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• Change keyframe interval losslessly to produce mpeg-dash content

  25 mars 2023, par Eeel

  I have a case where i have a mkv file encoded to a 2.5 GB file with x264/CRF settings, in this file group of pictures are not of equal duration (i.e 2,4 or 6 seconds ...).

  


  Now i want to create a mpeg-dash version of the file by extracting the video track to mp4 and set the keyframe interval to 2sec losslessly preserving size (minus other audio and subtitle tracks)

  


  What i already have that work :

  


  Fix keyframe to 2s with x264 :

  


  -codec:v libx264 -force_key_frames 'expr:gte(t,n_forced*2)' -movflags faststart


  


  But it require also encoding settings that change the quality :

  


  -b:v 3500k -maxrate 6000k -bufsize 3500k


  


  In this case i don't need to change the quality from CRF encoding, just change keyframe interval and set faststart flag.

  


  note :
I have detailed bitrate informations about the file obtained by parsing output of ffprobe : average, min and max bitrate in kb/s.
Please avoid solution using -crf 0, mpeg-dash files are later crypted using MP4Box that crash with CRF encoded files.

  


  How can i do this using ffmpeg ?

  


  Edit :

  


  Sorry my question is not clear, i'm fine with re-encode, i want to preserve quality as much as possible.

  


  Using a little more than source mean bitrate for the -b:v parameter the resulting file size is almost same as source, metric test results are not as good i expect :

  


  PSNR 41.03 (expected 44+)
VMAF 76.32 (expected 92+)


  


  Is my bitrate approch good ? Is there anything i can try to improve metric results ?

  


• DASH package (mpd) I made freezes after raising the onratechange event

  7 mars 2016, par Nick Birke

  I am trying to created an adaptive stream from an mp4 file. I have a decent amount of experience at doing streaming, and have successfully implemented smooth streaming via Silverlight. We want a solution for everything that works in HTML5. I am pursuing DASH. So here are the steps I take...

  1. Resample the mp4 to different sizes using ffmpeg.
  2. Ensure the files are properly fragmented using Bento4s mp4Fragment utility.
  3. Create the DASH mpd file and associated segments using Bento4s mp4dash utility.

  I have done a lot of work to learn each of these utilities and create a process that gets to output that I think will work. To create reliable DASH artifacts. But it seems I am doing something wrong. Here are examples of command lines I run.

  For step one I create three different files... for three different rates and sizes... (these may not be the exact command lines, they are from old notes... but the parameter values are the ones I am using for sure)

  ffmpeg -y -i C:\_SIMULATED_SHARE_C\ff\big_buck_bunny.mp4 -c:v libx264 -x264opts keyint=24:min-keyint=24:no-scenecut -b:v 1500k -maxrate 1500k -bufsize 1000k -vf "scale=-1:720" C:\_SIMULATED_SHARE_C\ff\output\outputfile720.mp4
  
  
  
  ffmpeg -y -i C:\_SIMULATED_SHARE_C\ff\big_buck_bunny.mp4 -c:v libx264 -x264opts keyint=24:min-keyint=24:no-scenecut -b:v 800k -maxrate 800k -bufsize 500k -vf "scale=-1:540" C:\_SIMULATED_SHARE_C\ff\output\outputfile540.mp4
  
  
  
  ffmpeg -y -i C:\_SIMULATED_SHARE_C\ff\big_buck_bunny.mp4 -c:v libx264 -x264opts keyint=24:min-keyint=24:no-scenecut -b:v 400k -maxrate 400k -bufsize 400k -vf "scale=-1:360" C:\_SIMULATED_SHARE_C\ff\output\outputfile360.mp4

  So that gives you the three files that need to be fragmented. So I fragment them using the mp4fragment utility from Bento4. That command line is simple so I will not offer an example.

  The I use Bento4s mp4dash to create the dash. Something like this...

  "E:\\_INSTALL\\Bento4\\Bento4-SDK-1-4-3-607.x86-microsoft-win32-vs2010\\Bento4-SDK-1-4-3-607.x86-microsoft-win32-vs2010\\bin\\mp4dash.exe --mpd-name=\"\\\\d9fqt52\\_SIMULATED_SHARE_C\\ff\\output\\dash\\something.mpd\" -f -o \"\\\\d9fqt52\\_SIMULATED_SHARE_C\\ff\\output\\dash\" \"\\\\d9fqt52\\_SIMULATED_SHARE_C\\ff\\output\\bunny360f.mp4\" \"\\\\d9fqt52\\_SIMULATED_SHARE_C\\ff\\output\\bunny540f.mp4\" \"\\\\d9fqt52\\_SIMULATED_SHARE_C\\ff\\output\\bunny720f.mp4\" "

  This runs ok. And creates the mpd file, an audio folder with segment files, an a video folder with 3 folders each with the segment files.

  I am able to configure IIS to play the mpd ok. As well as the segement files. The video plays fine... and then it stops. It freezes between 50 and 60 seconds. Right before it freezes I can confirm that the onratechange event of the HTML5 video tag is raised. This is an event that is raised with the rate of play is changed. I do nothing to change this it just happens.

  The actual video in question is about 1hr long. Also I am using the dash.js library as a player.

  If you can identify any components or specifics I should change please let me know !

  UPDATE ON MAR 7, 2016

  As requested here is the MPD content...

  <?xml version="1.0" ?>
  
  <mpd mediapresentationduration="PT51M51.909S" minbuffertime="PT0.80S" profiles="urn:mpeg:dash:profile:isoff-live:2011" type="static" xmlns="urn:mpeg:dash:schema:mpd:2011">
  
    
  
    <period>
  
      
  
      <adaptationset lang="en" mimetype="audio/mp4" segmentalignment="true" startwithsap="1">
  
        <segmenttemplate duration="801" initialization="$RepresentationID$/init.mp4" media="$RepresentationID$/seg-$Number$.m4f" startnumber="1" timescale="1000"></segmenttemplate>
  
        <representation audiosamplingrate="48000" bandwidth="132491" codecs="mp4a.40.2">
  
          <audiochannelconfiguration schemeiduri="urn:mpeg:dash:23003:3:audio_channel_configuration:2011" value="2"></audiochannelconfiguration>
  
        </representation>
  
      </adaptationset>
  
      
  
      <adaptationset maxheight="720" maxwidth="1280" mimetype="video/mp4" minheight="540" minwidth="640" segmentalignment="true" startwithsap="1">
  
        <segmenttemplate duration="801" initialization="$RepresentationID$/init.mp4" media="$RepresentationID$/seg-$Number$.m4f" startnumber="1" timescale="1000"></segmenttemplate>
  
        <representation bandwidth="785536" codecs="avc1.64001F" framerate="30000/1001" height="540" scantype="progressive" width="960"></representation>
  
        <representation bandwidth="403537" codecs="avc1.64001E" framerate="30000/1001" height="360" scantype="progressive" width="640"></representation>
  
        <representation bandwidth="1496514" codecs="avc1.64001F" framerate="30000/1001" height="720" scantype="progressive" width="1280"></representation>
  
      </adaptationset>
  
    </period>
  
  </mpd>

  UPDATE ON MAR 7, 2016

  Here is the console output for two different videos that just stop for some unknown reason between 50 and 60s

  ///ABS VIDEO 
  
  
  
  58393][rulesController] [RULES]: playbackTimeRule [Fragment:download,82,MediaSegment,0video] Default 
  
  dash.all.js:11 [58395][rulesController] [RULES]: sameTimeRequestRule [Fragment:download,82,MediaSegment,0,video] Default 
  
  dash.all.js:11 [58401][indexHandler][audio] Getting the request for time: 82.082 
  
  dash.all.js:11 [58403][indexHandler][audio] Index for time 82.082 is 81 
  
  dash.all.js:11 [58405][indexHandler][audio] SegmentTemplate: 81.08099999999999 / 1361.235 
  
  dash.all.js:11 [58406][indexHandler][audio] SegmentTemplate: 82.082 / 1361.235 
  
  dash.all.js:11 [58407][rulesController] [RULES]: playbackTimeRule [Fragment:download,82,MediaSegment,0audio] Default 
  
  dash.all.js:11 [58417][fragmentLoader] loaded video:MediaSegment:82.082 (200, 18ms, 2ms) 
  
  dash.all.js:11 [58419][rulesController] [RULES]: sameTimeRequestRule [Fragment:download,82,MediaSegment,0,audio] Default 
  
  dash.all.js:11 [58435][fragmentLoader] loaded audio:MediaSegment:82.082 (200, 14ms, 0ms) 
  
  dash.all.js:11 [59390][indexHandler][video] Getting the request for time: 83.083 
  
  dash.all.js:11 [59392][indexHandler][video] Index for time 83.083 is 82 
  
  dash.all.js:11 [59393][indexHandler][video] SegmentTemplate: 82.082 / 1361.235 
  
  dash.all.js:11 [59394][indexHandler][video] SegmentTemplate: 83.08299999999998 / 1361.235 
  
  dash.all.js:11 [59395][rulesController] [RULES]: playbackTimeRule [Fragment:download,83,MediaSegment,0video] Default 
  
  dash.all.js:11 [59396][rulesController] [RULES]: sameTimeRequestRule [Fragment:download,83,MediaSegment,0,video] Default 
  
  dash.all.js:11 [59401][indexHandler][audio] Getting the request for time: 83.083 
  
  dash.all.js:11 [59403][indexHandler][audio] Index for time 83.083 is 82 
  
  dash.all.js:11 [59404][indexHandler][audio] SegmentTemplate: 82.082 / 1361.235 
  
  dash.all.js:11 [59406][indexHandler][audio] SegmentTemplate: 83.08299999999998 / 1361.235 
  
  dash.all.js:11 [59408][rulesController] [RULES]: playbackTimeRule [Fragment:download,83,MediaSegment,0audio] Default 
  
  dash.all.js:11 [59416][fragmentLoader] loaded video:MediaSegment:83.08299999999998 (200, 17ms, 1ms) 
  
  dash.all.js:11 [59418][rulesController] [RULES]: sameTimeRequestRule [Fragment:download,83,MediaSegment,0,audio] Default 
  
  dash.all.js:11 [59437][fragmentLoader] loaded audio:MediaSegment:83.08299999999998 (200, 14ms, 1ms) 
  
  dash.all.js:11 [59902][scheduleController][video] Stalling Buffer 
  
  dash.all.js:11 [59903][bufferController][video] Waiting for more buffer before starting playback. 
  
  dash.all.js:11 [59906][scheduleController][audio] Stalling Buffer 
  
  dash.all.js:11 [59907][bufferController][audio] Waiting for more buffer before starting playback. 
  
  dash.all.js:11 [63684][playbackController] <video> ratechange:  0 
  
  
  
  
  
  
  
  
  
  ///HOG VIDEO
  
  
  
  [58250][rulesController] [RULES]: playbackTimeRule [Fragment:download,105,MediaSegment,0audio] Default 
  
  dash.all.js:11 [58266][fragmentLoader] loaded video:MediaSegment:84.105 (200, 28ms, 1ms) 
  
  dash.all.js:11 [58269][rulesController] [RULES]: sameTimeRequestRule [Fragment:download,105,MediaSegment,0,audio] Default 
  
  dash.all.js:11 [58287][fragmentLoader] loaded audio:MediaSegment:84.105 (200, 14ms, 1ms) 
  
  dash.all.js:11 [58982][indexHandler][video] Getting the request for time: 84.906 
  
  dash.all.js:11 [58983][indexHandler][video] Index for time 84.906 is 105 
  
  dash.all.js:11 [58984][indexHandler][video] SegmentTemplate: 84.105 / 3111.909 
  
  dash.all.js:11 [58984][indexHandler][video] SegmentTemplate: 84.906 / 3111.909 
  
  dash.all.js:11 [58985][rulesController] [RULES]: playbackTimeRule [Fragment:download,106,MediaSegment,0video] Default 
  
  dash.all.js:11 [58986][rulesController] [RULES]: sameTimeRequestRule [Fragment:download,106,MediaSegment,0,video] Default 
  
  dash.all.js:11 [58989][indexHandler][audio] Getting the request for time: 84.906 
  
  dash.all.js:11 [58990][indexHandler][audio] Index for time 84.906 is 105 
  
  dash.all.js:11 [58991][indexHandler][audio] SegmentTemplate: 84.105 / 3111.909 
  
  dash.all.js:11 [58992][indexHandler][audio] SegmentTemplate: 84.906 / 3111.909 
  
  dash.all.js:11 [58993][rulesController] [RULES]: playbackTimeRule [Fragment:download,106,MediaSegment,0audio] Default 
  
  dash.all.js:11 [59002][fragmentLoader] loaded video:MediaSegment:84.906 (200, 14ms, 1ms) 
  
  dash.all.js:11 [59003][rulesController] [RULES]: sameTimeRequestRule [Fragment:download,106,MediaSegment,0,audio] Default 
  
  dash.all.js:11 [59014][fragmentLoader] loaded audio:MediaSegment:84.906 (200, 8ms, 1ms) 
  
  dash.all.js:11 [59735][scheduleController][video] Stalling Buffer 
  
  dash.all.js:11 [59736][bufferController][video] Waiting for more buffer before starting playback. 
  
  dash.all.js:11 [59738][scheduleController][audio] Stalling Buffer 
  
  dash.all.js:11 [59739][bufferController][audio] Waiting for more buffer before starting playback. 
  
  dash.all.js:11 [61695][playbackController] <video> ratechange:  0 
  
  </video></video>

• FFMPEG ldash 1 low latency option but dash.js not low latency and buggy with lag and start always at 0 cannot control

  7 avril 2021, par Jintor

  I can't figure out how to fix this. playing a supposed low latency mpeg-dash manifest but it's with lots of lag, and play-stop-wait-play-stop-wait....

  


  I have latest ubuntu with latest ffmpeg

  


  here the command

  


  ffmpeg -re -i file.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 -bufsize 969k -ldash 1 -streaming 1 -use_template 0 -use_timeline 1 -seg_duration 1 -remove_at_exit 0 -f dash index.mpd


  


  and player side

  


  <code class="echappe-js">&lt;script src='http://stackoverflow.com/templates/account_js/dashjs/dash.3.1.0.min.js'&gt;&lt;/script&gt;&#xA;    
  &#xA;    &lt;script&gt;&amp;#xA;    (function(){&amp;#xA;        var url = &quot;index.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: 3,&amp;#xA;                 liveCatchup: {&amp;#xA;                    enabled: true,&amp;#xA;                    minDrift: 0.05,&amp;#xA;                    maxDrift: 0,&amp;#xA;                    playbackRate: 0.5,&amp;#xA;                    latencyThreshold: 30    &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;
  

  


  but it's NOT low latency, It forces to start at 0 and cannot control the video

  


  is there a better config setup and what need to be fixed : ffmpeg options or dash.js config