From 8d36d36e7446563f39948c9f71491a19e2bc6c87 Mon Sep 17 00:00:00 2001 From: Stefano Sabatini Date: Tue, 12 Aug 2008 10:07:28 +0000 Subject: [PATCH] Add to the ffmpeg docs an usage example showing how to extract images from a video. Originally committed as revision 14711 to svn://svn.ffmpeg.org/ffmpeg/trunk --- doc/ffmpeg-doc.texi | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/doc/ffmpeg-doc.texi b/doc/ffmpeg-doc.texi index cb82230855..1660980e03 100644 --- a/doc/ffmpeg-doc.texi +++ b/doc/ffmpeg-doc.texi @@ -140,6 +140,25 @@ The mapping is particularly useful for DVD transcoding to get the desired audio language. NOTE: To see the supported input formats, use @code{ffmpeg -formats}. + +* You can extract images from a video: + +@example +ffmpeg -i foo.avi -r 1 -s WxH -f image2 foo-%03d.jpeg +@end example + +This will extract one video frame per second from the video and will +output them in files named @file{foo-001.jpeg}, @file{foo-002.jpeg}, +etc. Images will be rescaled to fit the new WxH values. + +The syntax @code{foo-%03d.jpeg} specifies to use a decimal number +composed of three digits padded with zeroes to express the sequence +number. It is the same syntax supported by the C printf function, but +only formats accepting a normal integer are suitable. + +If you want to extract just a limited number of frames, you can use the +above command in combination with the -vframes or -t option, or in +combination with -ss to start extracting from a certain point in time. @c man end @chapter Invocation