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

[Mark Himsley]

On 29/03/11 22:53, Stefano Sabatini wrote:
> 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.
>
> [...]

Thank you. Very clear.
I note that I also need to take into account 
av_pix_fmt_descriptors[inlink->format].log2_chroma_w in the number of 
bytes to memcopy.

I just need to test some more PIX_FMTs and I'll send another patch.

-- 
Mark