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• mpegts muxer, DVB subtitles encoder : common DVB subtitles payload

  11 janvier 2014, par Serhii Marchuk

  mpegts muxer, DVB subtitles encoder : common DVB subtitles payload
  Improved DVB subtitles encoder to generate AVPacket.data in the same
  
  format as generates MPEGTS demuxer + DVB subtitles parser. So now single
  
  format of DVB subtitles data is used across all the components of FFmpeg :
  
  only subtitles payload WITHOUT 0x20 0x00 bytes at the beginning and 0xFF
  
  trailing byte.
  Improved MPEGTS muxer to support format of DVB subtitles in
  
  AVPacket.data described above : while muxing we add two bytes 0x20 0x00 to
  
  the beginning of and 0xFF to the end of DVB subtitles payload.
  The patch fixes DVB subtitle copy problems : tickets #2989 fully and #2024
  
  partly.
  Signed-off-by : Clément Bœsch <u@pkh.me>
  

  • [DH] libavcodec/dvbsub.c
  • [DH] libavcodec/version.h
  • [DH] libavformat/mpegtsenc.c
  • [DH] libavformat/version.h

• dashjs can't find initialization segment on manifest.mpd

  30 avril 2016, par Abelardo Mendoza

  I am following this tutorial to stream a WebM. I have no issues running the ffmpeg commands to generate the videos/audio/manifest files but when I try to run it locally, there’s no video or audio at all and dashjs floods the console with :

  Searching for initialization.    
  
  Start searching for initialization.     
  
  Perform init search: http://localhost:8080/video_1280x720_500k.webm    
  
  Perform SIDX load: http://localhost:8080/video_640x360_750k.webm     
  
  Perform SIDX load: http://localhost:8080/video_1280x720_500k.webm 

  Writing that to console until I stop the server. I have tried using other mpd files such as this, which is used on the dashjs quickstart and it plays the video without any problems.

  I used this guide to install the latest version of ffmpeg on Ubuntu 14.04 LTS :

  ffmpeg version N-79688-g3cb3ddd Copyright (c) 2000-2016 the FFmpeg developers
  
  built with gcc 5.3.0 (Ubuntu 5.3.0-3ubuntu1~14.04) 20151204
  
  configuration: --prefix=/home/ab/cpp/ffmpeg_build --pkg-config-flags=--static --extra-cflags=-I/home/ab/cpp/ffmpeg_build/include --extra-ldflags=-L/home/ab/cpp/ffmpeg/lib --bindir=/home/ab/bin --enable-gpl --enable-libass --enable-libfdk-aac --enable-libfreetype --enable-libmp3lame --enable-libopus --enable-libtheora --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libx265 --enable-nonfree
  
  libavutil      55. 23.100 / 55. 23.100
  
  libavcodec     57. 38.100 / 57. 38.100
  
  libavformat    57. 34.103 / 57. 34.103
  
  libavdevice    57.  0.101 / 57.  0.101
  
  libavfilter     6. 44.100 /  6. 44.100
  
  libswscale      4.  1.100 /  4.  1.100
  
  libswresample   2.  0.101 /  2.  0.101
  
  libpostproc    54.  0.100 / 54.  0.100

  When running on ffmpeg :

  ffmpeg \
  
   -f webm_dash_manifest -i video_160x90_250k.webm \
  
   -f webm_dash_manifest -i video_320x180_500k.webm \
  
   -f webm_dash_manifest -i video_640x360_750k.webm \
  
   -f webm_dash_manifest -i video_640x360_1000k.webm \
  
   -f webm_dash_manifest -i video_1280x720_500k.webm \
  
   -f webm_dash_manifest -i audio_128k.webm \
  
   -c copy -map 0 -map 1 -map 2 -map 3 -map 4 -map 5 \
  
   -f webm_dash_manifest \
  
   -adaptation_sets "id=0,streams=0,1,2,3,4 id=1,streams=5" \
  
   manifest.mpd

  It generates the following manifest.mpd :

  <?xml version="1.0" encoding="UTF-8"?>
  
  <mpd xmlns="urn:mpeg:DASH:schema:MPD:2011" type="static" mediapresentationduration="PT117.726S" minbuffertime="PT1S" profiles="urn:webm:dash:profile:webm-on-demand:2012">
  
    <period start="PT0S" duration="PT117.726S">
  
      <adaptationset mimetype="video/webm" codecs="vp9" lang="eng" bitstreamswitching="true" subsegmentalignment="true" subsegmentstartswithsap="1">
  
        <representation bandwidth="198155" width="160" height="90">
  
          <baseurl>video_160x90_250k.webm</baseurl>
  
          <segmentbase indexrange="2007834-2008211">
  
            <initialization range="0-437"></initialization>
  
          </segmentbase>
  
        </representation>
  
        <representation bandwidth="459264" width="320" height="180">
  
          <baseurl>video_320x180_500k.webm</baseurl>
  
          <segmentbase indexrange="4459996-4460374">
  
            <initialization range="0-439"></initialization>
  
          </segmentbase>
  
        </representation>
  
        <representation bandwidth="718495" width="640" height="360">
  
          <baseurl>video_640x360_750k.webm</baseurl>
  
          <segmentbase indexrange="6614036-6614414">
  
            <initialization range="0-441"></initialization>
  
          </segmentbase>
  
        </representation>
  
        <representation bandwidth="931445" width="640" height="360">
  
          <baseurl>video_640x360_1000k.webm</baseurl>
  
          <segmentbase indexrange="8309082-8309460">
  
            <initialization range="0-441"></initialization>
  
          </segmentbase>
  
        </representation>
  
        <representation bandwidth="821274" width="1280" height="720">
  
          <baseurl>video_1280x720_500k.webm</baseurl>
  
          <segmentbase indexrange="8728812-8729190">
  
            <initialization range="0-441"></initialization>
  
          </segmentbase>
  
        </representation>
  
      </adaptationset>
  
      <adaptationset mimetype="audio/webm" codecs="vorbis" lang="eng" audiosamplingrate="44100" bitstreamswitching="true" subsegmentalignment="true" subsegmentstartswithsap="1">
  
        <representation bandwidth="107104">
  
          <baseurl>audio_128k.webm</baseurl>
  
          <segmentbase indexrange="1538710-1539184">
  
            <initialization range="0-4112"></initialization>
  
          </segmentbase>
  
        </representation>
  
      </adaptationset>
  
    </period>
  
  </mpd>

  The index.html has a few changes because dash.js changed the way the player gets initialized.

      
  
          
  
          
  
          <code class="echappe-js">&lt;script src=&quot;http://cdn.dashjs.org/latest/dash.all.debug.js&quot;&gt;&lt;/script&gt;
  
              
          
  

  And here is Chromium’s log file. I’m converting this webm from this site.

  If I missed out any other relevant information or if anyone can guide me into the right direction, please let me know.

  Edit :

  Like Will Law mentioned, using the Shaka Player worked without any issues with my current manifest. Hope this helps anyone else.

• what is the proper way for text in multi-pass encoding using ffmpeg

  4 juin 2016, par Camelius Chukwubuikem Ubah

  cpulimit -l 180 ffmpeg-static/ffmpeg -ss 0 -t 8.96 -i ’/var/www/html/Videos2/Character Jack/Happy/happy birthday scene.mp4’ -filter_complex ’[0] drawtext=textfile=scene2.txt:fontsize=199.68:fontfile=/var/www/html/fonts/Arial.ttf:x=288:y=409:fontcolor_expr=ffffff%eif~: clip(1+(255*t/4)\, 0\, 255)\:x\:2’ -pass 1 -f h264 -y - > /dev/null &&

  cpulimit -l 180 ffmpeg-static/ffmpeg -ss 0 -t 8.96 -i ’/var/www/html/Videos2/Character Jack/Happy/happy birthday scene.mp4’ -i ’/var/www/html/Userfiles/Users/blaze/Projects/earl3x/audio/scene2_music.x.mp3’ -filter_complex ’[1] volume=0.95 [au1] ; [0][au1] amix=inputs=2:duration=shortest’ -c:v copy -c:a libmp3lame -pix_fmt yuv420p -preset ultrafast -shortest -movflags faststart -y -pass 2 /var/www/html/Userfiles/Users/blaze/example/earl4x/scene2.mp4

  What i’m trying to achieve ?
  encoding text elements / graphics on the first pass
  and encoding Sound (audio) on the second pass

  the first pass and second pass runs fine ( with no errors at all)
  and the output has no artifact.

  however the text is totally no where to be found !
  what it seems like is that , the second pass had no idea there was a first pass with text encoded in it.

  what will be the right way to run / format the command ?

  thanks