[FFmpeg-devel] [PATCH] doc/filters: update SITI description

[Werner Robitza]

On Wed, Mar 1, 2023 at 1:15 AM Thilo Borgmann <thilo.borgmann at mail.de> wrote:
>
> Am 28.02.23 um 18:12 schrieb Werner Robitza:
> > On Tue, Feb 28, 2023 at 2:16 PM Thilo Borgmann <thilo.borgmann at mail.de> wrote:
> >>
> >> Am 28.02.23 um 14:13 schrieb Thilo Borgmann:
> >>> Am 28.02.23 um 12:42 schrieb Werner Robitza:
> >>>> The filter implements the 'legacy' version from a superseded recommendation.
> >>>> ---
> >>>>    doc/filters.texi | 8 +++++---
> >>>>    1 file changed, 5 insertions(+), 3 deletions(-)
> >>>>
> >>>> diff --git a/doc/filters.texi b/doc/filters.texi
> >>>> index 47e92b9269..25574cd55c 100644
> >>>> --- a/doc/filters.texi
> >>>> +++ b/doc/filters.texi
> >>>> @@ -21593,9 +21593,11 @@ ffmpeg -i input1.mkv -i input2.mkv -filter_complex "[0:v][1:v] signature=nb_inpu
> >>>>    @anchor{siti}
> >>>>    @section siti
> >>>> -Calculate Spatial Info (SI) and Temporal Info (TI) scores for a video, as defined
> >>>> -in ITU-T P.910: Subjective video quality assessment methods for multimedia
> >>>> -applications. Available PDF at @url{https://www.itu.int/rec/T-REC-P.910-199909-S/en }.
> >>>> +Calculate Spatial Information (SI) and Temporal Information (TI) scores for a video,
> >>>> +as defined in ITU-T Rec. P.910 (11/21): Subjective video quality assessment methods
> >>>> +for multimedia applications. Available PDF at @url{https://www.itu.int/rec/T-REC-P.910-202111-S/en}.
> >>>> +Note that this is a legacy implementation that corresponds to a superseded recommendation.
> >>>> +Refer to ITU-T Rec. P.910 (07/22) for the latest version.
> >>>>    It accepts the following option:
> >>>
> >>> Ok.
> >>
> >> You might want to add the URL of the current spec, though:
> >> https://www.itu.int/rec/T-REC-P.910-202207-I/en
> >
> > Sure, patch attached.
>
> Looks better but wait - why did you change the implemented version from 09/99 to 11/21 in the first place?
> (Does this not even make it more wrong?)

No, as the (legacy) definition of SI/TI is the same, no matter if you
are using the version from '99 or '21. It was only changed in '22.
But it is common practice to refer to the latest versions of ITU-T
recommendations where possible.
(If only to avoid people looking at really outdated versions and then
citing/using something from those.)