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| author | Kevin Mark <kmark937@gmail.com> | 2017-06-12 01:59:05 -0400 |
|---|---|---|
| committer | Ronald S. Bultje <rsbultje@gmail.com> | 2017-06-19 14:24:55 -0400 |
| commit | 5aea18cbd8828da885d76d528fcbf5b2fd6834ca (patch) | |
| tree | 4a75c99fb7a980cd91868e4ecdeca2f14704d24b | |
| parent | c7a2a379fd0517f5c7d716ecf468f935fe4802de (diff) | |
| download | ffmpeg-5aea18cbd8828da885d76d528fcbf5b2fd6834ca.tar.gz | |
doc/filters: Correct scale doc regarding w/h <= 0
According to libavfilter/scale.c, if the width and height are both
less than or equal to 0 then the input size is used for both
dimensions. It does not need to be -1. -1:-1 is the same as 0:0 which
is the same as -10:-42, etc.
if (w < 0 && h < 0)
eval_w = eval_h = 0;
The documentation for the zscale filter has also been updated since the
behavior is identical.
Signed-off-by: Kevin Mark <kmark937@gmail.com>
Signed-off-by: Ronald S. Bultje <rsbultje@gmail.com>
| -rw-r--r-- | doc/filters.texi | 39 |
1 files changed, 20 insertions, 19 deletions
diff --git a/doc/filters.texi b/doc/filters.texi index 0e6a896eeb..11092a8d70 100644 --- a/doc/filters.texi +++ b/doc/filters.texi @@ -12335,17 +12335,18 @@ the complete list of scaler options. Set the output video dimension expression. Default value is the input dimension. -If the value is 0, the input width is used for the output. +If the @var{width} or @var{w} value is 0, the input width is used for +the output. If the @var{height} or @var{h} value is 0, the input height +is used for the output. -If one of the values is -1, the scale filter will use a value that -maintains the aspect ratio of the input image, calculated from the -other specified dimension. If both of them are -1, the input size is -used +If one and only one of the values is -n with n >= 1, the scale filter +will use a value that maintains the aspect ratio of the input image, +calculated from the other specified dimension. After that it will, +however, make sure that the calculated dimension is divisible by n and +adjust the value if necessary. -If one of the values is -n with n > 1, the scale filter will also use a value -that maintains the aspect ratio of the input image, calculated from the other -specified dimension. After that it will, however, make sure that the calculated -dimension is divisible by n and adjust the value if necessary. +If both values are -n with n >= 1, the behavior will be identical to +both values being set to 0 as previously detailed. See below for the list of accepted constants for use in the dimension expression. @@ -15478,18 +15479,18 @@ The filter accepts the following options. Set the output video dimension expression. Default value is the input dimension. -If the @var{width} or @var{w} is 0, the input width is used for the output. -If the @var{height} or @var{h} is 0, the input height is used for the output. +If the @var{width} or @var{w} value is 0, the input width is used for +the output. If the @var{height} or @var{h} value is 0, the input height +is used for the output. -If one of the values is -1, the zscale filter will use a value that -maintains the aspect ratio of the input image, calculated from the -other specified dimension. If both of them are -1, the input size is -used +If one and only one of the values is -n with n >= 1, the zscale filter +will use a value that maintains the aspect ratio of the input image, +calculated from the other specified dimension. After that it will, +however, make sure that the calculated dimension is divisible by n and +adjust the value if necessary. -If one of the values is -n with n > 1, the zscale filter will also use a value -that maintains the aspect ratio of the input image, calculated from the other -specified dimension. After that it will, however, make sure that the calculated -dimension is divisible by n and adjust the value if necessary. +If both values are -n with n >= 1, the behavior will be identical to +both values being set to 0 as previously detailed. See below for the list of accepted constants for use in the dimension expression. |