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• FFmpeg : How do i use this script to concatenate incoming segments

  5 juillet 2017, par NGage

  I’d like to use this script but i don’t know how it should be applied. I was going to use it for encoding tv-shows and be able to start encoding as i had cut out the first segment.

  According to the ffmpeg-wiki (where i found the script) it says : "Concatenation becomes troublesome, if next clip for concatenation does not exist at the moment, because decoding won’t start until the whole list is read. However, it is possible to refer another list at the end of the current list :"

  Bear in mind that i dont know to much about bash

  #!/bin/bash
  
  
  
  fn_concat_init() {
  
  echo "fn_concat_init"
  
  concat_pls=`mktemp -u -p . concat.XXXXXXXXXX.txt`
  
  concat_pls="${concat_pls#./}"
  
  echo "concat_pls=${concat_pls:?}"
  
  mkfifo "${concat_pls:?}"
  
  echo
  
  }
  
  
  
  fn_concat_feed() {
  
  echo "fn_concat_feed ${1:?}"
  
  {
  
      >&2 echo "removing ${concat_pls:?}"
  
      rm "${concat_pls:?}"
  
      concat_pls=
  
      >&2 fn_concat_init
  
      echo 'ffconcat version 1.0'
  
      echo "file '${1:?}'"
  
      echo "file '${concat_pls:?}'"
  
  } >"${concat_pls:?}"
  
  echo
  
  }
  
  
  
  fn_concat_end() {
  
  echo "fn_concat_end"
  
  {
  
      >&2 echo "removing ${concat_pls:?}"
  
      rm "${concat_pls:?}"
  
      # not writing header.
  
  } >"${concat_pls:?}"
  
  echo
  
  }
  
  
  
  fn_concat_init
  
  
  
  echo "launching ffmpeg ... all.mkv"
  
  timeout 60s ffmpeg -y -re -loglevel warning -i "${concat_pls:?}" -pix_fmt 
  
  yuv422p all.mkv &
  
  
  
  ffplaypid=$!
  
  
  
  
  
  echo "generating some test data..."
  
  i=0; for c in red yellow green blue; do
  
  ffmpeg -loglevel warning -y -f lavfi -i testsrc=s=720x576:r=12:d=4 -pix_fmt 
  
  yuv422p -vf "drawbox=w=50:h=w:t=w:c=${c:?}" test$i.mkv
  
  fn_concat_feed test$i.mkv
  
  ((i++));
  
  echo
  
  done
  
  echo "done"
  
  
  
  fn_concat_end
  
  
  
  wait "${ffplaypid:?}"
  
  
  
  echo "done encoding all.mkv"

• dds : Fix palette decoding

  21 juillet 2015, par Vittorio Giovara

  dds : Fix palette decoding
  Red and blue channels were decoded in the wrong order.
  Found-By : ami_stuff
  

  • [DH] libavcodec/dds.c
  • [DH] tests/ref/fate/dds-pal
  • [DH] tests/ref/fate/dds-pal-ati

• FFMPEG - why zoompan causes unexpected stretching ?

  14 septembre 2020, par Sarmad S.

  I have two images as input, both are 1600x1066. I am vertically stacking them. Then I am drawing a box and vertically stacking that box under both of the image. Inside of the box I write text, then I output a video that is 1080x1920. Everything works well, until I use zoompan to zoom in on the images, I get weird behavior. basically all input images including the box stretchs (shrink) vertically and no longer fit the entire height of the video which is 1920.

  


  The command (removed some drawtext commands from it) :

  


  -filter_complex 
"color=s=1600x1066:color=blue, drawtext=fontfile=font.otf: text='My Text':fontcolor=white: fontsize=30: x=50: y=50[box]; 
[0]scale=4000x4000,zoompan=z='min(zoom+0.0015,1.5)':x='iw/2-(iw/zoom/2)':y='ih/2-(ih/zoom/2)':d=125:s=1600x1066[z0];
[1]scale=4000x4000,zoompan=z='min(zoom+0.0015,1.5)':x='iw/2-(iw/zoom/2)':y='ih/2-(ih/zoom/2)':d=125:s=1600x1066[z1];
[z0][z1][box]vstack=inputs=3"


  


  How do I fix this ? I want to zoom in without stretching the images

  


  Before using zoompan this is how the video looks like (I want to keep it this way while zooming in the images) :


  


  After using zoompan this is how the video looks like :