[FFmpeg-devel] [PATCH 2/4] lavd: add device capabilities API

[Lukasz M]

On 16 February 2014 18:45, Michael Niedermayer <michaelni at gmx.at> wrote:

> On Sun, Feb 16, 2014 at 01:28:03PM +0100, Lukasz Marek wrote:
> >
> > >>This version still has one open issue: how does it express a limited
> set of
> > >>frame sizes. For example, if a webcam supports exactly 640×480 and
> 320×240.
> > >>Does it return { 320, 640 } for the width and { 240, 480 } for the
> height?
> > >>Is the application supposed to try each width in turn and query the
> > >>corresponding range for height? It works, although it is a bit
> cumbersome,
> > >>but it is not intuitive: maybe add a comment, or do it like that in the
> > >>examples.
> > >
> > >maybe AV_OPT_TYPE_IMAGE_SIZE, should be used
> >
> > Can AV_OPT_TYPE_IMAGE_SIZE be represented in AVOptionRange?
> > I'm asking because I'm willing to change that, but not sure it is
> > doable without changing AVOptionRange struct.
>
> it was certainly intended to be representable
> see for example opt_list()
>
> and of course things can be done differently if needed


I did check it quickly and it seems image size is represented as string
("640x480" for example)
I haven't found how range of image sizes should be represented.

If there is no format defined then I can propose something like that
"100x100-640x480"
or
"100-640x100-480"