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• failed to read iv from the auxiliary info

  9 décembre 2017, par diS

  Passing encryption key and kid to mp4 muxer to encrypt the dash segments. With ffmpeg command generating dash single file for playback. But when I play using ffplay I see failed to read the IV from auxiliary info

  ffmpeg -y -f mp4 -i SampleVideo_1280x720_20mb.mp4 -map 0:v:0 -c copy -f dash -encryption_scheme cenc-aes-ctr -encryption_key <key> -encryption_kid <kid> -min_seg_duration 4000000 -use_timeline 1 -use_template 1 -single_file 1 ./enc.mpd
  
  
  
  ffplay enc-stream0.m4s -decryption_key <key>
  
  </key></kid></key>

  I get the error

  [mov,mp4,m4a,3gp,3g2,mj2 @ 0x7fa3040008c0] failed to read iv from the
  auxiliary info

  On side note : don not see playback error when single file generated using mp4 muxer alone. Any inputs ? thanks...

• Parse dynamic mpd file with Media Source Extensions

  17 février 2023, par FrankC

  I just started learning about adaptive streaming, and currently I'm working on a project that needs showing a live video. In order to control some of the elements in mpd file, I determined to use MSE instead of dash.js. I refer to the code at the following URL :https://learn.microsoft.com/en-us/previous-versions/windows/internet-explorer/ie-developer/samples/dn551368(v=vs.85)
But I found out that there is no "Initialization" tag or "range" attribute in my mpd file. I don't find any relative attribute as well. By the way I'm use nginx-rtmp + ffmpeg to generate dash file.
So here is my dash file looks like

  


  &lt;?xml version="1.0"?>&#xA; &#xA;  <period start="PT0S">&#xA;    &#xA;      &#xA;        &#xA;          <segmenttimeline>&#xA;             <s t="0" d="10000"></s>&#xA;             <s t="10000" d="10000"></s>&#xA;             <s t="20000" d="5000"></s>&#xA;             <s t="25000" d="10000"></s>&#xA;          </segmenttimeline>&#xA;        &#xA;      &#xA;    &#xA;  </period>&#xA;&#xA;

  


  My question is :
1.Did I have any missing parameters in using ffmpeg or nginx-rtmp resulting in losting tag in mpd file ?
2.Or there is other way to setup "Initialization"/"range" attribute and let my program work ?
3.I also curious about why my mpd file doesn't have a baseURL element ?

  


  ※My mpd file works fine with dash.js, I can see the video properly

  


  THANKS A LOT

  


• Replacing one segment of fragmented mp4

  24 mai 2023, par Stsh4lson

  I created mpeg-dash stream with fragmented mp4 stream with init.m4a and .m4s segments using following command :

  


  ffmpeg -i $1 -c:v h264_nvenc -c:a aac -g 100 \
    -sc_threshold 0 -reset_timestamps 1 -an -map v:0 -s:0 1920x1080 \
    -profile:v baseline -level:v 5.0 -streaming 1 \
    -s:1 1920x1080 -use_template 1 -use_timeline 0 \
    -seg_duration 4 -frag_duration 1 -frag_type duration -pix_fmt yuv420p \
    -f dash $2


  


  I also generated second mpeg-dash vod with same ffmpeg command and i want to replace some segments in the first video with segments form second video.
When i just replace segments manually the video is frozen at that segment.

  


  Additionally when i replace segments that are in the same timestamp, i replace segment no.1 with segment no.1 etc. everything works fine.
Segments that are replaces with different segments from the same videos are also freezing.

  


  And when i do cat init_stream0.m4s chunk_segment0001.m4s chunk_segment0003.m4s > combined.mp4, constructed video has 12 seconds in player with missing video from 4s to 8s.

  


  I suspect that there is some timeline information in segments but i can find no information about structure of those m4s segments, and h264 has suposedly no timeline information.

  


  Do .m4s fragments in mpeg-dash have some internal timestamp information, and can i overwrite/replace this timestamp info ?