[FFmpeg-devel] [PATCH] Add negate filter.

[Stefano Sabatini]

On date Sunday 2010-11-28 03:09:35 +0100, Michael Niedermayer encoded:
> On Fri, Nov 26, 2010 at 05:32:13PM +0100, Stefano Sabatini wrote:
[...]
> > +static void draw_slice(AVFilterLink *inlink, int y, int h, int slice_dir)
> > +{
> > +    NegContext *neg = inlink->dst->priv;
> > +    AVFilterLink *outlink = inlink->dst->outputs[0];
> > +    AVFilterBufferRef *inpic  = inlink ->cur_buf;
> > +    AVFilterBufferRef *outpic = outlink->out_buf;
> > +    uint8_t *inrow, *outrow;
> > +    int i, j, plane;
> > +
> > +    if (inlink->format == PIX_FMT_MONOWHITE || inlink->format == PIX_FMT_MONOBLACK) {
> > +        inrow  = inpic ->data[0] + y * inpic ->linesize[0];
> > +        outrow = outpic->data[0] + y * outpic->linesize[0];
> > +        for (i = 0; i < h; i++) {
> > +            for (j = 0; j < inlink->w >> 3; j++)
> > +                outrow[j] = ~inrow[j];
> > +            inrow  += inpic ->linesize[0];
> > +            outrow += outpic->linesize[0];
> > +        }
> > +    } else {
> > +        /* luma plane */
> > +        inrow  = inpic ->data[0] + y * inpic-> linesize[0];
> > +        outrow = outpic->data[0] + y * outpic->linesize[0];
> > +        for (i = 0; i < h; i ++) {
> > +            for(j = 0; j < inlink->w; j++)
> > +                outrow[j] = 255 - inrow[j] + neg->off_y;
> > +            inrow  += inpic ->linesize[0];
> > +            outrow += outpic->linesize[0];
> > +        }
> > +
> > +        /* chroma planes */
> > +        for (plane = 1; plane < 3; plane++) {
> > +            inrow  = inpic-> data[plane] + (y >> neg->vsub) * inpic ->linesize[plane];
> > +            outrow = outpic->data[plane] + (y >> neg->vsub) * outpic->linesize[plane];
> > +
> > +            for (i = 0; i < h >> neg->vsub; i++) {
> > +                for (j = 0; j < inlink->w >> neg->hsub; j++)
> > +                    outrow[j] = 255 - inrow[j] + neg->off_uv;
> > +                inrow  += inpic ->linesize[plane];
> > +                outrow += outpic->linesize[plane];
> > +            }
> > +        }
> 
> the user should be able to selct which planes are negated

Good idea, updated.
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