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Show webM/Matroska comments with unknown comment keys in File page's Metadata section
Open, LowPublicFeature

Description

Feature summary (what you would like to be able to do and where):

File contains

ffprobe Nihon-buyō_performance_at_the_Kennedy_Center.webm
ffprobe version 4.4.6 Copyright (c) 2007-2025 the FFmpeg developers
  built with Apple clang version 17.0.0 (clang-1700.0.13.5)
  configuration: --prefix=/opt/local --cc=/usr/bin/clang --datadir=/opt/local/share/data/ffmpeg --docdir=/opt/local/share/doc/ffmpeg --mandir=/opt/local/share/man --enable-audiotoolbox --disable-indev=jack --disable-libjack --disable-libopencore-amrnb --disable-libopencore-amrwb --disable-libxcb --disable-libxcb-shm --disable-libxcb-xfixes --enable-opencl --disable-outdev=xv --enable-sdl2 --disable-securetransport --enable-videotoolbox --enable-avfilter --enable-avresample --enable-fontconfig --enable-gnutls --enable-libass --enable-libbluray --enable-libdav1d --enable-libfreetype --enable-libfribidi --enable-libmodplug --enable-libmp3lame --enable-libopenjpeg --enable-libopus --enable-librsvg --enable-libsoxr --enable-libspeex --enable-libtheora --enable-libvorbis --enable-libvpx --enable-libwebp --enable-libzimg --enable-libzvbi --enable-lzma --enable-pthreads --enable-shared --enable-swscale --enable-zlib --enable-libaom --enable-libsvtav1 --arch=arm64 --enable-gpl --enable-libvidstab --enable-libx264 --enable-libx265 --enable-libxvid --enable-postproc
  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 'Nihon-buyō_performance_at_the_Kennedy_Center.webm':
  Metadata:
    COM.ANDROID.MODEL: Pixel 7
    MAJOR_BRAND     : isom
    MINOR_VERSION   : 131072
    COMPATIBLE_BRANDS: isomiso2mp41
    COM.ANDROID.CAPTURE.FPS: 60.000000
    LOCATION        : +38.8944-77.0560/
    LOCATION-eng    : +38.8944-77.0560/
    COM.ANDROID.MANUFACTURER: Google
    ENCODER         : Lavf58.76.100
  Duration: 00:04:55.57, start: -0.007000, bitrate: 13551 kb/s
  Stream #0:0(eng): Video: vp9 (Profile 0), yuv420p(tv, bt709, progressive), 1920x1080, SAR 1:1 DAR 16:9, 59.94 fps, 59.94 tbr, 1k tbn, 1k tbc (default)
    Metadata:
      HANDLER_NAME    : VideoHandle
      VENDOR_ID       : [0][0][0][0]
      ENCODER         : Lavc58.134.100 libvpx-vp9
      DURATION        : 00:04:55.569000000
  Stream #0:1(eng): Audio: opus, 48000 Hz, stereo, fltp (default)
    Metadata:
      HANDLER_NAME    : SoundHandle
      VENDOR_ID       : [0][0][0][0]
      ENCODER         : Lavc58.134.100 libopus
      DURATION        : 00:04:55.553000000

From this information, the following comments are not represented in the Metadata list, as the WebMHandler only extracts known keys.

original file data
    COM.ANDROID.MODEL: Pixel 7
    COM.ANDROID.CAPTURE.FPS: 60.000000
    LOCATION        : +38.8944-77.0560/
    LOCATION-eng    : +38.8944-77.0560/
    COM.ANDROID.MANUFACTURER: Google

ffmpeg injected metadata ????:
    MAJOR_BRAND     : isom
    MINOR_VERSION   : 131072
    COMPATIBLE_BRANDS: isomiso2mp41
    ENCODER         : Lavf58.76.100

One of the problems with webm/matroska metadata, is that there isn't really a good specification for it.

Also "-eng" and the dots are not even allowed characters in Matroska comment tag names (only capital letters, numbers, and underscores for). ffmpeg seems to be preserving this, but technically its not spec compliant it seems.
And that trailing / on the coordinates is also suspect of an ffmpeg conversion problem, but those are all upstream problems.

We want at least location to be shown in the metadata. Additional comments should perhaps show (If their tagname is compliant) as UserComment lines.

Event Timeline

TheDJ renamed this task from Show Matroska comments of unknown comment keys Metadata section to Show webM/Matroska comments with unknown comment keys in File page's Metadata section.Nov 25 2025, 10:51 AM
TheDJ triaged this task as Low priority.

Along with location, date of creation is one of the other fairly important pieces of metadata that isn't currently being displayed for the example file. Is that part of the same issue?