iOS Crash on Photon Room Join — EXC_BREAKPOINT in UnityFramework webrtc::AudioProcessingImpl::~Audio

[muratunlu0]

Hi everyone,

When using Unity with Dissonance Voice Chat and Photon PUN2, the application crashes on iOS right after joining a Photon room. The crash log points to WebRTC audio processing shutdown. Here’s the crash trace:

UnityFramework`webrtc::AudioProcessingImpl::~AudioProcessingImpl:
Thread 71: EXC_BREAKPOINT (code=1, subcode=0x10c9c3bd0)

And here are the last logs right before the crash:

[Dissonance:Network] (10:25:36.480) PhotonServer: Created server with SessionId:***
Dissonance.Logs:SendLogMessage(String, LogLevel)
Dissonance.Log:WriteLog(LogLevel, String)
Dissonance.Log:Info(String, TA)
Dissonance.Integrations.PhotonUnityNetworking2.PhotonServer:.ctor(PhotonCommsNetwork)
Dissonance.Integrations.PhotonUnityNetworking2.PhotonCommsNetwork:CreateServer(Unit)
Dissonance.Networking.BaseCommsNetwork5:StartServer(TServerParam) Dissonance.Networking.Session:Enter() Dissonance.Networking.BaseCommsNetwork5:Update()
Dissonance.Integrations.PhotonUnityNetworking2.PhotonCommsNetwork:Update()

[Dissonance:Network] (10:25:36.480) PhotonServer: Connected
Dissonance.Logs:SendLogMessage(String, LogLevel)
Dissonance.Log:WriteLog(LogLevel, String)
Dissonance.Networking.Session:Enter()
Dissonance.Networking.BaseCommsNetwork`5:Update()
Dissonance.Integrations.PhotonUnityNetworking2.PhotonCommsNetwork:Update()

[Dissonance:Recording] (10:25:36.951) BasicMicrophoneCapture: Began mic capture (SampleRate:48000Hz, FrameSize:960, Buffer Limit:2^13, Latency:20ms, Device:'')
Dissonance.Logs:SendLogMessage(String, LogLevel)
Dissonance.Log:WriteLog(LogLevel, String)
Dissonance.Log:WriteLogFormat(LogLevel, String, TA, TB, TC, TD, TE)
Dissonance.Audio.Capture.BasicMicrophoneCapture:StartCapture(String)
Dissonance.Audio.Capture.CapturePipelineManager:RestartTransmissionPipeline(String)
Dissonance.Audio.Capture.CapturePipelineManager:Update(Boolean, Single)
Dissonance.DissonanceComms:Update()

[Dissonance:Core] (10:25:36.955) AudioPluginDissonanceNative: Rnnoise is not supported on this platform
Dissonance.Logs:WriteMultithreadedLogs()
Dissonance.DissonanceComms:Update()

[Dissonance:Recording] (10:25:36.959) CapturePipelineManager: Detected a frame skip, forcing capture pipeline reset (Delta Time:0.3998876)
Dissonance.Logs:SendLogMessage(String, LogLevel)
Dissonance.Log:WriteLog(LogLevel, String)
Dissonance.Audio.Capture.CapturePipelineManager:Update(Boolean, Single)
Dissonance.DissonanceComms:Update()

Has anyone experienced this problem with microphone capture on iOS causing WebRTC audio shutdown?
Any help or workarounds would be greatly appreciated. Thank you for help!

[martindevans]

Sorry for the slow reply, I'm catching up after the Christmas break!

Unfortunately this isn't something anyone else has reported, so I don't have an immediate workaround.

The last thing in the log is a "frame skip" (basically a dropped frame) which causes Dissonance to reset itself, that's probably why webrtc is being shutdown and that's when the issue happens. One potential workaround: You could disable the frameskip detection (Assets/Plugins/Dissonance/Core/FrameSkipDetector.cs, find IsFrameSkip and make it return false). I suspect this will just delay the issue until later though.

UnityFrameworkwebrtc::AudioProcessingImpl::~AudioProcessingImpl:`

That UnityFramework at the start is potentially a red flag. Dissonance ships some parts of webrtc (for audio processing). This looks like it's a symbol from another version of webrtc shipped by Unity. Due to static linking on iOS it's possible they could be interfering with one another (getting linked together and sharing some state when they're not really related to each other). Do you have any packages installed that may be adding webrtc to your application?