DelayedSoundFeedbackDemo MATLAB internal error

  • PsychtoolboxVersion - 3.0.16
  • Ubuntu 20.04 LTS , MATLAB 2020a
  • XPS with intel i7-3537u, intel GPU

MATLAB keeps on crushing while running

DelayedSoundFeedbackDemo(4, [], 44100, [], 2)

Before the crush I communicates that the device most likely won’t perform well. No other information on error is displayed until MAtlab communicates internal error and crushes. I sent the report to mathworks and they said that ‘Their analysis indicates that the issue is unknown’.

When I run the demo with following configuration

DelayedSoundFeedbackDemo(4, [], 44100, [], [])

I get long list of warnings

WARNING: SOUND ONSET TIMING SCREWED!! THE SYSTEM IS NOT UP TO THE TASK/OVERLOADED!
Requested onset at time 1598556619.640672 seconds, but audio stream is already at time 1598556619.648834 seconds
--> We will be at least 8.161783 msecs too late!
PsychPortAudio-WARNING: Underrun of audio playback buffer detected during streaming refill at approximate play position 0.012472 secs [3.219955 msecs behind]. Sound will be skipped, timing may be wrong and audible glitches may occur!
WARNING: SOUND ONSET TIMING SCREWED!! THE SYSTEM IS NOT UP TO THE TASK/OVERLOADED!
Requested onset at time 1598556619.640672 seconds, but audio stream is already at time 1598556619.651327 seconds
--> We will lose at least the first 10.655165 msecs of the sound signal!

followed by

PsychPortAudio-WARNING: Underrun of audio playback buffer detected during streaming refill at approximate play position 2.362132 secs [3.219955 msecs behind]. Sound will be skipped, timing may be wrong and audible glitches may occur!
PsychPortAudio-WARNING: Underrun of audio playback buffer detected during streaming refill at approximate play position 2.367120 secs [5.714286 msecs behind]. Sound will be skipped, timing may be wrong and audible glitches may occur!
PsychPortAudio-WARNING: Underrun of audio playback buffer detected during streaming refill at approximate play position 2.369615 secs [5.714286 msecs behind]. Sound will be skipped, timing may be wrong and audible glitches may occur!
PsychPortAudio-WARNING: Underrun of audio playback buffer detected during streaming refill at approximate play position 2.372109 secs [3.219955 msecs behind]. Sound will be skipped, timing may be wrong and audible glitches may occur!

that go forever until I interrupt it. Only then the playback of recorded sound starts, and loops forever.

I see how this post is awkward and difficult to help with but I can’t really move from here. I’m trying to set up a Continous Stream Paradigm, where souds are ‘appended’ to buffer based on animal’s behavior. I can’t append to the Buffer using PsychPortAudio(‘Fillbuffer’) - it ndicates the audio device is not in playback mode - maybe stopped playing - it looks like after i start the device the script doesnt contiinue until the end of the playback. I get the minimum to work, load the buffer and start the device after each iteration. I get it to work only on one deviceID - sysdefault - the output from the driver indicates that the latency should be around 20ms - it shows that for every latency mode from 0-4. Every other device distorts the audio - recreated on 2 different machines, both with Ubuntu 20.04. I guess my question is: is it possible it’s the new Ubuntu’s fault, should I try to downgrade?

The crash didn’t happen on Ubuntu 18/04 with MATLAB 2019a on the same machine. I can successfully use other than default devices when I allow higher latency.

Requesting only 4 msecs total feedback delay is likely infeasible on almost any soundcard and system, as it would require less than 2 msecs latency on the input side and output side and Matlab/Octave processing combined. Only very few pro soundcards can do that on specially configured systems. If i remember correctly, around 10 -20 msecs is a more attainable goal with typical machines and onboard soundchip under Linux. That Matlab crashes is not good though, but i’d need to see that crash report so see if it points to some specific reason for the crash.