Audio distortion on Big Sur 11.6

[redlester]

Have recently set up a new (to me) Mac, which is a 2013 Mac Pro, 6 core, 3.5GHz, 32GB RAM with a clean install of Mojave then immediately updated to Big Sur. All is functioning well.

Playing mp4 videos on VLC 3.0.16 produces absolutely dreadful audio distortion, and brief total audio dropouts roughly every ten seconds, on all videos. The same videos play perfectly on Quicktime.

I don't know where to start with the Advanced Options, does anyone have any guidance for this?

My audio is via a UAD Apollo 8 Thunderbolt audio interface.

[unidan]

Hi, can you post verbose logs during playback ? It could happen if the external audio device requires too much latency and it should appear in the logs.

[redlester]

Not sure if I've done this correctly but see below:

main debug: VLC media player - 3.0.16 Vetinari
main debug: Copyright © 1996-2021 the VideoLAN team
main debug: revision 3.0.16-0-g5e70837d8d
main debug: configured with /Users/d-fu/vlc-3.0/extras/package/macosx/../../../configure '--prefix=/Users/d-fu/vlc-3.0/build/vlc_install_dir' '--enable-macosx' '--enable-merge-ffmpeg' '--enable-osx-notifications' '--enable-faad' '--enable-flac' '--enable-theora' '--enable-shout' '--enable-ncurses' '--enable-twolame' '--enable-realrtsp' '--enable-libass' '--enable-macosx-avfoundation' '--disable-skins2' '--disable-xcb' '--disable-caca' '--disable-pulse' '--disable-sdl-image' '--disable-vnc' '--build=x86_64-apple-darwin17' '--host=x86_64-apple-darwin17' '--with-macosx-version-min=10.7' '--with-macosx-sdk=/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk' '--with-breakpad=https://mac.crashes.videolan.org' 'build_alias=x86_64-apple-darwin17' 'host_alias=x86_64-apple-darwin17' 'CC=/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang' 'CFLAGS=-g -arch x86_64' 'LDFLAGS=-arch x86_64' 'CXX=/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang++' 'CXXFLAGS=-g -arch x86_64' 'OBJC=/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang' 'OBJCFLAGS=-g -arch x86_64'
main warning: playback too late (60262): up-sampling
main warning: timing screwed (drift: 122037 us): stopping resampling
main warning: playback too late (122183): up-sampling
main warning: playback way too late (182610): flushing buffers
main warning: playback too late (60140): up-sampling
main warning: timing screwed (drift: 122389 us): stopping resampling
main warning: playback too late (122285): up-sampling
main warning: playback way too late (183179): flushing buffers
main warning: playback too late (60744): up-sampling
main warning: timing screwed (drift: 126124 us): stopping resampling
main warning: playback too late (125999): up-sampling
main warning: playback way too late (181163): flushing buffers
main warning: playback too late (60093): up-sampling
main warning: timing screwed (drift: 120802 us): stopping resampling
main warning: playback too late (120697): up-sampling
main warning: playback way too late (182545): flushing buffers
main warning: playback too late (60578): up-sampling
main warning: timing screwed (drift: 122113 us): stopping resampling
main warning: playback too late (121987): up-sampling
main warning: playback way too late (180039): flushing buffers
main warning: playback too late (65364): up-sampling
main warning: timing screwed (drift: 132360 us): stopping resampling
main warning: playback too late (132235): up-sampling
main warning: playback way too late (183498): flushing buffers
main warning: playback too late (60869): up-sampling
main warning: timing screwed (drift: 123105 us): stopping resampling
main warning: playback too late (122999): up-sampling
main warning: playback way too late (180104): flushing buffers
main warning: playback too late (61259): up-sampling
main warning: timing screwed (drift: 123118 us): stopping resampling
main warning: playback too late (122993): up-sampling
main warning: playback way too late (184240): flushing buffers
main warning: playback too late (60571): up-sampling
main warning: timing screwed (drift: 121458 us): stopping resampling
main warning: playback too late (121353): up-sampling
main warning: playback way too late (181405): flushing buffers
main warning: playback too late (60392): up-sampling
main warning: timing screwed (drift: 121463 us): stopping resampling
main warning: playback too late (121336): up-sampling
main warning: playback way too late (182811): flushing buffers
main warning: playback too late (60175): up-sampling
main warning: timing screwed (drift: 124514 us): stopping resampling
main warning: playback too late (124390): up-sampling
main warning: playback way too late (180628): flushing buffers
main warning: playback too late (60445): up-sampling
main warning: timing screwed (drift: 122502 us): stopping resampling
main warning: playback too late (122399): up-sampling
main warning: playback way too late (182984): flushing buffers
main warning: playback too late (60054): up-sampling
main debug: incoming request - stopping current input
main debug: killing decoder fourcc `h264'
main debug: removing module "avcodec"
main debug: saving a free vout
main debug: reusing provided vout
main debug: killing decoder fourcc `mp4a'
main debug: removing module "faad"
main debug: removing module "samplerate"
main debug: removing module "scaletempo"
auhal debug: Stopping the auhal module
macosx debug: Store current playback position of 0.112190
main debug: removing module "float_mixer"
main debug: keeping audio output
main debug: removing module "mp4"
mp4 debug: freeing all memory
main debug: Program doesn't contain anymore ES
main debug: removing module "record"
main debug: removing module "cache_read"
main debug: removing module "filesystem"
main debug: dead input
main debug: nothing to play
main debug: destroying useless vout
main debug: removing module "caopengllayer"
main debug: removing module "freetype"
main debug: removing module "yuvp"
main debug: removing module "swscale"
macosx debug: toggle playlist from state: removed splitview 0, minimized view 0. Event 2
macosx debug: toggle playlist to state: removed splitview 0, minimized view 0
macosx debug: Playback has been ended
macosx debug: Releasing IOKit monitor sleep blocker (35689)

[redlester]

Just to update on this for anyone in the future;

The problem is not with VLC, the issue is the fact I had a USB 2.0 audio interface (Native Instruments Komplete Audio 6) connected to the Mac. It was actually set up as an aggregate device with my UAD Apollo 8 Thunderbolt interface. After trying absolutely everything, when I unplug the USB audio interface the crackling goes away.

I believe my Mac is a 2018 version of the 2013 Mac Pro, is this something that's a known issue with that model?