1. 状况形容
在 M1 芯片的 macOS 12.3.1 的零碎上装置了最新的 VLC 视频播放器，并将音量调至 200%，此时播放低频且富裕变动的音乐，JBL 蓝牙播放器会呈现咔次的炸音且细节全糊，原本流动的声音一卡一卡的，很刺耳。
2. 修复
把 VLC 设定的音量调至 100% 及以下即可。
3. 剖析
因为我之前看另一部电影把声音调至了 200% 且没有呈现任何问题，我想晓得问题出在哪里。
猜想是 vlc 的音量冲破 100% 时的算法会做相当于批改音轨内容的操作，导致解析失败，而放出杂音。
首先，这个电影文件用 ffprobe 能够看到
$ ffprobe Dune.2021.UHD.BluRay.2160p.x265.10bit.DoVi.2Audio.mUHD-FRDS.mkv
ffprobe version 4.4 Copyright (c) 2007-2021 the FFmpeg developers
built with Apple clang version 12.0.5 (clang-1205.0.22.9)
configuration: --prefix=/opt/homebrew/Cellar/ffmpeg/4.4_2 --enable-shared --enable-pthreads --enable-version3 --cc=clang --host-cflags= --host-ldflags= --enable-ffplay --enable-gnutls --enable-gpl --enable-libaom --enable-libbluray --enable-libdav1d --enable-libmp3lame --enable-libopus --enable-librav1e --enable-librubberband --enable-libsnappy --enable-libsrt --enable-libtesseract --enable-libtheora --enable-libvidstab --enable-libvorbis --enable-libvpx --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libxvid --enable-lzma --enable-libfontconfig --enable-libfreetype --enable-frei0r --enable-libass --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libspeex --enable-libsoxr --enable-libzmq --enable-libzimg --disable-libjack --disable-indev=jack --enable-avresample --enable-videotoolbox
libavutil 56. 70.100 / 56. 70.100
libavcodec 58.134.100 / 58.134.100
libavformat 58. 76.100 / 58. 76.100
libavdevice 58. 13.100 / 58. 13.100
libavfilter 7.110.100 / 7.110.100
libavresample 4. 0. 0 / 4. 0. 0
libswscale 5. 9.100 / 5. 9.100
libswresample 3. 9.100 / 3. 9.100
libpostproc 55. 9.100 / 55. 9.100
[matroska,webm @ 0x13b019600] Could not find codec parameters for stream 5 (Subtitle: hdmv_pgs_subtitle (pgssub)): unspecified size
Consider increasing the value for the 'analyzeduration' (0) and 'probesize' (5000000) options
[matroska,webm @ 0x13b019600] Could not find codec parameters for stream 6 (Subtitle: hdmv_pgs_subtitle (pgssub)): unspecified size
Consider increasing the value for the 'analyzeduration' (0) and 'probesize' (5000000) options
[matroska,webm @ 0x13b019600] Could not find codec parameters for stream 7 (Subtitle: hdmv_pgs_subtitle (pgssub)): unspecified size
Consider increasing the value for the 'analyzeduration' (0) and 'probesize' (5000000) options
Input #0, matroska,webm, from 'Dune.2021.UHD.BluRay.2160p.x265.10bit.DoVi.2Audio.mUHD-FRDS.mkv':
Metadata:
encoder : libebml v1.4.2 + libmatroska v1.6.4
creation_time : 2021-12-25T09:11:56.000000Z
Duration: 02:35:26.64, start: 0.000000, bitrate: 22814 kb/s
Chapters:
Chapter #0:0: start 0.000000, end 196.154289
Metadata:
title : 第 01 章
Chapter #0:1: start 196.154289, end 774.815689
Metadata:
title : 第 02 章
Chapter #0:2: start 774.815689, end 1320.736067
Metadata:
title : 第 03 章
Chapter #0:3: start 1320.736067, end 1756.921822
Metadata:
title : 第 04 章
Chapter #0:4: start 1756.921822, end 2350.931911
Metadata:
title : 第 05 章
Chapter #0:5: start 2350.931911, end 2839.795289
Metadata:
title : 第 06 章
Chapter #0:6: start 2839.795289, end 3413.493400
Metadata:
title : 第 07 章
Chapter #0:7: start 3413.493400, end 4010.381356
Metadata:
title : 第 08 章
Chapter #0:8: start 4010.381356, end 4604.891956
Metadata:
title : 第 09 章
Chapter #0:9: start 4604.891956, end 5160.655489
Metadata:
title : 第 10 章
Chapter #0:10: start 5160.655489, end 5760.379622
Metadata:
title : 第 11 章
Chapter #0:11: start 5760.379622, end 6309.469822
Metadata:
title : 第 12 章
Chapter #0:12: start 6309.469822, end 6830.323489
Metadata:
title : 第 13 章
Chapter #0:13: start 6830.323489, end 7418.536111
Metadata:
title : 第 14 章
Chapter #0:14: start 7418.536111, end 7933.342067
Metadata:
title : 第 15 章
Chapter #0:15: start 7933.342067, end 8445.770667
Metadata:
title : 第 16 章
Chapter #0:16: start 8445.770667, end 8847.797289
Metadata:
title : 第 17 章
Chapter #0:17: start 8847.797289, end 9326.635000
Metadata:
title : 第 18 章
Stream #0:0: Video: hevc (Main 10), yuv420p10le(tv, bt2020nc/bt2020/smpte2084), 3840x1604, SAR 1:1 DAR 960:401, 23.98 fps, 23.98 tbr, 1k tbn, 23.98 tbc (default)
Metadata:
BPS : 14748974
DURATION : 02:35:26.609000000
NUMBER_OF_FRAMES: 223615
NUMBER_OF_BYTES : 17194739399
_STATISTICS_WRITING_APP: mkvmerge v62.0.0 ('Apollo') 64-bit
_STATISTICS_WRITING_DATE_UTC: 2021-12-25 09:11:56
_STATISTICS_TAGS: BPS DURATION NUMBER_OF_FRAMES NUMBER_OF_BYTES
Stream #0:1(eng): Audio: truehd, 48000 Hz, 7.1, s32 (24 bit) (default)
Metadata:
title : 原声
BPS : 3242671
DURATION : 02:35:26.610000000
NUMBER_OF_FRAMES: 11191931
NUMBER_OF_BYTES : 3780391034
_STATISTICS_WRITING_APP: mkvmerge v62.0.0 ('Apollo') 64-bit
_STATISTICS_WRITING_DATE_UTC: 2021-12-25 09:11:56
_STATISTICS_TAGS: BPS DURATION NUMBER_OF_FRAMES NUMBER_OF_BYTES
Stream #0:2(chi): Audio: dts (DTS-HD MA), 48000 Hz, 7.1, s32p (24 bit) (default)
Metadata:
title : 上译国语
BPS : 4702403
DURATION : 02:35:26.635000000
NUMBER_OF_FRAMES: 874372
NUMBER_OF_BYTES : 5482200184
_STATISTICS_WRITING_APP: mkvmerge v62.0.0 ('Apollo') 64-bit
_STATISTICS_WRITING_DATE_UTC: 2021-12-25 09:11:56
_STATISTICS_TAGS: BPS DURATION NUMBER_OF_FRAMES NUMBER_OF_BYTES
Stream #0:3(chi): Subtitle: hdmv_pgs_subtitle, 1920x1080 (default)
Metadata:
title : 国配特效
BPS : 13781
DURATION : 02:35:25.483000000
NUMBER_OF_FRAMES: 3269
NUMBER_OF_BYTES : 16064721
SOURCE_ID : 0012ab
_STATISTICS_WRITING_APP: mkvmerge v62.0.0 ('Apollo') 64-bit
_STATISTICS_WRITING_DATE_UTC: 2021-12-25 09:11:56
_STATISTICS_TAGS: BPS DURATION NUMBER_OF_FRAMES NUMBER_OF_BYTES SOURCE_ID
Stream #0:4(chi): Subtitle: hdmv_pgs_subtitle, 1920x1080
Metadata:
title : 双语特效
BPS : 20918
DURATION : 02:35:25.483000000
NUMBER_OF_FRAMES: 3203
NUMBER_OF_BYTES : 24384886
SOURCE_ID : 0012a9
_STATISTICS_WRITING_APP: mkvmerge v62.0.0 ('Apollo') 64-bit
_STATISTICS_WRITING_DATE_UTC: 2021-12-25 09:11:56
_STATISTICS_TAGS: BPS DURATION NUMBER_OF_FRAMES NUMBER_OF_BYTES SOURCE_ID
Stream #0:5(chi): Subtitle: hdmv_pgs_subtitle
Metadata:
title : 简中
BPS : 20158
DURATION : 02:28:42.914000000
NUMBER_OF_FRAMES: 2514
NUMBER_OF_BYTES : 22484517
_STATISTICS_WRITING_APP: mkvmerge v62.0.0 ('Apollo') 64-bit
_STATISTICS_WRITING_DATE_UTC: 2021-12-25 09:11:56
_STATISTICS_TAGS: BPS DURATION NUMBER_OF_FRAMES NUMBER_OF_BYTES
Stream #0:6(chi): Subtitle: hdmv_pgs_subtitle
Metadata:
title : 繁中
BPS : 19753
DURATION : 02:35:12.929000000
NUMBER_OF_FRAMES: 2360
NUMBER_OF_BYTES : 22995600
SOURCE_ID : 0012a5
_STATISTICS_WRITING_APP: mkvmerge v62.0.0 ('Apollo') 64-bit
_STATISTICS_WRITING_DATE_UTC: 2021-12-25 09:11:56
_STATISTICS_TAGS: BPS DURATION NUMBER_OF_FRAMES NUMBER_OF_BYTES SOURCE_ID
Stream #0:7(chi): Subtitle: hdmv_pgs_subtitle
Metadata:
title : 繁中
BPS : 18295
DURATION : 02:35:12.929000000
NUMBER_OF_FRAMES: 2514
NUMBER_OF_BYTES : 21297928
SOURCE_ID : 0012a6
_STATISTICS_WRITING_APP: mkvmerge v62.0.0 ('Apollo') 64-bit
_STATISTICS_WRITING_DATE_UTC: 2021-12-25 09:11:56
_STATISTICS_TAGS: BPS DURATION NUMBER_OF_FRAMES NUMBER_OF_BYTES SOURCE_ID其中，视频 Video: hevc (Main 10), yuv420p10le(tv, bt2020nc/bt2020/smpte2084), 3840x1604, SAR 1:1 DAR 960:401, 23.98 fps, 23.98 tbr, 1k tbn, 23.98 tbc (default)，4k 24fps，且码率是 14748974，大略是 1.76MB/s。
音轨有两个，英语的是杜比全景声，上译国语的是 DTS-HD，码率别离达到了 0.39MB/ s 和 0.56MB/s。
感叹一下，这个码率简直相当于按下面的 4k 降到 1080P（1920*1080，靠近 1 /4）的码率了，如果是一首 3 分钟的音乐，按 0.39MB/s，就有 70MB 了。
之前看的是
$ ffprobe Malena\ 2000\ 1080p\ BluRay\ DD+5.1\ x264-Geek.mkv
ffprobe version 4.4 Copyright (c) 2007-2021 the FFmpeg developers
built with Apple clang version 12.0.5 (clang-1205.0.22.9)
configuration: --prefix=/opt/homebrew/Cellar/ffmpeg/4.4_2 --enable-shared --enable-pthreads --enable-version3 --cc=clang --host-cflags= --host-ldflags= --enable-ffplay --enable-gnutls --enable-gpl --enable-libaom --enable-libbluray --enable-libdav1d --enable-libmp3lame --enable-libopus --enable-librav1e --enable-librubberband --enable-libsnappy --enable-libsrt --enable-libtesseract --enable-libtheora --enable-libvidstab --enable-libvorbis --enable-libvpx --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libxvid --enable-lzma --enable-libfontconfig --enable-libfreetype --enable-frei0r --enable-libass --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libspeex --enable-libsoxr --enable-libzmq --enable-libzimg --disable-libjack --disable-indev=jack --enable-avresample --enable-videotoolbox
libavutil 56. 70.100 / 56. 70.100
libavcodec 58.134.100 / 58.134.100
libavformat 58. 76.100 / 58. 76.100
libavdevice 58. 13.100 / 58. 13.100
libavfilter 7.110.100 / 7.110.100
libavresample 4. 0. 0 / 4. 0. 0
libswscale 5. 9.100 / 5. 9.100
libswresample 3. 9.100 / 3. 9.100
libpostproc 55. 9.100 / 55. 9.100
Input #0, matroska,webm, from 'Malena 2000 1080p BluRay DD+5.1 x264-Geek.mkv':
Metadata:
title : Malèna [2000] by Giuseppe Tornatore / Uncut / KOR BD
encoder : libebml v1.4.0 + libmatroska v1.6.2
creation_time : 2021-10-08T11:56:47.000000Z
Duration: 01:48:05.02, start: 0.000000, bitrate: 18216 kb/s
Chapters:
Chapter #0:0: start 0.000000, end 245.787000
Metadata:
title : Opening Credits
Chapter #0:1: start 245.787000, end 345.720000
Metadata:
title : Shut Up And Watch!
Chapter #0:2: start 345.720000, end 434.976000
Metadata:
title : Latin Teacher's Daughter
Chapter #0:3: start 434.976000, end 548.423000
Metadata:
title : Measuring Up
Chapter #0:4: start 548.423000, end 744.827000
Metadata:
title : Long Pants And A Promise
Chapter #0:5: start 744.827000, end 936.227000
Metadata:
title : Her Husband Gone Off To War
Chapter #0:6: start 936.227000, end 1132.298000
Metadata:
title : Ma L'Amore No
Chapter #0:7: start 1132.298000, end 1295.503000
Metadata:
title : Imaging It
Chapter #0:8: start 1295.503000, end 1583.123000
Metadata:
title : A Stroll Through The Streets
Chapter #0:9: start 1583.123000, end 1644.476000
Metadata:
title : Great Jealousy
Chapter #0:10: start 1644.476000, end 1885.634000
Metadata:
title : A Beautiful, Silent Outsider
Chapter #0:11: start 1885.634000, end 2157.906000
Metadata:
title : Mourning With Malena
Chapter #0:12: start 2157.906000, end 2303.092000
Metadata:
title : Malena's Protector
Chapter #0:13: start 2303.092000, end 2476.933000
Metadata:
title : Stealing Malena's Underwear
Chapter #0:14: start 2476.933000, end 2520.768000
Metadata:
title : A Very Long Night
Chapter #0:15: start 2520.768000, end 2714.962000
Metadata:
title : Prisoner Of The House
Chapter #0:16: start 2714.962000, end 2804.343000
Metadata:
title : You're Dishonored
Chapter #0:17: start 2804.343000, end 2944.150000
Metadata:
title : Lieutenant And Dentist
Chapter #0:18: start 2944.150000, end 3131.628000
Metadata:
title : Dishonor For Malena
Chapter #0:19: start 3131.628000, end 3582.412000
Metadata:
title : Ill Fated, Alone And Beautiful
Chapter #0:20: start 3582.412000, end 3818.523000
Metadata:
title : Don't Marry Him
Chapter #0:21: start 3818.523000, end 4008.838000
Metadata:
title : Lawyer's Restribution
Chapter #0:22: start 4008.838000, end 4174.712000
Metadata:
title : Aerial Assault
Chapter #0:23: start 4174.712000, end 4452.281000
Metadata:
title : In The Lord's Hands
Chapter #0:24: start 4452.281000, end 4621.534000
Metadata:
title : A New Malena
Chapter #0:25: start 4621.534000, end 4752.289000
Metadata:
title : Possessed By The Devil
Chapter #0:26: start 4752.289000, end 5026.271000
Metadata:
title : It's My First Time
Chapter #0:27: start 5026.271000, end 5319.940000
Metadata:
title : A Wicked End
Chapter #0:28: start 5319.940000, end 5905.817000
Metadata:
title : Nine Scordia's Return
Chapter #0:29: start 5905.817000, end 6485.024000
Metadata:
title : Regaining One's Dignity / End Credits
Stream #0:0(ita): Video: h264 (High), yuv420p(tv, bt709/bt709/unknown, progressive), 1920x818, SAR 1:1 DAR 960:409, 23.98 fps, 23.98 tbr, 1k tbn, 47.95 tbc (default)
Metadata:
title : Geek @ MTeam
BPS-eng : 17191376
DURATION-eng : 01:48:04.979000000
NUMBER_OF_FRAMES-eng: 155484
NUMBER_OF_BYTES-eng: 13935714442
_STATISTICS_WRITING_APP-eng: mkvmerge v51.0.0 ('I Wish') 64-bit
_STATISTICS_WRITING_DATE_UTC-eng: 2021-10-08 11:56:47
_STATISTICS_TAGS-eng: BPS DURATION NUMBER_OF_FRAMES NUMBER_OF_BYTES
Stream #0:1(ita): Audio: eac3, 48000 Hz, 5.1(side), fltp, 1023 kb/s (default)
Metadata:
title : Italian / Dolby Digital Plus / 5.1 / 1023 kbps
BPS-eng : 1023000
DURATION-eng : 01:48:05.024000000
NUMBER_OF_FRAMES-eng: 607971
NUMBER_OF_BYTES-eng: 829272444
_STATISTICS_WRITING_APP-eng: mkvmerge v51.0.0 ('I Wish') 64-bit
_STATISTICS_WRITING_DATE_UTC-eng: 2021-10-08 11:56:47
_STATISTICS_TAGS-eng: BPS DURATION NUMBER_OF_FRAMES NUMBER_OF_BYTES
Stream #0:2(eng): Subtitle: subrip (default)
Metadata:
title : English / R2DVD / Medusa / srt
BPS-eng : 31
DURATION-eng : 01:43:36.366000000
NUMBER_OF_FRAMES-eng: 668
NUMBER_OF_BYTES-eng: 24327
_STATISTICS_WRITING_APP-eng: mkvmerge v51.0.0 ('I Wish') 64-bit
_STATISTICS_WRITING_DATE_UTC-eng: 2021-10-08 11:56:47
_STATISTICS_TAGS-eng: BPS DURATION NUMBER_OF_FRAMES NUMBER_OF_BYTES
Stream #0:3(chi): Subtitle: subrip
Metadata:
title : Simplified / Custom / CnSCG / srt
BPS-eng : 27
DURATION-eng : 01:47:58.000000000
NUMBER_OF_FRAMES-eng: 703
NUMBER_OF_BYTES-eng: 22433
_STATISTICS_WRITING_APP-eng: mkvmerge v51.0.0 ('I Wish') 64-bit
_STATISTICS_WRITING_DATE_UTC-eng: 2021-10-08 11:56:47
_STATISTICS_TAGS-eng: BPS DURATION NUMBER_OF_FRAMES NUMBER_OF_BYTES
Stream #0:4(chi): Subtitle: subrip
Metadata:
title : Traditional / Custom / CnSCG / srt
BPS-eng : 27
DURATION-eng : 01:47:58.000000000
NUMBER_OF_FRAMES-eng: 703
NUMBER_OF_BYTES-eng: 22433
_STATISTICS_WRITING_APP-eng: mkvmerge v51.0.0 ('I Wish') 64-bit
_STATISTICS_WRITING_DATE_UTC-eng: 2021-10-08 11:56:47
_STATISTICS_TAGS-eng: BPS DURATION NUMBER_OF_FRAMES NUMBER_OF_BYTES能够看到这里 h264 的 1080P 的视频码率（17191376）比前一个 h265 的 4k 的视频码率（14748974）还大。。。
查到一部 1080P H265 压缩的是 9510 kbps, 压缩了靠近 45%。。。
VIDEO CODEC.....: x265, CRF, Main 10@L5@High
FRAMERATE.......: 24.000 FPS
VIDEO BITRATE...: 9510 kbps