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Diffstat (limited to 'doc/filters.texi')
| -rw-r--r-- | doc/filters.texi | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/doc/filters.texi b/doc/filters.texi index cd590573cf..0adec4b809 100644 --- a/doc/filters.texi +++ b/doc/filters.texi @@ -6373,6 +6373,33 @@ Full range (0-255 in case of 8bit luma) "Mpeg" range (16-235 in case of 8bit luma) @end table +@item force_original_aspect_ratio +Enable decreasing or increasing output video width or height if necessary to +keep the original aspect ratio. Possible values: + +@table @samp +@item disable +Scale the video as specified and disable this feature. + +@item decrease +The output video dimensions will automatically be decreased if needed. + +@item increase +The output video dimensions will automatically be increased if needed. + +@end table + +One useful instance of this option is that when you know a specific device's +maximum allowed resolution, you can use this to limit the output video to +that, while retaining the aspect ratio. For example, device A allows +1280x720 playback, and your video is 1920x800. Using this option (set it to +decrease) and specifying 1280x720 to the command line makes the output +1280x533. + +Please note that this is a different thing than specifying -1 for @option{w} +or @option{h}, you still need to specify the output resolution for this option +to work. + @end table The values of the @var{w} and @var{h} options are expressions |