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• Metal Gear Solid VP3 Easter Egg

  4 août 2011, par Multimedia Mike — Game Hacking

  Metal Gear Solid : The Twin Snakes for the Nintendo GameCube is very heavy on the cutscenes. Most of them are animated in real-time but there are a bunch of clips — normally of a more photo-realistic nature — that the developers needed to compress using a conventional video codec. What did they decide to use for this task ? On2 VP3 (forerunner of Theora) in a custom transport format. This is only the second game I have seen in the wild that uses pure On2 VP3 (first was a horse game). Reimar and I sorted out most of the details sometime ago. I sat down today and wrote a FFmpeg / Libav demuxer for the format, mostly to prove to myself that I still could.

  Things went pretty smoothly. We suspected that there was an integer field that indicated the frame rate, but 18 fps is a bit strange. I kept fixating on a header field that read 0x41F00000. Where have I seen that number before ? Oh, of course — it’s the number 30.0 expressed as an IEEE 32-bit float. The 4XM format pulled the same trick.

  Hexadecimal Easter Egg
  I know I finished the game years ago but I really can’t recall any of the clips present in the samples directory. The file mgs1-60.vp3 contains a computer screen granting the player access and illustrates this with a hexdump. It looks something like this :

  
  
  

  Funny, there are only 22 bytes on a line when there should be 32 according to the offsets. But, leave it to me to try to figure out what the file type is, regardless. I squinted and copied the first 22 bytes into a file :

   1F 8B 08 00   85 E2 17 38   00 03 EC 3A   0D 78 54 D5
   38 00 03 EC   3A 0D
  

  And the answer to the big question :

  $ file mgsfile
  mgsfile : gzip compressed data, from Unix, last modified : Wed Oct 27 22:43:33 1999
  

  A gzip’d file from 1999. I don’t know why I find this stuff so interesting, but I do. I guess it’s no more and less strange than writing playback systems like this.

• How to add Overlay/Watermark Text opacity or transparency by FFmpeg ?

  28 novembre 2022, par ujjally

  I want to add overlay/watermark text into video with custom opacity or transparency like 50%(0.5) and 80%(0.8)

  


  I tried the below code but the opacity color automatically set to black.

  


  ffmpeg -i video.mp4 -vf drawtext="fontfile='C\:/Users/BRIGHT/AppData/Local/Microsoft/WINDOWS/fonts/RacingSansOne-Regular.ttf':text='YouTube.com':fontsize=h/15:fontcolor=yellow@0.5:bordercolor=white:borderw=1:y=(h-text_h*24):x=(mod(-0.5*n\,w+tw)-tw)" -codec:a copy output.mp4


  


• SpipMotion - Surveiller les encodages

  3 juin 2010

  Il faut notifier les utilisateurs (et peut être les admins) :

  • lors de la réussite de l’encodage
  • lorsque l’encodage se révèle impossible (essais de X fois)

  Il faut stopper les tentatives d’encodages qui échouent plus de X fois et envoyer un email aux admins afin qu’ils puissent débugguer

  Il faut vérifier périodiquement que la file d’attente ne soit pas bloquées

  Ajouter des appels au journal (fonction du plugin bigbrother ou de SPIP 2.2) pour loguer correctement les encodages