[FFmpeg-devel] [PATCH v6] doc/filters: add 4x4 layout example for xstack filter

[lance.lmwang at gmail.com]

From: Limin Wang <lance.lmwang at gmail.com>

Reviewed-by: Gyan <ffmpeg at gyani.pro>
Signed-off-by: Limin Wang <lance.lmwang at gmail.com>
---
 doc/filters.texi | 55 ++++++++++++++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 52 insertions(+), 3 deletions(-)

diff --git a/doc/filters.texi b/doc/filters.texi
index e6f8bf0..581a96b 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -19060,6 +19060,13 @@ terminates. Default value is 0.
 @itemize
 @item
 Display 4 inputs into 2x2 grid.
+
+Below is the 4 inputs position:
+ at example
+input1(0, 0)  | input3(w0, 0)
+input2(0, h0) | input4(w0, h0)
+ at end example
+
 Note that if inputs are of different sizes unused gaps might appear,
 as not all of output video is used.
 @example
@@ -19068,6 +19075,15 @@ xstack=inputs=4:layout=0_0|0_h0|w0_0|w0_h0
 
 @item
 Display 4 inputs into 1x4 grid.
+
+Below is the 4 inputs position:
+ at example
+input1(0, 0)
+input2(0, h0)
+input3(0, h0+h1)
+input4(0, h0+h1+h2)
+ at end example
+
 Note that if inputs are of different sizes unused gaps might appear,
 as not all of output video is used.
 @example
@@ -19076,11 +19092,44 @@ xstack=inputs=4:layout=0_0|0_h0|0_h0+h1|0_h0+h1+h2
 
 @item
 Display 9 inputs into 3x3 grid.
-Note that if inputs are of different sizes unused gaps might appear,
-as not all of output video is used.
+
+Below is the 9 inputs position:
 @example
-xstack=inputs=9:layout=w3_0|w3_h0+h2|w3_h0|0_h4|0_0|w3+w1_0|0_h1+h2|w3+w1_h0|w3+w1_h1+h2
+input1(0, 0)       | input4(w0, 0)      | input7(w0+w3, 0)
+input2(0, h0)      | input5(w0, h0)     | input8(w0+w3, h0)
+input3(0, h0+h1)   | input6(w0, h0+h1)  | input9(w0+w3, h0+h1)
 @end example
+
+Note that if the input size is different, there may be unused gaps or
+overlaps.  For example, if the height of input4 is greater than input1,
+input5 will overlaid the top of input4, if the width of input5 is less
+than input4, then input5 will have unused gaps.
+
+ at example
+xstack=inputs=9:layout=0_0|0_h0|0_h0+h1|w0_0|w0_h0|w0_h0+h1|w0+w3_0|w0+w3_h0|w0+w3_h0+h1
+ at end example
+
+ at item
+Display 16 inputs into 4x4 grid.
+
+Below is the 16 inputs position:
+ at example
+input1(0, 0)       | input5(w0, 0)       | input9 (w0+w4, 0)       | input13(w0+w4+w8, 0)
+input2(0, h0)      | input6(w0, h0)      | input10(w0+w4, h0)      | input14(w0+w4+w8, h0)
+input3(0, h0+h1)   | input7(w0, h0+h1)   | input11(w0+w4, h0+h1)   | input15(w0+w4+w8, h0+h1)
+input4(0, h0+h1+h2)| input8(w0, h0+h1+h2)| input12(w0+w4, h0+h1+h2)| input16(w0+w4+w8, h0+h1+h2)
+ at end example
+
+Note that if the input size is different, there may be unused gaps or
+overlaps. For example, if the height of input5 is greater than input1,
+input6 will overlaid the top of input5, if the width of input6 is less
+than input5, then input6 will have unused gaps.
+
+ at example
+xstack=inputs=16:layout=0_0|0_h0|0_h0+h1|0_h0+h1+h2|w0_0|w0_h0|w0_h0+h1|w0_h0+h1+h2|w0+w4_0|
+w0+w4_h0|w0+w4_h0+h1|w0+w4_h0+h1+h2|w0+w4+w8_0|w0+w4+w8_h0|w0+w4+w8_h0+h1|w0+w4+w8_h0+h1+h2
+ at end example
+
 @end itemize
 
 @anchor{yadif}
-- 
2.6.4