libavfilter/vf_bwdif.c - third_party/ffmpeg - Git at Google

 /*
  * BobWeaver Deinterlacing Filter
  * Copyright (C) 2016 Thomas Mundt <loudmax@yahoo.de>
  *
  * Based on YADIF (Yet Another Deinterlacing Filter)
  * Copyright (C) 2006-2011 Michael Niedermayer <michaelni@gmx.at>
  *               2010      James Darnley <james.darnley@gmail.com>
  *
  * With use of Weston 3 Field Deinterlacing Filter algorithm
  * Copyright (C) 2012 British Broadcasting Corporation, All Rights Reserved
  * Author of de-interlace algorithm: Jim Easterbrook for BBC R&D
  * Based on the process described by Martin Weston for BBC R&D
  *
  * 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
  */

 #include "libavutil/avassert.h"
 #include "libavutil/common.h"
 #include "libavutil/opt.h"
 #include "libavutil/pixdesc.h"
 #include "libavutil/imgutils.h"
 #include "avfilter.h"
 #include "formats.h"
 #include "internal.h"
 #include "video.h"
 #include "bwdif.h"

 /*
  * Filter coefficients coef_lf and coef_hf taken from BBC PH-2071 (Weston 3 Field Deinterlacer).
  * Used when there is spatial and temporal interpolation.
  * Filter coefficients coef_sp are used when there is spatial interpolation only.
  * Adjusted for matching visual sharpness impression of spatial and temporal interpolation.
  */
 static const uint16_t coef_lf[2] = { 4309, 213 };
 static const uint16_t coef_hf[3] = { 5570, 3801, 1016 };
 static const uint16_t coef_sp[2] = { 5077, 981 };

 typedef struct ThreadData {
     AVFrame *frame;
     int plane;
     int w, h;
     int parity;
     int tff;
 } ThreadData;

 #define FILTER_INTRA() \
     for (x = 0; x < w; x++) { \
         interpol = (coef_sp[0] * (cur[mrefs] + cur[prefs]) - coef_sp[1] * (cur[mrefs3] + cur[prefs3])) >> 13; \
         dst[0] = av_clip(interpol, 0, clip_max); \
  \
         dst++; \
         cur++; \
     }

 #define FILTER1() \
     for (x = 0; x < w; x++) { \
         int c = cur[mrefs]; \
         int d = (prev2[0] + next2[0]) >> 1; \
         int e = cur[prefs]; \
         int temporal_diff0 = FFABS(prev2[0] - next2[0]); \
         int temporal_diff1 =(FFABS(prev[mrefs] - c) + FFABS(prev[prefs] - e)) >> 1; \
         int temporal_diff2 =(FFABS(next[mrefs] - c) + FFABS(next[prefs] - e)) >> 1; \
         int diff = FFMAX3(temporal_diff0 >> 1, temporal_diff1, temporal_diff2); \
  \
         if (!diff) { \
             dst[0] = d; \
         } else {

 #define SPAT_CHECK() \
             int b = ((prev2[mrefs2] + next2[mrefs2]) >> 1) - c; \
             int f = ((prev2[prefs2] + next2[prefs2]) >> 1) - e; \
             int dc = d - c; \
             int de = d - e; \
             int max = FFMAX3(de, dc, FFMIN(b, f)); \
             int min = FFMIN3(de, dc, FFMAX(b, f)); \
             diff = FFMAX3(diff, min, -max);

 #define FILTER_LINE() \
             SPAT_CHECK() \
             if (FFABS(c - e) > temporal_diff0) { \
                 interpol = (((coef_hf[0] * (prev2[0] + next2[0]) \
                     - coef_hf[1] * (prev2[mrefs2] + next2[mrefs2] + prev2[prefs2] + next2[prefs2]) \
                     + coef_hf[2] * (prev2[mrefs4] + next2[mrefs4] + prev2[prefs4] + next2[prefs4])) >> 2) \
                     + coef_lf[0] * (c + e) - coef_lf[1] * (cur[mrefs3] + cur[prefs3])) >> 13; \
             } else { \
                 interpol = (coef_sp[0] * (c + e) - coef_sp[1] * (cur[mrefs3] + cur[prefs3])) >> 13; \
             }

 #define FILTER_EDGE() \
             if (spat) { \
                 SPAT_CHECK() \
             } \
             interpol = (c + e) >> 1;

 #define FILTER2() \
             if (interpol > d + diff) \
                 interpol = d + diff; \
             else if (interpol < d - diff) \
                 interpol = d - diff; \
  \
             dst[0] = av_clip(interpol, 0, clip_max); \
         } \
  \
         dst++; \
         cur++; \
         prev++; \
         next++; \
         prev2++; \
         next2++; \
     }

 static void filter_intra(void *dst1, void *cur1, int w, int prefs, int mrefs,
                          int prefs3, int mrefs3, int parity, int clip_max)
 {
     uint8_t *dst = dst1;
     uint8_t *cur = cur1;
     int interpol, x;

     FILTER_INTRA()
 }

 static void filter_line_c(void *dst1, void *prev1, void *cur1, void *next1,
                           int w, int prefs, int mrefs, int prefs2, int mrefs2,
                           int prefs3, int mrefs3, int prefs4, int mrefs4,
                           int parity, int clip_max)
 {
     uint8_t *dst   = dst1;
     uint8_t *prev  = prev1;
     uint8_t *cur   = cur1;
     uint8_t *next  = next1;
     uint8_t *prev2 = parity ? prev : cur ;
     uint8_t *next2 = parity ? cur  : next;
     int interpol, x;

     FILTER1()
     FILTER_LINE()
     FILTER2()
 }

 static void filter_edge(void *dst1, void *prev1, void *cur1, void *next1,
                         int w, int prefs, int mrefs, int prefs2, int mrefs2,
                         int parity, int clip_max, int spat)
 {
     uint8_t *dst   = dst1;
     uint8_t *prev  = prev1;
     uint8_t *cur   = cur1;
     uint8_t *next  = next1;
     uint8_t *prev2 = parity ? prev : cur ;
     uint8_t *next2 = parity ? cur  : next;
     int interpol, x;

     FILTER1()
     FILTER_EDGE()
     FILTER2()
 }

 static void filter_intra_16bit(void *dst1, void *cur1, int w, int prefs, int mrefs,
                                int prefs3, int mrefs3, int parity, int clip_max)
 {
     uint16_t *dst = dst1;
     uint16_t *cur = cur1;
     int interpol, x;

     FILTER_INTRA()
 }

 static void filter_line_c_16bit(void *dst1, void *prev1, void *cur1, void *next1,
                                 int w, int prefs, int mrefs, int prefs2, int mrefs2,
                                 int prefs3, int mrefs3, int prefs4, int mrefs4,
                                 int parity, int clip_max)
 {
     uint16_t *dst   = dst1;
     uint16_t *prev  = prev1;
     uint16_t *cur   = cur1;
     uint16_t *next  = next1;
     uint16_t *prev2 = parity ? prev : cur ;
     uint16_t *next2 = parity ? cur  : next;
     int interpol, x;

     FILTER1()
     FILTER_LINE()
     FILTER2()
 }

 static void filter_edge_16bit(void *dst1, void *prev1, void *cur1, void *next1,
                               int w, int prefs, int mrefs, int prefs2, int mrefs2,
                               int parity, int clip_max, int spat)
 {
     uint16_t *dst   = dst1;
     uint16_t *prev  = prev1;
     uint16_t *cur   = cur1;
     uint16_t *next  = next1;
     uint16_t *prev2 = parity ? prev : cur ;
     uint16_t *next2 = parity ? cur  : next;
     int interpol, x;

     FILTER1()
     FILTER_EDGE()
     FILTER2()
 }

 static int filter_slice(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs)
 {
     BWDIFContext *s = ctx->priv;
     ThreadData *td  = arg;
     int linesize = s->cur->linesize[td->plane];
     int clip_max = (1 << (s->csp->comp[td->plane].depth)) - 1;
     int df = (s->csp->comp[td->plane].depth + 7) / 8;
     int refs = linesize / df;
     int slice_start = (td->h *  jobnr   ) / nb_jobs;
     int slice_end   = (td->h * (jobnr+1)) / nb_jobs;
     int y;

     for (y = slice_start; y < slice_end; y++) {
         if ((y ^ td->parity) & 1) {
             uint8_t *prev = &s->prev->data[td->plane][y * linesize];
             uint8_t *cur  = &s->cur ->data[td->plane][y * linesize];
             uint8_t *next = &s->next->data[td->plane][y * linesize];
             uint8_t *dst  = &td->frame->data[td->plane][y * td->frame->linesize[td->plane]];
             if (!s->inter_field) {
                 s->filter_intra(dst, cur, td->w, (y + df) < td->h ? refs : -refs,
                                 y > (df - 1) ? -refs : refs,
                                 (y + 3*df) < td->h ? 3 * refs : -refs,
                                 y > (3*df - 1) ? -3 * refs : refs,
                                 td->parity ^ td->tff, clip_max);
             } else if ((y < 4) || ((y + 5) > td->h)) {
                 s->filter_edge(dst, prev, cur, next, td->w,
                                (y + df) < td->h ? refs : -refs,
                                y > (df - 1) ? -refs : refs,
                                refs << 1, -(refs << 1),
                                td->parity ^ td->tff, clip_max,
                                (y < 2) || ((y + 3) > td->h) ? 0 : 1);
             } else {
                 s->filter_line(dst, prev, cur, next, td->w,
                                refs, -refs, refs << 1, -(refs << 1),
                                3 * refs, -3 * refs, refs << 2, -(refs << 2),
                                td->parity ^ td->tff, clip_max);
             }
         } else {
             memcpy(&td->frame->data[td->plane][y * td->frame->linesize[td->plane]],
                    &s->cur->data[td->plane][y * linesize], td->w * df);
         }
     }
     return 0;
 }

 static void filter(AVFilterContext *ctx, AVFrame *dstpic,
                    int parity, int tff)
 {
     BWDIFContext *bwdif = ctx->priv;
     ThreadData td = { .frame = dstpic, .parity = parity, .tff = tff };
     int i;

     for (i = 0; i < bwdif->csp->nb_components; i++) {
         int w = dstpic->width;
         int h = dstpic->height;

         if (i == 1 || i == 2) {
             w = AV_CEIL_RSHIFT(w, bwdif->csp->log2_chroma_w);
             h = AV_CEIL_RSHIFT(h, bwdif->csp->log2_chroma_h);
         }

         td.w     = w;
         td.h     = h;
         td.plane = i;

         ctx->internal->execute(ctx, filter_slice, &td, NULL, FFMIN(h, ff_filter_get_nb_threads(ctx)));
     }
     if (!bwdif->inter_field) {
         bwdif->inter_field = 1;
     }

     emms_c();
 }

 static int return_frame(AVFilterContext *ctx, int is_second)
 {
     BWDIFContext *bwdif = ctx->priv;
     AVFilterLink *link  = ctx->outputs[0];
     int tff, ret;

     if (bwdif->parity == -1) {
         tff = bwdif->cur->interlaced_frame ?
               bwdif->cur->top_field_first : 1;
     } else {
         tff = bwdif->parity ^ 1;
     }

     if (is_second) {
         bwdif->out = ff_get_video_buffer(link, link->w, link->h);
         if (!bwdif->out)
             return AVERROR(ENOMEM);

         av_frame_copy_props(bwdif->out, bwdif->cur);
         bwdif->out->interlaced_frame = 0;
         if (bwdif->inter_field < 0)
             bwdif->inter_field = 0;
     }

     filter(ctx, bwdif->out, tff ^ !is_second, tff);

     if (is_second) {
         int64_t cur_pts  = bwdif->cur->pts;
         int64_t next_pts = bwdif->next->pts;

         if (next_pts != AV_NOPTS_VALUE && cur_pts != AV_NOPTS_VALUE) {
             bwdif->out->pts = cur_pts + next_pts;
         } else {
             bwdif->out->pts = AV_NOPTS_VALUE;
         }
     }
     ret = ff_filter_frame(ctx->outputs[0], bwdif->out);

     bwdif->frame_pending = (bwdif->mode&1) && !is_second;
     return ret;
 }

 static int checkstride(BWDIFContext *bwdif, const AVFrame *a, const AVFrame *b)
 {
     int i;
     for (i = 0; i < bwdif->csp->nb_components; i++)
         if (a->linesize[i] != b->linesize[i])
             return 1;
     return 0;
 }

 static void fixstride(AVFilterLink *link, AVFrame *f)
 {
     AVFrame *dst = ff_default_get_video_buffer(link, f->width, f->height);
     if(!dst)
         return;
     av_frame_copy_props(dst, f);
     av_image_copy(dst->data, dst->linesize,
                   (const uint8_t **)f->data, f->linesize,
                   dst->format, dst->width, dst->height);
     av_frame_unref(f);
     av_frame_move_ref(f, dst);
     av_frame_free(&dst);
 }

 static int filter_frame(AVFilterLink *link, AVFrame *frame)
 {
     AVFilterContext *ctx = link->dst;
     BWDIFContext *bwdif = ctx->priv;

     av_assert0(frame);

     if (bwdif->frame_pending)
         return_frame(ctx, 1);

     if (bwdif->prev)
         av_frame_free(&bwdif->prev);
     bwdif->prev = bwdif->cur;
     bwdif->cur  = bwdif->next;
     bwdif->next = frame;

     if (!bwdif->cur) {
         bwdif->cur = av_frame_clone(bwdif->next);
         if (!bwdif->cur)
             return AVERROR(ENOMEM);
         bwdif->inter_field = 0;
     }

     if (checkstride(bwdif, bwdif->next, bwdif->cur)) {
         av_log(ctx, AV_LOG_VERBOSE, "Reallocating frame due to differing stride\n");
         fixstride(link, bwdif->next);
     }
     if (checkstride(bwdif, bwdif->next, bwdif->cur))
         fixstride(link, bwdif->cur);
     if (bwdif->prev && checkstride(bwdif, bwdif->next, bwdif->prev))
         fixstride(link, bwdif->prev);
     if (checkstride(bwdif, bwdif->next, bwdif->cur) || (bwdif->prev && checkstride(bwdif, bwdif->next, bwdif->prev))) {
         av_log(ctx, AV_LOG_ERROR, "Failed to reallocate frame\n");
         return -1;
     }

     if (!bwdif->prev)
         return 0;

     if ((bwdif->deint && !bwdif->cur->interlaced_frame) ||
         ctx->is_disabled ||
         (bwdif->deint && !bwdif->prev->interlaced_frame && bwdif->prev->repeat_pict) ||
         (bwdif->deint && !bwdif->next->interlaced_frame && bwdif->next->repeat_pict)
     ) {
         bwdif->out  = av_frame_clone(bwdif->cur);
         if (!bwdif->out)
             return AVERROR(ENOMEM);

         av_frame_free(&bwdif->prev);
         if (bwdif->out->pts != AV_NOPTS_VALUE)
             bwdif->out->pts *= 2;
         return ff_filter_frame(ctx->outputs[0], bwdif->out);
     }

     bwdif->out = ff_get_video_buffer(ctx->outputs[0], link->w, link->h);
     if (!bwdif->out)
         return AVERROR(ENOMEM);

     av_frame_copy_props(bwdif->out, bwdif->cur);
     bwdif->out->interlaced_frame = 0;

     if (bwdif->out->pts != AV_NOPTS_VALUE)
         bwdif->out->pts *= 2;

     return return_frame(ctx, 0);
 }

 static int request_frame(AVFilterLink *link)
 {
     AVFilterContext *ctx = link->src;
     BWDIFContext *bwdif = ctx->priv;
     int ret;

     if (bwdif->frame_pending) {
         return_frame(ctx, 1);
         return 0;
     }

     if (bwdif->eof)
         return AVERROR_EOF;

     ret  = ff_request_frame(link->src->inputs[0]);

     if (ret == AVERROR_EOF && bwdif->cur) {
         AVFrame *next = av_frame_clone(bwdif->next);

         if (!next)
             return AVERROR(ENOMEM);

         bwdif->inter_field = -1;
         next->pts = bwdif->next->pts * 2 - bwdif->cur->pts;

         filter_frame(link->src->inputs[0], next);
         bwdif->eof = 1;
     } else if (ret < 0) {
         return ret;
     }

     return 0;
 }

 static av_cold void uninit(AVFilterContext *ctx)
 {
     BWDIFContext *bwdif = ctx->priv;

     av_frame_free(&bwdif->prev);
     av_frame_free(&bwdif->cur );
     av_frame_free(&bwdif->next);
 }

 static int query_formats(AVFilterContext *ctx)
 {
     static const enum AVPixelFormat pix_fmts[] = {
         AV_PIX_FMT_YUV410P, AV_PIX_FMT_YUV411P, AV_PIX_FMT_YUV420P,
         AV_PIX_FMT_YUV422P, AV_PIX_FMT_YUV440P, AV_PIX_FMT_YUV444P,
         AV_PIX_FMT_YUVJ411P, AV_PIX_FMT_YUVJ420P,
         AV_PIX_FMT_YUVJ422P, AV_PIX_FMT_YUVJ440P, AV_PIX_FMT_YUVJ444P,
         AV_PIX_FMT_YUV420P9, AV_PIX_FMT_YUV422P9, AV_PIX_FMT_YUV444P9,
         AV_PIX_FMT_YUV420P10, AV_PIX_FMT_YUV422P10, AV_PIX_FMT_YUV444P10,
         AV_PIX_FMT_YUV420P12, AV_PIX_FMT_YUV422P12, AV_PIX_FMT_YUV444P12,
         AV_PIX_FMT_YUV420P14, AV_PIX_FMT_YUV422P14, AV_PIX_FMT_YUV444P14,
         AV_PIX_FMT_YUV420P16, AV_PIX_FMT_YUV422P16, AV_PIX_FMT_YUV444P16,
         AV_PIX_FMT_YUVA420P, AV_PIX_FMT_YUVA422P, AV_PIX_FMT_YUVA444P,
         AV_PIX_FMT_YUVA420P9, AV_PIX_FMT_YUVA422P9, AV_PIX_FMT_YUVA444P9,
         AV_PIX_FMT_YUVA420P10, AV_PIX_FMT_YUVA422P10, AV_PIX_FMT_YUVA444P10,
         AV_PIX_FMT_YUVA420P16, AV_PIX_FMT_YUVA422P16, AV_PIX_FMT_YUVA444P16,
         AV_PIX_FMT_GBRP, AV_PIX_FMT_GBRP9, AV_PIX_FMT_GBRP10,
         AV_PIX_FMT_GBRP12, AV_PIX_FMT_GBRP14, AV_PIX_FMT_GBRP16,
         AV_PIX_FMT_GBRAP, AV_PIX_FMT_GBRAP16,
         AV_PIX_FMT_GRAY8, AV_PIX_FMT_GRAY16,
         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 int config_props(AVFilterLink *link)
 {
     AVFilterContext *ctx = link->src;
     BWDIFContext *s = link->src->priv;

     link->time_base.num = link->src->inputs[0]->time_base.num;
     link->time_base.den = link->src->inputs[0]->time_base.den * 2;
     link->w             = link->src->inputs[0]->w;
     link->h             = link->src->inputs[0]->h;

     if(s->mode&1)
         link->frame_rate = av_mul_q(link->src->inputs[0]->frame_rate, (AVRational){2,1});

     if (link->w < 3 || link->h < 3) {
         av_log(ctx, AV_LOG_ERROR, "Video of less than 3 columns or lines is not supported\n");
         return AVERROR(EINVAL);
     }

     s->csp = av_pix_fmt_desc_get(link->format);
     if (s->csp->comp[0].depth > 8) {
         s->filter_intra = filter_intra_16bit;
         s->filter_line  = filter_line_c_16bit;
         s->filter_edge  = filter_edge_16bit;
     } else {
         s->filter_intra = filter_intra;
         s->filter_line  = filter_line_c;
         s->filter_edge  = filter_edge;
     }

     if (ARCH_X86)
         ff_bwdif_init_x86(s);

     return 0;
 }


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

 #define CONST(name, help, val, unit) { name, help, 0, AV_OPT_TYPE_CONST, {.i64=val}, INT_MIN, INT_MAX, FLAGS, unit }

 static const AVOption bwdif_options[] = {
     { "mode",   "specify the interlacing mode", OFFSET(mode), AV_OPT_TYPE_INT, {.i64=BWDIF_MODE_SEND_FIELD}, 0, 1, FLAGS, "mode"},
     CONST("send_frame", "send one frame for each frame", BWDIF_MODE_SEND_FRAME, "mode"),
     CONST("send_field", "send one frame for each field", BWDIF_MODE_SEND_FIELD, "mode"),

     { "parity", "specify the assumed picture field parity", OFFSET(parity), AV_OPT_TYPE_INT, {.i64=BWDIF_PARITY_AUTO}, -1, 1, FLAGS, "parity" },
     CONST("tff",  "assume top field first",    BWDIF_PARITY_TFF,  "parity"),
     CONST("bff",  "assume bottom field first", BWDIF_PARITY_BFF,  "parity"),
     CONST("auto", "auto detect parity",        BWDIF_PARITY_AUTO, "parity"),

     { "deint", "specify which frames to deinterlace", OFFSET(deint), AV_OPT_TYPE_INT, {.i64=BWDIF_DEINT_ALL}, 0, 1, FLAGS, "deint" },
     CONST("all",        "deinterlace all frames",                       BWDIF_DEINT_ALL,        "deint"),
     CONST("interlaced", "only deinterlace frames marked as interlaced", BWDIF_DEINT_INTERLACED, "deint"),

     { NULL }
 };

 AVFILTER_DEFINE_CLASS(bwdif);

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

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

 AVFilter ff_vf_bwdif = {
     .name          = "bwdif",
     .description   = NULL_IF_CONFIG_SMALL("Deinterlace the input image."),
     .priv_size     = sizeof(BWDIFContext),
     .priv_class    = &bwdif_class,
     .uninit        = uninit,
     .query_formats = query_formats,
     .inputs        = avfilter_vf_bwdif_inputs,
     .outputs       = avfilter_vf_bwdif_outputs,
     .flags         = AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL | AVFILTER_FLAG_SLICE_THREADS,
 };
	/*
	* BobWeaver Deinterlacing Filter
	* Copyright (C) 2016 Thomas Mundt <loudmax@yahoo.de>
	*
	* Based on YADIF (Yet Another Deinterlacing Filter)
	* Copyright (C) 2006-2011 Michael Niedermayer <michaelni@gmx.at>
	* 2010 James Darnley <james.darnley@gmail.com>
	*
	* With use of Weston 3 Field Deinterlacing Filter algorithm
	* Copyright (C) 2012 British Broadcasting Corporation, All Rights Reserved
	* Author of de-interlace algorithm: Jim Easterbrook for BBC R&D
	* Based on the process described by Martin Weston for BBC R&D
	*
	* 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
	*/

	#include "libavutil/avassert.h"
	#include "libavutil/common.h"
	#include "libavutil/opt.h"
	#include "libavutil/pixdesc.h"
	#include "libavutil/imgutils.h"
	#include "avfilter.h"
	#include "formats.h"
	#include "internal.h"
	#include "video.h"
	#include "bwdif.h"

	/*
	* Filter coefficients coef_lf and coef_hf taken from BBC PH-2071 (Weston 3 Field Deinterlacer).
	* Used when there is spatial and temporal interpolation.
	* Filter coefficients coef_sp are used when there is spatial interpolation only.
	* Adjusted for matching visual sharpness impression of spatial and temporal interpolation.
	*/
	static const uint16_t coef_lf[2] = { 4309, 213 };
	static const uint16_t coef_hf[3] = { 5570, 3801, 1016 };
	static const uint16_t coef_sp[2] = { 5077, 981 };

	typedef struct ThreadData {
	AVFrame *frame;
	int plane;
	int w, h;
	int parity;
	int tff;
	} ThreadData;

	#define FILTER_INTRA() \
	for (x = 0; x < w; x++) { \
	interpol = (coef_sp[0] * (cur[mrefs] + cur[prefs]) - coef_sp[1] * (cur[mrefs3] + cur[prefs3])) >> 13; \
	dst[0] = av_clip(interpol, 0, clip_max); \
	\
	dst++; \
	cur++; \
	}

	#define FILTER1() \
	for (x = 0; x < w; x++) { \
	int c = cur[mrefs]; \
	int d = (prev2[0] + next2[0]) >> 1; \
	int e = cur[prefs]; \
	int temporal_diff0 = FFABS(prev2[0] - next2[0]); \
	int temporal_diff1 =(FFABS(prev[mrefs] - c) + FFABS(prev[prefs] - e)) >> 1; \
	int temporal_diff2 =(FFABS(next[mrefs] - c) + FFABS(next[prefs] - e)) >> 1; \
	int diff = FFMAX3(temporal_diff0 >> 1, temporal_diff1, temporal_diff2); \
	\
	if (!diff) { \
	dst[0] = d; \
	} else {

	#define SPAT_CHECK() \
	int b = ((prev2[mrefs2] + next2[mrefs2]) >> 1) - c; \
	int f = ((prev2[prefs2] + next2[prefs2]) >> 1) - e; \
	int dc = d - c; \
	int de = d - e; \
	int max = FFMAX3(de, dc, FFMIN(b, f)); \
	int min = FFMIN3(de, dc, FFMAX(b, f)); \
	diff = FFMAX3(diff, min, -max);

	#define FILTER_LINE() \
	SPAT_CHECK() \
	if (FFABS(c - e) > temporal_diff0) { \
	interpol = (((coef_hf[0] * (prev2[0] + next2[0]) \
	- coef_hf[1] * (prev2[mrefs2] + next2[mrefs2] + prev2[prefs2] + next2[prefs2]) \
	+ coef_hf[2] * (prev2[mrefs4] + next2[mrefs4] + prev2[prefs4] + next2[prefs4])) >> 2) \
	+ coef_lf[0] * (c + e) - coef_lf[1] * (cur[mrefs3] + cur[prefs3])) >> 13; \
	} else { \
	interpol = (coef_sp[0] * (c + e) - coef_sp[1] * (cur[mrefs3] + cur[prefs3])) >> 13; \
	}

	#define FILTER_EDGE() \
	if (spat) { \
	SPAT_CHECK() \
	} \
	interpol = (c + e) >> 1;

	#define FILTER2() \
	if (interpol > d + diff) \
	interpol = d + diff; \
	else if (interpol < d - diff) \
	interpol = d - diff; \
	\
	dst[0] = av_clip(interpol, 0, clip_max); \
	} \
	\
	dst++; \
	cur++; \
	prev++; \
	next++; \
	prev2++; \
	next2++; \
	}

	static void filter_intra(void dst1, void cur1, int w, int prefs, int mrefs,
	int prefs3, int mrefs3, int parity, int clip_max)
	{
	uint8_t *dst = dst1;
	uint8_t *cur = cur1;
	int interpol, x;

	FILTER_INTRA()
	}

	static void filter_line_c(void dst1, void prev1, void cur1, void next1,
	int w, int prefs, int mrefs, int prefs2, int mrefs2,
	int prefs3, int mrefs3, int prefs4, int mrefs4,
	int parity, int clip_max)
	{
	uint8_t *dst = dst1;
	uint8_t *prev = prev1;
	uint8_t *cur = cur1;
	uint8_t *next = next1;
	uint8_t *prev2 = parity ? prev : cur ;
	uint8_t *next2 = parity ? cur : next;
	int interpol, x;

	FILTER1()
	FILTER_LINE()
	FILTER2()
	}

	static void filter_edge(void dst1, void prev1, void cur1, void next1,
	int w, int prefs, int mrefs, int prefs2, int mrefs2,
	int parity, int clip_max, int spat)
	{
	uint8_t *dst = dst1;
	uint8_t *prev = prev1;
	uint8_t *cur = cur1;
	uint8_t *next = next1;
	uint8_t *prev2 = parity ? prev : cur ;
	uint8_t *next2 = parity ? cur : next;
	int interpol, x;

	FILTER1()
	FILTER_EDGE()
	FILTER2()
	}

	static void filter_intra_16bit(void dst1, void cur1, int w, int prefs, int mrefs,
	int prefs3, int mrefs3, int parity, int clip_max)
	{
	uint16_t *dst = dst1;
	uint16_t *cur = cur1;
	int interpol, x;

	FILTER_INTRA()
	}

	static void filter_line_c_16bit(void dst1, void prev1, void cur1, void next1,
	int w, int prefs, int mrefs, int prefs2, int mrefs2,
	int prefs3, int mrefs3, int prefs4, int mrefs4,
	int parity, int clip_max)
	{
	uint16_t *dst = dst1;
	uint16_t *prev = prev1;
	uint16_t *cur = cur1;
	uint16_t *next = next1;
	uint16_t *prev2 = parity ? prev : cur ;
	uint16_t *next2 = parity ? cur : next;
	int interpol, x;

	FILTER1()
	FILTER_LINE()
	FILTER2()
	}

	static void filter_edge_16bit(void dst1, void prev1, void cur1, void next1,
	int w, int prefs, int mrefs, int prefs2, int mrefs2,
	int parity, int clip_max, int spat)
	{
	uint16_t *dst = dst1;
	uint16_t *prev = prev1;
	uint16_t *cur = cur1;
	uint16_t *next = next1;
	uint16_t *prev2 = parity ? prev : cur ;
	uint16_t *next2 = parity ? cur : next;
	int interpol, x;

	FILTER1()
	FILTER_EDGE()
	FILTER2()
	}

	static int filter_slice(AVFilterContext ctx, void arg, int jobnr, int nb_jobs)
	{
	BWDIFContext *s = ctx->priv;
	ThreadData *td = arg;
	int linesize = s->cur->linesize[td->plane];
	int clip_max = (1 << (s->csp->comp[td->plane].depth)) - 1;
	int df = (s->csp->comp[td->plane].depth + 7) / 8;
	int refs = linesize / df;
	int slice_start = (td->h * jobnr ) / nb_jobs;
	int slice_end = (td->h * (jobnr+1)) / nb_jobs;
	int y;

	for (y = slice_start; y < slice_end; y++) {
	if ((y ^ td->parity) & 1) {
	uint8_t prev = &s->prev->data[td->plane][y linesize];
	uint8_t cur = &s->cur ->data[td->plane][y linesize];
	uint8_t next = &s->next->data[td->plane][y linesize];
	uint8_t dst = &td->frame->data[td->plane][y td->frame->linesize[td->plane]];
	if (!s->inter_field) {
	s->filter_intra(dst, cur, td->w, (y + df) < td->h ? refs : -refs,
	y > (df - 1) ? -refs : refs,
	(y + 3df) < td->h ? 3 refs : -refs,
	y > (3df - 1) ? -3 refs : refs,
	td->parity ^ td->tff, clip_max);
	} else if ((y < 4) \|\| ((y + 5) > td->h)) {
	s->filter_edge(dst, prev, cur, next, td->w,
	(y + df) < td->h ? refs : -refs,
	y > (df - 1) ? -refs : refs,
	refs << 1, -(refs << 1),
	td->parity ^ td->tff, clip_max,
	(y < 2) \|\| ((y + 3) > td->h) ? 0 : 1);
	} else {
	s->filter_line(dst, prev, cur, next, td->w,
	refs, -refs, refs << 1, -(refs << 1),
	3 * refs, -3 * refs, refs << 2, -(refs << 2),
	td->parity ^ td->tff, clip_max);
	}
	} else {
	memcpy(&td->frame->data[td->plane][y * td->frame->linesize[td->plane]],
	&s->cur->data[td->plane][y * linesize], td->w * df);
	}
	}
	return 0;
	}

	static void filter(AVFilterContext ctx, AVFrame dstpic,
	int parity, int tff)
	{
	BWDIFContext *bwdif = ctx->priv;
	ThreadData td = { .frame = dstpic, .parity = parity, .tff = tff };
	int i;

	for (i = 0; i < bwdif->csp->nb_components; i++) {
	int w = dstpic->width;
	int h = dstpic->height;

	if (i == 1 \|\| i == 2) {
	w = AV_CEIL_RSHIFT(w, bwdif->csp->log2_chroma_w);
	h = AV_CEIL_RSHIFT(h, bwdif->csp->log2_chroma_h);
	}

	td.w = w;
	td.h = h;
	td.plane = i;

	ctx->internal->execute(ctx, filter_slice, &td, NULL, FFMIN(h, ff_filter_get_nb_threads(ctx)));
	}
	if (!bwdif->inter_field) {
	bwdif->inter_field = 1;
	}

	emms_c();
	}

	static int return_frame(AVFilterContext *ctx, int is_second)
	{
	BWDIFContext *bwdif = ctx->priv;
	AVFilterLink *link = ctx->outputs[0];
	int tff, ret;

	if (bwdif->parity == -1) {
	tff = bwdif->cur->interlaced_frame ?
	bwdif->cur->top_field_first : 1;
	} else {
	tff = bwdif->parity ^ 1;
	}

	if (is_second) {
	bwdif->out = ff_get_video_buffer(link, link->w, link->h);
	if (!bwdif->out)
	return AVERROR(ENOMEM);

	av_frame_copy_props(bwdif->out, bwdif->cur);
	bwdif->out->interlaced_frame = 0;
	if (bwdif->inter_field < 0)
	bwdif->inter_field = 0;
	}

	filter(ctx, bwdif->out, tff ^ !is_second, tff);

	if (is_second) {
	int64_t cur_pts = bwdif->cur->pts;
	int64_t next_pts = bwdif->next->pts;

	if (next_pts != AV_NOPTS_VALUE && cur_pts != AV_NOPTS_VALUE) {
	bwdif->out->pts = cur_pts + next_pts;
	} else {
	bwdif->out->pts = AV_NOPTS_VALUE;
	}
	}
	ret = ff_filter_frame(ctx->outputs[0], bwdif->out);

	bwdif->frame_pending = (bwdif->mode&1) && !is_second;
	return ret;
	}

	static int checkstride(BWDIFContext bwdif, const AVFrame a, const AVFrame *b)
	{
	int i;
	for (i = 0; i < bwdif->csp->nb_components; i++)
	if (a->linesize[i] != b->linesize[i])
	return 1;
	return 0;
	}

	static void fixstride(AVFilterLink link, AVFrame f)
	{
	AVFrame *dst = ff_default_get_video_buffer(link, f->width, f->height);
	if(!dst)
	return;
	av_frame_copy_props(dst, f);
	av_image_copy(dst->data, dst->linesize,
	(const uint8_t **)f->data, f->linesize,
	dst->format, dst->width, dst->height);
	av_frame_unref(f);
	av_frame_move_ref(f, dst);
	av_frame_free(&dst);
	}

	static int filter_frame(AVFilterLink link, AVFrame frame)
	{
	AVFilterContext *ctx = link->dst;
	BWDIFContext *bwdif = ctx->priv;

	av_assert0(frame);

	if (bwdif->frame_pending)
	return_frame(ctx, 1);

	if (bwdif->prev)
	av_frame_free(&bwdif->prev);
	bwdif->prev = bwdif->cur;
	bwdif->cur = bwdif->next;
	bwdif->next = frame;

	if (!bwdif->cur) {
	bwdif->cur = av_frame_clone(bwdif->next);
	if (!bwdif->cur)
	return AVERROR(ENOMEM);
	bwdif->inter_field = 0;
	}

	if (checkstride(bwdif, bwdif->next, bwdif->cur)) {
	av_log(ctx, AV_LOG_VERBOSE, "Reallocating frame due to differing stride\n");
	fixstride(link, bwdif->next);
	}
	if (checkstride(bwdif, bwdif->next, bwdif->cur))
	fixstride(link, bwdif->cur);
	if (bwdif->prev && checkstride(bwdif, bwdif->next, bwdif->prev))
	fixstride(link, bwdif->prev);
	if (checkstride(bwdif, bwdif->next, bwdif->cur) \|\| (bwdif->prev && checkstride(bwdif, bwdif->next, bwdif->prev))) {
	av_log(ctx, AV_LOG_ERROR, "Failed to reallocate frame\n");
	return -1;
	}

	if (!bwdif->prev)
	return 0;

	if ((bwdif->deint && !bwdif->cur->interlaced_frame) \|\|
	ctx->is_disabled \|\|
	(bwdif->deint && !bwdif->prev->interlaced_frame && bwdif->prev->repeat_pict) \|\|
	(bwdif->deint && !bwdif->next->interlaced_frame && bwdif->next->repeat_pict)
	) {
	bwdif->out = av_frame_clone(bwdif->cur);
	if (!bwdif->out)
	return AVERROR(ENOMEM);

	av_frame_free(&bwdif->prev);
	if (bwdif->out->pts != AV_NOPTS_VALUE)
	bwdif->out->pts *= 2;
	return ff_filter_frame(ctx->outputs[0], bwdif->out);
	}

	bwdif->out = ff_get_video_buffer(ctx->outputs[0], link->w, link->h);
	if (!bwdif->out)
	return AVERROR(ENOMEM);

	av_frame_copy_props(bwdif->out, bwdif->cur);
	bwdif->out->interlaced_frame = 0;

	if (bwdif->out->pts != AV_NOPTS_VALUE)
	bwdif->out->pts *= 2;

	return return_frame(ctx, 0);
	}

	static int request_frame(AVFilterLink *link)
	{
	AVFilterContext *ctx = link->src;
	BWDIFContext *bwdif = ctx->priv;
	int ret;

	if (bwdif->frame_pending) {
	return_frame(ctx, 1);
	return 0;
	}

	if (bwdif->eof)
	return AVERROR_EOF;

	ret = ff_request_frame(link->src->inputs[0]);

	if (ret == AVERROR_EOF && bwdif->cur) {
	AVFrame *next = av_frame_clone(bwdif->next);

	if (!next)
	return AVERROR(ENOMEM);

	bwdif->inter_field = -1;
	next->pts = bwdif->next->pts * 2 - bwdif->cur->pts;

	filter_frame(link->src->inputs[0], next);
	bwdif->eof = 1;
	} else if (ret < 0) {
	return ret;
	}

	return 0;
	}

	static av_cold void uninit(AVFilterContext *ctx)
	{
	BWDIFContext *bwdif = ctx->priv;

	av_frame_free(&bwdif->prev);
	av_frame_free(&bwdif->cur );
	av_frame_free(&bwdif->next);
	}

	static int query_formats(AVFilterContext *ctx)
	{
	static const enum AVPixelFormat pix_fmts[] = {
	AV_PIX_FMT_YUV410P, AV_PIX_FMT_YUV411P, AV_PIX_FMT_YUV420P,
	AV_PIX_FMT_YUV422P, AV_PIX_FMT_YUV440P, AV_PIX_FMT_YUV444P,
	AV_PIX_FMT_YUVJ411P, AV_PIX_FMT_YUVJ420P,
	AV_PIX_FMT_YUVJ422P, AV_PIX_FMT_YUVJ440P, AV_PIX_FMT_YUVJ444P,
	AV_PIX_FMT_YUV420P9, AV_PIX_FMT_YUV422P9, AV_PIX_FMT_YUV444P9,
	AV_PIX_FMT_YUV420P10, AV_PIX_FMT_YUV422P10, AV_PIX_FMT_YUV444P10,
	AV_PIX_FMT_YUV420P12, AV_PIX_FMT_YUV422P12, AV_PIX_FMT_YUV444P12,
	AV_PIX_FMT_YUV420P14, AV_PIX_FMT_YUV422P14, AV_PIX_FMT_YUV444P14,
	AV_PIX_FMT_YUV420P16, AV_PIX_FMT_YUV422P16, AV_PIX_FMT_YUV444P16,
	AV_PIX_FMT_YUVA420P, AV_PIX_FMT_YUVA422P, AV_PIX_FMT_YUVA444P,
	AV_PIX_FMT_YUVA420P9, AV_PIX_FMT_YUVA422P9, AV_PIX_FMT_YUVA444P9,
	AV_PIX_FMT_YUVA420P10, AV_PIX_FMT_YUVA422P10, AV_PIX_FMT_YUVA444P10,
	AV_PIX_FMT_YUVA420P16, AV_PIX_FMT_YUVA422P16, AV_PIX_FMT_YUVA444P16,
	AV_PIX_FMT_GBRP, AV_PIX_FMT_GBRP9, AV_PIX_FMT_GBRP10,
	AV_PIX_FMT_GBRP12, AV_PIX_FMT_GBRP14, AV_PIX_FMT_GBRP16,
	AV_PIX_FMT_GBRAP, AV_PIX_FMT_GBRAP16,
	AV_PIX_FMT_GRAY8, AV_PIX_FMT_GRAY16,
	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 int config_props(AVFilterLink *link)
	{
	AVFilterContext *ctx = link->src;
	BWDIFContext *s = link->src->priv;

	link->time_base.num = link->src->inputs[0]->time_base.num;
	link->time_base.den = link->src->inputs[0]->time_base.den * 2;
	link->w = link->src->inputs[0]->w;
	link->h = link->src->inputs[0]->h;

	if(s->mode&1)
	link->frame_rate = av_mul_q(link->src->inputs[0]->frame_rate, (AVRational){2,1});

	if (link->w < 3 \|\| link->h < 3) {
	av_log(ctx, AV_LOG_ERROR, "Video of less than 3 columns or lines is not supported\n");
	return AVERROR(EINVAL);
	}

	s->csp = av_pix_fmt_desc_get(link->format);
	if (s->csp->comp[0].depth > 8) {
	s->filter_intra = filter_intra_16bit;
	s->filter_line = filter_line_c_16bit;
	s->filter_edge = filter_edge_16bit;
	} else {
	s->filter_intra = filter_intra;
	s->filter_line = filter_line_c;
	s->filter_edge = filter_edge;
	}

	if (ARCH_X86)
	ff_bwdif_init_x86(s);

	return 0;
	}


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

	#define CONST(name, help, val, unit) { name, help, 0, AV_OPT_TYPE_CONST, {.i64=val}, INT_MIN, INT_MAX, FLAGS, unit }

	static const AVOption bwdif_options[] = {
	{ "mode", "specify the interlacing mode", OFFSET(mode), AV_OPT_TYPE_INT, {.i64=BWDIF_MODE_SEND_FIELD}, 0, 1, FLAGS, "mode"},
	CONST("send_frame", "send one frame for each frame", BWDIF_MODE_SEND_FRAME, "mode"),
	CONST("send_field", "send one frame for each field", BWDIF_MODE_SEND_FIELD, "mode"),

	{ "parity", "specify the assumed picture field parity", OFFSET(parity), AV_OPT_TYPE_INT, {.i64=BWDIF_PARITY_AUTO}, -1, 1, FLAGS, "parity" },
	CONST("tff", "assume top field first", BWDIF_PARITY_TFF, "parity"),
	CONST("bff", "assume bottom field first", BWDIF_PARITY_BFF, "parity"),
	CONST("auto", "auto detect parity", BWDIF_PARITY_AUTO, "parity"),

	{ "deint", "specify which frames to deinterlace", OFFSET(deint), AV_OPT_TYPE_INT, {.i64=BWDIF_DEINT_ALL}, 0, 1, FLAGS, "deint" },
	CONST("all", "deinterlace all frames", BWDIF_DEINT_ALL, "deint"),
	CONST("interlaced", "only deinterlace frames marked as interlaced", BWDIF_DEINT_INTERLACED, "deint"),

	{ NULL }
	};

	AVFILTER_DEFINE_CLASS(bwdif);

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

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

	AVFilter ff_vf_bwdif = {
	.name = "bwdif",
	.description = NULL_IF_CONFIG_SMALL("Deinterlace the input image."),
	.priv_size = sizeof(BWDIFContext),
	.priv_class = &bwdif_class,
	.uninit = uninit,
	.query_formats = query_formats,
	.inputs = avfilter_vf_bwdif_inputs,
	.outputs = avfilter_vf_bwdif_outputs,
	.flags = AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL \| AVFILTER_FLAG_SLICE_THREADS,
	};