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• What video codecs work on Google Chromebook

  3 mars 2019, par MonkeyDLuffy

  I’m trying to put a show on my friends Google Chromebook but the mp4 files show up black when trying to watch them on said Chromebook, audio works fine. I found out that it is a video encoding problem but I cannot find a list of video formats that work on the Chromebook. I have ffmpeg and handbrake to try and test some things, but if someone could tell me a ffmpeg code that will convert the video files into a format that works on a Google Chromebook that would help a lot.

  What I’ve tried :

  ffmpeg -i "Game of Thrones S02E01 The North Remembers.mkv" codec mpeg "Game of Thrones S02E01 The North Remembers.mp4"

  Which gives error :

  [NULL @ 00000177196ea500] Unable to find a suitable output format for
  ’codec’ codec : Invalid argument

• 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.

• FFmpeg version 4.0.1 cannot find h264 encoder

  3 juillet 2018, par Cristiano

  Today I updated FFmpeg to version 4.0.1 and my existing project cannot compile anymore. In particular avcodec_find_encoder(AV_CODEC_ID_H264) always returns null. I tried to reinstall the libx264 but nothing changed.
  I also tried to call avcodec_find_encoder_by_name("libx264") and it works, but avcodec_open2() returns error.