[FFmpeg-devel] [PATCH 3/3] add digital cinema frame sizes

[Stefano Sabatini]

On date Saturday 2013-02-02 17:11:19 -0500, Dave Rice encoded:
> 
> On Feb 2, 2013, at 3:43 PM, Stefano Sabatini <stefasab at gmail.com> wrote:
> 
> > On date Saturday 2013-02-02 19:45:54 +0100, Michaël Cinquin encoded:
> >> On 2 févr. 2013, at 16:21, Stefano Sabatini wrote:
> >>>> 
> >>>>    { "hd480",     852, 480 },
> >>>>    { "hd720",    1280, 720 },
> >>>>    { "hd1080",   1920,1080 },
> >>>> +    { "2K",       2048,1080 }, /* Digital Cinema System Specification */
> >>>> +    { "4K",       4096,2160 }, /* Digital Cinema System Specification */
> >>> 
> >>> LGTM after checking Wikipedia, I'll push the three patches tomorrow
> >>> (this one with a micro bump), if no-one thinks this is wrong.
> >> 
> >> 
> >> 2048x1080 (code name "full container") is not very common for Digital Cinema.
> >> 
> >> What is used in the field is
> >> 2048x858 : 2.39 aspect ratio ==> preset for projector is "Scope"
> >> 1998x1080 : 1.85 aspect ratio ==> preset for projector is "Flat"
> >> 
> >> For 4K, it the same with 2x the numbers.
> >> 
> >> Perhaps then resolution could be 
> >> {"2Kfc",       2048x1080},
> >> {"2Kflat",       1998x1080},
> >> {"2Kscope",       2048x858},
> >> {"4Kfc",       4096x2160},
> >> {"4Kflat",       3996x2160},
> >> {"4Kscope",       4096x1716}
> > 
> > Guys I'll happy leave this to someone which is more familiar with the
> > field where the abbreviations are used, I'll push once you find an
> > acceptable agreement. We could support both variants ("2K/2Kfc") if
> > that doesn't lead to much confusion.
> 
> I agree with Michaël recommendation to make it more specific. How about:
> 
> diff --git a/doc/syntax.texi b/doc/syntax.texi
> index a3aabce..6e4cac4 100644
> --- a/doc/syntax.texi
> +++ b/doc/syntax.texi
> @@ -170,6 +186,18 @@ The following abbreviations are recognized:
>  1280x720
>  @item hd1080
>  1920x1080
> + at item 2K
> +2048x1080
> + at item 2Kflat
> +1998x1080
> + at item 2Kscope
> +2048x858
> + at item 4K
> +4096x2160
> + at item 4Kflat
> +3996x2160
> + at item 4Kscope
> +4096x1716
>  @end table
> 
> diff --git a/libavutil/parseutils.c b/libavutil/parseutils.c
> index ca40569..4f49ef8 100644
> --- a/libavutil/parseutils.c
> +++ b/libavutil/parseutils.c
> @@ -109,6 +109,12 @@ static const VideoSizeAbbr video_size_abbrs[] = {
>      { "hd480",     852, 480 },
>      { "hd720",    1280, 720 },
>      { "hd1080",   1920,1080 },
> +    { "2K",       2048,1080 }, /* Digital Cinema System Specification */
> +    { "2Kflat",   1998,1080 },
> +    { "2Kscope",  2048, 858 },
> +    { "4K",       4096,2160 }, /* Digital Cinema System Specification */
> +    { "4Kflat",   3996,2160 },
> +    { "4Kscope",  4096,1716 },
>  };
> 
> I left out "full container" from 2K and 4K since as you say this is a code name, while these sizes are official according to the spec.
> Dave

Now my only concern are the upcased characters, currently all
abbreviations are low-case (even if the "official" spelling is upcase,
as in "VGA"), so I'd suggest to consider the all-lowcase variants
(e.g. "4Kscope" -> "4kscope").

Is that acceptable?

Alternatively we may support case insensitive matching, like we do
with colors.
-- 
FFmpeg = Fiendish Fundamental Miracolous Purposeless Eccentric Genius