demuxers.texi 2.4 KB

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  1. @chapter Demuxers
  2. @c man begin DEMUXERS
  3. Demuxers are configured elements in FFmpeg which allow to read the
  4. multimedia streams from a particular type of file.
  5. When you configure your FFmpeg build, all the supported demuxers
  6. are enabled by default. You can list all available ones using the
  7. configure option "--list-demuxers".
  8. You can disable all the demuxers using the configure option
  9. "--disable-demuxers", and selectively enable a single demuxer with
  10. the option "--enable-demuxer=@var{DEMUXER}", or disable it
  11. with the option "--disable-demuxer=@var{DEMUXER}".
  12. The option "-formats" of the ff* tools will display the list of
  13. enabled demuxers.
  14. The description of some of the currently available demuxers follows.
  15. @section image2
  16. Image file demuxer.
  17. This demuxer reads from a list of image files specified by a pattern.
  18. The filename of each file to read must contain a sequential number,
  19. which specifies the position of the file in the sequence.
  20. The pattern must contain the string "%d" or "%0@var{N}d", which
  21. specifies the position of the characters representing the seqential
  22. number in each filename matched by the pattern. If the form
  23. "%d0@var{N}d" is used, the string representing the number in each
  24. filename is 0-padded and @var{N} is the total number of 0-padded
  25. digits representing the number. The literal character '%' can be
  26. specified in the pattern with the string "%%".
  27. The first filename of the file sequence specified by the pattern must
  28. contain a number inclusively contained between 0 and 4, all the
  29. following numbers must be sequential.
  30. The pattern may contain a suffix which is used to automatically
  31. determine the format of the images contained in the files.
  32. For example the pattern "img-%03d.bmp" will match a sequence of
  33. filenames of the form @file{img-001.bmp}, @file{img-002.bmp}, ...,
  34. @file{img-010.bmp}, etc.; the pattern "i%%m%%g-%d.jpg" will match a
  35. sequence of filenames of the form @file{i%m%g-1.jpg},
  36. @file{i%m%g-2.jpg}, ..., @file{i%m%g-10.jpg}, etc.
  37. The size, the pixel format, and the format of each image must be the
  38. same for all the files in the sequence.
  39. The following example shows how to use @file{ffmpeg} for creating a
  40. video from the images in the file sequence @file{img-001.jpeg},
  41. @file{img-002.jpeg}, ..., assuming an input framerate of 10 frames per
  42. second:
  43. @example
  44. ffmpeg -r 10 -f image2 -i 'img-%03d.jpeg' out.avi
  45. @end example
  46. @c man end INPUT DEVICES