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• Use FFMPEG to generate MPD files for MPEG-DASH adaptive streaming

  9 octobre 2020, par CMOS

  So I am trying to setup adaptive streaming and I have what I think is 80-90% of the problem finished. Right now I ingest my source video, transcode it into 5 resolutions each with 3 bitrates (low, medium, high) and then I split all of those videos into 5 second chunks so that the user can always have the best viewing possible. Now I am at the point where I need to generate / create my MPD manifest file and I am having a hard time figuring out how. Almost everyone just says to use MP4Box but their license is too restrictive for my project.

  



  Is there anyway to generate a MPD file using FFMPEG when I segment my video ? or maybe generate a HLS that I can then convert into a MPD manifest ? Any info would be awesome, this is my current FFMPEG command (working)

  



  Note the $ variables are inputs into a bash script that set the input file, bitrate and scale.

  



  /usr/bin/ffmpeg \
  -re \
  -i $1 \
  -an \
  -c:v libx264 \
  -b:v $7 \
  -b:a 196k \
  -strict -2 \
  -movflags faststart \
  -pix_fmt yuv420p \
  -vf "scale='$4:trunc(ow/a/2)*2'" \
  -flags -global_header \
  -map 0 \
  -f segment \
  -segment_time 5 \
  -segment_list test.m3u8 \
  -segment_format mpegts \
  $2%05d.mp4


  


• ffmpeg : Concatenating videos with different codecs, sizes and formats [duplicate]

  10 juillet 2021, par Hitman47

  I am looking to concatenate a list of videos using ffmpeg that are of different sources, but the audio always goes out of sync and sometimes the playback speed goes wild.

  


  Even in the case of preconverting them separately to the same codec/size/frame rate, then trying to mux them together with codec copy, i get the same issues, so it must be something about mapping or timings.

  


  I am using the following parameters

  


  ffmpeg -f concat -safe 0 -i list.txt -map_metadata -1 -vf scale=480x270 -c:v libx265 -preset ultrafast -flags2 "fast" -vb 150k -max_interleave_delta 0 -r 22 -c:a opus -ab 30k -ac 1 -strict -2 -x265-params "--pmode --pme --ctu=32 --merange=20" output.mkv


  


  I have tried -max_interleave_delta 0 and disabling the experimental 'opus' codec and the nonstandard -flags2 "fast". The result is still broken

  


  These are the warnings i get in the output :
[mov,mp4,m4a,3gp,3g2,mj2 @ 0x561090282280] Auto-inserting h264_mp4toannexb bitstream filter [concat @ 0x56108d88f400] DTS 1498384 < 4488000 out of order

  


  If this is very hard to pull off, would you suggest using something other than ffmpeg ?

  


• ffmpeg determine frame number for fade filter

  16 juin 2016, par Gert Gottschalk

  I am looking for an easy way to set the time points for the fade filter. Particularly for the fade-out at the end. At best would be a time based format. I understand the fade filter works based on frames. But is there a way to change that to time stamp ? Particularly in the end I have a hard time getting the number of the last frame. Some means to tell the fade filter to start the fade 0.5sec before the end would be awesome. Maybe something like :

  -filter:v 'fade=out:-0.5:0.3'

  Read : ’start fade out 0.5sec before end and have fade take 0.3sec. I.e. have 0.2sec of black at the end.

  I would also be OK if this would be in frame number counts.

  My grief right now is that the frame count i.e. reported by ffprobe seems to be somewhat half of what it really is. A fade filter applied on the count provided by ffprobe turn my video to black about half-way through the clip. I’m not sure what I’m missing there.

  Again my primary question is : How to determine the correct frame number for the fade out filter ?

  Thanks,
  Gert