[deb_ffmpeg.git] / ffmpeg / libavfilter / vf_perspective.c

/*
 * Copyright (c) 2002 Michael Niedermayer <michaelni@gmx.at>
 * Copyright (c) 2013 Paul B Mahol
 *
 * 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
 */

#include "libavutil/eval.h"
#include "libavutil/imgutils.h"
#include "libavutil/pixdesc.h"
#include "libavutil/opt.h"
#include "avfilter.h"
#include "formats.h"
#include "internal.h"
#include "video.h"

#define SUB_PIXEL_BITS  8
#define SUB_PIXELS      (1 << SUB_PIXEL_BITS)
#define COEFF_BITS      11

#define LINEAR 0
#define CUBIC  1

typedef struct PerspectiveContext {
    const AVClass *class;
    char *expr_str[4][2];
    double ref[4][2];
    int32_t (*pv)[2];
    int32_t coeff[SUB_PIXELS][4];
    int interpolation;
    int linesize[4];
    int height[4];
    int hsub, vsub;
    int nb_planes;
    int sense;

    int (*perspective)(AVFilterContext *ctx,
                       void *arg, int job, int nb_jobs);
} PerspectiveContext;

#define OFFSET(x) offsetof(PerspectiveContext, x)
#define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM

enum PERSPECTIVESense {
    PERSPECTIVE_SENSE_SOURCE      = 0, ///< coordinates give locations in source of corners of destination.
    PERSPECTIVE_SENSE_DESTINATION = 1, ///< coordinates give locations in destination of corners of source.
};

static const AVOption perspective_options[] = {
    { "x0", "set top left x coordinate",     OFFSET(expr_str[0][0]), AV_OPT_TYPE_STRING, {.str="0"}, 0, 0, FLAGS },
    { "y0", "set top left y coordinate",     OFFSET(expr_str[0][1]), AV_OPT_TYPE_STRING, {.str="0"}, 0, 0, FLAGS },
    { "x1", "set top right x coordinate",    OFFSET(expr_str[1][0]), AV_OPT_TYPE_STRING, {.str="W"}, 0, 0, FLAGS },
    { "y1", "set top right y coordinate",    OFFSET(expr_str[1][1]), AV_OPT_TYPE_STRING, {.str="0"}, 0, 0, FLAGS },
    { "x2", "set bottom left x coordinate",  OFFSET(expr_str[2][0]), AV_OPT_TYPE_STRING, {.str="0"}, 0, 0, FLAGS },
    { "y2", "set bottom left y coordinate",  OFFSET(expr_str[2][1]), AV_OPT_TYPE_STRING, {.str="H"}, 0, 0, FLAGS },
    { "x3", "set bottom right x coordinate", OFFSET(expr_str[3][0]), AV_OPT_TYPE_STRING, {.str="W"}, 0, 0, FLAGS },
    { "y3", "set bottom right y coordinate", OFFSET(expr_str[3][1]), AV_OPT_TYPE_STRING, {.str="H"}, 0, 0, FLAGS },
    { "interpolation", "set interpolation", OFFSET(interpolation), AV_OPT_TYPE_INT, {.i64=LINEAR}, 0, 1, FLAGS, "interpolation" },
    {      "linear", "", 0, AV_OPT_TYPE_CONST, {.i64=LINEAR}, 0, 0, FLAGS, "interpolation" },
    {       "cubic", "", 0, AV_OPT_TYPE_CONST, {.i64=CUBIC},  0, 0, FLAGS, "interpolation" },
    { "sense",   "specify the sense of the coordinates", OFFSET(sense), AV_OPT_TYPE_INT, {.i64=PERSPECTIVE_SENSE_SOURCE}, 0, 1, FLAGS, "sense"},
    {       "source", "specify locations in source to send to corners in destination",
                0, AV_OPT_TYPE_CONST, {.i64=PERSPECTIVE_SENSE_SOURCE}, 0, 0, FLAGS, "sense"},
    {       "destination", "specify locations in destination to send corners of source",
                0, AV_OPT_TYPE_CONST, {.i64=PERSPECTIVE_SENSE_DESTINATION}, 0, 0, FLAGS, "sense"},

    { NULL }
};

AVFILTER_DEFINE_CLASS(perspective);

static int query_formats(AVFilterContext *ctx)
{
    static const enum AVPixelFormat pix_fmts[] = {
        AV_PIX_FMT_YUVA444P, AV_PIX_FMT_YUVA422P, AV_PIX_FMT_YUVA420P,
        AV_PIX_FMT_YUVJ444P, AV_PIX_FMT_YUVJ440P, AV_PIX_FMT_YUVJ422P,AV_PIX_FMT_YUVJ420P, AV_PIX_FMT_YUVJ411P,
        AV_PIX_FMT_YUV444P, AV_PIX_FMT_YUV440P, AV_PIX_FMT_YUV422P, AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUV411P, AV_PIX_FMT_YUV410P,
        AV_PIX_FMT_GBRP, AV_PIX_FMT_GBRAP, AV_PIX_FMT_GRAY8, AV_PIX_FMT_NONE
    };

    ff_set_common_formats(ctx, ff_make_format_list(pix_fmts));
    return 0;
}

static inline double get_coeff(double d)
{
    double coeff, A = -0.60;

    d = fabs(d);

    if (d < 1.0)
        coeff = (1.0 - (A + 3.0) * d * d + (A + 2.0) * d * d * d);
    else if (d < 2.0)
        coeff = (-4.0 * A + 8.0 * A * d - 5.0 * A * d * d + A * d * d * d);
    else
        coeff = 0.0;

    return coeff;
}

static const char *const var_names[] = {   "W",   "H",        NULL };
enum                                   { VAR_W, VAR_H, VAR_VARS_NB };

static int config_input(AVFilterLink *inlink)
{
    double x0, x1, x2, x3, x4, x5, x6, x7, x8, q;
    double t0, t1, t2, t3;
    AVFilterContext *ctx = inlink->dst;
    PerspectiveContext *s = ctx->priv;
    double (*ref)[2] = s->ref;
    const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
    double values[VAR_VARS_NB] = { [VAR_W] = inlink->w, [VAR_H] = inlink->h };
    int h = inlink->h;
    int w = inlink->w;
    int x, y, i, j, ret;

    for (i = 0; i < 4; i++) {
        for (j = 0; j < 2; j++) {
            if (!s->expr_str[i][j])
                return AVERROR(EINVAL);
            ret = av_expr_parse_and_eval(&s->ref[i][j], s->expr_str[i][j],
                                         var_names, &values[0],
                                         NULL, NULL, NULL, NULL,
                                         0, 0, ctx);
            if (ret < 0)
                return ret;
        }
    }

    s->hsub = desc->log2_chroma_w;
    s->vsub = desc->log2_chroma_h;
    s->nb_planes = av_pix_fmt_count_planes(inlink->format);
    if ((ret = av_image_fill_linesizes(s->linesize, inlink->format, inlink->w)) < 0)
        return ret;

    s->height[1] = s->height[2] = FF_CEIL_RSHIFT(inlink->h, desc->log2_chroma_h);
    s->height[0] = s->height[3] = inlink->h;

    s->pv = av_realloc_f(s->pv, w * h, 2 * sizeof(*s->pv));
    if (!s->pv)
        return AVERROR(ENOMEM);

    switch (s->sense) {
    case PERSPECTIVE_SENSE_SOURCE:
        x6 = ((ref[0][0] - ref[1][0] - ref[2][0] + ref[3][0]) *
              (ref[2][1] - ref[3][1]) -
             ( ref[0][1] - ref[1][1] - ref[2][1] + ref[3][1]) *
              (ref[2][0] - ref[3][0])) * h;
        x7 = ((ref[0][1] - ref[1][1] - ref[2][1] + ref[3][1]) *
              (ref[1][0] - ref[3][0]) -
             ( ref[0][0] - ref[1][0] - ref[2][0] + ref[3][0]) *
              (ref[1][1] - ref[3][1])) * w;
        q =  ( ref[1][0] - ref[3][0]) * (ref[2][1] - ref[3][1]) -
             ( ref[2][0] - ref[3][0]) * (ref[1][1] - ref[3][1]);

        x0 = q * (ref[1][0] - ref[0][0]) * h + x6 * ref[1][0];
        x1 = q * (ref[2][0] - ref[0][0]) * w + x7 * ref[2][0];
        x2 = q *  ref[0][0] * w * h;
        x3 = q * (ref[1][1] - ref[0][1]) * h + x6 * ref[1][1];
        x4 = q * (ref[2][1] - ref[0][1]) * w + x7 * ref[2][1];
        x5 = q *  ref[0][1] * w * h;
        x8 = q * w * h;
        break;
    case PERSPECTIVE_SENSE_DESTINATION:
        t0 = ref[0][0] * (ref[3][1] - ref[1][1]) +
             ref[1][0] * (ref[0][1] - ref[3][1]) +
             ref[3][0] * (ref[1][1] - ref[0][1]);
        t1 = ref[1][0] * (ref[2][1] - ref[3][1]) +
             ref[2][0] * (ref[3][1] - ref[1][1]) +
             ref[3][0] * (ref[1][1] - ref[2][1]);
        t2 = ref[0][0] * (ref[3][1] - ref[2][1]) +
             ref[2][0] * (ref[0][1] - ref[3][1]) +
             ref[3][0] * (ref[2][1] - ref[0][1]);
        t3 = ref[0][0] * (ref[1][1] - ref[2][1]) +
             ref[1][0] * (ref[2][1] - ref[0][1]) +
             ref[2][0] * (ref[0][1] - ref[1][1]);

        x0 = t0 * t1 * w * (ref[2][1] - ref[0][1]);
        x1 = t0 * t1 * w * (ref[0][0] - ref[2][0]);
        x2 = t0 * t1 * w * (ref[0][1] * ref[2][0] - ref[0][0] * ref[2][1]);
        x3 = t1 * t2 * h * (ref[1][1] - ref[0][1]);
        x4 = t1 * t2 * h * (ref[0][0] - ref[1][0]);
        x5 = t1 * t2 * h * (ref[0][1] * ref[1][0] - ref[0][0] * ref[1][1]);
        x6 = t1 * t2 * (ref[1][1] - ref[0][1]) +
             t0 * t3 * (ref[2][1] - ref[3][1]);
        x7 = t1 * t2 * (ref[0][0] - ref[1][0]) +
             t0 * t3 * (ref[3][0] - ref[2][0]);
        x8 = t1 * t2 * (ref[0][1] * ref[1][0] - ref[0][0] * ref[1][1]) +
             t0 * t3 * (ref[2][0] * ref[3][1] - ref[2][1] * ref[3][0]);
        break;
    }

    for (y = 0; y < h; y++){
        for (x = 0; x < w; x++){
            int u, v;

            u = (int)floor(SUB_PIXELS * (x0 * x + x1 * y + x2) /
                                        (x6 * x + x7 * y + x8) + 0.5);
            v = (int)floor(SUB_PIXELS * (x3 * x + x4 * y + x5) /
                                        (x6 * x + x7 * y + x8) + 0.5);

            s->pv[x + y * w][0] = u;
            s->pv[x + y * w][1] = v;
        }
    }

    for (i = 0; i < SUB_PIXELS; i++){
        double d = i / (double)SUB_PIXELS;
        double temp[4];
        double sum = 0;

        for (j = 0; j < 4; j++)
            temp[j] = get_coeff(j - d - 1);

        for (j = 0; j < 4; j++)
            sum += temp[j];

        for (j = 0; j < 4; j++)
            s->coeff[i][j] = (int)floor((1 << COEFF_BITS) * temp[j] / sum + 0.5);
    }

    return 0;
}

typedef struct ThreadData {
    uint8_t *dst;
    int dst_linesize;
    uint8_t *src;
    int src_linesize;
    int w, h;
    int hsub, vsub;
} ThreadData;

static int resample_cubic(AVFilterContext *ctx, void *arg,
                          int job, int nb_jobs)
{
    PerspectiveContext *s = ctx->priv;
    ThreadData *td = arg;
    uint8_t *dst = td->dst;
    int dst_linesize = td->dst_linesize;
    uint8_t *src = td->src;
    int src_linesize = td->src_linesize;
    int w = td->w;
    int h = td->h;
    int hsub = td->hsub;
    int vsub = td->vsub;
    int start = (h * job) / nb_jobs;
    int end   = (h * (job+1)) / nb_jobs;
    const int linesize = s->linesize[0];
    int x, y;

    for (y = start; y < end; y++) {
        int sy = y << vsub;
        for (x = 0; x < w; x++) {
            int u, v, subU, subV, sum, sx;

            sx   = x << hsub;
            u    = s->pv[sx + sy * linesize][0] >> hsub;
            v    = s->pv[sx + sy * linesize][1] >> vsub;
            subU = u & (SUB_PIXELS - 1);
            subV = v & (SUB_PIXELS - 1);
            u  >>= SUB_PIXEL_BITS;
            v  >>= SUB_PIXEL_BITS;

            if (u > 0 && v > 0 && u < w - 2 && v < h - 2){
                const int index = u + v*src_linesize;
                const int a = s->coeff[subU][0];
                const int b = s->coeff[subU][1];
                const int c = s->coeff[subU][2];
                const int d = s->coeff[subU][3];

                sum = s->coeff[subV][0] * (a * src[index - 1 -     src_linesize] + b * src[index - 0 -     src_linesize]  +
                                      c *      src[index + 1 -     src_linesize] + d * src[index + 2 -     src_linesize]) +
                      s->coeff[subV][1] * (a * src[index - 1                   ] + b * src[index - 0                   ]  +
                                      c *      src[index + 1                   ] + d * src[index + 2                   ]) +
                      s->coeff[subV][2] * (a * src[index - 1 +     src_linesize] + b * src[index - 0 +     src_linesize]  +
                                      c *      src[index + 1 +     src_linesize] + d * src[index + 2 +     src_linesize]) +
                      s->coeff[subV][3] * (a * src[index - 1 + 2 * src_linesize] + b * src[index - 0 + 2 * src_linesize]  +
                                      c *      src[index + 1 + 2 * src_linesize] + d * src[index + 2 + 2 * src_linesize]);
            } else {
                int dx, dy;

                sum = 0;

                for (dy = 0; dy < 4; dy++) {
                    int iy = v + dy - 1;

                    if (iy < 0)
                        iy = 0;
                    else if (iy >= h)
                        iy = h-1;
                    for (dx = 0; dx < 4; dx++) {
                        int ix = u + dx - 1;

                        if (ix < 0)
                            ix = 0;
                        else if (ix >= w)
                            ix = w - 1;

                        sum += s->coeff[subU][dx] * s->coeff[subV][dy] * src[ ix + iy * src_linesize];
                    }
                }
            }

            sum = (sum + (1<<(COEFF_BITS * 2 - 1))) >> (COEFF_BITS * 2);
            sum = av_clip(sum, 0, 255);
            dst[x + y * dst_linesize] = sum;
        }
    }
    return 0;
}

static int resample_linear(AVFilterContext *ctx, void *arg,
                           int job, int nb_jobs)
{
    PerspectiveContext *s = ctx->priv;
    ThreadData *td = arg;
    uint8_t *dst = td->dst;
    int dst_linesize = td->dst_linesize;
    uint8_t *src = td->src;
    int src_linesize = td->src_linesize;
    int w = td->w;
    int h = td->h;
    int hsub = td->hsub;
    int vsub = td->vsub;
    int start = (h * job) / nb_jobs;
    int end   = (h * (job+1)) / nb_jobs;
    const int linesize = s->linesize[0];
    int x, y;

    for (y = start; y < end; y++){
        int sy = y << vsub;
        for (x = 0; x < w; x++){
            int u, v, subU, subV, sum, sx, index, subUI, subVI;

            sx   = x << hsub;
            u    = s->pv[sx + sy * linesize][0] >> hsub;
            v    = s->pv[sx + sy * linesize][1] >> vsub;
            subU = u & (SUB_PIXELS - 1);
            subV = v & (SUB_PIXELS - 1);
            u  >>= SUB_PIXEL_BITS;
            v  >>= SUB_PIXEL_BITS;

            index = u + v * src_linesize;
            subUI = SUB_PIXELS - subU;
            subVI = SUB_PIXELS - subV;

            if ((unsigned)u < (unsigned)(w - 1)){
                if((unsigned)v < (unsigned)(h - 1)){
                    sum = subVI * (subUI * src[index] + subU * src[index + 1]) +
                          subV  * (subUI * src[index + src_linesize] + subU * src[index + src_linesize + 1]);
                    sum = (sum + (1 << (SUB_PIXEL_BITS * 2 - 1)))>> (SUB_PIXEL_BITS * 2);
                } else {
                    if (v < 0)
                        v = 0;
                    else
                        v = h - 1;
                    index = u + v * src_linesize;
                    sum   = subUI * src[index] + subU * src[index + 1];
                    sum   = (sum + (1 << (SUB_PIXEL_BITS - 1))) >> SUB_PIXEL_BITS;
                }
            } else {
                if (u < 0)
                    u = 0;
                else
                    u = w - 1;
                if ((unsigned)v < (unsigned)(h - 1)){
                    index = u + v * src_linesize;
                    sum   = subVI * src[index] + subV * src[index + src_linesize];
                    sum   = (sum + (1 << (SUB_PIXEL_BITS - 1))) >> SUB_PIXEL_BITS;
                } else {
                    if (v < 0)
                        v = 0;
                    else
                        v = h - 1;
                    index = u + v * src_linesize;
                    sum   = src[index];
                }
            }

            sum = av_clip(sum, 0, 255);
            dst[x + y * dst_linesize] = sum;
        }
    }
    return 0;
}

static av_cold int init(AVFilterContext *ctx)
{
    PerspectiveContext *s = ctx->priv;

    switch (s->interpolation) {
    case LINEAR: s->perspective = resample_linear; break;
    case CUBIC:  s->perspective = resample_cubic;  break;
    }

    return 0;
}

static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
{
    AVFilterContext *ctx = inlink->dst;
    AVFilterLink *outlink = ctx->outputs[0];
    PerspectiveContext *s = ctx->priv;
    AVFrame *out;
    int plane;

    out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
    if (!out) {
        av_frame_free(&frame);
        return AVERROR(ENOMEM);
    }
    av_frame_copy_props(out, frame);

    for (plane = 0; plane < s->nb_planes; plane++) {
        int hsub = plane == 1 || plane == 2 ? s->hsub : 0;
        int vsub = plane == 1 || plane == 2 ? s->vsub : 0;
        ThreadData td = {.dst = out->data[plane],
                         .dst_linesize = out->linesize[plane],
                         .src = frame->data[plane],
                         .src_linesize = frame->linesize[plane],
                         .w = s->linesize[plane],
                         .h = s->height[plane],
                         .hsub = hsub,
                         .vsub = vsub };
        ctx->internal->execute(ctx, s->perspective, &td, NULL, FFMIN(td.h, ctx->graph->nb_threads));
    }

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

static av_cold void uninit(AVFilterContext *ctx)
{
    PerspectiveContext *s = ctx->priv;

    av_freep(&s->pv);
}

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

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

AVFilter ff_vf_perspective = {
    .name          = "perspective",
    .description   = NULL_IF_CONFIG_SMALL("Correct the perspective of video."),
    .priv_size     = sizeof(PerspectiveContext),
    .init          = init,
    .uninit        = uninit,
    .query_formats = query_formats,
    .inputs        = perspective_inputs,
    .outputs       = perspective_outputs,
    .priv_class    = &perspective_class,
    .flags         = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC | AVFILTER_FLAG_SLICE_THREADS,
};
Commit	Line	Data
2ba45a60 DM	1	/*
	2	* Copyright (c) 2002 Michael Niedermayer <michaelni@gmx.at>
	3	* Copyright (c) 2013 Paul B Mahol
	4	*
	5	* This file is part of FFmpeg.
	6	*
	7	* FFmpeg is free software; you can redistribute it and/or
	8	* modify it under the terms of the GNU General Public
	9	* License as published by the Free Software Foundation; either
	10	* version 2 of the License, or (at your option) any later version.
	11	*
	12	* FFmpeg is distributed in the hope that it will be useful,
	13	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	14	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	15	* GNU General Public License for more details.
	16	*
	17	* You should have received a copy of the GNU General Public License along
	18	* with FFmpeg; if not, write to the Free Software
	19	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
	20	*/
	21
	22	#include "libavutil/eval.h"
	23	#include "libavutil/imgutils.h"
	24	#include "libavutil/pixdesc.h"
	25	#include "libavutil/opt.h"
	26	#include "avfilter.h"
	27	#include "formats.h"
	28	#include "internal.h"
	29	#include "video.h"
	30
	31	#define SUB_PIXEL_BITS 8
	32	#define SUB_PIXELS (1 << SUB_PIXEL_BITS)
	33	#define COEFF_BITS 11
	34
	35	#define LINEAR 0
	36	#define CUBIC 1
	37
	38	typedef struct PerspectiveContext {
	39	const AVClass *class;
	40	char *expr_str[4][2];
	41	double ref[4][2];
	42	int32_t (*pv)[2];
	43	int32_t coeff[SUB_PIXELS][4];
	44	int interpolation;
	45	int linesize[4];
	46	int height[4];
	47	int hsub, vsub;
	48	int nb_planes;
f6fa7814	49	int sense;
2ba45a60 DM	50
	51	int (perspective)(AVFilterContext ctx,
	52	void *arg, int job, int nb_jobs);
	53	} PerspectiveContext;
	54
	55	#define OFFSET(x) offsetof(PerspectiveContext, x)
	56	#define FLAGS AV_OPT_FLAG_FILTERING_PARAM\|AV_OPT_FLAG_VIDEO_PARAM
	57
f6fa7814 DM	58	enum PERSPECTIVESense {
	59	PERSPECTIVE_SENSE_SOURCE = 0, ///< coordinates give locations in source of corners of destination.
	60	PERSPECTIVE_SENSE_DESTINATION = 1, ///< coordinates give locations in destination of corners of source.
	61	};
	62
2ba45a60 DM	63	static const AVOption perspective_options[] = {
	64	{ "x0", "set top left x coordinate", OFFSET(expr_str[0][0]), AV_OPT_TYPE_STRING, {.str="0"}, 0, 0, FLAGS },
	65	{ "y0", "set top left y coordinate", OFFSET(expr_str[0][1]), AV_OPT_TYPE_STRING, {.str="0"}, 0, 0, FLAGS },
	66	{ "x1", "set top right x coordinate", OFFSET(expr_str[1][0]), AV_OPT_TYPE_STRING, {.str="W"}, 0, 0, FLAGS },
	67	{ "y1", "set top right y coordinate", OFFSET(expr_str[1][1]), AV_OPT_TYPE_STRING, {.str="0"}, 0, 0, FLAGS },
	68	{ "x2", "set bottom left x coordinate", OFFSET(expr_str[2][0]), AV_OPT_TYPE_STRING, {.str="0"}, 0, 0, FLAGS },
	69	{ "y2", "set bottom left y coordinate", OFFSET(expr_str[2][1]), AV_OPT_TYPE_STRING, {.str="H"}, 0, 0, FLAGS },
	70	{ "x3", "set bottom right x coordinate", OFFSET(expr_str[3][0]), AV_OPT_TYPE_STRING, {.str="W"}, 0, 0, FLAGS },
	71	{ "y3", "set bottom right y coordinate", OFFSET(expr_str[3][1]), AV_OPT_TYPE_STRING, {.str="H"}, 0, 0, FLAGS },
	72	{ "interpolation", "set interpolation", OFFSET(interpolation), AV_OPT_TYPE_INT, {.i64=LINEAR}, 0, 1, FLAGS, "interpolation" },
	73	{ "linear", "", 0, AV_OPT_TYPE_CONST, {.i64=LINEAR}, 0, 0, FLAGS, "interpolation" },
	74	{ "cubic", "", 0, AV_OPT_TYPE_CONST, {.i64=CUBIC}, 0, 0, FLAGS, "interpolation" },
f6fa7814 DM	75	{ "sense", "specify the sense of the coordinates", OFFSET(sense), AV_OPT_TYPE_INT, {.i64=PERSPECTIVE_SENSE_SOURCE}, 0, 1, FLAGS, "sense"},
	76	{ "source", "specify locations in source to send to corners in destination",
	77	0, AV_OPT_TYPE_CONST, {.i64=PERSPECTIVE_SENSE_SOURCE}, 0, 0, FLAGS, "sense"},
	78	{ "destination", "specify locations in destination to send corners of source",
	79	0, AV_OPT_TYPE_CONST, {.i64=PERSPECTIVE_SENSE_DESTINATION}, 0, 0, FLAGS, "sense"},
	80
2ba45a60 DM	81	{ NULL }
	82	};
	83
	84	AVFILTER_DEFINE_CLASS(perspective);
	85
	86	static int query_formats(AVFilterContext *ctx)
	87	{
	88	static const enum AVPixelFormat pix_fmts[] = {
	89	AV_PIX_FMT_YUVA444P, AV_PIX_FMT_YUVA422P, AV_PIX_FMT_YUVA420P,
	90	AV_PIX_FMT_YUVJ444P, AV_PIX_FMT_YUVJ440P, AV_PIX_FMT_YUVJ422P,AV_PIX_FMT_YUVJ420P, AV_PIX_FMT_YUVJ411P,
	91	AV_PIX_FMT_YUV444P, AV_PIX_FMT_YUV440P, AV_PIX_FMT_YUV422P, AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUV411P, AV_PIX_FMT_YUV410P,
	92	AV_PIX_FMT_GBRP, AV_PIX_FMT_GBRAP, AV_PIX_FMT_GRAY8, AV_PIX_FMT_NONE
	93	};
	94
	95	ff_set_common_formats(ctx, ff_make_format_list(pix_fmts));
	96	return 0;
	97	}
	98
	99	static inline double get_coeff(double d)
	100	{
	101	double coeff, A = -0.60;
	102
	103	d = fabs(d);
	104
	105	if (d < 1.0)
	106	coeff = (1.0 - (A + 3.0) * d * d + (A + 2.0) * d * d * d);
	107	else if (d < 2.0)
	108	coeff = (-4.0 * A + 8.0 * A * d - 5.0 * A * d * d + A * d * d * d);
	109	else
	110	coeff = 0.0;
	111
	112	return coeff;
	113	}
	114
	115	static const char *const var_names[] = { "W", "H", NULL };
	116	enum { VAR_W, VAR_H, VAR_VARS_NB };
	117
	118	static int config_input(AVFilterLink *inlink)
	119	{
f6fa7814 DM	120	double x0, x1, x2, x3, x4, x5, x6, x7, x8, q;
f6fa7814 DM	121	double t0, t1, t2, t3;
2ba45a60 DM	122	AVFilterContext *ctx = inlink->dst;
	123	PerspectiveContext *s = ctx->priv;
	124	double (*ref)[2] = s->ref;
	125	const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
	126	double values[VAR_VARS_NB] = { [VAR_W] = inlink->w, [VAR_H] = inlink->h };
	127	int h = inlink->h;
	128	int w = inlink->w;
	129	int x, y, i, j, ret;
	130
	131	for (i = 0; i < 4; i++) {
	132	for (j = 0; j < 2; j++) {
	133	if (!s->expr_str[i][j])
	134	return AVERROR(EINVAL);
	135	ret = av_expr_parse_and_eval(&s->ref[i][j], s->expr_str[i][j],
	136	var_names, &values[0],
	137	NULL, NULL, NULL, NULL,
	138	0, 0, ctx);
	139	if (ret < 0)
	140	return ret;
	141	}
	142	}
	143
	144	s->hsub = desc->log2_chroma_w;
	145	s->vsub = desc->log2_chroma_h;
	146	s->nb_planes = av_pix_fmt_count_planes(inlink->format);
	147	if ((ret = av_image_fill_linesizes(s->linesize, inlink->format, inlink->w)) < 0)
	148	return ret;
	149
	150	s->height[1] = s->height[2] = FF_CEIL_RSHIFT(inlink->h, desc->log2_chroma_h);
	151	s->height[0] = s->height[3] = inlink->h;
	152
	153	s->pv = av_realloc_f(s->pv, w * h, 2 * sizeof(*s->pv));
	154	if (!s->pv)
	155	return AVERROR(ENOMEM);
	156
f6fa7814 DM	157	switch (s->sense) {
	158	case PERSPECTIVE_SENSE_SOURCE:
	159	x6 = ((ref[0][0] - ref[1][0] - ref[2][0] + ref[3][0]) *
	160	(ref[2][1] - ref[3][1]) -
	161	( ref[0][1] - ref[1][1] - ref[2][1] + ref[3][1]) *
	162	(ref[2][0] - ref[3][0])) * h;
	163	x7 = ((ref[0][1] - ref[1][1] - ref[2][1] + ref[3][1]) *
	164	(ref[1][0] - ref[3][0]) -
	165	( ref[0][0] - ref[1][0] - ref[2][0] + ref[3][0]) *
	166	(ref[1][1] - ref[3][1])) * w;
	167	q = ( ref[1][0] - ref[3][0]) * (ref[2][1] - ref[3][1]) -
	168	( ref[2][0] - ref[3][0]) * (ref[1][1] - ref[3][1]);
	169
	170	x0 = q * (ref[1][0] - ref[0][0]) * h + x6 * ref[1][0];
	171	x1 = q * (ref[2][0] - ref[0][0]) * w + x7 * ref[2][0];
	172	x2 = q * ref[0][0] * w * h;
	173	x3 = q * (ref[1][1] - ref[0][1]) * h + x6 * ref[1][1];
	174	x4 = q * (ref[2][1] - ref[0][1]) * w + x7 * ref[2][1];
	175	x5 = q * ref[0][1] * w * h;
	176	x8 = q * w * h;
	177	break;
	178	case PERSPECTIVE_SENSE_DESTINATION:
	179	t0 = ref[0][0] * (ref[3][1] - ref[1][1]) +
	180	ref[1][0] * (ref[0][1] - ref[3][1]) +
	181	ref[3][0] * (ref[1][1] - ref[0][1]);
	182	t1 = ref[1][0] * (ref[2][1] - ref[3][1]) +
	183	ref[2][0] * (ref[3][1] - ref[1][1]) +
	184	ref[3][0] * (ref[1][1] - ref[2][1]);
	185	t2 = ref[0][0] * (ref[3][1] - ref[2][1]) +
	186	ref[2][0] * (ref[0][1] - ref[3][1]) +
	187	ref[3][0] * (ref[2][1] - ref[0][1]);
	188	t3 = ref[0][0] * (ref[1][1] - ref[2][1]) +
	189	ref[1][0] * (ref[2][1] - ref[0][1]) +
	190	ref[2][0] * (ref[0][1] - ref[1][1]);
	191
	192	x0 = t0 * t1 * w * (ref[2][1] - ref[0][1]);
	193	x1 = t0 * t1 * w * (ref[0][0] - ref[2][0]);
	194	x2 = t0 * t1 * w * (ref[0][1] * ref[2][0] - ref[0][0] * ref[2][1]);
	195	x3 = t1 * t2 * h * (ref[1][1] - ref[0][1]);
	196	x4 = t1 * t2 * h * (ref[0][0] - ref[1][0]);
	197	x5 = t1 * t2 * h * (ref[0][1] * ref[1][0] - ref[0][0] * ref[1][1]);
	198	x6 = t1 * t2 * (ref[1][1] - ref[0][1]) +
	199	t0 * t3 * (ref[2][1] - ref[3][1]);
	200	x7 = t1 * t2 * (ref[0][0] - ref[1][0]) +
	201	t0 * t3 * (ref[3][0] - ref[2][0]);
	202	x8 = t1 * t2 * (ref[0][1] * ref[1][0] - ref[0][0] * ref[1][1]) +
	203	t0 * t3 * (ref[2][0] * ref[3][1] - ref[2][1] * ref[3][0]);
	204	break;
	205	}
2ba45a60 DM	206
	207	for (y = 0; y < h; y++){
	208	for (x = 0; x < w; x++){
	209	int u, v;
	210
	211	u = (int)floor(SUB_PIXELS * (x0 * x + x1 * y + x2) /
f6fa7814	212	(x6 * x + x7 * y + x8) + 0.5);
2ba45a60	213	v = (int)floor(SUB_PIXELS * (x3 * x + x4 * y + x5) /
f6fa7814	214	(x6 * x + x7 * y + x8) + 0.5);
2ba45a60 DM	215
	216	s->pv[x + y * w][0] = u;
	217	s->pv[x + y * w][1] = v;
	218	}
	219	}
	220
	221	for (i = 0; i < SUB_PIXELS; i++){
	222	double d = i / (double)SUB_PIXELS;
	223	double temp[4];
	224	double sum = 0;
	225
	226	for (j = 0; j < 4; j++)
	227	temp[j] = get_coeff(j - d - 1);
	228
	229	for (j = 0; j < 4; j++)
	230	sum += temp[j];
	231
	232	for (j = 0; j < 4; j++)
	233	s->coeff[i][j] = (int)floor((1 << COEFF_BITS) * temp[j] / sum + 0.5);
	234	}
	235
	236	return 0;
	237	}
	238
	239	typedef struct ThreadData {
	240	uint8_t *dst;
	241	int dst_linesize;
	242	uint8_t *src;
	243	int src_linesize;
	244	int w, h;
	245	int hsub, vsub;
	246	} ThreadData;
	247
	248	static int resample_cubic(AVFilterContext ctx, void arg,
	249	int job, int nb_jobs)
	250	{
	251	PerspectiveContext *s = ctx->priv;
	252	ThreadData *td = arg;
	253	uint8_t *dst = td->dst;
	254	int dst_linesize = td->dst_linesize;
	255	uint8_t *src = td->src;
	256	int src_linesize = td->src_linesize;
	257	int w = td->w;
	258	int h = td->h;
	259	int hsub = td->hsub;
	260	int vsub = td->vsub;
	261	int start = (h * job) / nb_jobs;
	262	int end = (h * (job+1)) / nb_jobs;
	263	const int linesize = s->linesize[0];
	264	int x, y;
	265
	266	for (y = start; y < end; y++) {
	267	int sy = y << vsub;
	268	for (x = 0; x < w; x++) {
	269	int u, v, subU, subV, sum, sx;
	270
	271	sx = x << hsub;
	272	u = s->pv[sx + sy * linesize][0] >> hsub;
	273	v = s->pv[sx + sy * linesize][1] >> vsub;
	274	subU = u & (SUB_PIXELS - 1);
	275	subV = v & (SUB_PIXELS - 1);
	276	u >>= SUB_PIXEL_BITS;
	277	v >>= SUB_PIXEL_BITS;
	278
279	if (u > 0 && v > 0 && u < w - 2 && v < h - 2){
280	const int index = u + v*src_linesize;
281	const int a = s->coeff[subU][0];
282	const int b = s->coeff[subU][1];
283	const int c = s->coeff[subU][2];
284	const int d = s->coeff[subU][3];
285
286	sum = s->coeff[subV][0] * (a * src[index - 1 - src_linesize] + b * src[index - 0 - src_linesize] +
287	c * src[index + 1 - src_linesize] + d * src[index + 2 - src_linesize]) +
288	s->coeff[subV][1] * (a * src[index - 1 ] + b * src[index - 0 ] +
289	c * src[index + 1 ] + d * src[index + 2 ]) +
290	s->coeff[subV][2] * (a * src[index - 1 + src_linesize] + b * src[index - 0 + src_linesize] +
291	c * src[index + 1 + src_linesize] + d * src[index + 2 + src_linesize]) +
292	s->coeff[subV][3] * (a * src[index - 1 + 2 * src_linesize] + b * src[index - 0 + 2 * src_linesize] +
293	c * src[index + 1 + 2 * src_linesize] + d * src[index + 2 + 2 * src_linesize]);
294	} else {
295	int dx, dy;
296
297	sum = 0;
298
299	for (dy = 0; dy < 4; dy++) {
300	int iy = v + dy - 1;
301
302	if (iy < 0)
303	iy = 0;
304	else if (iy >= h)
305	iy = h-1;
306	for (dx = 0; dx < 4; dx++) {
307	int ix = u + dx - 1;
308
309	if (ix < 0)
310	ix = 0;
311	else if (ix >= w)
312	ix = w - 1;
313
314	sum += s->coeff[subU][dx] * s->coeff[subV][dy] * src[ ix + iy * src_linesize];
315	}
316	}
317	}
318
319	sum = (sum + (1<<(COEFF_BITS * 2 - 1))) >> (COEFF_BITS * 2);
320	sum = av_clip(sum, 0, 255);
321	dst[x + y * dst_linesize] = sum;
322	}
323	}
324	return 0;
325	}
326
327	static int resample_linear(AVFilterContext ctx, void arg,
328	int job, int nb_jobs)
329	{
330	PerspectiveContext *s = ctx->priv;
331	ThreadData *td = arg;
332	uint8_t *dst = td->dst;
333	int dst_linesize = td->dst_linesize;
334	uint8_t *src = td->src;
335	int src_linesize = td->src_linesize;
336	int w = td->w;
337	int h = td->h;
338	int hsub = td->hsub;
339	int vsub = td->vsub;
340	int start = (h * job) / nb_jobs;
341	int end = (h * (job+1)) / nb_jobs;
342	const int linesize = s->linesize[0];
343	int x, y;
344
345	for (y = start; y < end; y++){
346	int sy = y << vsub;
347	for (x = 0; x < w; x++){
348	int u, v, subU, subV, sum, sx, index, subUI, subVI;
349
350	sx = x << hsub;
351	u = s->pv[sx + sy * linesize][0] >> hsub;
352	v = s->pv[sx + sy * linesize][1] >> vsub;
353	subU = u & (SUB_PIXELS - 1);
354	subV = v & (SUB_PIXELS - 1);
355	u >>= SUB_PIXEL_BITS;
356	v >>= SUB_PIXEL_BITS;
357
358	index = u + v * src_linesize;
359	subUI = SUB_PIXELS - subU;
360	subVI = SUB_PIXELS - subV;
361
362	if ((unsigned)u < (unsigned)(w - 1)){
363	if((unsigned)v < (unsigned)(h - 1)){
364	sum = subVI * (subUI * src[index] + subU * src[index + 1]) +
365	subV * (subUI * src[index + src_linesize] + subU * src[index + src_linesize + 1]);
366	sum = (sum + (1 << (SUB_PIXEL_BITS * 2 - 1)))>> (SUB_PIXEL_BITS * 2);
367	} else {
368	if (v < 0)
369	v = 0;
370	else
371	v = h - 1;
372	index = u + v * src_linesize;
373	sum = subUI * src[index] + subU * src[index + 1];
374	sum = (sum + (1 << (SUB_PIXEL_BITS - 1))) >> SUB_PIXEL_BITS;
375	}
376	} else {
377	if (u < 0)
378	u = 0;
379	else
380	u = w - 1;
381	if ((unsigned)v < (unsigned)(h - 1)){
382	index = u + v * src_linesize;
383	sum = subVI * src[index] + subV * src[index + src_linesize];
384	sum = (sum + (1 << (SUB_PIXEL_BITS - 1))) >> SUB_PIXEL_BITS;
385	} else {
386	if (v < 0)
387	v = 0;
388	else
389	v = h - 1;
390	index = u + v * src_linesize;
391	sum = src[index];
392	}
393	}
394
395	sum = av_clip(sum, 0, 255);
396	dst[x + y * dst_linesize] = sum;
397	}
398	}
399	return 0;
400	}
401
402	static av_cold int init(AVFilterContext *ctx)
403	{
404	PerspectiveContext *s = ctx->priv;
405
406	switch (s->interpolation) {
407	case LINEAR: s->perspective = resample_linear; break;
408	case CUBIC: s->perspective = resample_cubic; break;
409	}
410
411	return 0;
412	}
413
414	static int filter_frame(AVFilterLink inlink, AVFrame frame)
415	{
416	AVFilterContext *ctx = inlink->dst;
417	AVFilterLink *outlink = ctx->outputs[0];
418	PerspectiveContext *s = ctx->priv;
419	AVFrame *out;
420	int plane;
421
422	out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
423	if (!out) {
424	av_frame_free(&frame);
425	return AVERROR(ENOMEM);
426	}
427	av_frame_copy_props(out, frame);
428
429	for (plane = 0; plane < s->nb_planes; plane++) {
430	int hsub = plane == 1 \|\| plane == 2 ? s->hsub : 0;
431	int vsub = plane == 1 \|\| plane == 2 ? s->vsub : 0;
432	ThreadData td = {.dst = out->data[plane],
433	.dst_linesize = out->linesize[plane],
434	.src = frame->data[plane],
435	.src_linesize = frame->linesize[plane],
436	.w = s->linesize[plane],
437	.h = s->height[plane],
438	.hsub = hsub,
439	.vsub = vsub };
440	ctx->internal->execute(ctx, s->perspective, &td, NULL, FFMIN(td.h, ctx->graph->nb_threads));
441	}
442
443	av_frame_free(&frame);
444	return ff_filter_frame(outlink, out);
445	}
446
447	static av_cold void uninit(AVFilterContext *ctx)
448	{
449	PerspectiveContext *s = ctx->priv;
450
451	av_freep(&s->pv);
452	}
453
454	static const AVFilterPad perspective_inputs[] = {
455	{
456	.name = "default",
457	.type = AVMEDIA_TYPE_VIDEO,
458	.filter_frame = filter_frame,
459	.config_props = config_input,
460	},
461	{ NULL }
462	};
463
464	static const AVFilterPad perspective_outputs[] = {
465	{
466	.name = "default",
467	.type = AVMEDIA_TYPE_VIDEO,
468	},
469	{ NULL }
470	};
471
472	AVFilter ff_vf_perspective = {
473	.name = "perspective",
474	.description = NULL_IF_CONFIG_SMALL("Correct the perspective of video."),
475	.priv_size = sizeof(PerspectiveContext),
476	.init = init,
477	.uninit = uninit,
478	.query_formats = query_formats,
479	.inputs = perspective_inputs,
480	.outputs = perspective_outputs,
481	.priv_class = &perspective_class,
482	.flags = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC \| AVFILTER_FLAG_SLICE_THREADS,
483	};