[FFmpeg-devel] [PATCH] add top video filter

[Stefano Sabatini]

On date Tuesday 2011-03-29 22:02:53 +0100, Mark Himsley encoded:
> On 29/03/11 17:50, Stefano Sabatini wrote:
> >On date Monday 2011-03-28 14:47:20 +0100, Mark Himsley encoded:
[...]
> >>+            for (plane = 0; plane<  4&&  outpic->data[plane]; plane++) {
> >>+                cpy_dst = outpic->data[plane] + y * outpic->linesize[plane];
> >>+                if (top->dst_tff) {
> >>+                    for (i = 0; i<  h; i++) {
> >>+                        if (1 + y + i<  outpic->video->h) {
> >>+                            memcpy(cpy_dst, cpy_dst + outpic->linesize[plane], outpic->linesize[plane]);
> >
> >You're copying more than it is required, outpic->linesize[plane] ->  line_step[plane] * w;
> 
> Am I?
> I want to copy a whole line, from line+1 to line.
> Where does w some from BTW?

Plane buffers are usually padded, so you may have:
linesize[plane] > pixel_step*w

Copying more than it is required is a waste of CPU, also you shouldn't
write beyond the image region.

w is the image width, that you can retrieve in inlink->w or in
outpic->video->w.

[...]
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