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• FFMPEG (WINDOWS) - Jerky Videos with vidstabdetect & vidstabtransform

  26 avril 2016, par Onish Mistry

  I require to stabilize multiple video clips and finally stitch all the clips, along with images into one final video. These "Scenes" consisting video clips as well as images also can have overlays like Texts and/or other Images.

  Basically the code I have in place as of now does everything for me just fine, where all the video clips are first converted into frame images. It then reads all the frames, puts on the overlays, adds a fade transition in-between "Scenes".

  Coming to the issue I am facing with stabilization, when I extract image frames out of the stabilized video clip and simply try to recreate video from those extracted image frames, it comes out with a weird jerk, almost like as if it is missing those stabilization calculations or something, not sure. It still looks a bit stabilized but with missing frames. I have checked duration and number of frames extracted, everything matches with the source, non-stabilized video.

  Below is the command used to stabilize the video, result of which is a perfectly stabilized video.

  ffmpeg -i 1.MOV -r 30 -vf vidstabdetect=result="transforms.trf" -f null NUL && ffmpeg -i 1.MOV -r 30 -vf vidstabtransform=smoothing=30:input="transforms.trf" -vcodec libx264 -b:v 2000k -f mp4 results.mp4

  Below is the command I use for video to image :

  ffmpeg -i results.mp4 -r 30 -qscale 1 -f image2 %d.jpg

  Below is the command I use for image to video :

  ffmpeg -i %d.jpg -r 30 -vcodec libx264 -b:v 2000k -f mp4 final.mp4

  Any help or suggestions are welcomed and appreciated.

  Thanks,

• Android and ffmpeg, x264 bitrate and videosize

  11 décembre 2012, par brux

  I am concatenating two mp4 files by first converting them to mpeg, once I have concatenated the mpegs I want to produce a final larger mp4.

  The following code works fine in order to produce the mpegs

  ffmpeg -i one.mp4 -q:v 2 -vcodec mpeg2video -acodec copy one.mpg
  
  
  
  
  
  
  
  ffmpeg -i two.mp4 -q:v 2 -vcodec mpeg2video -acodec copy two.mpg

  After concatenating these 2 files (using java) I produce the final mp4 like this :

  ffmpeg -i joined.mpg -vcodec libx264 -acodec copy joined.mp4

  The command works and a low quality mp4 is produced since I am not specifying a 'bitrate' or 'videosize' in the MediaRecorder class object.

  Here are the settings I use on my MediaRecorder object when encoding the video in Android

          mediaRecorder.setAudioSource(MediaRecorder.AudioSource.CAMCORDER);
  
          mediaRecorder.setVideoSource(MediaRecorder.VideoSource.CAMERA);
  
          mediaRecorder.setOutputFormat(MediaRecorder.OutputFormat.MPEG_4);
  
          mediaRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
  
          mediaRecorder.setVideoEncoder(MediaRecorder.VideoEncoder.H264);

  if I add the following two lines in order to increase the bitrate and videosize of one.mp4 and two.mp4 then the resultant mp4's playback fine using the default player on android, but after converting to mpg and then concatenating and then using the above ffmpeg command to encode a new mp4, th resultant joined.mp4 is less quality than the original mp4's are started out with (one.mp4 and two.mp4)

          mediaRecorder.setVideoEncodingBitRate(2000000);
  
          mediaRecorder.setVideoSize(800, 480);

  Do i need to add more parameters to my ffmpeg commands in order to do this successfully ?

• Révision 24162 : Ticket #4245 : Correction empêchant la création de certains répertoires, s’ils on...

  11 décembre 2018, par marcimat@rezo.net

  À partir de SPIP 3.3-dev, on supprime la gestion de la constante _CREER_DIR_PLAT de la fonction `sous_repertoire` ; on tolère un _ final sur les noms de répertoires à créer.

  Corrige, entre autres un bug dans le plugin Bigup empêchant la réception de certains fichiers.