Audiotrack warnings: resetting master clock: coefficient too unstable

Sample: dog_meme.mp4

(in the current setup, it's from branch: https://code.videolan.org/alexandre-janniaux/vlc/-/commits/android-build/2, but no other changes on audiotrack time reporting have been done).

No audio glitch is heard, but there are multiple warnings happening during the whole playback.

Playing with --aout=audiotrack --no-video:

01-20 17:48:30.300 19073 19073 D VLC     : [b400007b361d0860/2ba] main libvlc: configured with /home/janniaux/Projects/videolabs/vlc/configure  '--host=aarch64-linux-android21' '--prefix=/usr/local/linux-android' '--libdir=/usr/local/linux-android/lib/arm64-v8a' '--with-contribs=/home/janniaux/Projects/videolabs/vlc/contrib/aarch64-linux-android' '--with-a52=/home/janniaux/Projects/videolabs/vlc/contrib/aarch64-linux-android' '--disable-vlc' '--disable-chromecast' '--disable-harfbuzz' '--disable-freetype' '--disable-libplacebo' '--disable-gme' '--disable-libass' '--disable-lua' '--disable-xcb' '--disable-v4l2' '--disable-alsa' '--disable-fluidsynth' '--disable-fluidlite' '--enable-gles2' 'CC=/home/janniaux/Android/android-ndk-r25b//toolchains/llvm/prebuilt/linux-x86_64/bin//aarch64-linux-android21-clang' 'CXX=/home/janniaux/Android/android-ndk-r25b//toolchains/llvm/prebuilt/linux-x86_64/bin//aarch64-linux-android21-clang++' 'AR=/home/janniaux/Android/android-ndk-r25b//toolchains/llvm/prebuilt/linux-x86_64/bin//llvm-ar' 'AS=/home/janniaux/Android/andr
01-20 17:48:30.300 19073 19073 D VLC     : [b400007b361d0860/326] main libvlc: searching plug-in modules
01-20 17:48:30.300 19073 19073 D VLC     : [b400007b361d0860/347] main libvlc: loading plugins cache file /data/app/~~Q7UQnlbVEtPeuAB01gCxpQ==/org.videolan.nativesample-nKlm_zQl25zV8wxDMLogJw==/lib/arm64//plugins.dat
01-20 17:48:30.300 19073 19073 W VLC     : [b400007b361d0860/35c] main libvlc: cannot read /data/app/~~Q7UQnlbVEtPeuAB01gCxpQ==/org.videolan.nativesample-nKlm_zQl25zV8wxDMLogJw==/lib/arm64//plugins.dat: No such file or directory
01-20 17:48:30.300 19073 19073 D VLC     : [b400007b361d0860/378] main libvlc: recursively browsing `/data/app/~~Q7UQnlbVEtPeuAB01gCxpQ==/org.videolan.nativesample-nKlm_zQl25zV8wxDMLogJw==/lib/arm64/'
01-20 17:48:30.300 19073 19073 D VLC     : [b400007b361d0860/5bd] main libvlc: plug-ins loaded: 466 modules
01-20 17:48:30.300 19073 19073 D VLC     : [0000007fdb2dea40/5cd] main generic: looking for logger module matching "any": 4 candidates
01-20 17:48:30.300 19073 19073 D VLC     : [0000007fdb2dea40/5ea] main generic: using logger module "android"
01-20 17:48:30.300 19073 19073 D VLC     : [0000007fdb2dea20/4a81] main generic: looking for tracer module matching "none": 0 candidates
01-20 17:48:30.300 19073 19073 D VLC     : [0000007fdb2dea20/4a81] main generic: no tracer modules matched with name none
01-20 17:48:30.300 19073 19073 D VLC     : [b400007b361d0860/4a81] main libvlc: translation test: code is "C"
01-20 17:48:30.300 19073 19073 D VLC     : [0000007fdb2de9f0/4a81] main generic: looking for keystore module matching "memory": 1 candidates
01-20 17:48:30.300 19073 19073 D VLC     : [0000007fdb2de9f0/4a81] main generic: using keystore module "memory"
01-20 17:48:30.300 19073 19073 D VLC     : [b400007b361d0860/4a81] main libvlc: CPU has capabilities FPU
01-20 17:48:30.303 19073 19073 D VLC     : [b400007b50755700/4a81] main player: creating audio output
01-20 17:48:30.303 19073 19073 D VLC     : [0000007fdb2dea00/4a81] main generic: looking for audio output module matching "audiotrack": 3 candidates
01-20 17:48:30.303 19073 19073 D VLC     : [0000007fdb2dea00/4a81] main generic: using audio output module "device"
01-20 17:48:30.304 19073 19073 D VLC     : [b400007b50755700/4a81] main player: keeping audio output

Results in

01-20 17:48:30.545 19073 19166 D VLC     : [0000007aa91fba80/4ade] http generic: connection failed
01-20 17:48:30.547 19073 19160 D VLC     : [b400007b360d2000/4ad8] main input: Buffering 100%
01-20 17:48:30.547 19073 19160 D VLC     : [b400007b360d2000/4ad8] main input: Stream buffering done (1250 ms in 91 ms)
01-20 17:48:30.608 19073 19170 E VLC     : [b400007b41d91230/4ae2] audiotrack generic: GetStaticFieldID(AudioFormat.ENCODING_PCM_32BIT) failed
01-20 17:48:30.608 19073 19170 D VLC     : [b400007b41d91230/4ae2] audiotrack generic: using WRITE_BYTEARRAYV23
01-20 17:48:30.623 19073 19170 D VLC     : [b400007b41d91230/4ae2] main generic: VLC will output: 's16l' 48000 Hz Stereo frame=1 samples/4 bytes
01-20 17:48:30.623 19073 19170 D VLC     : [b400007b41d91230/4ae2] audiotrack generic: using AudioTrack API
01-20 17:48:30.623 19073 19170 D VLC     : [b400007b5a51e480/4ae2] main audio output: output 's16l' 48000 Hz Stereo frame=1 samples/4 bytes
01-20 17:48:30.623 19073 19170 D VLC     : [0000007aa80fd690/4ae2] main generic: looking for audio volume module matching "any": 2 candidates
01-20 17:48:30.623 19073 19170 D VLC     : [0000007aa80fd690/4ae2] main generic: using audio volume module "integer_mixer"
01-20 17:48:30.623 19073 19170 D VLC     : [b400007b5a51e480/4ae2] main audio output: input 'f32l' 44100 Hz Stereo frame=1 samples/8 bytes
01-20 17:48:30.623 19073 19170 D VLC     : [0000007aa80fd4b0/4ae2] main generic: looking for audio filter module matching "scaletempo": 1 candidates
01-20 17:48:30.623 19073 19170 D VLC     : [b400007b360c5e80/4ae2] scaletempo audio filter: format: 44100 rate, 2 nch, 4 bps, fl32
01-20 17:48:30.623 19073 19170 D VLC     : [b400007b360c5e80/4ae2] scaletempo audio filter: params: 30 stride, 0.200 overlap, 14 search
01-20 17:48:30.623 19073 19170 D VLC     : [b400007b360c5e80/4ae2] scaletempo audio filter: 1.000 scale, 1323.000 stride_in, 1323 stride_out, 1059 standing, 264 overlap, 617 search, 2204 queue, fl32 mode
01-20 17:48:30.623 19073 19170 D VLC     : [0000007aa80fd4b0/4ae2] main generic: using audio filter module "scaletempo"
01-20 17:48:30.623 19073 19170 D VLC     : [b400007b5a51e480/4ae2] main audio output: conversion: 'f32l'->'f32l' 44100 Hz->44100 Hz Stereo->Stereo
01-20 17:48:30.623 19073 19170 D VLC     : [b400007b5a51e480/4ae2] main audio output: conversion pipeline complete
01-20 17:48:30.623 19073 19170 D VLC     : [b400007b5a51e480/4ae2] main audio output: conversion: 'f32l'->'s16l' 44100 Hz->44100 Hz Stereo->Stereo
01-20 17:48:30.623 19073 19170 D VLC     : [0000007aa80fd480/4ae2] main generic: looking for audio converter module matching "any": 8 candidates
01-20 17:48:30.623 19073 19170 D VLC     : [b400007b360c5700/4ae2] audio_format audio converter: f32l->s16l, bits per sample: 32->16
01-20 17:48:30.623 19073 19170 D VLC     : [0000007aa80fd480/4ae2] main generic: using audio converter module "audio_format"
01-20 17:48:30.623 19073 19170 D VLC     : [b400007b5a51e480/4ae2] main audio output: conversion pipeline complete
01-20 17:48:30.623 19073 19170 D VLC     : [0000007aa80fd540/4ae2] main generic: looking for audio resampler module matching "any": 2 candidates
01-20 17:48:30.624 19073 19170 D VLC     : [b400007b360c5c00/4ae2] soxr audio resampler: Using SoX Resampler with 'cr32' engine and 'Medium 16-bit with medium roll-off' quality to convert s16l/44100Hz to s16l/48000Hz.
01-20 17:48:30.624 19073 19170 D VLC     : [0000007aa80fd540/4ae2] main generic: using audio resampler module "soxr"
01-20 17:48:30.624 19073 19160 D VLC     : [b400007b360d2000/4ad8] main input: Decoder wait done in 76 ms
01-20 17:48:30.837 19073 19166 D VLC     : [b400007b50711c60/4ade] prefetch stream filter: end of stream
01-20 17:48:31.785 19073 19170 W VLC     : [b400007b50712280/4ae2] main generic: resetting master clock: coefficient too unstable: 0.638458
01-20 17:48:32.786 19073 19170 W VLC     : [b400007b50712280/4ae2] main generic: resetting master clock: coefficient too unstable: 0.734884
01-20 17:48:33.786 19073 19170 W VLC     : [b400007b50712280/4ae2] main generic: resetting master clock: coefficient too unstable: 0.751163
01-20 17:48:37.036 19073 19170 W VLC     : [b400007b50712280/4ae2] main generic: resetting master clock: coefficient too unstable: 0.794780
01-20 17:48:37.535 19073 19170 W VLC     : [b400007b50712280/4ae2] main generic: resetting master clock: coefficient too unstable: 0.789276
01-20 17:48:42.285 19073 19170 W VLC     : [b400007b50712280/4ae2] main generic: resetting master clock: coefficient too unstable: 1.231912
01-20 17:48:42.785 19073 19170 W VLC     : [b400007b50712280/4ae2] main generic: resetting master clock: coefficient too unstable: 0.793196
01-20 17:48:43.036 19073 19170 W VLC     : [b400007b50712280/4ae2] main generic: resetting master clock: coefficient too unstable: 0.750991
01-20 17:48:43.535 19073 19170 W VLC     : [b400007b50712280/4ae2] main generic: resetting master clock: coefficient too unstable: 0.750172
01-20 17:48:48.286 19073 19170 W VLC     : [b400007b50712280/4ae2] main generic: resetting master clock: coefficient too unstable: 1.231223
01-20 17:48:48.785 19073 19170 W VLC     : [b400007b50712280/4ae2] main generic: resetting master clock: coefficient too unstable: 0.794100
01-20 17:48:49.537 19073 19170 W VLC     : [b400007b50712280/4ae2] main generic: resetting master clock: coefficient too unstable: 0.753316
01-20 17:48:51.536 19073 19170 W VLC     : [b400007b50712280/4ae2] main generic: resetting master clock: coefficient too unstable: 1.231912
01-20 17:48:54.285 19073 19170 W VLC     : [b400007b50712280/4ae2] main generic: resetting master clock: coefficient too unstable: 1.224634
01-20 17:48:55.285 19073 19170 W VLC     : [b400007b50712280/4ae2] main generic: resetting master clock: coefficient too unstable: 0.791990
01-20 17:48:55.785 19073 19170 W VLC     : [b400007b50712280/4ae2] main generic: resetting master clock: coefficient too unstable: 0.791473
01-20 17:48:56.035 19073 19170 W VLC     : [b400007b50712280/4ae2] main generic: resetting master clock: coefficient too unstable: 0.749096
01-20 17:48:56.535 19073 19170 W VLC     : [b400007b50712280/4ae2] main generic: resetting master clock: coefficient too unstable: 0.787080
01-20 17:48:58.035 19073 19160 D VLC     : [b400007b360d2000/4ad8] main input: EOF reached
01-20 17:48:58.284 19073 19160 D VLC     : [b400007b360d2000/4ad8] main input: waiting decoder fifos to empty
01-20 17:48:58.385 19073 19160 D VLC     : [b400007b360d2000/4ad8] main input: waiting decoder fifos to empty
01-20 17:48:58.485 19073 19160 D VLC     : [b400007b360d2000/4ad8] main input: waiting decoder fifos to empty
01-20 17:48:58.586 19073 19160 D VLC     : [b400007b360d2000/4ad8] main input: waiting decoder fifos to empty
01-20 17:48:58.687 19073 19160 D VLC     : [b400007b360d2000/4ad8] main input: waiting decoder fifos to empty
01-20 17:48:58.787 19073 19160 D VLC     : [b400007b360d2000/4ad8] main input: waiting decoder fifos to empty
01-20 17:48:58.888 19073 19160 D VLC     : [b400007b360d2000/4ad8] main input: waiting decoder fifos to empty
01-20 17:48:58.988 19073 19160 D VLC     : [b400007b360d2000/4ad8] main input: waiting decoder fifos to empty
01-20 17:48:59.088 19073 19160 D VLC     : [b400007b360d2000/4ad8] main input: waiting decoder fifos to empty
01-20 17:48:59.189 19073 19160 D VLC     : [b400007b360d2000/4ad8] main input: waiting decoder fifos to empty
01-20 17:48:59.289 19073 19160 D VLC     : [b400007b360d2000/4ad8] main input: waiting decoder fifos to empty
01-20 17:48:59.389 19073 19160 D VLC     : [b400007b360d2000/4ad8] main input: waiting decoder fifos to empty
01-20 17:48:59.490 19073 19160 D VLC     : [b400007b360d2000/4ad8] main input: waiting decoder fifos to empty
01-20 17:48:59.591 19073 19160 D VLC     : [b400007b360d2000/4ad8] main input: waiting decoder fifos to empty
01-20 17:48:59.691 19073 19160 D VLC     : [b400007b360d2000/4ad8] main input: waiting decoder fifos to empty
01-20 17:48:59.794 19073 19160 D VLC     : [b400007b41c30000/4ad8] main decoder: killing decoder fourcc `mp4a'
01-20 17:48:59.795 19073 19160 D VLC     : [b400007b41c30000/4ad8] main decoder: removing "audio decoder" module "avcodec"
01-20 17:48:59.795 19073 19160 D VLC     : [b400007b360c5c00/4ad8] main audio resampler: removing "audio resampler" module "soxr"
01-20 17:48:59.795 19073 19160 D VLC     : [b400007b360c5e80/4ad8] main audio filter: removing "audio filter" module "scaletempo"
01-20 17:48:59.795 19073 19160 D VLC     : [b400007b360c5700/4ad8] main audio converter: removing "audio converter" module "audio_format"
01-20 17:48:59.811 19073 19160 D VLC     : [b400007b360cab10/4ad8] main volume: removing "audio volume" module "integer_mixer"
01-20 17:48:59.811 19073 19160 D VLC     : [b400007b50755700/4ad8] main player: keeping audio output
01-20 17:48:59.811 19073 19160 D VLC     : [b400007b360d2000/4ad8] main input: ES track unselected: 'audio/2' (fourcc: 'mp4a')
01-20 17:48:59.811 19073 19160 D VLC     : [b400007b50711e20/4ad8] main demux: removing "demux" module "mp4"
01-20 17:48:59.811 19073 19160 D VLC     : [b400007b50711e20/4ad8] main demux: attempt to destroy nonexistent variable "module-name"
01-20 17:48:59.811 19073 19160 D VLC     : [b400007b50711e20/4ad8] mp4 demux: freeing all memory
01-20 17:48:59.811 19073 19160 D VLC     : [b400007b360d2000/4ad8] main input: ES track deleted: 'video/1' (fourcc: 'h264')
01-20 17:48:59.811 19073 19160 D VLC     : [b400007b360d2000/4ad8] main input: ES track deleted: 'audio/2' (fourcc: 'mp4a')
01-20 17:48:59.811 19073 19160 D VLC     : [b400007b360d2000/4ad8] main input: Program doesn't contain anymore ES
01-20 17:48:59.811 19073 19160 D VLC     : [b400007b50711d40/4ad8] main stream filter: removing "stream_filter" module "record"
01-20 17:48:59.811 19073 19160 D VLC     : [b400007b50711c60/4ad8] main stream filter: removing "stream_filter" module "prefetch"
01-20 17:48:59.812 19073 19160 D VLC     : [b400007b50711aa0/4ad8] main access: removing "access" module "http"
01-20 17:48:59.813 19073 19159 D VLC     : [b400007b360d2000/4ad7] main input: destroying input for 'dog_meme.mp4'