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• 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.

• ffmpeg : check videos conformance for dash before concat

  26 janvier 2018, par Massimo Vantaggio

  I wrote a small bash file that reads a folder, generates a playlist, concatenates, adds a logo and encode the big video result for dash ready, i would like to implement it by checking before all videos conformance : if they have same fps, same resolution, same time base etc.
  Below my situation :

  #!/bin/bash
  
  # CONCAT DEMUXER
  
  #This demuxer reads a list of #files and other directives from a text file and demuxes them one after the other, as if #all their packets had been muxed together. All files must have the same streams (same #codecs, same time base, etc.) but can be wrapped in different container formats.
  
  
  
  
  
  
  
  printf "file '%s'\n" *.mp4 > playlist.txt
  
  ffmpeg -auto_convert 1 -f concat -safe 0 -i playlist.txt -c:a aac -b:a 384k -ar 48000 -ac 2 -async 1 -vsync 1 -c:v libx264 -x264opts 'keyint=50:min-keyint=50:no-scenecut' -r 25 -b:v 2400k -maxrate 2400k -bufsize 1200k -vf "scale=-1:432" -vf "movie=stable.png [watermark]; [in][watermark] overlay=main_w-overlay_w-10:10 [out]" out.mp4
  
  clear
  
  echo “VIDEO CONCAT COMPLETED”

  For example below i find this bash that calculate the total duration in second of the videos of the folder, unfortunately I’m unable to put the result into variable.. I’m newbie of bash.

  times=()
  
  for f in *.ts; do
  
      _t=$(ffmpeg -i "$f" 2>&1 | grep "Duration" | grep -o " [0-9:.]*, " | head -n1 | tr ',' ' ' | awk -F: '{ print ($1 * 3600) + ($2 * 60) + $3 }')
  
      times+=("$_t")
  
  done
  
  echo "${times[@]}" | sed 's/ /+/g' | bc

  I wish to check if the videos have the same fps, and same resolution before process, and to get into variable this duration.
  Thanks
  Massimo

• Combine MPEG-DASH segments (ex, init.mp4 + segments.m4s) back to a full source.mp4 ?

  11 juin 2020, par Drake Guan

  GPAC, http://gpac.wp.mines-telecom.fr/, can be used to do video segmentation along with MPEG-DASH spec. One type of results is a combination of init files (ex, init.mp4) and several roughly fixed-duration segments (ex, segment-%d.m4s). What if I just got those results and I like to reverse/combine them back to one full source.mp4 file ? Can I use GPAC or ffmpeg for this ?