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• FFMPEG reports different (wrong) video resolution compared to how it actually plays

  30 mars 2015, par Emiliano

  Quick question, i have a movie, which was cut and rendered with Sony Vegas from its original format to a .wmv file. Here comes the tricky part, movie when played, either with VLC or WMP, has a resolution of 656x480 ... BUT when i run a ffmpeg -i on it, it says it has a resolution of 600x480 ....

  I took the time of actually capturing a frame and croping it with photoshop and its 656 and not 600 like ffmpeg its reporting, why would this could be happening ? How could i fix the headers resolution ? Would that have any impact on video re-rendering ? As i said, VLC and WMP seems not to care about the incorrect headers and are playing it right, BUT, jwplayer seems to be using the header information, which i don’t blame him, its correct to do that, but why the video headers could be wrong ?

  ffmpeg -i trailer.wmv

  Input #0, asf, from ’trailer.wmv’ :
  Duration : 00:01:04.93, start : 3.000000, bitrate : 2144 kb/s
  Stream #0.0 : Audio : wmav2, 44100 Hz, mono, 32 kb/s
  Stream #0.1 : Video : wmv3, yuv420p, 600x480 [PAR 59:54 DAR 295:216], 2065 kb/
  s, 25.00 tb(r)

  And yeah, the PAR/DAR parameters are also wrong, but honestly, i don’t understand that technical shit, usually watch video and make sure it look good, any feedback would be appreciated :P

  Is there a way to change the container information with ffmpeg so applications that actually do use the container information don’t render video incorrectly ?

• How to increase resolution in ffmpeg with rawvideo [closed]

  2 novembre 2020, par Jamie Hutber

  I am using my DSLR with loopback to use as a webcam, however the resolution is locked at 640x426 and I cannot seem to find a way to make this larger as the stream itself is 1080p from the camera.

  


  sudo modprobe v4l2loopback video_nr=2 exclusive_caps=1,1,1 card_label='Screenshare' && gphoto2 --stdout --capture-movie | ffmpeg -i - -vcodec rawvideo -pix_fmt yuv420p -threads 0 -f v4l2 /dev/video2


  


• check media resolution, if resolution is big ffmpeg it, if output is smaller than original delete the original else delete the output

  13 avril 2015, par The Wolf

  I have my storage VPS filled with videos, and hoping I can free up some space, their resolution is pretty big so I decided to re encode them with ffmpeg to a smaller resolution, I am doing every thing manually, first I check using mediainfo test5.mkv the resolution

  ...
  
  Width                                    : 1 280 pixels
  
  ...

  if the width is greater than 720 pixels I issue the following command :

  ffmpeg -i 'test5.mkv' -vf scale=720:-2 -acodec copy -vcodec libx264 -scodec copy -threads 12 -crf 28 -x264-params keyint=240:min-keyint=20 -preset:v slow '[Encoded] test5.mkv'

  then after that I delete the original video if the output has smaller size than the original

  I am hoping there is a script that can automate this, like I will run on a directory then, it will look for all .mkv to subdirectories recursively to perform this checks and actions. How to do this ?

  Also, I am worried that it could fail if I reach automation, since there are special characters in the video’s name of some like single quotes, double quotes, or `, so I will it can be escaped properly.

  Thanks !

  After some google I ended up with the following snippet, I am worried if this is enough, but I’m afraid to run it since I am not sure if it would damage my unix

  #!/bin/sh
  
  
  
  for file in *.{mkv}; do
  
  target="[720p]-${file%.*}.mkv"
  
  [[ -f "$target" ]] && { echo "skipping $file - $target exists" ; continue; }
  
  
  
  
  
  eval $(ffprobe -v error -of flat=s=_ -select_streams v:0 -show_entries stream=height,width "$file")
  
  size=${streams_stream_0_width}x${streams_stream_0_height}
  
  if [ "$streams_stream_0_width" -ge 720 ]; then
  
  echo ffmpeg -i "$file" -vf scale=720:-2 -acodec copy -vcodec libx264 -scodec copy -threads 12 -crf 28 -x264-params keyint=240:min-keyint=20 -preset:v slow "$target"
  
  
  
  fi
  
  done

  can somebody please tell me if my snippet should work ?

  UPDATE

  as it turns out if [ "$streams_stream_0_width" -ge 720 ]; then fails because the width is not integer ? line 10: [: : integer expression expected I am not sure why it is not integer, how can I make it integer ?