestSinkHandler, that clearly demonstrate the problem. Just run the solution.

[rolfbjarne]

Thanks, I can reproduce it, and a fix is in progress.