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

[Gyan]

On 26-09-2019 12:22 PM, Limin Wang wrote:
> On Wed, Sep 25, 2019 at 09:26:58PM +0530, Gyan wrote:
>> 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.
> I have tested with different width videos, it's better to same width for every column.
> Please check my last update version, please ignore the first one, it's wrong version.
That's a user's choice but warn about the possibility of overlapping as 
well.

Gyan