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• FFMPEG MPEG-DASH playback - Update SPS and PPS info on receiving init segment

  4 novembre 2014, par Chakkra

  I am trying to playback a DASH stream using libdash (for MPD parsing) and FFMPEG (for fmp4 parsing). When we don’t switch between Representations, FFMPEG was able to successfully parse the fmp4 file and give proper SPS and PPS info for the video stream (H.264 video).

  When we implement the adaptive bitrate switching logic to switch between Representations of an Adaptation set, FFMPEG is not able to update the SPS and PPS data. Even after we give the init segment to FFMPEG (of the newly switched Representaion), the SPS and PPS data were not updated ? May I know, how can we get the SPS and PPS info for the newly switched Representation segments from FFMPEG ?

  Thanks and Regards.

• MPEG Dash output generated by FFMPEG not working

  8 janvier 2019, par Anto Joy

  I created a dash output sample_video.mpd file using ffmpeg, but when I tried to play it using dash js the video was just loading and nothing else.
  Below is the generated 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="PT1M2.3S" minbuffertime="PT20.0S">
  
  <programinformation>
  
  </programinformation>
  
  <period start="PT0.0S">
  
      <adaptationset contenttype="video" segmentalignment="true" bitstreamswitching="true" lang="und">
  
          <representation mimetype="video/mp4" codecs="avc1.640015" bandwidth="255520" width="426" height="240" framerate="24/1">
  
              <segmenttemplate timescale="12288" initialization="init-stream$RepresentationID$.m4s" media="chunk-stream$RepresentationID$-$Number%05d$.m4s" startnumber="3">
  
                  <segmenttimeline>
  
                      <s t="198656" d="69120"></s>
  
                      <s d="75264"></s>
  
                      <s d="174592"></s>
  
                      <s d="122880"></s>
  
                      <s d="125440"></s>
  
                  </segmenttimeline>
  
              </segmenttemplate>
  
          </representation>
  
          <representation mimetype="video/mp4" codecs="avc1.64001e" bandwidth="726596" width="854" height="480" framerate="24/1">
  
              <segmenttemplate timescale="12288" initialization="init-stream$RepresentationID$.m4s" media="chunk-stream$RepresentationID$-$Number%05d$.m4s" startnumber="3">
  
                  <segmenttimeline>
  
                      <s t="198656" d="69120"></s>
  
                      <s d="75264"></s>
  
                      <s d="174592"></s>
  
                      <s d="122880"></s>
  
                      <s d="125440"></s>
  
                  </segmenttimeline>
  
              </segmenttemplate>
  
          </representation>
  
          <representation mimetype="video/mp4" codecs="avc1.64001f" bandwidth="1433314" width="1280" height="720" framerate="24/1">
  
              <segmenttemplate timescale="12288" initialization="init-stream$RepresentationID$.m4s" media="chunk-stream$RepresentationID$-$Number%05d$.m4s" startnumber="3">
  
                  <segmenttimeline>
  
                      <s t="198656" d="69120"></s>
  
                      <s d="75264"></s>
  
                      <s d="174592"></s>
  
                      <s d="122880"></s>
  
                      <s d="125440"></s>
  
                  </segmenttimeline>
  
              </segmenttemplate>
  
          </representation>
  
      </adaptationset>
  
      <adaptationset contenttype="audio" segmentalignment="true" bitstreamswitching="true" lang="und">
  
          <representation mimetype="audio/mp4" codecs="mp4a.40.2" bandwidth="341000" audiosamplingrate="48000">
  
              <audiochannelconfiguration schemeiduri="urn:mpeg:dash:23003:3:audio_channel_configuration:2011" value="6"></audiochannelconfiguration>
  
              <segmenttemplate timescale="48000" initialization="init-stream$RepresentationID$.m4s" media="chunk-stream$RepresentationID$-$Number%05d$.m4s" startnumber="3">
  
                  <segmenttimeline>
  
                      <s t="772096" d="270336"></s>
  
                      <s d="293888"></s>
  
                      <s d="681984"></s>
  
                      <s d="480256"></s>
  
                      <s d="492544"></s>
  
                  </segmenttimeline>
  
              </segmenttemplate>
  
          </representation>
  
          <representation mimetype="audio/mp4" codecs="mp4a.40.2" bandwidth="341000" audiosamplingrate="48000">
  
              <audiochannelconfiguration schemeiduri="urn:mpeg:dash:23003:3:audio_channel_configuration:2011" value="6"></audiochannelconfiguration>
  
              <segmenttemplate timescale="48000" initialization="init-stream$RepresentationID$.m4s" media="chunk-stream$RepresentationID$-$Number%05d$.m4s" startnumber="3">
  
                  <segmenttimeline>
  
                      <s t="772096" d="270336"></s>
  
                      <s d="293888"></s>
  
                      <s d="681984"></s>
  
                      <s d="480256"></s>
  
                      <s d="492544"></s>
  
                  </segmenttimeline>
  
              </segmenttemplate>
  
          </representation>
  
          <representation mimetype="audio/mp4" codecs="mp4a.40.2" bandwidth="341000" audiosamplingrate="48000">
  
              <audiochannelconfiguration schemeiduri="urn:mpeg:dash:23003:3:audio_channel_configuration:2011" value="6"></audiochannelconfiguration>
  
              <segmenttemplate timescale="48000" initialization="init-stream$RepresentationID$.m4s" media="chunk-stream$RepresentationID$-$Number%05d$.m4s" startnumber="3">
  
                  <segmenttimeline>
  
                      <s t="772096" d="270336"></s>
  
                      <s d="293888"></s>
  
                      <s d="681984"></s>
  
                      <s d="480256"></s>
  
                      <s d="492544"></s>
  
                  </segmenttimeline>
  
              </segmenttemplate>
  
          </representation>
  
      </adaptationset>
  
  </period>
  
  </mpd>

  The following is the ffmpeg command that i used to generate multi bitrate video

  ffmpeg -y -i sample_video.mp4 ^
  
  -c:v libx264 -x264opts "keyint=24:min-keyint=24:no-scenecut" -r 24 ^
  
  -c:a aac -b:a 128k ^
  
  -bf 1 -b_strategy 0 -sc_threshold 0 -pix_fmt yuv420p ^
  
  -map 0:v:0 -map 0:a:0 -map 0:v:0 -map 0:a:0 -map 0:v:0 -map 0:a:0 ^
  
  -b:v:0 250k  -filter:v:0 "scale=-2:240" -profile:v:0 baseline ^
  
  -b:v:1 750k  -filter:v:1 "scale=-2:480" -profile:v:1 main ^
  
  -b:v:2 1500k -filter:v:2 "scale=-2:720" -profile:v:2 high ^
  
  sample_dash.mp4

  and to generate the mpd file

  ffmpeg -y -re -i sample_dash.mp4 ^
  
  -map 0 ^
  
  -use_timeline 1 -use_template 1 -window_size 5 -adaptation_sets 
  
  "id=0,streams=v id=1,streams=a" ^
  
  -f dash sample_video.mpd

  Also I saw in the chrome network tab that only init-stream4.m4s and init-stream5.m4s was called.

• movenc : use similar logic to DASH when writing bit rate to ISML

  28 septembre 2016, par Jan Ekström

  movenc : use similar logic to DASH when writing bit rate to ISML
  This way, in case of bit rate not being set, max_bitrate will be
  
  used instead. This enables, for example, re-using max_bitrate
  
  information from the input or doing transcoding with a rate
  
  control mode that is not bit rate based.
  Signed-off-by : Jan Ekström <jeebjp@gmail.com>
  
  Signed-off-by : Michael Niedermayer <michael@niedermayer.cc>
  

  • [DH] libavformat/movenc.c