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• Creating a convertAll() function that converts all .filetype in working directory

  5 janvier 2019, par Risviltsov

  I seem to not know proper bash syntax ; despite this, I’ve tried to create a tool that changes the dimensions of all files of a ffmpeg-accepted filetype in the working directory and converts it to another ffmpeg-accepted filetype. In this instance, this tool converts all .webm files over 1080x720 into 1080x-1 or -1x720 .mp4 files. If the .webm file is under 1080x720, the new .mp4 file will have the same dimensions.

  However, there’s a wrench in the tool.

  convertAll () {
  
  local wantedWidth = 1080
  
  local wantedHeight = 720
  
  for i in *.webm; do
  
  local newWidth = $i.width
  
  local newHeight = $i.height
  
  until [$newWidth <= $wantedWidth && $newHeight <= $wantedHeight]; do
  
  if [$videoWidth > $wantedWidth]; then
  
  newHeight = $newWidth*($wantedWidth/$newWidth)
  
  newWidth = $newWidth*($wantedWidth/$newWidth)
  
  fi
  
  if [$videoHeight > $wantedHeight]; then
  
  newWidth = $newWidth*($wantedHeight/$newHeight)
  
  newHeight = $newHeight*($wantedHeight/$newHeight)
  
  fi
  
  done
  
  ffmpeg -i "$i" -vf scale=$newWidth:$newHeight "${i%.*}.mp4";
  
  done
  
  echo "All files have been converted."
  
  }

  What this returns is a bunch of lines that look like this :

  bash: [: missing ']'
  
  bash: [: missing ']'
  
  bash: =: No such file or directory

  My best guess is that BASH can’t do mathematics, and that I’m declaring and editing my variables incorrectly.

  I’d like some input on this --- my lack of experience is really getting me here.

• Revision 8d7f53f04c : Account for rate error in GF group Q calculation. When GF group adaptive maxQ i

  20 février 2015, par paulwilkins

  Changed Paths :
   Modify /vp9/encoder/vp9_firstpass.c

  
   Modify /vp9/vp9_cx_iface.c

  
  
  Account for rate error in GF group Q calculation.

  When GF group adaptive maxQ is enabled this patch accounts
  somewhat for accumulated error in the rate control.

  This improves accuracy quite a bit on many clips especially
  when there is overshoot.

  Examples when the overshoot and undershoot command line
  parameters are set to 100 :

  Hall @ 1200 overshoot is reduced from 67-24%.
  Akiyo @ 400 undershoot is reduced from 28%-15%.

  Setting a lower value for undershoot or overshoot still
  reduces the error further.

  Impact on metrics is mixed with some gains in average psnr
  but generally a little lower (e.g. 0.5%) on overall and ssim.

  The GF group adaptation is still off by default in this patch.
  Compared to with the head, enabling this mode now gives
  big average psnr gains on the YT sets (e.g. YT_HD >11.2%),
  a drop in overall PSNR (YT-HD 3.9%) and a smaller drop or
  neutral for SSIM.

  Change-Id : If4b32cd0740d3fb941317b374f9c2951954eee90

• Suggestion query : Someone should add 'percent-complete' to ffmpeg's status line

  19 février 2018, par Dave

  I use the PC-platform’s ffmpeg (on Windows and Linux). I’ve always
  wondered why, down on that bottom dynamic status line, it does NOT
  show a ’percent-complete’ value.

  e.g. There’s already a line showing what time-line value is being worked
  on, so I’d expect it would be straight-forward to grab total duration, compute percent-complete, and show it, right after the running time value. Or,
  if based on frames, then show it in parentheses after the frame value.

  The reason I think it would be straight-forward is because I see it
  discussed in detail, for ffmpeg on Android, here :
  How to add progress bar to FFMPEG android
  and it talks about time-values and frame-count based calculations.

  Any volunteers to tackle this ? ^ ;)