/*
* Copyright (c) 2014-2015 Michael Niedermayer <michaelni@gmx.at>
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with FFmpeg; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
/**
* @todo switch to dualinput
*/
#include "libavutil/avassert.h"
#include "libavutil/imgutils.h"
#include "libavutil/opt.h"
#include "internal.h"
#include "lavfutils.h"
#define MAX_MIPMAPS 5
typedef struct FOCContext {
AVClass *class;
float threshold;
int mipmaps;
int xmin, ymin, xmax, ymax;
char *obj_filename;
int last_x, last_y;
AVFrame *obj_frame;
AVFrame *needle_frame[MAX_MIPMAPS];
AVFrame *haystack_frame[MAX_MIPMAPS];
} FOCContext;
#define OFFSET(x) offsetof(FOCContext, x)
#define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
static const AVOption find_rect_options[] = {
{ "object", "object bitmap filename", OFFSET(obj_filename), AV_OPT_TYPE_STRING, {.str = NULL}, .flags = FLAGS },
{ "threshold", "set threshold", OFFSET(threshold), AV_OPT_TYPE_FLOAT, {.dbl = 0.5}, 0, 1.0, FLAGS },
{ "mipmaps", "set mipmaps", OFFSET(mipmaps), AV_OPT_TYPE_INT, {.i64 = 3}, 1, MAX_MIPMAPS, FLAGS },
{ "xmin", "", OFFSET(xmin), AV_OPT_TYPE_INT, {.i64 = 0}, 0, INT_MAX, FLAGS },
{ "ymin", "", OFFSET(ymin), AV_OPT_TYPE_INT, {.i64 = 0}, 0, INT_MAX, FLAGS },
{ "xmax", "", OFFSET(xmax), AV_OPT_TYPE_INT, {.i64 = 0}, 0, INT_MAX, FLAGS },
{ "ymax", "", OFFSET(ymax), AV_OPT_TYPE_INT, {.i64 = 0}, 0, INT_MAX, FLAGS },
{ NULL }
};
AVFILTER_DEFINE_CLASS(find_rect);
static int query_formats(AVFilterContext *ctx)
{
static const enum AVPixelFormat pix_fmts[] = {
AV_PIX_FMT_YUV420P,
AV_PIX_FMT_YUVJ420P,
AV_PIX_FMT_NONE
};
return ff_set_common_formats(ctx, ff_make_format_list(pix_fmts));
}
static AVFrame *downscale(AVFrame *in)
{
int x, y;
AVFrame *frame = av_frame_alloc();
uint8_t *src, *dst;
if (!frame)
return NULL;
frame->format = in->format;
frame->width = (in->width + 1) / 2;
frame->height = (in->height+ 1) / 2;
if (av_frame_get_buffer(frame, 32) < 0) {
av_frame_free(&frame);
return NULL;
}
src = in ->data[0];
dst = frame->data[0];
for(y = 0; y < frame->height; y++) {
for(x = 0; x < frame->width; x++) {
dst[x] = ( src[2*x+0]
+ src[2*x+1]
+ src[2*x+0 + in->linesize[0]]
+ src[2*x+1 + in->linesize[0]]
+ 2) >> 2;
}
src += 2*in->linesize[0];
dst += frame->linesize[0];
}
return frame;
}
static float compare(const AVFrame *haystack, const AVFrame *obj, int offx, int offy)
{
int x,y;
int o_sum_v = 0;
int h_sum_v = 0;
int64_t oo_sum_v = 0;
int64_t hh_sum_v = 0;
int64_t oh_sum_v = 0;
float c;
int n = obj->height * obj->width;
const uint8_t *odat = obj ->data[0];
const uint8_t *hdat = haystack->data[0] + offx + offy * haystack->linesize[0];
int64_t o_sigma, h_sigma;
for(y = 0; y < obj->height; y++) {
for(x = 0; x < obj->width; x++) {
int o_v = odat[x];
int h_v = hdat[x];
o_sum_v += o_v;
h_sum_v += h_v;
oo_sum_v += o_v * o_v;
hh_sum_v += h_v * h_v;
oh_sum_v += o_v * h_v;
}
odat += obj->linesize[0];
hdat += haystack->linesize[0];
}
o_sigma = n*oo_sum_v - o_sum_v*(int64_t)o_sum_v;
h_sigma = n*hh_sum_v - h_sum_v*(int64_t)h_sum_v;
if (o_sigma == 0 || h_sigma == 0)
return 1.0;
c = (n*oh_sum_v - o_sum_v*(int64_t)h_sum_v) / (sqrt(o_sigma)*sqrt(h_sigma));
return 1 - fabs(c);
}
static int config_input(AVFilterLink *inlink)
{
AVFilterContext *ctx = inlink->dst;
FOCContext *foc = ctx->priv;
if (foc->xmax <= 0)
foc->xmax = inlink->w - foc->obj_frame->width;
if (foc->ymax <= 0)
foc->ymax = inlink->h - foc->obj_frame->height;
return 0;
}
static float search(FOCContext *foc, int pass, int maxpass, int xmin, int xmax, int ymin, int ymax, int *best_x, int *best_y, float best_score)
{
int x, y;
if (pass + 1 <= maxpass) {
int sub_x, sub_y;
search(foc, pass+1, maxpass, xmin>>1, (xmax+1)>>1, ymin>>1, (ymax+1)>>1, &sub_x, &sub_y, 1.0);
xmin = FFMAX(xmin, 2*sub_x - 4);
xmax = FFMIN(xmax, 2*sub_x + 4);
ymin = FFMAX(ymin, 2*sub_y - 4);
ymax = FFMIN(ymax, 2*sub_y + 4);
}
for (y = ymin; y <= ymax; y++) {
for (x = xmin; x <= xmax; x++) {
float score = compare(foc->haystack_frame[pass], foc->needle_frame[pass], x, y);
av_assert0(score != 0);
if (score < best_score) {
best_score = score;
*best_x = x;
*best_y = y;
}
}
}
return best_score;
}
static int filter_frame(AVFilterLink *inlink, AVFrame *in)
{
AVFilterContext *ctx = inlink->dst;
FOCContext *foc = ctx->priv;
float best_score;
int best_x, best_y;
int i;
foc->haystack_frame[0] = av_frame_clone(in);
for (i=1; i<foc->mipmaps; i++) {
foc->haystack_frame[i] = downscale(foc->haystack_frame[i-1]);
}
best_score = search(foc, 0, 0,
FFMAX(foc->xmin, foc->last_x - 8),
FFMIN(foc->xmax, foc->last_x + 8),
FFMAX(foc->ymin, foc->last_y - 8),
FFMIN(foc->ymax, foc->last_y + 8),
&best_x, &best_y, 1.0);
best_score = search(foc, 0, foc->mipmaps - 1, foc->xmin, foc->xmax, foc->ymin, foc->ymax,
&best_x, &best_y, best_score);
for (i=0; i<MAX_MIPMAPS; i++) {
av_frame_free(&foc->haystack_frame[i]);
}
if (best_score > foc->threshold) {
return ff_filter_frame(ctx->outputs[0], in);
}
av_log(ctx, AV_LOG_DEBUG, "Found at %d %d score %f\n", best_x, best_y, best_score);
foc->last_x = best_x;
foc->last_y = best_y;
av_frame_make_writable(in);
av_dict_set_int(&in->metadata, "lavfi.rect.w", foc->obj_frame->width, 0);
av_dict_set_int(&in->metadata, "lavfi.rect.h", foc->obj_frame->height, 0);
av_dict_set_int(&in->metadata, "lavfi.rect.x", best_x, 0);
av_dict_set_int(&in->metadata, "lavfi.rect.y", best_y, 0);
return ff_filter_frame(ctx->outputs[0], in);
}
static av_cold void uninit(AVFilterContext *ctx)
{
FOCContext *foc = ctx->priv;
int i;
for (i = 0; i < MAX_MIPMAPS; i++) {
av_frame_free(&foc->needle_frame[i]);
av_frame_free(&foc->haystack_frame[i]);
}
if (foc->obj_frame)
av_freep(&foc->obj_frame->data[0]);
av_frame_free(&foc->obj_frame);
}
static av_cold int init(AVFilterContext *ctx)
{
FOCContext *foc = ctx->priv;
int ret, i;
if (!foc->obj_filename) {
av_log(ctx, AV_LOG_ERROR, "object filename not set\n");
return AVERROR(EINVAL);
}
foc->obj_frame = av_frame_alloc();
if (!foc->obj_frame)
return AVERROR(ENOMEM);
if ((ret = ff_load_image(foc->obj_frame->data, foc->obj_frame->linesize,
&foc->obj_frame->width, &foc->obj_frame->height,
&foc->obj_frame->format, foc->obj_filename, ctx)) < 0)
return ret;
if (foc->obj_frame->format != AV_PIX_FMT_GRAY8) {
av_log(ctx, AV_LOG_ERROR, "object image is not a grayscale image\n");
return AVERROR(EINVAL);
}
foc->needle_frame[0] = av_frame_clone(foc->obj_frame);
for (i = 1; i < foc->mipmaps; i++) {
foc->needle_frame[i] = downscale(foc->needle_frame[i-1]);
if (!foc->needle_frame[i])
return AVERROR(ENOMEM);
}
return 0;
}
static const AVFilterPad foc_inputs[] = {
{
.name = "default",
.type = AVMEDIA_TYPE_VIDEO,
.config_props = config_input,
.filter_frame = filter_frame,
},
{ NULL }
};
static const AVFilterPad foc_outputs[] = {
{
.name = "default",
.type = AVMEDIA_TYPE_VIDEO,
},
{ NULL }
};
AVFilter ff_vf_find_rect = {
.name = "find_rect",
.description = NULL_IF_CONFIG_SMALL("Find a user specified object."),
.priv_size = sizeof(FOCContext),
.init = init,
.uninit = uninit,
.query_formats = query_formats,
.inputs = foc_inputs,
.outputs = foc_outputs,
.priv_class = &find_rect_class,
};