[FFmpeg-devel] [PATCH 2/2] Add hflip filter.

[Stefano Sabatini]

On date Wednesday 2010-08-04 14:23:49 +0200, Michael Niedermayer encoded:
> On Sat, Jul 31, 2010 at 02:07:29AM +0200, Stefano Sabatini wrote:
[...]
> > +static void draw_slice(AVFilterLink *inlink, int y, int h, int slice_dir)
> > +{
> > +    FlipContext *flip = inlink->dst->priv;
> > +    AVFilterPicRef *inpic  = inlink->cur_pic;
> > +    AVFilterPicRef *outpic = inlink->dst->outputs[0]->outpic;
> > +    uint8_t *inrow, *outrow;
> > +    int i, j, plane, step, hsub, vsub;
> > +
> > +    for (plane = 0; plane < 4 && inpic->data[plane]; plane++) {
> > +        step = flip->max_step[plane];
> > +        hsub = (plane == 1 || plane == 2) ? flip->hsub : 0;
> > +        vsub = (plane == 1 || plane == 2) ? flip->vsub : 0;
> > +
> > +        outrow = outpic->data[plane] + (y>>vsub) * outpic->linesize[plane];
> > +        inrow  = inpic ->data[plane] + (y>>vsub) * inpic ->linesize[plane] + ((inlink->w >> hsub) - 1) * step;
> > +        for (i = 0; i < h>>vsub; i++) {
> > +            for (j = 0; j < (inlink->w >> hsub); j++)
> > +                memcpy(outrow + j*step, inrow - j*step, step);
> 
> variable length memcpy on a per pixel base is slow

Updated.

I didn't manage to understand how bswap/dsputils may be used, I don't
know if that would improve it.

Regards.
-- 
FFmpeg = Frightening and Friendly Mere Pure Erroneous Gargoyle