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/*
* Copyright (C) 2007 Richard Spindler (author of frei0r plugin from which this was derived)
* Copyright (C) 2014 Daniel Oberhoff
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser 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
*/
/**
* @file
* Lenscorrection filter, algorithm from the frei0r plugin with the same name
*/
#include <stdlib.h>
#include <math.h>
#include "libavutil/opt.h"
#include "libavutil/intreadwrite.h"
#include "libavutil/pixdesc.h"
#include "avfilter.h"
#include "internal.h"
#include "video.h"
typedef struct LenscorrectionCtx {
const AVClass *av_class;
int width;
int height;
int hsub, vsub;
int nb_planes;
double cx, cy, k1, k2;
int32_t *correction[4];
} LenscorrectionCtx;
#define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
static const AVOption lenscorrection_options[] = {
{ "cx", "set relative center x", offsetof(LenscorrectionCtx, cx), AV_OPT_TYPE_DOUBLE, {.dbl=0.5}, 0, 1, .flags=FLAGS },
{ "cy", "set relative center y", offsetof(LenscorrectionCtx, cy), AV_OPT_TYPE_DOUBLE, {.dbl=0.5}, 0, 1, .flags=FLAGS },
{ "k1", "set quadratic distortion factor", offsetof(LenscorrectionCtx, k1), AV_OPT_TYPE_DOUBLE, {.dbl=0.0}, -1, 1, .flags=FLAGS },
{ "k2", "set double quadratic distortion factor", offsetof(LenscorrectionCtx, k2), AV_OPT_TYPE_DOUBLE, {.dbl=0.0}, -1, 1, .flags=FLAGS },
{ NULL }
};
AVFILTER_DEFINE_CLASS(lenscorrection);
typedef struct ThreadData {
AVFrame *in, *out;
int w, h;
int plane;
int xcenter, ycenter;
int32_t *correction;
} ThreadData;
static int filter_slice(AVFilterContext *ctx, void *arg, int job, int nb_jobs)
{
ThreadData *td = arg;
AVFrame *in = td->in;
AVFrame *out = td->out;
const int w = td->w, h = td->h;
const int xcenter = td->xcenter;
const int ycenter = td->ycenter;
const int start = (h * job ) / nb_jobs;
const int end = (h * (job+1)) / nb_jobs;
const int plane = td->plane;
const int inlinesize = in->linesize[plane];
const int outlinesize = out->linesize[plane];
const uint8_t *indata = in->data[plane];
uint8_t *outrow = out->data[plane] + start * outlinesize;
int i;
for (i = start; i < end; i++, outrow += outlinesize) {
const int off_y = i - ycenter;
uint8_t *out = outrow;
int j;
for (j = 0; j < w; j++) {
const int off_x = j - xcenter;
const int64_t radius_mult = td->correction[j + i*w];
const int x = xcenter + ((radius_mult * off_x + (1<<23))>>24);
const int y = ycenter + ((radius_mult * off_y + (1<<23))>>24);
const char isvalid = x > 0 && x < w - 1 && y > 0 && y < h - 1;
*out++ = isvalid ? indata[y * inlinesize + x] : 0;
}
}
return 0;
}
static int query_formats(AVFilterContext *ctx)
{
static const enum AVPixelFormat pix_fmts[] = {
AV_PIX_FMT_YUV410P,
AV_PIX_FMT_YUV444P, AV_PIX_FMT_YUVJ444P,
AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUVJ420P,
AV_PIX_FMT_YUVA444P, AV_PIX_FMT_YUVA420P,
AV_PIX_FMT_YUV422P,
AV_PIX_FMT_GBRP, AV_PIX_FMT_GBRAP,
AV_PIX_FMT_NONE
};
AVFilterFormats *fmts_list = ff_make_format_list(pix_fmts);
if (!fmts_list)
return AVERROR(ENOMEM);
return ff_set_common_formats(ctx, fmts_list);
}
static av_cold void uninit(AVFilterContext *ctx)
{
LenscorrectionCtx *rect = ctx->priv;
int i;
for (i = 0; i < FF_ARRAY_ELEMS(rect->correction); i++) {
av_freep(&rect->correction[i]);
}
}
static int config_props(AVFilterLink *outlink)
{
AVFilterContext *ctx = outlink->src;
LenscorrectionCtx *rect = ctx->priv;
AVFilterLink *inlink = ctx->inputs[0];
const AVPixFmtDescriptor *pixdesc = av_pix_fmt_desc_get(inlink->format);
rect->hsub = pixdesc->log2_chroma_w;
rect->vsub = pixdesc->log2_chroma_h;
outlink->w = rect->width = inlink->w;
outlink->h = rect->height = inlink->h;
rect->nb_planes = av_pix_fmt_count_planes(inlink->format);
return 0;
}
static int filter_frame(AVFilterLink *inlink, AVFrame *in)
{
AVFilterContext *ctx = inlink->dst;
AVFilterLink *outlink = ctx->outputs[0];
LenscorrectionCtx *rect = (LenscorrectionCtx*)ctx->priv;
AVFrame *out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
int plane;
if (!out) {
av_frame_free(&in);
return AVERROR(ENOMEM);
}
av_frame_copy_props(out, in);
for (plane = 0; plane < rect->nb_planes; ++plane) {
int hsub = plane == 1 || plane == 2 ? rect->hsub : 0;
int vsub = plane == 1 || plane == 2 ? rect->vsub : 0;
int w = AV_CEIL_RSHIFT(rect->width, hsub);
int h = AV_CEIL_RSHIFT(rect->height, vsub);
int xcenter = rect->cx * w;
int ycenter = rect->cy * h;
int k1 = rect->k1 * (1<<24);
int k2 = rect->k2 * (1<<24);
ThreadData td = {
.in = in,
.out = out,
.w = w,
.h = h,
.xcenter = xcenter,
.ycenter = ycenter,
.plane = plane};
if (!rect->correction[plane]) {
int i,j;
const int64_t r2inv = (4LL<<60) / (w * w + h * h);
rect->correction[plane] = av_malloc_array(w, h * sizeof(**rect->correction));
if (!rect->correction[plane])
return AVERROR(ENOMEM);
for (j = 0; j < h; j++) {
const int off_y = j - ycenter;
const int off_y2 = off_y * off_y;
for (i = 0; i < w; i++) {
const int off_x = i - xcenter;
const int64_t r2 = ((off_x * off_x + off_y2) * r2inv + (1LL<<31)) >> 32;
const int64_t r4 = (r2 * r2 + (1<<27)) >> 28;
const int radius_mult = (r2 * k1 + r4 * k2 + (1LL<<27) + (1LL<<52))>>28;
rect->correction[plane][j * w + i] = radius_mult;
}
}
}
td.correction = rect->correction[plane];
ctx->internal->execute(ctx, filter_slice, &td, NULL, FFMIN(h, ff_filter_get_nb_threads(ctx)));
}
av_frame_free(&in);
return ff_filter_frame(outlink, out);
}
static const AVFilterPad lenscorrection_inputs[] = {
{
.name = "default",
.type = AVMEDIA_TYPE_VIDEO,
.filter_frame = filter_frame,
},
{ NULL }
};
static const AVFilterPad lenscorrection_outputs[] = {
{
.name = "default",
.type = AVMEDIA_TYPE_VIDEO,
.config_props = config_props,
},
{ NULL }
};
AVFilter ff_vf_lenscorrection = {
.name = "lenscorrection",
.description = NULL_IF_CONFIG_SMALL("Rectify the image by correcting for lens distortion."),
.priv_size = sizeof(LenscorrectionCtx),
.query_formats = query_formats,
.inputs = lenscorrection_inputs,
.outputs = lenscorrection_outputs,
.priv_class = &lenscorrection_class,
.uninit = uninit,
.flags = AVFILTER_FLAG_SLICE_THREADS,
};
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