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• ffmpeg use complex_filter only for a part of the video

  7 mars 2019, par Andy P

  I am trying to apply a filter to only the first few seconds of a video clip - and leave the rest of the video unchanged.

  why ?
  I got some video clips that I wanted to put on a website - unfortunatelly those clips are starting with a black background, which does not fit the website’s design. Therefor I was changing the background to transparent.

  I got that filter working from many of the great answers here (thanks to Gyan) and those videos are playing fine in common browsers :

  ffmpeg -i ${1} -filter_complex "[0]split[m][a];
  
  [a]geq='if(lt(lum(X,Y),16),0,255)',hue=s=0[al];
  
  [m][al]alphamerge,format=yuva420p" -c:v libvpx-vp9 -b:v 0 -crf 18 -an -auto-alt-ref 0 ${1}.webm

  the problem now : of course this replaces all black pixels during the video, which leads to many artefacts later on. Therefor I am searching for a way to apply that filter only to the first 5-ish seconds.

  I think I need a second split and a crop or a trim and a concat filter with a timestamp - but I can’t make it work :(

  ffmpeg -i ${1} -filter_complex "[0]split[f][s];
  
  [f]trim=start=0,duration=5[ft];
  
  [s]trim=start=6[st];
  
  [st]split[m][a];
  
  [a]geq='if(lt(lum(X,Y),16),0,255)',hue=s=0[al];
  
  [m][al]alphamerge,format=yuva420p[mal];
  
  [ft][mal]concat" -c:v libvpx-vp9 -b:v 0 -crf 18 -an -auto-alt-ref 0 ${1}.webm

• avfilter/yadif_common : factorize some part of the config_output and the uninit functions

  25 janvier 2024, par Marton Balint

  avfilter/yadif_common : factorize some part of the config_output and the uninit functions
  This unifies slightly diverged code and ensures that cc_fifo is always initialized.
  Signed-off-by : Marton Balint <cus@passwd.hu>
  

  • [DH] libavfilter/vf_bwdif.c
  • [DH] libavfilter/vf_bwdif_cuda.c
  • [DH] libavfilter/vf_bwdif_vulkan.c
  • [DH] libavfilter/vf_yadif.c
  • [DH] libavfilter/vf_yadif_cuda.c
  • [DH] libavfilter/vf_yadif_videotoolbox.m
  • [DH] libavfilter/yadif.h
  • [DH] libavfilter/yadif_common.c

• Adaptive part in MPD using MP4box

  28 janvier 2019, par enigmaVada

  I have used ffmpeg to encode audio and video files of my video sample.mp4 for the dash player. The commands are as follows :

  ffmpeg -i sample.mp4 -s 426x240 -c:v libx264 -b:v 640k -g 90 -an sample_video_240.mp4
  
  ffmpeg -i sample.mp4 -s 480x360 -c:v libx264 -b:v 960k -g 90 -an sample_video_360.mp4
  
  ffmpeg -i sample.mp4 -s 640x480 -c:v libx264 -b:v 1280k -g 90 -an sample_video_480.mp4
  
  ffmpeg -i sample.mp4 -s 1280x720 -c:v libx264 -b:v 2560k -g 90 -an sample_video_720.mp4
  
  
  
  ffmpeg -i sample.mp4 -c:a aac -b:a 128k -vn sample_audio.mp4

  I have generated 240p,360p,480p and 720p videos and audio file.

  Then I have used mp4box to generate the mpd file using the following command :

  mp4box -dash 10000 -rap -profile dashavc264:onDemand -mpd-title BBB -out sample.mpd -frag 5000 sample_audio.mp4 sample_video_240.mp4 sample_video_360.mp4 sample_video_480.mp4 sample_video_720.mp4 

  I am using the dash.js player to play the video. The problem is, the adaptive part of DASH isn’t working. The player is just using the 240p video and not switching to a better format even if proper bandwidth is available. I am checking using the network tab of chrome dev tools.

  What am i doing wrong ? Please help.

  Here is the mpd file for reference :

  <?xml version="1.0"?>
  
  
  
  <mpd xmlns="urn:mpeg:dash:schema:mpd:2011" minbuffertime="PT1.500S" type="static" mediapresentationduration="PT0H1M9.869S" maxsegmentduration="PT0H0M9.985S" profiles="urn:mpeg:dash:profile:isoff-on-demand:2011,http://dashif.org/guidelines/dash264">
  
   <programinformation moreinformationurl="http://gpac.io">
  
    
  
   </programinformation>
  
  
  
   <period duration="PT0H1M9.869S">
  
    <adaptationset segmentalignment="true" lang="und" subsegmentalignment="true" subsegmentstartswithsap="1">
  
     <representation mimetype="audio/mp4" codecs="mp4a.40.2" audiosamplingrate="44100" startwithsap="1" bandwidth="130920">
  
      <audiochannelconfiguration schemeiduri="urn:mpeg:dash:23003:3:audio_channel_configuration:2011" value="2"></audiochannelconfiguration>
  
      <baseurl>sample_audio_dashinit.mp4</baseurl>
  
      <segmentbase indexrangeexact="true" indexrange="902-1017">
  
        <initialization range="0-901"></initialization>
  
      </segmentbase>
  
     </representation>
  
    </adaptationset>
  
    <adaptationset segmentalignment="true" group="1" maxwidth="426" maxheight="240" maxframerate="30" par="426:240" lang="und" subsegmentalignment="true" subsegmentstartswithsap="1">
  
     <representation mimetype="video/mp4" codecs="avc1.640015" width="426" height="240" framerate="30" sar="1:1" startwithsap="1" bandwidth="590708">
  
      <baseurl>sample_video_240_dashinit.mp4</baseurl>
  
      <segmentbase indexrangeexact="true" indexrange="914-1053">
  
        <initialization range="0-913"></initialization>
  
      </segmentbase>
  
     </representation>
  
    </adaptationset>
  
    <adaptationset segmentalignment="true" group="1" maxwidth="640" maxheight="480" maxframerate="30" par="4:3" lang="und" subsegmentalignment="true" subsegmentstartswithsap="1">
  
     <representation mimetype="video/mp4" codecs="avc1.64001E" width="480" height="360" framerate="30" sar="1:1" startwithsap="1" bandwidth="883873">
  
      <baseurl>sample_video_360_dashinit.mp4</baseurl>
  
      <segmentbase indexrangeexact="true" indexrange="914-1053">
  
        <initialization range="0-913"></initialization>
  
      </segmentbase>
  
     </representation>
  
     <representation mimetype="video/mp4" codecs="avc1.64001E" width="640" height="480" framerate="30" sar="1:1" startwithsap="1" bandwidth="1188712">
  
      <baseurl>sample_video_480_dashinit.mp4</baseurl>
  
      <segmentbase indexrangeexact="true" indexrange="913-1052">
  
        <initialization range="0-912"></initialization>
  
      </segmentbase>
  
     </representation>
  
    </adaptationset>
  
    <adaptationset segmentalignment="true" group="1" maxwidth="1280" maxheight="720" maxframerate="30" par="16:9" lang="und" subsegmentalignment="true" subsegmentstartswithsap="1">
  
     <representation mimetype="video/mp4" codecs="avc1.64001F" width="1280" height="720" framerate="30" sar="1:1" startwithsap="1" bandwidth="2365717">
  
      <baseurl>sample_video_720_dashinit.mp4</baseurl>
  
      <segmentbase indexrangeexact="true" indexrange="914-1053">
  
        <initialization range="0-913"></initialization>
  
      </segmentbase>
  
     </representation>
  
    </adaptationset>
  
   </period>
  
  </mpd>