From e771d2e3fef4d2bcfc08b9eb37296f0e0af1f607 Mon Sep 17 00:00:00 2001 From: Stefano Sabatini Date: Wed, 26 Jan 2011 22:53:00 +0100 Subject: Add documentation for the image2 muxer. Signed-off-by: Ronald S. Bultje --- doc/muxers.texi | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 50 insertions(+) (limited to 'doc/muxers.texi') diff --git a/doc/muxers.texi b/doc/muxers.texi index c3dcf1171c..969051a082 100644 --- a/doc/muxers.texi +++ b/doc/muxers.texi @@ -18,4 +18,54 @@ enabled muxers. A description of some of the currently available muxers follows. +@section image2 + +Image file muxer. + +This muxer writes video frames to multiple 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 numbering in +the filenames. If the form "%d0@var{N}d" is used, the string +representing the number in each filename is 0-padded to @var{N} +digits. 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 will contain the number 1, all the following +numbers will be sequential. + +The pattern may contain a suffix which is used to automatically +determine the format of the image files to write. + +For example the pattern "img-%03d.bmp" will specify a sequence of +filenames of the form @file{img-001.bmp}, @file{img-002.bmp}, ..., +@file{img-010.bmp}, etc. +The pattern "img%%-%d.jpg" will specify a sequence of filenames of the +form @file{img%-1.jpg}, @file{img%-2.jpg}, ..., @file{img%-10.jpg}, +etc. + +The following example shows how to use @file{ffmpeg} for creating a +sequence of files @file{img-001.jpeg}, @file{img-002.jpeg}, ..., +taking one image every second from the input video: +@example +ffmpeg -i in.avi -r 1 -f image2 'img-%03d.jpeg' +@end example + +Note that with @file{ffmpeg}, if the format is not specified with the +@code{-f} option and the output filename specifies an image file +format, the image2 muxer is automatically selected, so the previous +command can be written as: +@example +ffmpeg -i in.avi -r 1 'img-%03d.jpeg' +@end example + +Note also that the pattern must not necessarily contain "%d" or +"%0@var{N}d", for example to create a single image file +@file{img.jpeg} from the input video you can employ the command: +@example +ffmpeg -i in.avi -f image2 -vframes 1 img.jpeg +@end example + @c man end MUXERS -- cgit v1.2.3