Clipping/Crackling when generating an auxiliary effect slot, even if not assigned an effect and passed to a source. Intensifies when passing to a source.

[BekimS]

Hello, I have been having an issue with effects/auxiliary effect slots. Whenever I have create an auxiliary effect slot, it causes a slight clipping/crackling when sounds are played, even if they do not have the effect slot passed into them and also when using AL_EFFECT_NULL. It becomes very obvious if I am using an effect like Reverb/EAXReverb.

ALuint effect;
alGenEffects(1, &effect);
alEffecti(effect, AL_EFFECT_TYPE, AL_EFFECT_NULL);
//alEffecti(effect, AL_EFFECT_TYPE, AL_EFFECT_EAXREVERB);

ALuint effectSlot;
alGenAuxiliaryEffectSlots(1, &effectSlot);
alAuxiliaryEffectSloti(effectSlot, AL_EFFECTSLOT_EFFECT, effect);

alGenSources(MAX_VOICES, alSourceIDs);
for (unsigned int i = 0; i < MAX_VOICES; i++)
{
	alSource3i(alSourceIDs[i], AL_AUXILIARY_SEND_FILTER, effectSlot, 0, AL_FILTER_NULL);
}

If anyone can point me in any direction on how to fix it that would be great.
Cheers.

[kcat]

Are you able to make a trace log? If you're on Windows, you can use this script to run the app and have it produce an alsoft_error.txt (just place the cmd file in the same folder as the exe, and drag the exe onto the cmd file). That should then contain log messages about the settings its using the hardware it's running on, which may indicate if there's a problem with the system keeping up with what it's being asked to do. This shouldn't normally be a problem with default auto-selected settings, but it's something to check.

If you're not on Windows, you can set the environment variable ALSOFT_LOGLEVEL to 3 and ALSOFT_LOGFILE to alsoft_error.txt before running the app to have it produce the same file in the current working directory. Make sure to clear the env vars afterward so OpenAL apps don't keep producing log files unnecessarily.

[BekimS]

Apologies for not mentioning what OS I'm using, that being Windows. Here's the log file that was produced after running my program for few seconds (a sound plays every 0.25 seconds constantly)

[ALSOFT] (II) Initializing library v1.25.2-83ea7236c HEAD
[ALSOFT] (II) Supported backends: wasapi, dsound, winmm, null, wave
[ALSOFT] (II) Loading config C:\Users\Bekim\AppData\Roaming\alsoft.ini...
[ALSOFT] (II) Got binary: C:\Users\Bekim\source\repos\00dsh\katana-engine\out\build\x64-debug\katana-engine, katana-engine.exe
[ALSOFT] (II) Loading config C:\Users\Bekim\source\repos\00dsh\katana-engine\out\build\x64-debug\katana-engine\alsoft.ini...
[ALSOFT] (II) Vendor ID: "AuthenticAMD"
[ALSOFT] (II) Name: "AMD Ryzen 5 5600X 6-Core Processor"
[ALSOFT] (II) Extensions: +SSE +SSE2 +SSE3 +SSE4.1
[ALSOFT] (II) Starting watcher thread
[ALSOFT] (II) Initialized backend "wasapi"
[ALSOFT] (II) Added "wasapi" for playback
[ALSOFT] (II) Added "wasapi" for capture
[ALSOFT] (II) Opening default playback device
[ALSOFT] (II) Got device "Headphones (Oculus Virtual Audio Device)", "{427156E7-55E5-48A2-8C0A-37BBC14A870C}", "{0.0.0.00000000}.{427156e7-55e5-48a2-8c0a-37bbc14a870c}"
[ALSOFT] (II) Got device "G27QC A (NVIDIA High Definition Audio)", "{5633B700-1107-4CF3-8DCF-1E71BE09425A}", "{0.0.0.00000000}.{5633b700-1107-4cf3-8dcf-1e71be09425a}"
[ALSOFT] (II) Got device "Headphones (Arctis Nova 3)", "{CA3E4E90-900A-40F6-BF74-BB9FD7FF989B}", "{0.0.0.00000000}.{ca3e4e90-900a-40f6-bf74-bb9fd7ff989b}"
[ALSOFT] (II) Got device "Headset Microphone (Oculus Virtual Audio Device)", "{A81D4482-FAD2-4B71-84EF-E512FBB7EBE5}", "{0.0.1.00000000}.{a81d4482-fad2-4b71-84ef-e512fbb7ebe5}"
[ALSOFT] (II) Got device "Microphone (Arctis Nova 3)", "{DA37A4CA-C723-47FA-84CA-1D6228352B27}", "{0.0.1.00000000}.{da37a4ca-c723-47fa-84ca-1d6228352b27}"
[ALSOFT] (II) Got device "Microphone (Steam Streaming Microphone)", "{E27AF67E-D010-48E4-A6CF-D7FFF8DBDEB1}", "{0.0.1.00000000}.{e27af67e-d010-48e4-a6cf-d7fff8dbdeb1}"
[ALSOFT] (II) Watcher thread started
[ALSOFT] (II) Created device 0x1f4cc369000, "OpenAL Soft on Headphones (Arctis Nova 3)"
[ALSOFT] (II) ALC_OUTPUT_LIMITER_SOFT = 1
[ALSOFT] (II) Pre-reset: Stereo, Float32, 48000hz, 512 / 1536 buffer
[ALSOFT] (II) Device mix format:
    FormatTag      = 0xfffe
    Channels       = 2
    SamplesPerSec  = 48000
    AvgBytesPerSec = 384000
    BlockAlign     = 8
    BitsPerSample  = 32
    Size           = 22
    Samples        = 32
    ChannelMask    = 0x3
    SubFormat      = {00000003-0000-0010-8000-00aa00389b71}
[ALSOFT] (II) Requesting playback format:
    FormatTag      = 0xfffe
    Channels       = 2
    SamplesPerSec  = 48000
    AvgBytesPerSec = 384000
    BlockAlign     = 8
    BitsPerSample  = 32
    Size           = 22
    Samples        = 32
    ChannelMask    = 0x3
    SubFormat      = {00000003-0000-0010-8000-00aa00389b71}
[ALSOFT] (II) Post-reset: Stereo, Float32, 48000hz, 480 / 1536 buffer
[ALSOFT] (II) Searching C:\Users\Bekim\source\repos\00dsh\katana-engine\out\build\x64-debug\katana-engine for *.mhr
[ALSOFT] (II) Adding built-in entry "!1_Built-In HRTF"
[ALSOFT] (II) Loading built-in HRTF 1...
[ALSOFT] (II) Detected data set format v3
[ALSOFT] (II) Loaded HRTF Built-In HRTF for sample rate 48000hz, 64-sample filter
[ALSOFT] (II) 1st order + Full HRTF rendering enabled, using "Built-In HRTF"
[ALSOFT] (II) Channel config, Main: 4, Real: 2
[ALSOFT] (II) Allocating 6 channels, 24576 bytes
[ALSOFT] (II) Min delay: 7.75, max delay: 33.50, FIR length: 64
[ALSOFT] (II) New max delay: 25.75, FIR length: 90
[ALSOFT] (II) Max sources: 256 (255 + 1), effect slots: 64, sends: 4
[ALSOFT] (II) Dithering disabled
[ALSOFT] (II) Output limiter enabled, 0.0000dB limit
[ALSOFT] (II) Fixed device latency: 1000000ns
[ALSOFT] (II) Post-start: Stereo, Float32, 48000hz, 480 / 1536 buffer
[ALSOFT] (II) Increasing allocated voices to 256
[ALSOFT] (II) Created context 0x1f4cc352240
[ALSOFT] (II) Increasing allocated context properties to 2
[ALSOFT] (II) Increasing allocated effect slots to 4
[ALSOFT] (II) Increasing allocated effect slot properties to 4
[ALSOFT] (II) Increasing allocated voice properties to 32
[ALSOFT] (II) Freeing context 0x1f4cc352240
[ALSOFT] (II) Freeing device 0x1f4cc369000
[ALSOFT] (II) HrtfStore 0x1f4cf18f7f0 decreasing refcount to 0
[ALSOFT] (II) Unloading unused HRTF !1_Built-In HRTF
 

[kcat]

Hmm, nothing looks out of the ordinary. No crazy number of voices or effect slots, using default resampler (cubic), and a plenty strong enough CPU.

Do you have some kind of power-saving mode enabled for the system? Something that would put CPU cores into a low-power mode when they're not very active? That can interfere with ensuring low-latency/time-sensitive threads are woken up to process what they need to in time. You can also try disabling HRTF, though as I mentioned it shouldn't be an issue given your CPU (or any vaguely half-modern CPU), either by creating an alsoft.ini:

[general]
hrtf=off

or using the ALC_SOFT_HRTF extension to set the ALC_HRTF_SOFT context creation attribute to ALC_FALSE (the default is ALC_DONT_CARE_SOFT, which will enable it if the device can be detected as being headphones or a headset, and disable it otherwise).

[Toast-t]

I've encountered the same or similar issue with auxiliary effect slots, although I've narrowed it down to the popping/cracking issue only presenting itself when an effect has been assigned to a effect slot with alAuxiliaryEffectSloti(). Simply generating an effect slot and an effect won't cause the issue to manifest, and I actually found that the more effects you have assigned to a slot, the worse and more frequent the popping/cracking gets.

I did trydisabling HRTF as well and that didn't seem to make any noticeable difference.

I also generated a log in case that helps at all.

[ALSOFT] (II) Initializing library v1.25.2-83ea7236c master
[ALSOFT] (II) Supported backends: wasapi, dsound, winmm, null, wave
[ALSOFT] (II) Loading config C:\Users\Bvank\AppData\Roaming\alsoft.ini...
[ALSOFT] (II) Got binary: C:\Users\Bvank\CLionProjects\TsunamiMoonlight\build, ProjectTsunamiMoonlight.exe
[ALSOFT] (II) Loading config C:\Users\Bvank\CLionProjects\TsunamiMoonlight\build\alsoft.ini...
[ALSOFT] (II) Vendor ID: "AuthenticAMD"
[ALSOFT] (II) Name: "AMD Ryzen 7 5800X 8-Core Processor"
[ALSOFT] (II) Extensions: +SSE +SSE2 +SSE3 +SSE4.1
[ALSOFT] (II) Starting watcher thread
[ALSOFT] (II) Initialized backend "wasapi"
[ALSOFT] (II) Added "wasapi" for playback
[ALSOFT] (II) Added "wasapi" for capture
[ALSOFT] (II) Opening default playback device
[ALSOFT] (II) Got device "3 - 24EA53 (AMD High Definition Audio Device)", "{26E783FE-9E73-4284-8CD0-0326733F74BC}", "{0.0.0.00000000}.{26e783fe-9e73-4284-8cd0-0326733f74bc}"
[ALSOFT] (II) Got device "Headphones (Oculus Virtual Audio Device)", "{4134B2FA-621B-471E-8B47-61930A7ED0E2}", "{0.0.0.00000000}.{4134b2fa-621b-471e-8b47-61930a7ed0e2}"
[ALSOFT] (II) Got device "1 - C27F390 (AMD High Definition Audio Device)", "{73712A1E-86F0-4363-9C05-0785417FFE87}", "{0.0.0.00000000}.{73712a1e-86f0-4363-9c05-0785417ffe87}"
[ALSOFT] (II) Got device "Headphones (H730 USB Gaming Headset)", "{F7CCA887-B695-45CF-954C-40FAD1A3139B}", "{0.0.0.00000000}.{f7cca887-b695-45cf-954c-40fad1a3139b}"
[ALSOFT] (II) Got device "Headset Microphone (Oculus Virtual Audio Device)", "{6A930587-F2E4-4FD1-B52D-C5B8202B51E7}", "{0.0.1.00000000}.{6a930587-f2e4-4fd1-b52d-c5b8202b51e7}"
[ALSOFT] (II) Got device "Microphone (H730 USB Gaming Headset)", "{E133EFB4-9352-42B8-A4C3-BD5EB5BF1591}", "{0.0.1.00000000}.{e133efb4-9352-42b8-a4c3-bd5eb5bf1591}"
[ALSOFT] (II) Got device "Microphone (NexiGo N60 FHD Webcam Audio)", "{E736F8C7-F5AC-4F41-B002-3B0AE674CEFB}", "{0.0.1.00000000}.{e736f8c7-f5ac-4f41-b002-3b0ae674cefb}"
[ALSOFT] (II) Watcher thread started
[ALSOFT] (II) Created device 0x1e63c98f060, "OpenAL Soft on Headphones (H730 USB Gaming Headset)"
[ALSOFT] (II) ALC_MAX_AUXILIARY_SENDS = 4
[ALSOFT] (II) Pre-reset: Stereo, Float32, 48000hz, 512 / 1536 buffer
[ALSOFT] (II) Device mix format:
    FormatTag      = 0xfffe
    Channels       = 2
    SamplesPerSec  = 48000
    AvgBytesPerSec = 384000
    BlockAlign     = 8
    BitsPerSample  = 32
    Size           = 22
    Samples        = 32
    ChannelMask    = 0x3
    SubFormat      = {00000003-0000-0010-8000-00aa00389b71}
[ALSOFT] (II) Requesting playback format:
    FormatTag      = 0xfffe
    Channels       = 2
    SamplesPerSec  = 48000
    AvgBytesPerSec = 384000
    BlockAlign     = 8
    BitsPerSample  = 32
    Size           = 22
    Samples        = 32
    ChannelMask    = 0x3
    SubFormat      = {00000003-0000-0010-8000-00aa00389b71}
[ALSOFT] (II) Post-reset: Stereo, Float32, 48000hz, 480 / 1536 buffer
[ALSOFT] (II) Searching C:\Users\Bvank\CLionProjects\TsunamiMoonlight\build for *.mhr
[ALSOFT] (II) Adding built-in entry "!1_Built-In HRTF"
[ALSOFT] (II) Loading built-in HRTF 1...
[ALSOFT] (II) Detected data set format v3
[ALSOFT] (II) Loaded HRTF Built-In HRTF for sample rate 48000hz, 64-sample filter
[ALSOFT] (II) 1st order + Full HRTF rendering enabled, using "Built-In HRTF"
[ALSOFT] (II) Channel config, Main: 4, Real: 2
[ALSOFT] (II) Allocating 6 channels, 24576 bytes
[ALSOFT] (II) Min delay: 7.75, max delay: 33.50, FIR length: 64
[ALSOFT] (II) New max delay: 25.75, FIR length: 90
[ALSOFT] (II) Max sources: 256 (255 + 1), effect slots: 64, sends: 4
[ALSOFT] (II) Dithering disabled
[ALSOFT] (II) Output limiter disabled
[ALSOFT] (II) Fixed device latency: 0ns
[ALSOFT] (II) Post-start: Stereo, Float32, 48000hz, 480 / 1536 buffer
[ALSOFT] (II) Increasing allocated voices to 256
[ALSOFT] (II) Created context 0x1e63c961fa0
[ALSOFT] (II) Increasing allocated context properties to 2
[ALSOFT] (II) Increasing allocated effect slots to 4
[ALSOFT] (II) Increasing allocated effect slot properties to 4
[ALSOFT] (II) Increasing allocated voice properties to 32

[kcat]

I've encountered the same or similar issue with auxiliary effect slots, although I've narrowed it down to the popping/cracking issue only presenting itself when an effect has been assigned to a effect slot with alAuxiliaryEffectSloti().

Does it happen even when the effect type is AL_EFFECT_NULL? Or does it happen only with non-null effect types?

Simply generating an effect slot and an effect won't cause the issue to manifest, and I actually found that the more effects you have assigned to a slot, the worse and more frequent the popping/cracking gets.

That is certainly odd. Setting effects on the same slot should only replace the effect being processed, but this description makes it sound like it's generating more and more effects to process.

[Toast-t]

I just tried setting the effect type to AL_EFFECT_NULL, and I'm still getting the popping/crackling sounds.

That is certainly odd. Setting effects on the same slot should only replace the effect being processed, but this description makes it sound like it's generating more and more effects to process.

Also sorry I should've been clearer about what I meant here. I didn't mean trying to add multiple effects to one effect slot, I meant the more effect slots you have that have their AL_EFFECTSLOT_EFFECT property set to individual effects, the more severe the noise artifacts manifest.

[BekimS]

I came across that distinction yesterday when it came to assigning an effect to a slot, my bad for not trying to narrow it down further initially. Disabling hrtf and messing with the configuration files still yields the same results, even on different hardware using different types of audio devices. I'll still try to tinker with the config files to see if something could work, I'll comment if anything happens.