PeerStreamer

@chapter Demuxers

@c man begin DEMUXERS

Demuxers are configured elements in FFmpeg which allow to read the

multimedia streams from a particular type of file.

When you configure your FFmpeg build, all the supported demuxers

are enabled by default. You can list all available ones using the

configure option "--list-demuxers".

You can disable all the demuxers using the configure option

"--disable-demuxers", and selectively enable a single demuxer with

the option "--enable-demuxer=@var{DEMUXER}", or disable it

with the option "--disable-demuxer=@var{DEMUXER}".

The option "-formats" of the ff* tools will display the list of

enabled demuxers.

The description of some of the currently available demuxers follows.

@section image2

Image file demuxer.

This demuxer reads from a list of image files specified by a pattern.

The pattern may contain the string "%d" or "%0@var{N}d", which

specifies the position of the characters representing a sequential

number in each filename matched by the pattern. If the form

"%d0@var{N}d" is used, the string representing the number in each

filename is 0-padded and @var{N} is the total number of 0-padded

digits representing the number. The literal character '%' can be

specified in the pattern with the string "%%".

If the pattern contains "%d" or "%0@var{N}d", the first filename of

the file list specified by the pattern must contain a number

inclusively contained between 0 and 4, all the following numbers must

be sequential. This limitation may be hopefully fixed.

The pattern may contain a suffix which is used to automatically

determine the format of the images contained in the files.

For example the pattern "img-%03d.bmp" will match a sequence of

filenames of the form @file{img-001.bmp}, @file{img-002.bmp}, ...,

@file{img-010.bmp}, etc.; the pattern "i%%m%%g-%d.jpg" will match a

sequence of filenames of the form @file{i%m%g-1.jpg},

@file{i%m%g-2.jpg}, ..., @file{i%m%g-10.jpg}, etc.

The size, the pixel format, and the format of each image must be the

same for all the files in the sequence.

The following example shows how to use @file{ffmpeg} for creating a

video from the images in the file sequence @file{img-001.jpeg},

@file{img-002.jpeg}, ..., assuming an input framerate of 10 frames per

second:

@example

ffmpeg -r 10 -f image2 -i 'img-%03d.jpeg' out.avi

@end example

Note that the pattern must not necessarily contain "%d" or

"%0@var{N}d", for example to convert a single image file

@file{img.jpeg} you can employ the command:

@example

ffmpeg -f image2 -i img.jpeg img.png

@end example

@c man end INPUT DEVICES