Recherche avancée

Médias (1)

Mot : - Tags -/artwork

Autres articles (86)

  • Organiser par catégorie

    17 mai 2013, par

    Dans MédiaSPIP, une rubrique a 2 noms : catégorie et rubrique.
    Les différents documents stockés dans MédiaSPIP peuvent être rangés dans différentes catégories. On peut créer une catégorie en cliquant sur "publier une catégorie" dans le menu publier en haut à droite ( après authentification ). Une catégorie peut être rangée dans une autre catégorie aussi ce qui fait qu’on peut construire une arborescence de catégories.
    Lors de la publication prochaine d’un document, la nouvelle catégorie créée sera proposée (...)

  • Récupération d’informations sur le site maître à l’installation d’une instance

    26 novembre 2010, par

    Utilité
    Sur le site principal, une instance de mutualisation est définie par plusieurs choses : Les données dans la table spip_mutus ; Son logo ; Son auteur principal (id_admin dans la table spip_mutus correspondant à un id_auteur de la table spip_auteurs)qui sera le seul à pouvoir créer définitivement l’instance de mutualisation ;
    Il peut donc être tout à fait judicieux de vouloir récupérer certaines de ces informations afin de compléter l’installation d’une instance pour, par exemple : récupérer le (...)

  • D’autres logiciels intéressants

    12 avril 2011, par

    On ne revendique pas d’être les seuls à faire ce que l’on fait ... et on ne revendique surtout pas d’être les meilleurs non plus ... Ce que l’on fait, on essaie juste de le faire bien, et de mieux en mieux...
    La liste suivante correspond à des logiciels qui tendent peu ou prou à faire comme MediaSPIP ou que MediaSPIP tente peu ou prou à faire pareil, peu importe ...
    On ne les connais pas, on ne les a pas essayé, mais vous pouvez peut être y jeter un coup d’oeil.
    Videopress
    Site Internet : (...)

Sur d’autres sites (10436)

  • FFMPEG - How to pipe RMS_level and pts_time metadata without generating unwanted metadata

    6 février 2020, par Tovi Newman

    I am trying to find the loudest (highest rms_level) moment in an audio file, but I need to pipe the metadata rather than write to a file.

    I converted the answer found here : [https://superuser.com/questions/1183663/determining-audio-level-peaks-with-ffmpeg][1]

    By removing the write to file command and adding a pipe.
    Here’s what I’ve got.

    ffmpeg -i loudSoft.mp3 -af astats=metadata=1:reset=1,ametadata=print:key=lavfi.astats.Overall.RMS_level -f null - 2> result.txt

    The only problem is, now I’ve got a lot of unwanted metadata before and after the RMS_level and pts_time data as well as [Parsed_ametadata_1 @ 0x7f9d42c37500] being printed on each line. None of that was being written when I was writing to a file instead of piping. (all I need is the time and the rms.)

    Here is an abridged version of what I get when I write to file :

    frame:0    pts:0       pts_time:0
    
lavfi.astats.Overall.RMS_level=-inf
    
frame:1    pts:47      pts_time:0.00106576
    
lavfi.astats.Overall.RMS_level=-165.163347
    
frame:2    pts:1199    pts_time:0.0271882
    
lavfi.astats.Overall.RMS_level=-99.736394
    
frame:3    pts:2351    pts_time:0.0533107
    
lavfi.astats.Overall.RMS_level=-88.112282
    
frame:4    pts:3503    pts_time:0.0794331
    
lavfi.astats.Overall.RMS_level=-86.554314
    
frame:5    pts:4655    pts_time:0.105556
    
lavfi.astats.Overall.RMS_level=-82.977501
    
frame:6    pts:5807    pts_time:0.131678
    
lavfi.astats.Overall.RMS_level=-79.698739
    
frame:7    pts:6959    pts_time:0.1578
    
lavfi.astats.Overall.RMS_level=-76.629393
    
frame:8    pts:8111    pts_time:0.183923
    
lavfi.astats.Overall.RMS_level=-71.581211
    
frame:9    pts:9263    pts_time:0.210045
    
lavfi.astats.Overall.RMS_level=-75.038503
    
frame:10   pts:10415   pts_time:0.236168

    And here is what I’m looking at :

    ffmpeg version 4.2.2 Copyright (c) 2000-2019 the FFmpeg developers
    
  built with Apple clang version 11.0.0 (clang-1100.0.33.16)
    
  configuration: --prefix=/usr/local/Cellar/ffmpeg/4.2.2_1 --enable-shared --enable-pthreads --enable-version3 --enable-avresample --cc=clang --host-cflags='-I/Library/Java/JavaVirtualMachines/adoptopenjdk-13.0.1.jdk/Contents/Home/include -I/Library/Java/JavaVirtualMachines/adoptopenjdk-13.0.1.jdk/Contents/Home/include/darwin -fno-stack-check' --host-ldflags= --enable-ffplay --enable-gnutls --enable-gpl --enable-libaom --enable-libbluray --enable-libmp3lame --enable-libopus --enable-librubberband --enable-libsnappy --enable-libtesseract --enable-libtheora --enable-libvidstab --enable-libvorbis --enable-libvpx --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxvid --enable-lzma --enable-libfontconfig --enable-libfreetype --enable-frei0r --enable-libass --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-librtmp --enable-libspeex --enable-libsoxr --enable-videotoolbox --disable-libjack --disable-indev=jack
    
  libavutil      56. 31.100 / 56. 31.100
    
  libavcodec     58. 54.100 / 58. 54.100
    
  libavformat    58. 29.100 / 58. 29.100
    
  libavdevice    58.  8.100 / 58.  8.100
    
  libavfilter     7. 57.100 /  7. 57.100
    
  libavresample   4.  0.  0 /  4.  0.  0
    
  libswscale      5.  5.100 /  5.  5.100
    
  libswresample   3.  5.100 /  3.  5.100
    
  libpostproc    55.  5.100 / 55.  5.100
    
Input #0, mp3, from 'loudSoft2.mp3':
    
  Metadata:
    
    encoder         : Lavf58.29.100
    
  Duration: 00:00:09.85, start: 0.025057, bitrate: 128 kb/s
    
    Stream #0:0: Audio: mp3, 44100 Hz, stereo, fltp, 128 kb/s
    
    Metadata:
    
      encoder         : Lavc58.54
    
Stream mapping:
    
  Stream #0:0 -> #0:0 (mp3 (mp3float) -> pcm_s16le (native))
    
Press [q] to stop, [?] for help
    
[Parsed_ametadata_1 @ 0x7f9d42c37500] frame:0    pts:0       pts_time:0
    
[Parsed_ametadata_1 @ 0x7f9d42c37500] lavfi.astats.Overall.RMS_level=-inf
    
Output #0, null, to 'pipe:':
    
  Metadata:
    
    encoder         : Lavf58.29.100
    
    Stream #0:0: Audio: pcm_s16le, 44100 Hz, stereo, s16, 1411 kb/s
    
    Metadata:
    
      encoder         : Lavc58.54.100 pcm_s16le
    
[Parsed_ametadata_1 @ 0x7f9d42c37500] frame:1    pts:47      pts_time:0.00106576
    
[Parsed_ametadata_1 @ 0x7f9d42c37500] lavfi.astats.Overall.RMS_level=-165.163347
    
[Parsed_ametadata_1 @ 0x7f9d42c37500] frame:2    pts:1199    pts_time:0.0271882
    
[Parsed_ametadata_1 @ 0x7f9d42c37500] lavfi.astats.Overall.RMS_level=-99.736394
    
[Parsed_ametadata_1 @ 0x7f9d42c37500] frame:3    pts:2351    pts_time:0.0533107
    

    

    
*** MIDDLE OMITTED FOR BREVITY ***
    

    

    
[Parsed_ametadata_1 @ 0x7f9d42c37500] lavfi.astats.Overall.RMS_level=-88.532185
    
[Parsed_ametadata_1 @ 0x7f9d42c37500] frame:375  pts:430895  pts_time:9.77086
    
[Parsed_ametadata_1 @ 0x7f9d42c37500] lavfi.astats.Overall.RMS_level=-88.594276
    
[Parsed_ametadata_1 @ 0x7f9d42c37500] frame:376  pts:432047  pts_time:9.79698
    
[Parsed_ametadata_1 @ 0x7f9d42c37500] lavfi.astats.Overall.RMS_level=-88.654138
    
size=N/A time=00:00:09.82 bitrate=N/A speed=82.6x    
    
video:0kB audio:1692kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: unknown
    
[Parsed_astats_0 @ 0x7f9d42c37280] Channel: 1
    
[Parsed_astats_0 @ 0x7f9d42c37280] DC offset: 0.000001
    
[Parsed_astats_0 @ 0x7f9d42c37280] Min level: -0.000106
    
[Parsed_astats_0 @ 0x7f9d42c37280] Max level: 0.000115
    
[Parsed_astats_0 @ 0x7f9d42c37280] Min difference: 0.000000
    
[Parsed_astats_0 @ 0x7f9d42c37280] Max difference: 0.000077
    
[Parsed_astats_0 @ 0x7f9d42c37280] Mean difference: 0.000017
    
[Parsed_astats_0 @ 0x7f9d42c37280] RMS difference: 0.000022
    
[Parsed_astats_0 @ 0x7f9d42c37280] Peak level dB: -78.752617
    
[Parsed_astats_0 @ 0x7f9d42c37280] RMS level dB: -88.654138
    
[Parsed_astats_0 @ 0x7f9d42c37280] RMS peak dB: -88.654138
    
[Parsed_astats_0 @ 0x7f9d42c37280] RMS trough dB: -88.654138
    
[Parsed_astats_0 @ 0x7f9d42c37280] Crest factor: 3.126627
    
[Parsed_astats_0 @ 0x7f9d42c37280] Flat factor: 0.000000
    
[Parsed_astats_0 @ 0x7f9d42c37280] Peak count: 2
    
[Parsed_astats_0 @ 0x7f9d42c37280] Bit depth: 32/32
    
[Parsed_astats_0 @ 0x7f9d42c37280] Dynamic range: 76.274252
    
[Parsed_astats_0 @ 0x7f9d42c37280] Zero crossings: 246
    
[Parsed_astats_0 @ 0x7f9d42c37280] Zero crossings rate: 0.222624
    
[Parsed_astats_0 @ 0x7f9d42c37280] Number of NaNs: 0
    
[Parsed_astats_0 @ 0x7f9d42c37280] Number of Infs: 0
    
[Parsed_astats_0 @ 0x7f9d42c37280] Number of denormals: 0
    
[Parsed_astats_0 @ 0x7f9d42c37280] Channel: 2
    
[Parsed_astats_0 @ 0x7f9d42c37280] DC offset: 0.000001
    
[Parsed_astats_0 @ 0x7f9d42c37280] Min level: -0.000106
    
[Parsed_astats_0 @ 0x7f9d42c37280] Max level: 0.000115
    
[Parsed_astats_0 @ 0x7f9d42c37280] Min difference: 0.000000
    
[Parsed_astats_0 @ 0x7f9d42c37280] Max difference: 0.000077
    
[Parsed_astats_0 @ 0x7f9d42c37280] Mean difference: 0.000017
    
[Parsed_astats_0 @ 0x7f9d42c37280] RMS difference: 0.000022
    
[Parsed_astats_0 @ 0x7f9d42c37280] Peak level dB: -78.752617
    
[Parsed_astats_0 @ 0x7f9d42c37280] RMS level dB: -88.654138
    
[Parsed_astats_0 @ 0x7f9d42c37280] RMS peak dB: -88.654138
    
[Parsed_astats_0 @ 0x7f9d42c37280] RMS trough dB: -88.654138
    
[Parsed_astats_0 @ 0x7f9d42c37280] Crest factor: 3.126627
    
[Parsed_astats_0 @ 0x7f9d42c37280] Flat factor: 0.000000
    
[Parsed_astats_0 @ 0x7f9d42c37280] Peak count: 2
    
[Parsed_astats_0 @ 0x7f9d42c37280] Bit depth: 32/32
    
[Parsed_astats_0 @ 0x7f9d42c37280] Dynamic range: 76.274252
    
[Parsed_astats_0 @ 0x7f9d42c37280] Zero crossings: 246
    
[Parsed_astats_0 @ 0x7f9d42c37280] Zero crossings rate: 0.222624
    
[Parsed_astats_0 @ 0x7f9d42c37280] Number of NaNs: 0
    
[Parsed_astats_0 @ 0x7f9d42c37280] Number of Infs: 0
    
[Parsed_astats_0 @ 0x7f9d42c37280] Number of denormals: 0
    
[Parsed_astats_0 @ 0x7f9d42c37280] Overall
    
[Parsed_astats_0 @ 0x7f9d42c37280] DC offset: 0.000001
    
[Parsed_astats_0 @ 0x7f9d42c37280] Min level: -0.000106
    
[Parsed_astats_0 @ 0x7f9d42c37280] Max level: 0.000115
    
[Parsed_astats_0 @ 0x7f9d42c37280] Min difference: 0.000000
    
[Parsed_astats_0 @ 0x7f9d42c37280] Max difference: 0.000077
    
[Parsed_astats_0 @ 0x7f9d42c37280] Mean difference: 0.000017
    
[Parsed_astats_0 @ 0x7f9d42c37280] RMS difference: 0.000022
    
[Parsed_astats_0 @ 0x7f9d42c37280] Peak level dB: -78.752617
    
[Parsed_astats_0 @ 0x7f9d42c37280] RMS level dB: -88.654138
    
[Parsed_astats_0 @ 0x7f9d42c37280] RMS peak dB: -88.654138
    
[Parsed_astats_0 @ 0x7f9d42c37280] RMS trough dB: -88.654138
    
[Parsed_astats_0 @ 0x7f9d42c37280] Flat factor: 0.000000
    
[Parsed_astats_0 @ 0x7f9d42c37280] Peak count: 2.000000
    
[Parsed_astats_0 @ 0x7f9d42c37280] Bit depth: 32/32
    
[Parsed_astats_0 @ 0x7f9d42c37280] Number of samples: 1105
    
[Parsed_astats_0 @ 0x7f9d42c37280] Number of NaNs: 0.000000
    
[Parsed_astats_0 @ 0x7f9d42c37280] Number of Infs: 0.000000
    
[Parsed_astats_0 @ 0x7f9d42c37280] Number of denormals: 0.000000

  • Rails FFMPEG - convert to webm gives error for encoder 'libvpx-vp9'

    7 mai 2019, par Milind

    I am testing video conversion to convert video file into mp4 and webm.
    I have also setup ffmpeg and compiled properly.Mp4 conversion succeeds but webm breaks always complaining as -

    The encoder 'libvpx-vp9' is experimental but experimental codecs are not enabled, add '-strict -2' if you want to use it.

    its strange as I aready have vp8 present -

    mike1011:~/workspace (s1) $ ffmpeg -encoders | grep -i vp
    
ffmpeg version git-2016-03-29-bf1495d Copyright (c) 2000-2016 the FFmpeg developers
    
  built with gcc 4.8 (Ubuntu 4.8.4-2ubuntu1~14.04.1)
    
  configuration: --enable-gpl --enable-libfaac --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-librtmp --enable-libtheora --enable-libvorbis --enable-libvpx --enable-libx264 --enable-nonfree --enable-version3
    
  libavutil      55. 19.100 / 55. 19.100
    
  libavcodec     57. 32.100 / 57. 32.100
    
  libavformat    57. 29.101 / 57. 29.101
    
  libavdevice    57.  0.101 / 57.  0.101
    
  libavfilter     6. 40.102 /  6. 40.102
    
  libswscale      4.  0.100 /  4.  0.100
    
  libswresample   2.  0.101 /  2.  0.101
    
  libpostproc    54.  0.100 / 54.  0.100
    
 V..... libvpx               libvpx VP8 (codec vp8)
    
 V..X.. libvpx-vp9           libvpx VP9 (codec vp9)
    
 V..... wrapped_avframe      AVFrame to AVPacket passthrough
    
 A..... wavpack              WavPack

    my model..video.rb looks like -

    has_attached_file :video,
    
   :styles => {
    
      :mp4video => { :geometry => '1280x720>', :format => 'mp4',
    
        :convert_options => { :output => { :vcodec => 'libx264', :movflags => '+faststart',  :strict => :experimental} } },
    
      :webmvideo => { :geometry => '1280x720>', :format => 'webm',
    
        :convert_options => { :output => { :vcodec => 'libvpx-vp9'} } }, 
    
      :oggvideo => { :geometry => '1280x720>', :format => 'ogg',
    
        :convert_options => { :output => { :vcodec => 'libtheora',
    
          :acodec => 'libvorbis',  :strict => :experimental } } },
    
      screenshot: { geometry: '640x480#',  :convert_options => {
    
        :output => { :vframes => 1, :s => '300x169', :ss => '00:00:02'} } }
    
    },    
    
    :processors => [:transcoder],
    
     ###other setting comes here
    

    
  ##using delayed-paperclip for background processing of videos
    
  process_in_background :video
    

    
  def process_delayed!
    
    unless self.video.job_is_processing
    
      self.video.job_is_processing = true
    
      self.video.post_processing = true
    
      self.video.reprocess!
    
      self.video.job_is_processing = false
    
    end  
    
  end  

    I am sharing my complete output below(with error highlighted :)) -

        2.4.1 :003 > v=Video.find 25
    
      Video Load (1.8ms)  SELECT  "videos".* FROM "videos" WHERE "videos"."id" = $1 LIMIT 1  [["id", 25]]
    
     => #<video></video>mp4", video_file_size: 1105773, video_updated_at: "2019-02-02 00:17:37", duration: 18.112, slug: "sample320-mp4-dbb96526-5db1-4c59-9152-615fc077eca7", active: true, created_at: "2019-02-02 00:17:37", updated_at: "2019-02-02 00:17:37", video_processing: true> 
    
    2.4.1 :004 > v.process_delayed!
    
    [paperclip] copying /videos/25/original/Sample320.mp4 to local file /tmp/6b5665997c56c12544e7069276f6660b20190203-677953-1jsw8d1.mp4
    
    [paperclip] Trying to link /tmp/6b5665997c56c12544e7069276f6660b20190203-677953-1jsw8d1.mp4 to /tmp/6b5665997c56c12544e7069276f6660b20190203-677953-1qmn2uk.mp4
    
    I, [2019-02-03T00:12:09.849885 #677953]  INFO -- : Running transcoding...
    
    ["/usr/local/bin/ffmpeg", "-y", "-i", "/tmp/6b5665997c56c12544e7069276f6660b20190203-677953-1jsw8d1.mp4", "-s", "360x240", "-aspect", "1.5", "/tmp/2f51a6ecbce019dcad28a46b5be980ec20190203-677953-rh2lh0.mp4"]
    

    
    I, [2019-02-03T00:12:16.060391 #677953]  INFO -- : Transcoding of /tmp/6b5665997c56c12544e7069276f6660b20190203-677953-1jsw8d1.mp4 to /tmp/2f51a6ecbce019dcad28a46b5be980ec20190203-677953-rh2lh0.mp4 succeeded
    

    
    [paperclip] Trying to link /tmp/2f51a6ecbce019dcad28a46b5be980ec20190203-677953-rh2lh0.mp4 to /tmp/2961027361de4afbbb86f7764a034ee020190203-677953-1g0vvwe.mp4
    
    I, [2019-02-03T00:12:16.082499 #677953]  INFO -- : Running transcoding...
    
    ["/usr/local/bin/ffmpeg", "-y", "-i", "/tmp/6b5665997c56c12544e7069276f6660b20190203-677953-1jsw8d1.mp4", "-s", "360x240", "-aspect", "1.5", "/tmp/2f51a6ecbce019dcad28a46b5be980ec20190203-677953-fv3pzs.webm"]
    

    
    E, [2019-02-03T00:12:16.202420 #677953] ERROR -- : Failed encoding...
    
    ["/usr/local/bin/ffmpeg", "-y", "-i", "/tmp/6b5665997c56c12544e7069276f6660b20190203-677953-1jsw8d1.mp4", "-s", "360x240", "-aspect", "1.5", "/tmp/2f51a6ecbce019dcad28a46b5be980ec20190203-677953-fv3pzs.webm"]
    

    
    ffmpeg version git-2016-03-29-bf1495d Copyright (c) 2000-2016 the FFmpeg developers
    
      built with gcc 4.8 (Ubuntu 4.8.4-2ubuntu1~14.04.1)
    
      configuration: --enable-gpl --enable-libfaac --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-librtmp --enable-libtheora --enable-libvorbis --enable-libvpx --enable-libx264 --enable-nonfree --enable-version3
    
      libavutil      55. 19.100 / 55. 19.100
    
      libavcodec     57. 32.100 / 57. 32.100
    
      libavformat    57. 29.101 / 57. 29.101
    
      libavdevice    57.  0.101 / 57.  0.101
    
      libavfilter     6. 40.102 /  6. 40.102
    
      libswscale      4.  0.100 /  4.  0.100
    
      libswresample   2.  0.101 /  2.  0.101
    
      libpostproc    54.  0.100 / 54.  0.100
    
    Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '/tmp/6b5665997c56c12544e7069276f6660b20190203-677953-1jsw8d1.mp4':
    
      Metadata:
    
        major_brand     : isom
    
        minor_version   : 512
    
        compatible_brands: isomiso2avc1mp41
    
        encoder         : Lavf57.76.100
    
      Duration: 00:00:18.11, start: 0.000000, bitrate: 488 kb/s
    
        Stream #0:0(und): Video: h264 (Constrained Baseline) (avc1 / 0x31637661), yuv420p, 360x240 [SAR 32:27 DAR 16:9], 353 kb/s, 25 fps, 25 tbr, 12800 tbn, 50 tbc (default)
    
        Metadata:
    
          handler_name    : VideoHandler
    
        Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 129 kb/s (default)
    
        Metadata:
    
          handler_name    : SoundHandler
    

    
XXXXXXXXXXXXXXXXXXXXXXXX====== HERE COMES THE ERROR========XXXXXXXXXXXX
    
    [libvpx-vp9 @ 0x3e3dec0] The encoder 'libvpx-vp9' is experimental but experimental codecs are not enabled, add '-strict -2' if you want to use it.
    

    
    Errors: encoded file is invalid. 
    

    
    Paperclip::Error: There was an error processing the transcoder for 6b5665997c56c12544e7069276f6660b20190203-677953-1jsw8d1
    
           ...

  • The ffmpeg webm_dash_manifest demuxer fails with webvtt subtitles

    30 janvier 2020, par Hyldrean

    I am trying to create a DASH manifest using ffmpeg and I encounter some difficulties with the subtitles. I get the error

    [webm_dash_manifest @ 0x55e19db48180] EBML header parsing failed
    
[webm_dash_manifest @ 0x55e19db48180] Failed to read file headers
    
subtitles.vtt: Operation not permitted

    The subtitles are encoded in the plain text webvtt format. I first assume that the EBML header are missing because the subtitles were not contained in a webm container. I then tried to create a webm file containing only the subtitles. It appears impossible.

    I think the problem comes from the webm_dash_manifest demuxer. It seeks metadata in a file with no metadata. However neither Google nor Stack Overflow give me an answer.

    The command I used :

    ffmpeg \
    
-f webm_dash_manifest -i video.webm \
    
-f webm_dash_manifest -i audio.webm \
    
-f webm_dash_manifest -i subtitles.vtt \
    
-map 0 -map 1 -map 2 \
    
-c copy \
    
-f webm_dash_manifest \
    
-adaptation_sets "id=0,streams=0 id=1,streams=1 id=2,stream=2" \
    
minimal.mpd

    and the ffmpeg output :

    ffmpeg version 3.2.14-1~deb9u1 Copyright (c) 2000-2019 the FFmpeg developers
    
  built with gcc 6.3.0 (Debian 6.3.0-18+deb9u1) 20170516
    
  configuration: --prefix=/usr --extra-version='1~deb9u1' --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --enable-gpl --disable-stripping --enable-avresample --enable-avisynth --enable-gnutls --enable-ladspa --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libebur128 --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libmp3lame --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librubberband --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxvid --enable-libzmq --enable-libzvbi --enable-omx --enable-openal --enable-opengl --enable-sdl2 --enable-libdc1394 --enable-libiec61883 --enable-chromaprint --enable-frei0r --enable-libopencv --enable-libx264 --enable-shared
    
  libavutil      55. 34.101 / 55. 34.101
    
  libavcodec     57. 64.101 / 57. 64.101
    
  libavformat    57. 56.101 / 57. 56.101
    
  libavdevice    57.  1.100 / 57.  1.100
    
  libavfilter     6. 65.100 /  6. 65.100
    
  libavresample   3.  1.  0 /  3.  1.  0
    
  libswscale      4.  2.100 /  4.  2.100
    
  libswresample   2.  3.100 /  2.  3.100
    
  libpostproc    54.  1.100 / 54.  1.100
    
[webm_dash_manifest @ 0x55e19db17160] Could not find codec parameters for stream 0 (Video: vp9, none, 1280x534): unspecified pixel format
    
Consider increasing the value for the 'analyzeduration' and 'probesize' options
    
Input #0, webm_dash_manifest, from 'video.webm':
    
  Metadata:
    
    title           : Cloud Atlas
    
    ENCODER         : Lavf58.35.104
    
  Duration: 00:05:00.01, bitrate: 998 kb/s
    
    Chapter #0:0: start 0.000000, end 300.000000
    
    Metadata:
    
      title           : Chapter 01
    
    Stream #0:0(eng): Video: vp9, none, 1280x534, SAR 1:1 DAR 640:267, 23.98 fps, 23.98 tbr, 1k tbn, 1k tbc (default) (forced)
    
    Metadata:
    
      title           : Video @ 6.9 Mbps [frame B:188517 Avg QP:20.66]
    
      ENCODER         : Lavc58.66.100 libvpx-vp9
    
      DURATION        : 00:05:00.008000000
    
      webm_dash_manifest_duration: 300008
    
      webm_dash_manifest_initialization_range: 900
    
      webm_dash_manifest_file_name: video.webm
    
      webm_dash_manifest_track_number: 1
    
      webm_dash_manifest_cues_start: 37455991
    
      webm_dash_manifest_cues_end: 37457486
    
      webm_dash_manifest_bandwidth: 1420427
    
      webm_dash_manifest_cluster_keyframe: 1
    
      webm_dash_manifest_cue_timestamps: 298715
    
Input #1, webm_dash_manifest, from 'audio.webm':
    
  Metadata:
    
    title           : Cloud Atlas
    
    ENCODER         : Lavf58.35.104
    
  Duration: 00:05:00.01, bitrate: 126 kb/s
    
    Chapter #1:0: start 0.000000, end 300.000000
    
    Metadata:
    
      title           : Chapter 01
    
    Stream #1:0(eng): Audio: opus, 48000 Hz, stereo, fltp (default)
    
    Metadata:
    
      title           : Audio Eng DTS 5.1 channels 24 bits @ 1509 Kbps cbr
    
      ENCODER         : Lavc58.66.100 libopus
    
      DURATION        : 00:05:00.007000000
    
      webm_dash_manifest_duration: 300007
    
      webm_dash_manifest_initialization_range: 838
    
      webm_dash_manifest_file_name: audio.webm
    
      webm_dash_manifest_track_number: 1
    
      webm_dash_manifest_cues_start: 4744091
    
      webm_dash_manifest_cues_end: 4745279
    
      webm_dash_manifest_bandwidth: 137531
    
      webm_dash_manifest_cluster_keyframe: 1
    
      webm_dash_manifest_cue_timestamps: 295000
    
[webm_dash_manifest @ 0x55e19db48180] EBML header parsing failed
    
[webm_dash_manifest @ 0x55e19db48180] Failed to read file headers
    
subtitles.vtt: Operation not permitted

    I noticed that ffmpeg -f webm_dash_manifest -i subtitles.vtt suffices to reproduce the error.

    I have also tried without the -f webm_dash_manifest flag, with no success :

    ffmpeg \
    
-f webm_dash_manifest -i video.webm \
    
-f webm_dash_manifest -i audio.webm \
    
-i subtitles.vtt \
    
-map 0 -map 1 -map 2 \
    
-c copy \
    
-f webm_dash_manifest \
    
-adaptation_sets "id=0,streams=0 id=1,streams=1 id=2,stream=2" minimal.mpd

    Output :

    ffmpeg version 3.2.14-1~deb9u1 Copyright (c) 2000-2019 the FFmpeg developers
    
  built with gcc 6.3.0 (Debian 6.3.0-18+deb9u1) 20170516
    
  configuration: --prefix=/usr --extra-version='1~deb9u1' --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --enable-gpl --disable-stripping --enable-avresample --enable-avisynth --enable-gnutls --enable-ladspa --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libebur128 --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libmp3lame --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librubberband --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxvid --enable-libzmq --enable-libzvbi --enable-omx --enable-openal --enable-opengl --enable-sdl2 --enable-libdc1394 --enable-libiec61883 --enable-chromaprint --enable-frei0r --enable-libopencv --enable-libx264 --enable-shared
    
  libavutil      55. 34.101 / 55. 34.101
    
  libavcodec     57. 64.101 / 57. 64.101
    
  libavformat    57. 56.101 / 57. 56.101
    
  libavdevice    57.  1.100 / 57.  1.100
    
  libavfilter     6. 65.100 /  6. 65.100
    
  libavresample   3.  1.  0 /  3.  1.  0
    
  libswscale      4.  2.100 /  4.  2.100
    
  libswresample   2.  3.100 /  2.  3.100
    
  libpostproc    54.  1.100 / 54.  1.100
    
[webm_dash_manifest @ 0x557f55dd1160] Could not find codec parameters for stream 0 (Video: vp9, none, 1280x534): unspecified pixel format
    
Consider increasing the value for the 'analyzeduration' and 'probesize' options
    
Input #0, webm_dash_manifest, from 'video.webm':
    
  Metadata:
    
    title           : Cloud Atlas
    
    ENCODER         : Lavf58.35.104
    
  Duration: 00:05:00.01, bitrate: 998 kb/s
    
    Chapter #0:0: start 0.000000, end 300.000000
    
    Metadata:
    
      title           : Chapter 01
    
    Stream #0:0(eng): Video: vp9, none, 1280x534, SAR 1:1 DAR 640:267, 23.98 fps, 23.98 tbr, 1k tbn, 1k tbc (default) (forced)
    
    Metadata:
    
      title           : Video @ 6.9 Mbps [frame B:188517 Avg QP:20.66]
    
      ENCODER         : Lavc58.66.100 libvpx-vp9
    
      DURATION        : 00:05:00.008000000
    
      webm_dash_manifest_duration: 300008
    
      webm_dash_manifest_initialization_range: 900
    
      webm_dash_manifest_file_name: video.webm
    
      webm_dash_manifest_track_number: 1
    
      webm_dash_manifest_cues_start: 37455991
    
      webm_dash_manifest_cues_end: 37457486
    
      webm_dash_manifest_bandwidth: 1420427
    
      webm_dash_manifest_cluster_keyframe: 1
    
      webm_dash_manifest_cue_timestamps: 298715
    
Input #1, webm_dash_manifest, from 'audio.webm':
    
  Metadata:
    
    title           : Cloud Atlas
    
    ENCODER         : Lavf58.35.104
    
  Duration: 00:05:00.01, bitrate: 126 kb/s
    
    Chapter #1:0: start 0.000000, end 300.000000
    
    Metadata:
    
      title           : Chapter 01
    
    Stream #1:0(eng): Audio: opus, 48000 Hz, stereo, fltp (default)
    
    Metadata:
    
      title           : Audio Eng DTS 5.1 channels 24 bits @ 1509 Kbps cbr
    
      ENCODER         : Lavc58.66.100 libopus
    
      DURATION        : 00:05:00.007000000
    
      webm_dash_manifest_duration: 300007
    
      webm_dash_manifest_initialization_range: 838
    
      webm_dash_manifest_file_name: audio.webm
    
      webm_dash_manifest_track_number: 1
    
      webm_dash_manifest_cues_start: 4744091
    
      webm_dash_manifest_cues_end: 4745279
    
      webm_dash_manifest_bandwidth: 137531
    
      webm_dash_manifest_cluster_keyframe: 1
    
      webm_dash_manifest_cue_timestamps: 295000
    
Input #2, webvtt, from 'subtitles.vtt':
    
  Duration: N/A, bitrate: N/A
    
    Stream #2:0: Subtitle: webvtt
    
Could not write header for output file #0 (incorrect codec parameters ?): Operation not permittedStream mapping:
    
  Stream #0:0 -> #0:0 (copy)
    
  Stream #1:0 -> #0:1 (copy)
    
  Stream #2:0 -> #0:2 (copy)
    
    Last message repeated 1 times

    Note : [webm_dash_manifest @ 0x557f55dd1160] Could not find codec parameters for stream 0 (Video: vp9, none, 1280x534): unspecified pixel format is harmless according to this post.

    The subtitles have been extracted with ffmpeg :

    ffmpeg -i "Cloud Atlas.mkv" -map 0:6 -t 00:05:00 -c:s webvtt -dash 1 subtitles.vtt

    Thank you for reading my long post, I have no idea what to do next.

    EDIT : The WebM Project website says : ’Initial WebM release does not support subtitles’. Has someone heard of a new release ? Or a convenient way to create DASH manifest with subtitles ?

Navigation