Musepack decoding is worse quality than the official mpc decoder

[ego-lay_atman-bay]

Summary of the bug:

I am trying to transcode an mpc (musepack) file to wav, however when I transcode this mpc file to wav, I get static that is not present when decoding using the official mpc decoder, which can be found ​here.

How to reproduce:

% ffmpeg -i .\m_lic_eqg_eg_stomp.mpc .\m_lic_eqg_eg_stomp-ffmpeg.wav

Here's the console output

ffmpeg started on 2024-10-22 at 20:18:26
Report written to "ffmpeg-20241022-201826.log"
Log level: 99
Command line:
"C:\\Users\\USER\\AppData\\Local\\Microsoft\\WinGet\\Links\\ffmpeg.exe" -report -v 9 -loglevel 99 -i ".\\m_lic_eqg_eg_stomp.mpc" ".\\m_lic_eqg_eg_stomp-ffmpeg.wav"
ffmpeg version 6.1-full_build-www.gyan.dev Copyright (c) 2000-2023 the FFmpeg developers
  built with gcc 12.2.0 (Rev10, Built by MSYS2 project)
  configuration: --enable-gpl --enable-version3 --enable-static --pkg-config=pkgconf --disable-w32threads --disable-autodetect --enable-fontconfig --enable-iconv --enable-gnutls --enable-libxml2 --enable-gmp --enable-bzlib --enable-lzma --enable-libsnappy --enable-zlib --enable-librist --enable-libsrt --enable-libssh --enable-libzmq --enable-avisynth --enable-libbluray --enable-libcaca --enable-sdl2 --enable-libaribb24 --enable-libaribcaption --enable-libdav1d --enable-libdavs2 --enable-libuavs3d --enable-libzvbi --enable-librav1e --enable-libsvtav1 --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxavs2 --enable-libxvid --enable-libaom --enable-libjxl --enable-libopenjpeg --enable-libvpx --enable-mediafoundation --enable-libass --enable-frei0r --enable-libfreetype --enable-libfribidi --enable-libharfbuzz --enable-liblensfun --enable-libvidstab --enable-libvmaf --enable-libzimg --enable-amf --enable-cuda-llvm --enable-cuvid --enable-ffnvcodec --enable-nvdec --enable-nvenc --enable-dxva2 --enable  libavutil      58. 29.100 / 58. 29.100
  libavcodec     60. 31.102 / 60. 31.102
  libavformat    60. 16.100 / 60. 16.100
  libavdevice    60.  3.100 / 60.  3.100
  libavfilter     9. 12.100 /  9. 12.100
  libswscale      7.  5.100 /  7.  5.100
  libswresample   4. 12.100 /  4. 12.100
  libpostproc    57.  3.100 / 57.  3.100
Splitting the commandline.
Reading option '-report' ... matched as option 'report' (generate a report) with argument '1'.
Reading option '-v' ... matched as option 'v' (set logging level) with argument '9'.
Reading option '-loglevel' ... matched as option 'loglevel' (set logging level) with argument '99'.
Reading option '-i' ... matched as output url with argument '.\m_lic_eqg_eg_stomp.mpc'.
Reading option '.\m_lic_eqg_eg_stomp-ffmpeg.wav' ... matched as output url.
Finished splitting the commandline.
Parsing a group of options: global .
Applying option report (generate a report) with argument 1.
Applying option v (set logging level) with argument 9.
Applying option loglevel (set logging level) with argument 99.
Successfully parsed a group of options.
Parsing a group of options: input url .\m_lic_eqg_eg_stomp.mpc.
Successfully parsed a group of options.
Opening an input file: .\m_lic_eqg_eg_stomp.mpc.
[AVFormatContext @ 00000175db2a3e40] Opening '.\m_lic_eqg_eg_stomp.mpc' for reading
[file @ 00000175db2a42c0] Setting default whitelist 'file,crypto,data'
Probing mp3 score:1 size:2048
Probing mpc8 score:100 size:2048
[mpc8 @ 00000175db2a3e40] Format mpc8 probed with size=2048 and score=100
st:0 removing common factor 256 from timebase
[mpc8 @ 00000175db2a3e40] Before avformat_find_stream_info() pos: 19 bytes read:32800 seeks:2 nb_streams:1
[mpc8 @ 00000175db2a3e40] max_analyze_duration 5000000 reached at 6912000 microseconds st:0
[mpc8 @ 00000175db2a3e40] stream 0: start_time: 0 duration: 92.16
[mpc8 @ 00000175db2a3e40] format: start_time: 0 duration: 92.16 (estimate from stream) bitrate=73 kb/s
[mpc8 @ 00000175db2a3e40] After avformat_find_stream_info() pos: 113155 bytes read:196685 seeks:4 frames:5
Input #0, mpc8, from '.\m_lic_eqg_eg_stomp.mpc':
  Duration: 00:01:32.16, start: 0.000000, bitrate: 73 kb/s
  Stream #0:0, 5, 288/125: Audio: musepack8, 32000 Hz, stereo, s16p
Successfully opened the file.
Parsing a group of options: output url .\m_lic_eqg_eg_stomp-ffmpeg.wav.
Successfully parsed a group of options.
Opening an output file: .\m_lic_eqg_eg_stomp-ffmpeg.wav.
[out#0/wav @ 00000175db2aca80] No explicit maps, mapping streams automatically...
[aost#0:0/pcm_s16le @ 00000175db29e540] Created audio stream from input stream 0:0
[file @ 00000175db2d5380] Setting default whitelist 'file,crypto,data'
Successfully opened the file.
Stream mapping:
  Stream #0:0 -> #0:0 (musepack8 (mpc8) -> pcm_s16le (native))
Press [q] to stop, [?] for help
detected 12 logical cores
[graph_0_in_0_0 @ 00000175db330600] Setting 'time_base' to value '1/32000'
[graph_0_in_0_0 @ 00000175db330600] Setting 'sample_rate' to value '32000'
[graph_0_in_0_0 @ 00000175db330600] Setting 'sample_fmt' to value 's16p'
[graph_0_in_0_0 @ 00000175db330600] Setting 'channel_layout' to value 'stereo'
[graph_0_in_0_0 @ 00000175db330600] tb:1/32000 samplefmt:s16p samplerate:32000 chlayout:stereo
[format_out_0_0 @ 00000175db330d80] Setting 'sample_fmts' to value 's16'
[format_out_0_0 @ 00000175db330d80] auto-inserting filter 'auto_aresample_0' between the filter 'Parsed_anull_0' and the filter 'format_out_0_0'
[AVFilterGraph @ 00000175db31a5c0] query_formats: 4 queried, 4 merged, 6 already done, 0 delayed
[auto_aresample_0 @ 00000175db331200] [SWR @ 00000175db331300] Using s16p internally between filters
[auto_aresample_0 @ 00000175db331200] ch:2 chl:stereo fmt:s16p r:32000Hz -> ch:2 chl:stereo fmt:s16 r:32000Hz
Output #0, wav, to '.\m_lic_eqg_eg_stomp-ffmpeg.wav':
  Metadata:
    ISFT            : Lavf60.16.100
  Stream #0:0, 0, 1/32000: Audio: pcm_s16le ([1][0][0][0] / 0x0001), 32000 Hz, stereo, s16, 1024 kb/s
    Metadata:
      encoder         : Lavc60.31.102 pcm_s16le
size=     243kB time=00:00:02.26 bitrate= 878.0kbits/s speed=N/A    
[in#0/mpc8 @ 00000175db28b180] EOF while reading input
[in#0/mpc8 @ 00000175db28b180] Terminating demuxer thread
[aist#0:0/musepack8 @ 00000175db2b6a40] Decoder thread received EOF packet
[aist#0:0/musepack8 @ 00000175db2b6a40] Decoder returned EOF, finishing
[aist#0:0/musepack8 @ 00000175db2b6a40] Terminating decoder thread
[out_0_0 @ 00000175db330c80] EOF on sink link out_0_0:default.
No more output streams to write to, finishing.
[out#0/wav @ 00000175db2aca80] All streams finished
[out#0/wav @ 00000175db2aca80] Terminating muxer thread
[AVIOContext @ 00000175db3174c0] Statistics: 11884118 bytes written, 4 seeks, 48 writeouts
[out#0/wav @ 00000175db2aca80] Output file #0 (.\m_lic_eqg_eg_stomp-ffmpeg.wav):
[out#0/wav @ 00000175db2aca80]   Output stream #0:0 (audio): 2579 frames encoded (2971008 samples); 2579 packets muxed (11884032 bytes); 
[out#0/wav @ 00000175db2aca80]   Total: 2579 packets (11884032 bytes) muxed
[out#0/wav @ 00000175db2aca80] video:0kB audio:11606kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.000656%
size=   11606kB time=00:01:32.80 bitrate=1024.4kbits/s speed=1.25e+03x    
[in#0/mpc8 @ 00000175db28b180] Input file #0 (.\m_lic_eqg_eg_stomp.mpc):
[in#0/mpc8 @ 00000175db28b180]   Input stream #0:0 (audio): 41 packets read (843738 bytes); 2579 frames decoded; 0 decode errors (2971008 samples); 
[in#0/mpc8 @ 00000175db28b180]   Total: 41 packets (843738 bytes) demuxed
[AVIOContext @ 00000175db2ace00] Statistics: 909598 bytes read, 4 seeks

Due to the filesize limit, I was only able to attach samples of the outputs of both ffmpeg and the musepack decoder, but I was able to upload the full original mpc file.