Avoid a null pointer dereference on oom in the aac encoder.

[ffmpeg] / doc / filters.texi

diff --git a/doc/filters.texi b/doc/filters.texi
index 6e616b26b4628a9938c590f3460984125684fa28..d120082660745f9354b16c3b299925947e2b5655 100644 (file)
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -2886,11 +2886,11 @@ This filter accepts the following options:
 @table @option
 @item x
 @item y
-Specify the top left corner coordinates of the box. Default to 0.
+The expressions which specify the top left corner coordinates of the box. Default to 0.
 
 @item width, w
 @item height, h
-Specify the width and height of the box, if 0 they are interpreted as
+The expressions which specify the width and height of the box, if 0 they are interpreted as
 the input width and height. Default to 0.
 
 @item color, c
@@ -2900,7 +2900,44 @@ value @code{invert} is used, the box edge color is the same as the
 video with inverted luma.
 
 @item thickness, t
-Set the thickness of the box edge. Default value is @code{3}.
+The expression which sets the thickness of the box edge. Default value is @code{3}.
+
+See below for the list of accepted constants.
+@end table
+
+The parameters for @var{x}, @var{y}, @var{w} and @var{h} and @var{t} are expressions containing the
+following constants:
+
+@table @option
+@item dar
+The input display aspect ratio, it is the same as (@var{w} / @var{h}) * @var{sar}.
+
+@item hsub
+@item vsub
+horizontal and vertical chroma subsample values. For example for the
+pixel format "yuv422p" @var{hsub} is 2 and @var{vsub} is 1.
+
+@item in_h, ih
+@item in_w, iw
+The input width and height.
+
+@item sar
+The input sample aspect ratio.
+
+@item x
+@item y
+The x and y offset coordinates where the box is drawn.
+
+@item w
+@item h
+The width and height of the drawn box.
+
+@item t
+The thickness of the drawn box.
+
+These constants allow the @var{x}, @var{y}, @var{w}, @var{h} and @var{t} expressions to refer to
+each other, so you may for example specify @code{y=x/dar} or @code{h=w/dar}.
+
 @end table
 
 @subsection Examples
@@ -2928,6 +2965,12 @@ Fill the box with pink color:
 @example
 drawbox=x=10:y=10:w=100:h=100:color=pink@@0.5:t=max
 @end example
+
+@item
+Draw a 2-pixel red 2.40:1 mask:
+@example
+drawbox=x=-t:y=0.5*(ih-iw/2.4)-t:w=iw+t*2:h=iw/2.4+t*2:t=2:c=red
+@end example
 @end itemize
 
 @section drawgrid
@@ -2939,11 +2982,11 @@ This filter accepts the following options:
 @table @option
 @item x
 @item y
-Specify the coordinates of some point of grid intersection (meant to configure offset). Both default to 0.
+The expressions which specify the coordinates of some point of grid intersection (meant to configure offset). Both default to 0.
 
 @item width, w
 @item height, h
-Specify the width and height of the grid cell, if 0 they are interpreted as the
+The expressions which specify the width and height of the grid cell, if 0 they are interpreted as the
 input width and height, respectively, minus @code{thickness}, so image gets
 framed. Default to 0.
 
@@ -2956,7 +2999,44 @@ Note that you can append opacity value (in range of 0.0 - 1.0)
 to color name after @@ sign.
 
 @item thickness, t
-Set the thickness of the grid line. Default value is @code{1}.
+The expression which sets the thickness of the grid line. Default value is @code{1}.
+
+See below for the list of accepted constants.
+@end table
+
+The parameters for @var{x}, @var{y}, @var{w} and @var{h} and @var{t} are expressions containing the
+following constants:
+
+@table @option
+@item dar
+The input display aspect ratio, it is the same as (@var{w} / @var{h}) * @var{sar}.
+
+@item hsub
+@item vsub
+horizontal and vertical chroma subsample values. For example for the
+pixel format "yuv422p" @var{hsub} is 2 and @var{vsub} is 1.
+
+@item in_h, ih
+@item in_w, iw
+The input grid cell width and height.
+
+@item sar
+The input sample aspect ratio.
+
+@item x
+@item y
+The x and y coordinates of some point of grid intersection (meant to configure offset).
+
+@item w
+@item h
+The width and height of the drawn cell.
+
+@item t
+The thickness of the drawn cell.
+
+These constants allow the @var{x}, @var{y}, @var{w}, @var{h} and @var{t} expressions to refer to
+each other, so you may for example specify @code{y=x/dar} or @code{h=w/dar}.
+
 @end table
 
 @subsection Examples
@@ -2967,6 +3047,12 @@ Draw a grid with cell 100x100 pixels, thickness 2 pixels, with color red and an
 @example
 drawgrid=width=100:height=100:thickness=2:color=red@@0.5
 @end example
+
+@item
+Draw a white 3x3 grid with an opacity of 50%:
+@example
+drawgrid=w=iw/3:h=ih/3:t=2:c=white@@0.5
+@end example
 @end itemize
 
 @anchor{drawtext}
@@ -3068,6 +3154,10 @@ The x and y offsets for the text shadow position with respect to the
 position of the text. They can be either positive or negative
 values. Default value for both is "0".
 
+@item start_number
+The starting frame number for the n/frame_num variable. The default value
+is "0".
+
 @item tabsize
 The size in number of spaces to use for rendering the tab.
 Default value is 4.
@@ -3535,7 +3625,7 @@ Default value is @var{auto}.
 
 @item mode
 Set the matching mode or strategy to use. @option{pc} mode is the safest in the
-sense that it wont risk creating jerkiness due to duplicate frames when
+sense that it won't risk creating jerkiness due to duplicate frames when
 possible, but if there are bad edits or blended fields it will end up
 outputting combed frames when a good match might actually exist. On the other
 hand, @option{pcn_ub} mode is the most risky in terms of creating jerkiness,