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

[Dave Rice]

On Feb 3, 2013, at 6:40 AM, Stefano Sabatini <stefasab at gmail.com> wrote:

> 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?

Standardizing to lowercase is acceptable to me. I probably should have done that in the first version of the patch.
Dave