[FFmpeg-devel] Why does vp56_init() sets avctx->width and avctx->height to 0?

[Aurelien Jacobs]

Stefano Sabatini wrote:

> Hi,
> 
> this causes a bug both in ffprobe (prints widht=size=0) and causes a
> division by 0 exception in libavfilter/vf_scale when it tryies to the
> parameters for the filter.
> 
> What's the point into setting those values to 0?

The point is that the actual frame width and height are not known
at this point. They only get known after parsing the header of the
first key frame.
And also don't forget that those value may change at every key frame.
The width/height is not an intrinsic property of a video stream, it's
a property of each individual frames.

Aurel