Xbr-filter

#include "libavutil/opt.h"
#include "libavutil/avassert.h"
#include "libavutil/pixdesc.h"
#include "internal.h"

#define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM

static int config_output(AVFilterLink *outlink)
{
    AVFilterContext *ctx = outlink->src;
    AVFilterLink *inlink = ctx->inputs[0];

    outlink->w = inlink->w * 2 ;
    outlink->h = inlink->h * 2 ;
    return 0;
}

static int filter_frame(AVFilterLink *inlink, AVFrame *in)
{
    AVFilterContext *ctx = inlink->dst;
    AVFilterLink *outlink = ctx->outputs[0];
    AVFrame *out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
    if (!out) {
        av_frame_free(&in);
        return AVERROR(ENOMEM);
    }
    int i,j;

    av_frame_copy_props(out, in);
    for(i=0;i<inlink->w*2;i++)
	for(j=0;j<inlink->h*2;j++)
	{
		*(out->data[0] + j*out->linesize[0] + i*3) = in->data[0] + (int)(j/2) * in->linesize[0] + (int)(i/2)*3;
		*(out->data[0] + j*out->linesize[0] + i*3 + 1) = in->data[0] + (int)(j/2) * in->linesize[0] + (int)(i/2)*3 + 1;
		*(out->data[0] + j*out->linesize[0] + i*3 + 2) = in->data[0] + (int)(j/2) * in->linesize[0] + (int)(i/2)*3 + 2;

	}

    out->width  = outlink->w;
    out->height = outlink->h;



    av_frame_free(&in);
    return ff_filter_frame(outlink, out);
}

static const AVFilterPad xbr_inputs[] = {
    {
        .name         = "default",
        .type         = AVMEDIA_TYPE_VIDEO,
        .filter_frame = filter_frame,
    },
    { NULL }
};

static const AVFilterPad xbr_outputs[] = {
    {
        .name         = "default",
        .type         = AVMEDIA_TYPE_VIDEO,
        .config_props = config_output,
    },
    { NULL }
};

AVFilter ff_vf_xbr = {
    .name          = "xbr",
    .description   = NULL_IF_CONFIG_SMALL("Scale the input by 2, 3 or 4 using the hq*x magnification algorithm."),
    .inputs        = xbr_inputs,
    .outputs       = xbr_outputs,
};