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  • Keeping control of your media in your hands

    13 avril 2011, par

    The vocabulary used on this site and around MediaSPIP in general, aims to avoid reference to Web 2.0 and the companies that profit from media-sharing.
    While using MediaSPIP, you are invited to avoid using words like "Brand", "Cloud" and "Market".
    MediaSPIP is designed to facilitate the sharing of creative media online, while allowing authors to retain complete control of their work.
    MediaSPIP aims to be accessible to as many people as possible and development is based on expanding the (...)

  • Création définitive du canal

    12 mars 2010, par

    Lorsque votre demande est validée, vous pouvez alors procéder à la création proprement dite du canal. Chaque canal est un site à part entière placé sous votre responsabilité. Les administrateurs de la plateforme n’y ont aucun accès.
    A la validation, vous recevez un email vous invitant donc à créer votre canal.
    Pour ce faire il vous suffit de vous rendre à son adresse, dans notre exemple "http://votre_sous_domaine.mediaspip.net".
    A ce moment là un mot de passe vous est demandé, il vous suffit d’y (...)

  • Les tâches Cron régulières de la ferme

    1er décembre 2010, par

    La gestion de la ferme passe par l’exécution à intervalle régulier de plusieurs tâches répétitives dites Cron.
    Le super Cron (gestion_mutu_super_cron)
    Cette tâche, planifiée chaque minute, a pour simple effet d’appeler le Cron de l’ensemble des instances de la mutualisation régulièrement. Couplée avec un Cron système sur le site central de la mutualisation, cela permet de simplement générer des visites régulières sur les différents sites et éviter que les tâches des sites peu visités soient trop (...)

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  • ffmpeg concat doesn't keep video speed/framerate ?

    28 août 2016, par Nick

    I have a bunch of small webm clips in directory vidchunks. These clips were generated using javascript MediaRecorder API.

    MediaRecorder code :

    var mRecorder;
    
var chunks = [];
    
navigator.mediaDevices.getUserMedia({
    
  audio: false,
    
  video: {
    
  width: 1280,
    
  height: 760,
    
  mozMediaSource: "screen",
    
  mediaSource: "screen"
    
}
    
}).then(function(stream) {
    
  mRecorder = new MediaRecorder(stream,{mimeType:"video/webm"});
    
  mRecorder.ondataavailable = function(event) {
    
    var blob = event.data;
    
    chunks.push(blob);
    
    var vidchunk = new Blob(chunks);
    
    // save to directory vid chunk.
    
  };
    
  mRecorder.start(5000);
    
}).catch(function(error) {
    
  console.log(error.message);
    
});

    Then, once I have a bunch of these 5 second clips, I merge them :

    ffmpeg -safe 0 \
    
-f concat -i <(for f in `ls vidchunks/* | sort -V`; do echo file $f; done) \
    
-c:v copy -r 30 -vsync drop test.webm

    When I play back these chunks individually, they play correctly. All 5 seconds of video are rendered smoothly.

    However, once I merge, some 5 second chunks are condensed to like 1 second. So the total video, which should be 50 seconds for 10 chunks, turns out to be like 38 seconds because three of the chunks got condensed to 1 second.

    Any ideas on how to fix this ?

    EDIT : I’ve tried :

    • without "-r 30 -vsync drop"
    • without "-c:v copy"

    No changes...

    EDIT2 (some ffprobe outputs) :

    ffprobe 1472343170-1.webm

    ffprobe version 2.8.6-1ubuntu2 Copyright (c) 2007-2016 the FFmpeg developers
    
  built with gcc 5.3.1 (Ubuntu 5.3.1-11ubuntu1) 20160311
    
  configuration: --prefix=/usr --extra-version=1ubuntu2 --build-suffix=-ffmpeg --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --cc=cc --cxx=g++ --enable-gpl --enable-shared --disable-stripping --disable-decoder=libopenjpeg --disable-decoder=libschroedinger --enable-avresample --enable-avisynth --enable-gnutls --enable-ladspa --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libmodplug --enable-libmp3lame --enable-libopenjpeg --enable-libopus --enable-libpulse --enable-librtmp --enable-libschroedinger --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-libzvbi --enable-openal --enable-opengl --enable-x11grab --enable-libdc1394 --enable-libiec61883 --enable-libzmq --enable-frei0r --enable-libx264 --enable-libopencv
    
  libavutil      54. 31.100 / 54. 31.100
    
  libavcodec     56. 60.100 / 56. 60.100
    
  libavformat    56. 40.101 / 56. 40.101
    
  libavdevice    56.  4.100 / 56.  4.100
    
  libavfilter     5. 40.101 /  5. 40.101
    
  libavresample   2.  1.  0 /  2.  1.  0
    
  libswscale      3.  1.101 /  3.  1.101
    
  libswresample   1.  2.101 /  1.  2.101
    
  libpostproc    53.  3.100 / 53.  3.100
    
Input #0, matroska,webm, from '1472343170-1.webm':
    
  Metadata:
    
    encoder         : Chrome
    
  Duration: N/A, start: 0.000000, bitrate: N/A
    
    Stream #0:0(eng): Video: vp8, yuv420p, 1280x760, SAR 1:1 DAR 32:19, 30 fps, 30 tbr, 1k tbn, 1k tbc (default)

    ffprobe 1472343245-16.webm

    ffprobe version 2.8.6-1ubuntu2 Copyright (c) 2007-2016 the FFmpeg developers
    
  built with gcc 5.3.1 (Ubuntu 5.3.1-11ubuntu1) 20160311
    
  configuration: --prefix=/usr --extra-version=1ubuntu2 --build-suffix=-ffmpeg --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --cc=cc --cxx=g++ --enable-gpl --enable-shared --disable-stripping --disable-decoder=libopenjpeg --disable-decoder=libschroedinger --enable-avresample --enable-avisynth --enable-gnutls --enable-ladspa --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libmodplug --enable-libmp3lame --enable-libopenjpeg --enable-libopus --enable-libpulse --enable-librtmp --enable-libschroedinger --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-libzvbi --enable-openal --enable-opengl --enable-x11grab --enable-libdc1394 --enable-libiec61883 --enable-libzmq --enable-frei0r --enable-libx264 --enable-libopencv
    
  libavutil      54. 31.100 / 54. 31.100
    
  libavcodec     56. 60.100 / 56. 60.100
    
  libavformat    56. 40.101 / 56. 40.101
    
  libavdevice    56.  4.100 / 56.  4.100
    
  libavfilter     5. 40.101 /  5. 40.101
    
  libavresample   2.  1.  0 /  2.  1.  0
    
  libswscale      3.  1.101 /  3.  1.101
    
  libswresample   1.  2.101 /  1.  2.101
    
  libpostproc    53.  3.100 / 53.  3.100
    
Input #0, matroska,webm, from '1472343245-16.webm':
    
  Metadata:
    
    encoder         : Chrome
    
  Duration: N/A, start: 0.000000, bitrate: N/A
    
    Stream #0:0(eng): Video: vp8, yuv420p, 1280x760, SAR 1:1 DAR 32:19, 30 fps, 30 tbr, 1k tbn, 1k tbc (default)

    ffprobe 1472343350-37.webm

    ffprobe version 2.8.6-1ubuntu2 Copyright (c) 2007-2016 the FFmpeg developers
    
  built with gcc 5.3.1 (Ubuntu 5.3.1-11ubuntu1) 20160311
    
  configuration: --prefix=/usr --extra-version=1ubuntu2 --build-suffix=-ffmpeg --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --cc=cc --cxx=g++ --enable-gpl --enable-shared --disable-stripping --disable-decoder=libopenjpeg --disable-decoder=libschroedinger --enable-avresample --enable-avisynth --enable-gnutls --enable-ladspa --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libmodplug --enable-libmp3lame --enable-libopenjpeg --enable-libopus --enable-libpulse --enable-librtmp --enable-libschroedinger --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-libzvbi --enable-openal --enable-opengl --enable-x11grab --enable-libdc1394 --enable-libiec61883 --enable-libzmq --enable-frei0r --enable-libx264 --enable-libopencv
    
  libavutil      54. 31.100 / 54. 31.100
    
  libavcodec     56. 60.100 / 56. 60.100
    
  libavformat    56. 40.101 / 56. 40.101
    
  libavdevice    56.  4.100 / 56.  4.100
    
  libavfilter     5. 40.101 /  5. 40.101
    
  libavresample   2.  1.  0 /  2.  1.  0
    
  libswscale      3.  1.101 /  3.  1.101
    
  libswresample   1.  2.101 /  1.  2.101
    
  libpostproc    53.  3.100 / 53.  3.100
    
Input #0, matroska,webm, from '1472343350-37.webm':
    
  Metadata:
    
    encoder         : Chrome
    
  Duration: N/A, start: 0.000000, bitrate: N/A
    
    Stream #0:0(eng): Video: vp8, yuv420p, 1280x760, SAR 1:1 DAR 32:19, 30 fps, 30 tbr, 1k tbn, 1k tbc (default)

    I also noticed that the merged video plays normal when the mouse is moving around on the screen, but when the mouse is not moving, it moves 5x faster.

    I know this because I have a timer on the screen that I’m recording, and I can see that the timer speeds up significantly when mouse isn’t moving but when mouse is moving, the timer moves at normal speed.

    EDIT3 :
    The DTS/PTS looks like resets after each file is merged :

    DTS -9223363446915256, next:6866667 st:0 invalid dropping
    
PTS -9223363446915256, next:6866667 invalid dropping st:0
    
DTS -9223363446915222, next:6900000 st:0 invalid dropping
    
PTS -9223363446915222, next:6900000 invalid dropping st:0
    
DTS -9223363446915188, next:6933333 st:0 invalid dropping
    
PTS -9223363446915188, next:6933333 invalid dropping st:0
    
[concat @ 0x1cde3e0] DTS -9223363446920184 < 5006 out of order
    
DTS -9223363446920184, next:5033333 st:0 invalid dropping
    
PTS -9223363446920184, next:5033333 invalid dropping st:0
    
DTS -9223363446920056, next:5066667 st:0 invalid dropping
    
PTS -9223363446920056, next:5066667 invalid dropping st:0
    
DTS -9223363446919956, next:5100000 st:0 invalid dropping
    
PTS -9223363446919956, next:5100000 invalid dropping st:0

    EDIT4 : Tried ffmpeg -i "$f" -y -c copy -fflags +genpts "$f" and then merge again.

    Works a lot better, but now other files are getting skipped.

    Here’s ffprobe from a file that’s skipped :

    Metadata:
    
    encoder         : Lavf56.40.101
    
  Duration: 00:00:01.17, start: 0.000000, bitrate: 428 kb/s
    
    Stream #0:0(eng): Video: vp8, yuv420p, 1280x760, SAR 1:1 DAR 32:19, 30 fps, 30 tbr, 1k tbn, 1k tbc (default)
    
[webm @ 0x1c01940] Codec for stream 0 does not use global headers but container format requires global headers
    
Output #0, webm, to '1472343225-12.webm':
    
  Metadata:
    
    encoder         : Lavf56.40.101
    
    Stream #0:0(eng): Video: vp8, yuv420p, 1280x760 [SAR 1:1 DAR 32:19], q=2-31, 30 fps, 30 tbr, 1k tbn, 1k tbc (default)
    
Stream mapping:
    
  Stream #0:0 -> #0:0 (copy)

    Here’s ffprobe from a file not skipped :

    Input #0, matroska,webm, from '1472343215-10.webm':
    
  Metadata:
    
    encoder         : Lavf56.40.101
    
  Duration: 00:00:05.03, start: 0.000000, bitrate: 80 kb/s
    
    Stream #0:0(eng): Video: vp8, yuv420p, 1280x760, SAR 1:1 DAR 32:19, 30 fps, 30 tbr, 1k tbn, 1k tbc (default)
    
[webm @ 0x1349940] Codec for stream 0 does not use global headers but container format requires global headers
    
Output #0, webm, to '1472343215-10.webm':
    
  Metadata:
    
    encoder         : Lavf56.40.101
    
    Stream #0:0(eng): Video: vp8, yuv420p, 1280x760 [SAR 1:1 DAR 32:19], q=2-31, 30 fps, 30 tbr, 1k tbn, 1k tbc (default)
    
Stream mapping:
    
  Stream #0:0 -> #0:0 (copy)

  • rtmp : Allocate the prev_pkt arrays dynamically

    11 octobre 2013, par Martin Storsjö
    rtmp : Allocate the prev_pkt arrays dynamically

    Normally, all channel ids are between 0 and 10, while they in
    
uncommon cases can have values up to 64k.
    

    This avoids allocating two arrays for up to 64k entries (at a total
    
of over 6 MB in size) each when most of them aren’t used at all.
    

    Signed-off-by : Martin Storsjö <martin@martin.st>
    • [DH] libavformat/rtmppkt.c
    • [DH] libavformat/rtmppkt.h
    • [DH] libavformat/rtmpproto.c

  • rtmp : Allocate the prev_pkt arrays dynamically

    11 octobre 2013, par Martin Storsjö
    rtmp : Allocate the prev_pkt arrays dynamically

    Normally, all channel ids are between 0 and 10, while they in
    
uncommon cases can have values up to 64k.
    

    This avoids allocating two arrays for up to 64k entries (at a total
    
of over 6 MB in size) each when most of them aren’t used at all.
    

    Signed-off-by : Martin Storsjö <martin@martin.st>
    • [DBH] libavformat/rtmppkt.c
    • [DBH] libavformat/rtmppkt.h
    • [DBH] libavformat/rtmpproto.c

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