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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;
  
         
  
  

• avutil/eval : Use even better PRNG

  2 janvier 2024, par Michael Niedermayer

  avutil/eval : Use even better PRNG
  This is the 64bit version of Chris Doty-Humphreys SFC64
  Compared to the LCGs these produce much better quality numbers.
  
  Compared to LFGs this needs less state. (our LFG has 224 byte
  
  state for its 32bit version) this has 32byte state
  
  Also the initialization for our LFG is slower.
  
  This is also much faster than KISS or PCG.
  This commit replaces the broken LCG used before.
  
  (broken as it had only a period 200M due to being put in a double)
  This changes the output from random() which is why libswresample.mak
  
  is updated, update was done using the command in libswresample.mak
  Signed-off-by : Michael Niedermayer <michael@niedermayer.cc>
  

  • [DH] libavutil/eval.c
  • [DH] libavutil/sfc64.h
  • [DH] tests/fate/libswresample.mak
  • [DH] tests/ref/fate/eval

• ffmpeg DASH encoding : always getting bitrate as 200k for vp9 codec

  29 novembre 2019, par Saurabh

  I am using following command, earlier put here : to generate DASH files :

  ffmpeg -y -nostdin -loglevel error -i "$1" \
  
          -map 0:v:0  -map 0:v:0 -map 0:v:0  -map 0:v:0  -map 0:v:0  -map 0:v:0 -map 0:a\?:0  \
  
          -maxrate:v:0 350k -bufsize:v:0 700k -c:v:0 libx264 -filter:v:0 "scale=320:-2"  \
  
          -maxrate:v:1 1000k -bufsize:v:1 2000k -c:v:1 libx264 -filter:v:1 "scale=640:-2"  \
  
          -maxrate:v:2 3000k -bufsize:v:2 6000k -c:v:2 libx264 -filter:v:2 "scale=1280:-2" \
  
          -maxrate:v:3 300k -minrate:v:3 100k -bufsize:v:3 600k -c:v:3 libvpx-vp9 -filter:v:3 "scale=320:-2"  \
  
          -maxrate:v:4 1088k -minrate:v:4 200k -bufsize:v:4 2176k -c:v:4 libvpx-vp9 -filter:v:4 "scale=640:-2"  \
  
          -maxrate:v:5 1500k -minrate:v:5 300k -bufsize:v:5 3000k -c:v:5 libvpx-vp9 -filter:v:5 "scale=1280:-2"  \
  
          -use_timeline 1  -use_template 1 -adaptation_sets "id=0,streams=0,1,2 id=1,streams=3,4,5 id=2,streams=a" \
  
          -threads 8 -crf 3 -seg_duration 5 -hls_init_time 1 -hls_time 5 -hls_playlist true -f dash "$2"

  The issue is, in the output, I always get bandwidth as 200k for vp9 codec(see output below), while for same video bandwidth for h264 codec varies as par resolution and quite less, I expected vp9 to be even less as it compresses more. I have tested using multiple different options like : -b:v, -deadline, -cpu-used -crf, etc, but not working expected with different values of these, What am I missing ?

  Sample output mpd 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" mediapresentationduration="PT25.4S" minbuffertime="PT15.0S">
  
      <programinformation>
  
      </programinformation>
  
      <period start="PT0.0S">
  
          <adaptationset contenttype="video" segmentalignment="true" bitstreamswitching="true" lang="und">
  
              <representation mimetype="video/mp4" codecs="avc1.64000c" bandwidth="104972" width="320" height="180" framerate="24000/1001">
  
                  <segmenttemplate timescale="24000" initialization="init-stream$RepresentationID$.m4s" media="chunk-stream$RepresentationID$-$Number%05d$.m4s" startnumber="1">
  
                      <segmenttimeline>
  
                          <s t="0" d="130130"></s>
  
                          <s d="250250"></s>
  
                          <s d="176176"></s>
  
                          <s d="54054"></s>
  
                      </segmenttimeline>
  
                  </segmenttemplate>
  
              </representation>
  
              <representation mimetype="video/mp4" codecs="avc1.64001e" bandwidth="227233" width="640" height="360" framerate="24000/1001">
  
                  <segmenttemplate timescale="24000" initialization="init-stream$RepresentationID$.m4s" media="chunk-stream$RepresentationID$-$Number%05d$.m4s" startnumber="1">
  
                      <segmenttimeline>
  
                          <s t="0" d="130130"></s>
  
                          <s d="250250"></s>
  
                          <s d="180180"></s>
  
                          <s d="50050"></s>
  
                      </segmenttimeline>
  
                  </segmenttemplate>
  
              </representation>
  
              <representation mimetype="video/mp4" codecs="avc1.64001f" bandwidth="616878" width="1280" height="720" framerate="24000/1001">
  
                  <segmenttemplate timescale="24000" initialization="init-stream$RepresentationID$.m4s" media="chunk-stream$RepresentationID$-$Number%05d$.m4s" startnumber="1">
  
                      <segmenttimeline>
  
                          <s t="0" d="130130"></s>
  
                          <s d="250250"></s>
  
                          <s d="180180"></s>
  
                          <s d="50050"></s>
  
                      </segmenttimeline>
  
                  </segmenttemplate>
  
              </representation>
  
          </adaptationset>
  
          <adaptationset contenttype="video" segmentalignment="true" bitstreamswitching="true" lang="und">
  
              <representation mimetype="video/mp4" codecs="vp09.00.11.08" bandwidth="200000" width="320" height="180" framerate="24000/1001">
  
                  <segmenttemplate timescale="24000" initialization="init-stream$RepresentationID$.m4s" media="chunk-stream$RepresentationID$-$Number%05d$.m4s" startnumber="1">
  
                      <segmenttimeline>
  
                          <s t="0" d="128128" r="3"></s>
  
                          <s d="98098"></s>
  
                      </segmenttimeline>
  
                  </segmenttemplate>
  
              </representation>
  
              <representation mimetype="video/mp4" codecs="vp09.00.21.08" bandwidth="200000" width="640" height="360" framerate="24000/1001">
  
                  <segmenttemplate timescale="24000" initialization="init-stream$RepresentationID$.m4s" media="chunk-stream$RepresentationID$-$Number%05d$.m4s" startnumber="1">
  
                      <segmenttimeline>
  
                          <s t="0" d="128128" r="3"></s>
  
                          <s d="98098"></s>
  
                      </segmenttimeline>
  
                  </segmenttemplate>
  
              </representation>
  
              <representation mimetype="video/mp4" codecs="vp09.00.31.08" bandwidth="200000" width="1280" height="720" framerate="24000/1001">
  
                  <segmenttemplate timescale="24000" initialization="init-stream$RepresentationID$.m4s" media="chunk-stream$RepresentationID$-$Number%05d$.m4s" startnumber="1">
  
                      <segmenttimeline>
  
                          <s t="0" d="128128" r="3"></s>
  
                          <s d="98098"></s>
  
                      </segmenttimeline>
  
                  </segmenttemplate>
  
              </representation>
  
          </adaptationset>
  
          <adaptationset contenttype="audio" segmentalignment="true" bitstreamswitching="true" lang="eng">
  
              <representation mimetype="audio/mp4" codecs="mp4a.40.2" bandwidth="128000" audiosamplingrate="44100">
  
                  <audiochannelconfiguration schemeiduri="urn:mpeg:dash:23003:3:audio_channel_configuration:2011" value="2"></audiochannelconfiguration>
  
                  <segmenttemplate timescale="44100" initialization="init-stream$RepresentationID$.m4s" media="chunk-stream$RepresentationID$-$Number%05d$.m4s" startnumber="1">
  
                      <segmenttimeline>
  
                          <s t="0" d="235520" r="3"></s>
  
                          <s d="180224"></s>
  
                      </segmenttimeline>
  
                  </segmenttemplate>
  
              </representation>
  
          </adaptationset>
  
      </period>
  
  </mpd>

  I am using this video, but it is coming same for all 30 sec video I have tried.