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• How to use argument with dash in name in ffmpeg-python ?

  8 mai 2023, par orderlyfashion

  Following is a simple ffmpeg command line for encoding an input video into a AV1 output with CRF 30 :

  


  ffmpeg -i input.mkv -c:v libsvtav1 -crf 30 output.mkv


  


  Converting that command line into the syntax of ffmpeg-python is pretty straight-forward :

  


  (
    ffmpeg
    .input('input.mkv')
    .output('output.mkv', vcodec='libsvtav1', crf=30)
    .run()
)


  


  However, what happens if we want to specify the fast-decode option ? In ffmpeg that would mean extending our command line to include -svtav1-params fast-decode=1, i.e. :

  


  ffmpeg -i input.mkv -c:v libsvtav1 -crf 30 -svtav1-params fast-decode=1 output.mkv


  


  How do we specify the same thing in ffmpeg-python ? Adding svtav1-params='fast-decode=1' into the output arguments results in invalid Python code since variables are not allowed to have dash in the name :

  


  (
    ffmpeg
    .input('input.mkv')
    .output('output.mkv', vcodec='libsvtav1', crf=30, svtav1-params='fast-decode=1')
    .run()
)
# Error: Expected parameter name


  


  Replacing the dash with an underscore in the name makes ffmpeg-python read it literally which doesn't translate into a valid ffmpeg command line.

  


  How is it possible to specify fast-decode and other svtav1-params specific arguments in ffmpeg-python ?

  


• FFMPEG Mpeg-DASH what attributes options and flags do we need to make H264 playable .mpd universally playable

  22 mars 2021, par Jintor

  I want to encode from any source to a universally playable .mpd with h264 codec.

  


  Here my command

  


  /usr/bin/ffmpeg -re -i 1.webm -c:v libx264 -preset ultrafast 
-tune zerolatency -c:a aac -ac 2 -strict -2 -crf 18 -profile:v baseline 
-maxrate 1000k -pix_fmt yuv420p -flags -global_header -streaming 1 
-use_template 1 -use_timeline 0 -seg_duration 2 -remove_at_exit 1 
-f dash index.mpd


  


  but with dash.js the log says

  


  dash.js videoCodec (video/mp4;codecs="avc1") is not supported.


  


  **EXTRA NOTE : When using -c:v libx264 and output in HLS .m3u8 —> it's working in all browsers

  


  HTML with dash.js

  


  <code class="echappe-js">&lt;script src=&quot;http://cdn.dashjs.org/latest/dash.all.min.js&quot;&gt;&lt;/script&gt;&#xA;    
  &#xA;    &lt;script&gt;&amp;#xA;    (function(){&amp;#xA;        var url = &quot;https://www.---domain--path-to.mpd&quot;;&amp;#xA;        var player = dashjs.MediaPlayer().create();&amp;#xA;        player.initialize(document.querySelector(&quot;#videoPlayer&quot;), url, true);&amp;#xA;player.updateSettings({&amp;#xA;            streaming: {&amp;#xA;                 lowLatencyEnabled: true, &amp;#xA;                 liveDelay: 4,&amp;#xA;                 liveCatchup: {&amp;#xA;                    minDrift: 0.02,&amp;#xA;                    maxDrift: 0,&amp;#xA;                    playbackRate: 0.5,&amp;#xA;                    latencyThreshold: 60    &amp;#xA;                  }&amp;#xA;            }&amp;#xA;        });&amp;#xA;    })();     &amp;#xA;    video = document.getElementById(&quot;videoPlayer&quot;);&amp;#xA;    video.addEventListener(&quot;loadedmetadata&quot;, function(){ video.muted = true; video.play(); }, false);&amp;#xA;    &lt;/script&gt;&#xA;
  

  


  I do have "-c:v libx264" but why dash.js sees avc1... I know that h264 have avc1, but how to fix this. Is it fixing the ffmpeg command or changing the player.initialize in the javascript

  


• Fix writing first audio Cues in dash mode.

  9 octobre 2014, par Frank Galligan

  Fix writing first audio Cues in dash mode.
  In dahsmode Matroska is not writing the first Cluster for every
  
  audio stream in the Cues element.
  Signed-off-by : Frank Galligan <frankgalligan@gmail.com>
  
  Reviewed-by : Vignesh Venkatasubramanian <vigneshv@google.com>
  
  Signed-off-by : Michael Niedermayer <michaelni@gmx.at>
  

  • [DH] libavformat/matroskaenc.c