There were warnings when processing it to pcm_s32le .wav with the latest FFmpeg, but it decoded without the aforementioned glitching.
& 'C:\Program Files\FFmpeg\bin\ffmpeg.exe' -i .\mus_ruins.ogg -c:a pcm_f32le mus_ruins.wav
ffmpeg version N-89310-g86cead5256 Copyright (c) 2000-2017 the FFmpeg developers
built with gcc 7.2.0 (GCC)
configuration: --enable-gpl --enable-version3 --enable-sdl2 --enable-bzlib --enable-fontconfig --enable-gnutls --enable-iconv --enable-libass --enable-libbluray --enable-libfreetype --enable-libmp3lame --enable-libopenjpeg --enable-libopus --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libtheora --enable-libtwolame --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libzimg --enable-lzma --enable-zlib --enable-gmp --enable-libvidstab --enable-libvorbis --enable-cuda --enable-cuvid --enable-d3d11va --enable-nvenc --enable-dxva2 --enable-avisynth --enable-libmfx
libavutil 56. 3.100 / 56. 3.100
libavcodec 58. 6.101 / 58. 6.101
libavformat 58. 2.103 / 58. 2.103
libavdevice 58. 0.100 / 58. 0.100
libavfilter 7. 5.100 / 7. 5.100
libswscale 5. 0.101 / 5. 0.101
libswresample 3. 0.101 / 3. 0.101
libpostproc 55. 0.100 / 55. 0.100
Input #0, ogg, from '.\mus_ruins.ogg':
Duration: 00:01:31.31, start: 0.000000, bitrate: 91 kb/s
Stream #0:0: Audio: vorbis, 44100 Hz, stereo, fltp, 112 kb/s
Metadata:
ENCODER : Lavc56.12.101 libvorbis
Stream mapping:
Stream #0:0 -> #0:0 (vorbis (native) -> pcm_f32le (native))
Press [q] to stop, [?] for help
Output #0, wav, to 'mus_ruins.wav':
Metadata:
ISFT : Lavf58.2.103
Stream #0:0: Audio: pcm_f32le ([3][0][0][0] / 0x0003), 44100 Hz, stereo, flt, 2822 kb/s
Metadata:
encoder : Lavc58.6.101 pcm_f32le
[wav @ 000001926c19c160] Non-monotonous DTS in output stream 0:0; previous: 403392, current: 403072; changing to 403392. This may result in incorrect timestamps in the output file.
[wav @ 000001926c19c160] Non-monotonous DTS in output stream 0:0; previous: 403392, current: 403200; changing to 403392. This may result in incorrect timestamps in the output file.
[wav @ 000001926c19c160] Non-monotonous DTS in output stream 0:0; previous: 537280, current: 536960; changing to 537280. This may result in incorrect timestamps in the output file.
[wav @ 000001926c19c160] Non-monotonous DTS in output stream 0:0; previous: 537280, current: 537088; changing to 537280. This may result in incorrect timestamps in the output file.
[wav @ 000001926c19c160] Non-monotonous DTS in output stream 0:0; previous: 537280, current: 537216; changing to 537280. This may result in incorrect timestamps in the output file.
[wav @ 000001926c19c160] Non-monotonous DTS in output stream 0:0; previous: 805696, current: 805376; changing to 805696. This may result in incorrect timestamps in the output file.
[wav @ 000001926c19c160] Non-monotonous DTS in output stream 0:0; previous: 805696, current: 805504; changing to 805696. This may result in incorrect timestamps in the output file.
[wav @ 000001926c19c160] Non-monotonous DTS in output stream 0:0; previous: 805696, current: 805632; changing to 805696. This may result in incorrect timestamps in the output file.
[wav @ 000001926c19c160] Non-monotonous DTS in output stream 0:0; previous: 1208000, current: 1207680; changing to 1208000. This may result in incorrect timestamps in the output file.
[wav @ 000001926c19c160] Non-monotonous DTS in output stream 0:0; previous: 1208000, current: 1207808; changing to 1208000. This may result in incorrect timestamps in the output file.
[wav @ 000001926c19c160] Non-monotonous DTS in output stream 0:0; previous: 1208000, current: 1207936; changing to 1208000. This may result in incorrect timestamps in the output file.
[wav @ 000001926c19c160] Non-monotonous DTS in output stream 0:0; previous: 1342656, current: 1342336; changing to 1342656. This may result in incorrect timestamps in the output file.
[wav @ 000001926c19c160] Non-monotonous DTS in output stream 0:0; previous: 1342656, current: 1342464; changing to 1342656. This may result in incorrect timestamps in the output file.
[wav @ 000001926c19c160] Non-monotonous DTS in output stream 0:0; previous: 1342656, current: 1342592; changing to 1342656. This may result in incorrect timestamps in the output file.
[wav @ 000001926c19c160] Non-monotonous DTS in output stream 0:0; previous: 1745216, current: 1744896; changing to 1745216. This may result in incorrect timestamps in the output file.
[wav @ 000001926c19c160] Non-monotonous DTS in output stream 0:0; previous: 1745216, current: 1745024; changing to 1745216. This may result in incorrect timestamps in the output file.
[wav @ 000001926c19c160] Non-monotonous DTS in output stream 0:0; previous: 1745216, current: 1745152; changing to 1745216. This may result in incorrect timestamps in the output file.
[wav @ 000001926c19c160] Non-monotonous DTS in output stream 0:0; previous: 2637120, current: 2636800; changing to 2637120. This may result in incorrect timestamps in the output file.
[wav @ 000001926c19c160] Non-monotonous DTS in output stream 0:0; previous: 2637120, current: 2636928; changing to 2637120. This may result in incorrect timestamps in the output file.
[wav @ 000001926c19c160] Non-monotonous DTS in output stream 0:0; previous: 2637120, current: 2637056; changing to 2637120. This may result in incorrect timestamps in the output file.
[wav @ 000001926c19c160] Non-monotonous DTS in output stream 0:0; previous: 3441984, current: 3441664; changing to 3441984. This may result in incorrect timestamps in the output file.
[wav @ 000001926c19c160] Non-monotonous DTS in output stream 0:0; previous: 3441984, current: 3441792; changing to 3441984. This may result in incorrect timestamps in the output file.
[wav @ 000001926c19c160] Non-monotonous DTS in output stream 0:0; previous: 3441984, current: 3441920; changing to 3441984. This may result in incorrect timestamps in the output file.
size= 31468kB time=00:01:31.33 bitrate=2822.4kbits/s speed= 428x
video:0kB audio:31468kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.000354%