[FFmpeg-devel] [PATCH] avformat: Add v210 demuxer

[Timothy Gu]

On Sat, Nov 07, 2015 at 10:22:34PM -0300, James Almer wrote:
> On 11/7/2015 9:45 PM, Timothy Gu wrote:
> > +#define OFFSET(x) offsetof(V210DemuxerContext, x)
> > +#define DEC AV_OPT_FLAG_DECODING_PARAM
> > +static const AVOption v210_options[] = {
> > +    { "video_size", "set frame size", OFFSET(width), AV_OPT_TYPE_IMAGE_SIZE, {.str = NULL}, 0, 0, DEC },
> 
> Isn't this what -s is for?
> 
> ffmpeg -s 1280x720 -f v210 -i INPUT

Well -s is only available for ffmpeg.c, unless I'm mistaken.

> 
> Also, in any case you're missing height.

AV_OPT_TYPE_IMAGE_SIZE works in an unorthodox way: it fills *(&width) with
the width and *(&width + 1) with the height. See
https://github.com/FFmpeg/FFmpeg/blob/master/libavutil/opt.c#L269

In the struct an `int height;` follows `int width;`, so this should work
fine.

> 
> > +    { "framerate", "set frame rate", OFFSET(framerate), AV_OPT_TYPE_VIDEO_RATE, {.str = "25"}, 0, 0, DEC },
> 
> Same here, -r. Assuming it works for the input stream.

Ditto.

Timothy