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• dash.js : four channels audio streaming

  19 juillet 2016, par Carlos Chacon

  Does dash.js supports 4 channels in the audio stream ?

  I’m using mp4 container : video : h254 and audio : AAC.

  For the case that the AAC audio stream is 2 channels it works fine, both video and audio play correctly. But 4 channels does NOT work.

  I’m using FFMPEG to create the files and WOWZA to setup the DASH streaming.

  For the case that the AAC audio stream is 4 channels I get the following error :

   Video can't be played because the file is corrupt.

  Command line to generate the 2-channels file :

  ffmpeg -i video_in.mp4 -i audio_in_4ch.wav -c:v copy -c:a aac -ac 2 output_2channels.mp4

  Command line to generate the 4-channels file :

  ffmpeg -i video_in.mp4 -i audio_in_4ch.wav -c:v copy -c:a aac -ac 4 output_4channels.mp4

  This is the fmmpeg -i information printed for each file :

  2 Channels output file details :

  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'output_2channels.mp4':
  
    Metadata:
  
      major_brand     : isom
  
      minor_version   : 512
  
      compatible_brands: isomiso2avc1mp41
  
      encoder         : Lavf57.37.101
  
    Duration: 00:00:17.59, start: 0.000000, bitrate: 901 kb/s
  
      Stream #0:0(eng): Video: h264 (Constrained Baseline) (avc1 / 0x31637661), yuv420p, 1024x512 [SAR 1:1 DAR 2:1], 894 kb/s, 29.97 fps, 29.97 tbr, 30k tbn, 59.94 tbc (default)
  
      Metadata:
  
        handler_name    : VideoHandler
  
      Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 129 kb/s (default)
  
      Metadata:
  
        handler_name    : SoundHandler

  4 Channels output file details :

  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'output_4channels.mp4':
  
    Metadata:
  
      major_brand     : isom
  
      minor_version   : 512
  
      compatible_brands: isomiso2avc1mp41
  
      encoder         : Lavf57.37.101
  
    Duration: 00:00:17.59, start: 0.000000, bitrate: 1038 kb/s
  
      Stream #0:0(eng): Video: h264 (Constrained Baseline) (avc1 / 0x31637661), yuv420p, 1024x512 [SAR 1:1 DAR 2:1], 894 kb/s, 29.97 fps, 29.97 tbr, 30k tbn, 59.94 tbc (default)
  
      Metadata:
  
        handler_name    : VideoHandler
  
      Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, 4.0, fltp, 265 kb/s (default)
  
      Metadata:
  
        handler_name    : SoundHandler

  4 Channels output file mdp file :

  <?xml version="1.0" encoding="UTF-8"?>
  
  <mpd xmlns="urn:mpeg:dash:schema:mpd:2011" profiles="urn:mpeg:dash:profile:isoff-live:2011" type="static" publishtime="2016-07-19T05:56:28Z" mediapresentationduration="PT17.585S" minbuffertime="PT1.5S">
  
  <programinformation>
  
      
  
  </programinformation>
  
  <location>http://192.168.0.103:1935/vod/_definst_/mp4:output_4channels.mp4/manifest_w882219731.mpd</location>
  
  <period start="PT0.0S">
  
      <baseurl>http://192.168.0.103:1935/vod/_definst_/mp4:output_4channels.mp4/</baseurl>
  
      <adaptationset mimetype="video/mp4" width="1024" height="512" par="1024:512" framerate="30000/1001" segmentalignment="true" startwithsap="1" subsegmentalignment="true" subsegmentstartswithsap="1">
  
          <segmenttemplate presentationtimeoffset="0" timescale="90000" media="chunk_ctvideo_rid$RepresentationID$_cs$Time$_w882219731_mpd.m4s" initialization="chunk_ctvideo_rid$RepresentationID$_cinit_w882219731_mpd.m4s">
  
              <segmenttimeline>
  
                  <s t="0" d="1582650"></s>
  
              </segmenttimeline>
  
          </segmenttemplate>
  
          <representation codecs="avc1.42c01e" sar="1:1" bandwidth="894760"></representation>
  
      </adaptationset>
  
      <adaptationset mimetype="audio/mp4" lang="eng" segmentalignment="true" startwithsap="1" subsegmentalignment="true" subsegmentstartswithsap="1">
  
          <audiochannelconfiguration schemeiduri="urn:mpeg:dash:23003:3:audio_channel_configuration:2011" value="2"></audiochannelconfiguration>
  
          <segmenttemplate presentationtimeoffset="0" timescale="48000" media="chunk_ctaudio_rid$RepresentationID$_cs$Time$_w882219731_mpd.m4s" initialization="chunk_ctaudio_rid$RepresentationID$_cinit_w882219731_mpd.m4s">
  
              <segmenttimeline>
  
                  <s t="0" d="844080"></s>
  
              </segmenttimeline>
  
          </segmenttemplate>
  
          <representation codecs="mp4a.40.2" audiosamplingrate="48000" bandwidth="265851">
  
          </representation>
  
      </adaptationset>
  
  </period>
  
  </mpd>

  HTML Player Code :

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

• 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.

• simple_idct : x86 : Drop disabled IDCT implementation

  1er août 2016, par Diego Biurrun

  simple_idct : x86 : Drop disabled IDCT implementation
  This gem has been disabled since 2001.
  

  • [DBH] libavcodec/x86/simple_idct.c