[FFmpeg-devel] [PATCH v4] doc/filters: add 4x4 layout example for xstack filter

[Gyan]

Ok, the formatting is fine except for one. See below.

On 25-09-2019 03:56 AM, lance.lmwang at gmail.com wrote:
> 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 | 42 +++++++++++++++++++++++++++++++++++++++++-
>   1 file changed, 41 insertions(+), 1 deletion(-)
>
> diff --git a/doc/filters.texi b/doc/filters.texi
> index e41384a..a8342c0 100644
> --- a/doc/filters.texi
> +++ b/doc/filters.texi
> @@ -19057,6 +19057,13 @@ 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
> @@ -19065,6 +19072,12 @@ 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)
Since this is 1 column x 4 rows, these should be different lines without 
the separator.

> + at end example
> +
>   Note that if inputs are of different sizes unused gaps might appear,
>   as not all of output video is used.
>   @example
> @@ -19073,11 +19086,38 @@ xstack=inputs=4:layout=0_0|0_h0|0_h0+h1|0_h0+h1+h2
>   
>   @item
>   Display 9 inputs into 3x3 grid.
> +
> +Below is the 9 inputs position:
> + at example
> +input1(0, 0)       | input4(w0, 0)      | input7(w0+w1, 0)
> +input2(0, h0)      | input5(w0, h0)     | input8(w0+w1, h0)
> +input3(0, h0+h1)   | input6(w0, h0+h1)  | input9(w0+w1, h0+h1)

Shouldn't the third column be at x = w0+w3? w1 is width of input2, right?

> + at end example
> +
>   Note that if inputs are of different sizes unused gaps might appear,
>   as not all of output video is used.
>   @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
> +xstack=inputs=9:layout=0_0|0_h0|0_h0+h1|w0_0|w0_h0|w0_h0+h1|w0+w1_0|w0+w1_h0|w0+w1_h0+h1
>   @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+w1, 0)       | input13(w0+w1+w2, 0)
> +input2(0, h0)      | input6(w0, h0)      | input10(w0+w1, h0)      | input14(w0+w1+w2, h0)
> +input3(0, h0+h1)   | input7(w0, h0+h1)   | input11(w0+w1, h0+h1)   | input15(w0+w1+w2, h0+h1)
> +input4(0, h0+h1+h2)| input8(w0, h0+h1+h2)| input12(w0+w1, h0+h1+h2)| input16(w0+w1+w2, h0+h1+h2)
Same as above.

You should also note that when videos are of different sizes, the videos 
may overlap e.g. if height of input5 is greater than input1, then input6 
will be overlaid on top of part of input5.

Gyan