[FFmpeg-devel] [PATCH 2/8] decklink: Add support for output of Active Format Description (AFD)

[Carl Eugen Hoyos]

2017-12-29 22:02 GMT+01:00 Devin Heitmueller <dheitmueller at ltnglobal.com>:
>
>> On Dec 29, 2017, at 3:48 PM, Carl Eugen Hoyos <ceffmpeg at gmail.com> wrote:
>>
>> 2017-12-29 19:12 GMT+01:00 Devin Heitmueller <dheitmueller at ltnglobal.com>:
>>
>>> +        /* FIXME: Should really rely on the coded_width but seems like that
>>> +           is not accessible to libavdevice outputs */
>>> +        if ((st->codecpar->width == 1280 && st->codecpar->height == 720) ||
>>> +            (st->codecpar->width == 1920 && st->codecpar->height == 1080))
>>> +            pkt->aspectRatio = ASPECT_16x9;
>>> +        else
>>> +            pkt->aspectRatio = ASPECT_4x3;
>>
>> I most likely won't use this (and I have never seen a decklink card)
>> so please feel free to ignore:
>> Similar code has caused some trouble with mxf files, is there
>> really no saner solution? Like comparing what the actual aspect
>> ratio is more similar to? Is SAR really always 1 for decklink?
>> ("All the world's a VAX.")
>
> So this is definitely a confusing block of code, and you aren’t the first one to
> ask about it (there were questions in the last round of review as well). The
> aspect ratio referred to here is actually of the original coded video - not how
> it’s supposed to be displayed.  Hence, for example, 720x480 in widescreen
> with a non-square PAR would still have the aspect ratio set to 4x3, since
> that particular field describes the coded video (i.e. *not* how it’s supposed
> to be rendered).

And a resolution of 1024x576 does not exist for decklink?

What about 1920x1088?

Carl Eugen