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• Are there any resources listing current codecs and formats not supported by FFmpeg ?

  4 mars 2020, par Alexander Swann

  We are building a service where we do not know what format/codec a video uploaded by a user is in. Due to the nature of the application, we expect input video formats to be very fragmented, diverse and niche. We are currently using FFmpeg to transcode input formats to a consistent output (e.g. mp4).

  Due to the above scenario, I would like to establish a general list of what formats and codecs are not currently supported by FFmpeg. This is so I can research other open source video transcoding tools which I can utilise to fill in the gaps and allow our service to be more reliable for the user.

  Are there resources online that can help at least get a general idea of what might not be supported by FFmpeg ?

• What are all the codecs and formats not supported by FFmpeg ?

  4 mars 2020, par Alexander Swann

  We are building a service where we do not know what format/codec a video uploaded by a user is in. Due to the nature of the application, we expect input video formats to be very fragmented, diverse and niche. We are currently using FFmpeg to transcode input formats to a consistent output (e.g. mp4).

  Due to the above scenario, I would like to establish a general list of what formats and codecs are not currently supported by FFmpeg. This is so I can research other open source video transcoding tools which I can utilise to fill in the gaps and allow our service to be more reliable for the user.

  Are there resources online that can help at least get a general idea of what might not be supported by FFmpeg ?

• Brute Force Dimensional Analysis

  15 juillet 2010, par Multimedia Mike — Game Hacking, Python

  I was poking at the data files of a really bad (is there any other kind ?) interactive movie video game known simply by one letter : D. The Sega Saturn version of the game is comprised primarily of Sega FILM/CPK files, about which I wrote the book. The second most prolific file type bears the extension ’.dg2’. Cursory examination of sample files revealed an apparently headerless format. Many of the video files are 288x144 in resolution. Multiplying that width by that height and then doubling it (as in, 2 bytes/pixel) yields 82944, which happens to be the size of a number of these DG2 files. Now, if only I had a tool that could take a suspected raw RGB file and convert it to a more standard image format.

  Here’s the FFmpeg conversion recipe I used :

   ffmpeg -f rawvideo -pix_fmt rgb555 -s 288x144 -i raw_file -y output.png
  

  So that covers the files that are suspected to be 288x144 in dimension. But what about other file sizes ? My brute force approach was to try all possible dimensions that would yield a particular file size. The Python code for performing this operation is listed at the end of this post.

  It’s interesting to view the progression as the script compresses to different sizes :

  
  
  

  That ’D’ is supposed to be red. So right away, we see that rgb555(le) is not the correct input format. Annoyingly, FFmpeg cannot handle rgb555be as a raw input format. But this little project worked well enough as a proof of concept.

  If you want to toy around with these files (and I know you do), I have uploaded a selection at : http://multimedia.cx/dg2/.

  Here is my quick Python script for converting one of these files to every acceptable resolution.

  work-out-resolution.py :
  

  PLAIN TEXT

  PYTHON :

  1. # !/usr/bin/python
  2.  
  3. import commands
  4. import math
  5. import os
  6. import sys
  7.  
  8. FFMPEG = "/path/to/ffmpeg"
  9.  
  10. def convert_file(width, height, filename) :
  11.  outfile = "%s-%dx%d.png" % (filename, width, height)
  12.  command = "%s -f rawvideo -pix_fmt rgb555 -s %dx%d -i %s -y %s" % (FFMPEG, width, height, filename, outfile)
  13.  commands.getstatusoutput(command)
  14.  
  15. if len(sys.argv) <2 :
  16.  print "USAGE : work-out-resolution.py <file>"
  17.  sys.exit(1)
  18.  
  19. filename = sys.argv[1]
  20. if not os.path.exists(filename) :
  21.  print filename + " does not exist"
  22.  sys.exit(1)
  23.  
  24. filesize = os.path.getsize(filename) / 2
  25.  
  26. limit = int(math.sqrt(filesize)) + 1
  27. for i in xrange(1, limit) :
  28.  if filesize % i == 0 and filesize & 1 == 0 :
  29.   convert_file(i, filesize / i, filename)
  30.   convert_file(filesize / i, i, filename)