ffmpeg | branch: master | Kevin Mark <kmark...@gmail.com> | Mon Jun 12 01:59:05
2017 -0400| [5aea18cbd8828da885d76d528fcbf5b2fd6834ca] | committer: Ronald S.
Bultje
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 <kmark...@gmail.com>
Signed-off-by: Ronald S. Bultje <rsbul...@gmail.com>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=5aea18cbd8828da885d76d528fcbf5b2fd6834ca
---
doc/filters.texi | 39 ++++++++++++++++++++-------------------
1 file 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.
_______________________________________________
ffmpeg-cvslog mailing list
ffmpeg-cvslog@ffmpeg.org
http://ffmpeg.org/mailman/listinfo/ffmpeg-cvslog
