|Version 1 (modified by llogan, 4 years ago) (diff)|
FFmpeg has access to many filters and more are added on a regular basis. To see what filters are available with your build see ffmpeg -filters. Refer to the libavfilter documentation for more information and examples. This wiki page is for user contributed examples and tips. Contributions to this page are encouraged.
Starting with something simple. Resize a 640x480 input to a 320x240 output.
ffmpeg -i input -vf scale=iw/2:-1 output
iw is input width. In this example the input width is 640. 640/2 = 320. The -1 tells the scale filter to preserve the aspect ratio of the output, so in this example the scale filter will choose a value of 240. See the libavfilter documentation for additional information.
Speed up your video
Increase the speed of a 20 minute video to fit 1 minute output. 1 minute / 20 minutes = 0.05.
ffmpeg -i input -vf setpts=0.05*PTS output
Note that this method will drop frames to achieve your desired speed.
Please show a complete command if you would like to add more examples.