FFmpeg 2.8.22
Since* 2.8
#

Scale (resize) the input video, based on a reference video.

See the scale filter for available options, scale2ref supports the same but uses the reference video instead of the main input as basis.

#

Examples

  • Scale a subtitle stream (b) to match the main video (a) in size before overlaying

    'scale2ref[b][a];[a][b]overlay'