/*
  * Copyright (c) 2010 Mark Heath mjpeg0 @ silicontrip dot org
  * Copyright (c) 2014 Clément Bœsch
  * Copyright (c) 2014 Dave Rice @dericed
  *
  * 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/intreadwrite.h"

 #include "libavutil/opt.h"
 #include "libavutil/pixdesc.h"
 #include "internal.h"
 
 enum FilterMode {
     FILTER_NONE = -1,
     FILTER_TOUT,
     FILTER_VREP,
     FILTER_BRNG,
     FILT_NUMB
 };
 

 typedef struct SignalstatsContext {

     const AVClass *class;
     int chromah;    // height of chroma plane
     int chromaw;    // width of chroma plane
     int hsub;       // horizontal subsampling
     int vsub;       // vertical subsampling

     int depth;      // pixel depth

     int fs;         // pixel count per frame
     int cfs;        // pixel count per frame of chroma planes

     int outfilter;  // FilterMode

     int filters;
     AVFrame *frame_prev;
     uint8_t rgba_color[4];
     int yuv_color[3];

     int nb_jobs;
     int *jobs_rets;

     int *histy, *histu, *histv, *histsat;
 

     AVFrame *frame_sat;
     AVFrame *frame_hue;

 } SignalstatsContext;
 

 typedef struct ThreadData {
     const AVFrame *in;
     AVFrame *out;
 } ThreadData;
 

 typedef struct ThreadDataHueSatMetrics {
     const AVFrame *src;
     AVFrame *dst_sat, *dst_hue;
 } ThreadDataHueSatMetrics;
 

 #define OFFSET(x) offsetof(SignalstatsContext, x)
 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
 
 static const AVOption signalstats_options[] = {
     {"stat", "set statistics filters", OFFSET(filters), AV_OPT_TYPE_FLAGS, {.i64=0}, 0, INT_MAX, FLAGS, "filters"},
         {"tout", "analyze pixels for temporal outliers",                0, AV_OPT_TYPE_CONST, {.i64=1<<FILTER_TOUT}, 0, 0, FLAGS, "filters"},

         {"vrep", "analyze video lines for vertical line repetition",    0, AV_OPT_TYPE_CONST, {.i64=1<<FILTER_VREP}, 0, 0, FLAGS, "filters"},

         {"brng", "analyze for pixels outside of broadcast range",       0, AV_OPT_TYPE_CONST, {.i64=1<<FILTER_BRNG}, 0, 0, FLAGS, "filters"},
     {"out", "set video filter", OFFSET(outfilter), AV_OPT_TYPE_INT, {.i64=FILTER_NONE}, -1, FILT_NUMB-1, FLAGS, "out"},
         {"tout", "highlight pixels that depict temporal outliers",              0, AV_OPT_TYPE_CONST, {.i64=FILTER_TOUT}, 0, 0, FLAGS, "out"},

         {"vrep", "highlight video lines that depict vertical line repetition",  0, AV_OPT_TYPE_CONST, {.i64=FILTER_VREP}, 0, 0, FLAGS, "out"},

         {"brng", "highlight pixels that are outside of broadcast range",        0, AV_OPT_TYPE_CONST, {.i64=FILTER_BRNG}, 0, 0, FLAGS, "out"},
     {"c",     "set highlight color", OFFSET(rgba_color), AV_OPT_TYPE_COLOR, {.str="yellow"}, .flags=FLAGS},
     {"color", "set highlight color", OFFSET(rgba_color), AV_OPT_TYPE_COLOR, {.str="yellow"}, .flags=FLAGS},
     {NULL}
 };
 
 AVFILTER_DEFINE_CLASS(signalstats);
 
 static av_cold int init(AVFilterContext *ctx)
 {
     uint8_t r, g, b;
     SignalstatsContext *s = ctx->priv;
 
     if (s->outfilter != FILTER_NONE)
         s->filters |= 1 << s->outfilter;
 
     r = s->rgba_color[0];
     g = s->rgba_color[1];
     b = s->rgba_color[2];
     s->yuv_color[0] = (( 66*r + 129*g +  25*b + (1<<7)) >> 8) +  16;
     s->yuv_color[1] = ((-38*r + -74*g + 112*b + (1<<7)) >> 8) + 128;
     s->yuv_color[2] = ((112*r + -94*g + -18*b + (1<<7)) >> 8) + 128;
     return 0;
 }
 
 static av_cold void uninit(AVFilterContext *ctx)
 {
     SignalstatsContext *s = ctx->priv;
     av_frame_free(&s->frame_prev);

     av_frame_free(&s->frame_sat);
     av_frame_free(&s->frame_hue);

     av_freep(&s->jobs_rets);

     av_freep(&s->histy);
     av_freep(&s->histu);
     av_freep(&s->histv);
     av_freep(&s->histsat);

 }
 
 static int query_formats(AVFilterContext *ctx)
 {
     // TODO: add more

     static const enum AVPixelFormat pix_fmts[] = {

         AV_PIX_FMT_YUV444P, AV_PIX_FMT_YUV422P, AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUV411P,

         AV_PIX_FMT_YUV440P,
         AV_PIX_FMT_YUVJ422P, AV_PIX_FMT_YUVJ444P, AV_PIX_FMT_YUVJ420P, AV_PIX_FMT_YUVJ411P,
         AV_PIX_FMT_YUVJ440P,

         AV_PIX_FMT_YUV444P9, AV_PIX_FMT_YUV422P9, AV_PIX_FMT_YUV420P9,
         AV_PIX_FMT_YUV444P10, AV_PIX_FMT_YUV422P10, AV_PIX_FMT_YUV420P10,
         AV_PIX_FMT_YUV440P10,
         AV_PIX_FMT_YUV444P12, AV_PIX_FMT_YUV422P12, AV_PIX_FMT_YUV420P12,
         AV_PIX_FMT_YUV440P12,
         AV_PIX_FMT_YUV444P14, AV_PIX_FMT_YUV422P14, AV_PIX_FMT_YUV420P14,
         AV_PIX_FMT_YUV444P16, AV_PIX_FMT_YUV422P16, AV_PIX_FMT_YUV420P16,

         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 AVFrame *alloc_frame(enum AVPixelFormat pixfmt, int w, int h)
 {
     AVFrame *frame = av_frame_alloc();
     if (!frame)
         return NULL;
 
     frame->format = pixfmt;
     frame->width  = w;
     frame->height = h;
 

     if (av_frame_get_buffer(frame, 32) < 0) {
         av_frame_free(&frame);

         return NULL;

     }

 
     return frame;
 }
 

 static int config_props(AVFilterLink *outlink)
 {
     AVFilterContext *ctx = outlink->src;
     SignalstatsContext *s = ctx->priv;
     AVFilterLink *inlink = outlink->src->inputs[0];
     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(outlink->format);
     s->hsub = desc->log2_chroma_w;
     s->vsub = desc->log2_chroma_h;

     s->depth = desc->comp[0].depth;
     if (s->depth > 8) {
         s->histy = av_malloc_array(1 << s->depth, sizeof(*s->histy));
         s->histu = av_malloc_array(1 << s->depth, sizeof(*s->histu));
         s->histv = av_malloc_array(1 << s->depth, sizeof(*s->histv));
         s->histsat = av_malloc_array(1 << s->depth, sizeof(*s->histsat));
 
         if (!s->histy || !s->histu || !s->histv || !s->histsat)
             return AVERROR(ENOMEM);
     }

 
     outlink->w = inlink->w;
     outlink->h = inlink->h;
 

     s->chromaw = AV_CEIL_RSHIFT(inlink->w, s->hsub);
     s->chromah = AV_CEIL_RSHIFT(inlink->h, s->vsub);

 
     s->fs = inlink->w * inlink->h;
     s->cfs = s->chromaw * s->chromah;
 

     s->nb_jobs   = FFMAX(1, FFMIN(inlink->h, ff_filter_get_nb_threads(ctx)));

     s->jobs_rets = av_malloc_array(s->nb_jobs, sizeof(*s->jobs_rets));
     if (!s->jobs_rets)
         return AVERROR(ENOMEM);

     s->frame_sat = alloc_frame(s->depth > 8 ? AV_PIX_FMT_GRAY16 : AV_PIX_FMT_GRAY8,  inlink->w, inlink->h);

     s->frame_hue = alloc_frame(AV_PIX_FMT_GRAY16, inlink->w, inlink->h);
     if (!s->frame_sat || !s->frame_hue)
         return AVERROR(ENOMEM);
 

     return 0;
 }
 

 static void burn_frame8(const SignalstatsContext *s, AVFrame *f, int x, int y)

 {
     const int chromax = x >> s->hsub;
     const int chromay = y >> s->vsub;
     f->data[0][y       * f->linesize[0] +       x] = s->yuv_color[0];
     f->data[1][chromay * f->linesize[1] + chromax] = s->yuv_color[1];
     f->data[2][chromay * f->linesize[2] + chromax] = s->yuv_color[2];
 }
 

 static void burn_frame16(const SignalstatsContext *s, AVFrame *f, int x, int y)
 {
     const int chromax = x >> s->hsub;
     const int chromay = y >> s->vsub;
     const int mult = 1 << (s->depth - 8);
     AV_WN16(f->data[0] + y       * f->linesize[0] +       x * 2, s->yuv_color[0] * mult);
     AV_WN16(f->data[1] + chromay * f->linesize[1] + chromax * 2, s->yuv_color[1] * mult);
     AV_WN16(f->data[2] + chromay * f->linesize[2] + chromax * 2, s->yuv_color[2] * mult);
 }
 
 static int filter8_brng(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs)

 {

     ThreadData *td = arg;
     const SignalstatsContext *s = ctx->priv;
     const AVFrame *in = td->in;
     AVFrame *out = td->out;
     const int w = in->width;
     const int h = in->height;
     const int slice_start = (h *  jobnr   ) / nb_jobs;
     const int slice_end   = (h * (jobnr+1)) / nb_jobs;

     int x, y, score = 0;
 

     for (y = slice_start; y < slice_end; y++) {

         const int yc = y >> s->vsub;
         const uint8_t *pluma    = &in->data[0][y  * in->linesize[0]];
         const uint8_t *pchromau = &in->data[1][yc * in->linesize[1]];
         const uint8_t *pchromav = &in->data[2][yc * in->linesize[2]];
 
         for (x = 0; x < w; x++) {
             const int xc = x >> s->hsub;
             const int luma    = pluma[x];
             const int chromau = pchromau[xc];
             const int chromav = pchromav[xc];
             const int filt = luma    < 16 || luma    > 235 ||
                 chromau < 16 || chromau > 240 ||
                 chromav < 16 || chromav > 240;
             score += filt;
             if (out && filt)

                 burn_frame8(s, out, x, y);
         }
     }
     return score;
 }
 
 static int filter16_brng(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs)
 {
     ThreadData *td = arg;
     const SignalstatsContext *s = ctx->priv;
     const AVFrame *in = td->in;
     AVFrame *out = td->out;
     const int mult = 1 << (s->depth - 8);
     const int w = in->width;
     const int h = in->height;
     const int slice_start = (h *  jobnr   ) / nb_jobs;
     const int slice_end   = (h * (jobnr+1)) / nb_jobs;
     int x, y, score = 0;
 
     for (y = slice_start; y < slice_end; y++) {
         const int yc = y >> s->vsub;
         const uint16_t *pluma    = (uint16_t *)&in->data[0][y  * in->linesize[0]];
         const uint16_t *pchromau = (uint16_t *)&in->data[1][yc * in->linesize[1]];
         const uint16_t *pchromav = (uint16_t *)&in->data[2][yc * in->linesize[2]];
 
         for (x = 0; x < w; x++) {
             const int xc = x >> s->hsub;
             const int luma    = pluma[x];
             const int chromau = pchromau[xc];
             const int chromav = pchromav[xc];
             const int filt = luma    < 16 * mult || luma    > 235 * mult ||
                 chromau < 16 * mult || chromau > 240 * mult ||
                 chromav < 16 * mult || chromav > 240 * mult;
             score += filt;
             if (out && filt)
                 burn_frame16(s, out, x, y);

         }

     }

     return score;
 }
 
 static int filter_tout_outlier(uint8_t x, uint8_t y, uint8_t z)
 {
     return ((abs(x - y) + abs (z - y)) / 2) - abs(z - x) > 4; // make 4 configurable?
 }
 

 static int filter8_tout(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs)

 {

     ThreadData *td = arg;
     const SignalstatsContext *s = ctx->priv;
     const AVFrame *in = td->in;
     AVFrame *out = td->out;
     const int w = in->width;
     const int h = in->height;
     const int slice_start = (h *  jobnr   ) / nb_jobs;
     const int slice_end   = (h * (jobnr+1)) / nb_jobs;

     const uint8_t *p = in->data[0];
     int lw = in->linesize[0];

     int x, y, score = 0, filt;
 

     for (y = slice_start; y < slice_end; y++) {

         if (y - 1 < 0 || y + 1 >= h)
             continue;

         // detect two pixels above and below (to eliminate interlace artefacts)
         // should check that video format is infact interlaced.

 
 #define FILTER(i, j) \

         filter_tout_outlier(p[(y-j) * lw + x + i], \
                             p[    y * lw + x + i], \
                             p[(y+j) * lw + x + i])

 
 #define FILTER3(j) (FILTER(-1, j) && FILTER(0, j) && FILTER(1, j))
 

         if (y - 2 >= 0 && y + 2 < h) {
             for (x = 1; x < w - 1; x++) {
                 filt = FILTER3(2) && FILTER3(1);
                 score += filt;
                 if (filt && out)

                     burn_frame8(s, out, x, y);
             }
         } else {
             for (x = 1; x < w - 1; x++) {
                 filt = FILTER3(1);
                 score += filt;
                 if (filt && out)
                     burn_frame8(s, out, x, y);
             }
         }
     }
     return score;
 }
 
 static int filter16_tout(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs)
 {
     ThreadData *td = arg;
     const SignalstatsContext *s = ctx->priv;
     const AVFrame *in = td->in;
     AVFrame *out = td->out;
     const int w = in->width;
     const int h = in->height;
     const int slice_start = (h *  jobnr   ) / nb_jobs;
     const int slice_end   = (h * (jobnr+1)) / nb_jobs;
     const uint16_t *p = (uint16_t *)in->data[0];
     int lw = in->linesize[0] / 2;
     int x, y, score = 0, filt;
 
     for (y = slice_start; y < slice_end; y++) {
 
         if (y - 1 < 0 || y + 1 >= h)
             continue;
 
         // detect two pixels above and below (to eliminate interlace artefacts)
         // should check that video format is infact interlaced.
 
         if (y - 2 >= 0 && y + 2 < h) {
             for (x = 1; x < w - 1; x++) {
                 filt = FILTER3(2) && FILTER3(1);
                 score += filt;
                 if (filt && out)
                     burn_frame16(s, out, x, y);

             }
         } else {
             for (x = 1; x < w - 1; x++) {
                 filt = FILTER3(1);
                 score += filt;
                 if (filt && out)

                     burn_frame16(s, out, x, y);

             }

         }
     }
     return score;
 }
 
 #define VREP_START 4
 

 static int filter8_vrep(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs)

 {

     ThreadData *td = arg;
     const SignalstatsContext *s = ctx->priv;
     const AVFrame *in = td->in;
     AVFrame *out = td->out;
     const int w = in->width;
     const int h = in->height;
     const int slice_start = (h *  jobnr   ) / nb_jobs;
     const int slice_end   = (h * (jobnr+1)) / nb_jobs;

     const uint8_t *p = in->data[0];
     const int lw = in->linesize[0];

     int x, y, score = 0;
 

     for (y = slice_start; y < slice_end; y++) {

         const int y2lw = (y - VREP_START) * lw;
         const int ylw  =  y               * lw;
         int filt, totdiff = 0;

         if (y < VREP_START)
             continue;
 

         for (x = 0; x < w; x++)

             totdiff += abs(p[y2lw + x] - p[ylw + x]);
         filt = totdiff < w;
 
         score += filt;
         if (filt && out)
             for (x = 0; x < w; x++)

                 burn_frame8(s, out, x, y);
     }
     return score * w;
 }
 
 static int filter16_vrep(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs)
 {
     ThreadData *td = arg;
     const SignalstatsContext *s = ctx->priv;
     const AVFrame *in = td->in;
     AVFrame *out = td->out;
     const int w = in->width;
     const int h = in->height;
     const int slice_start = (h *  jobnr   ) / nb_jobs;
     const int slice_end   = (h * (jobnr+1)) / nb_jobs;
     const uint16_t *p = (uint16_t *)in->data[0];
     const int lw = in->linesize[0] / 2;
     int x, y, score = 0;
 
     for (y = slice_start; y < slice_end; y++) {
         const int y2lw = (y - VREP_START) * lw;
         const int ylw  =  y               * lw;
         int64_t totdiff = 0;
         int filt;
 
         if (y < VREP_START)
             continue;
 
         for (x = 0; x < w; x++)
             totdiff += abs(p[y2lw + x] - p[ylw + x]);
         filt = totdiff < w;
 
         score += filt;
         if (filt && out)
             for (x = 0; x < w; x++)
                 burn_frame16(s, out, x, y);

     }
     return score * w;

 }
 
 static const struct {
     const char *name;

     int (*process8)(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs);
     int (*process16)(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs);

 } filters_def[] = {

     {"TOUT", filter8_tout, filter16_tout},
     {"VREP", filter8_vrep, filter16_vrep},
     {"BRNG", filter8_brng, filter16_brng},

     {NULL}
 };
 
 #define DEPTH 256
 

 static int compute_sat_hue_metrics8(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs)

 {
     int i, j;

     ThreadDataHueSatMetrics *td = arg;
     const SignalstatsContext *s = ctx->priv;
     const AVFrame *src = td->src;
     AVFrame *dst_sat = td->dst_sat;
     AVFrame *dst_hue = td->dst_hue;
 
     const int slice_start = (s->chromah *  jobnr   ) / nb_jobs;
     const int slice_end   = (s->chromah * (jobnr+1)) / nb_jobs;

 
     const int lsz_u = src->linesize[1];
     const int lsz_v = src->linesize[2];

     const uint8_t *p_u = src->data[1] + slice_start * lsz_u;
     const uint8_t *p_v = src->data[2] + slice_start * lsz_v;

 
     const int lsz_sat = dst_sat->linesize[0];
     const int lsz_hue = dst_hue->linesize[0];

     uint8_t *p_sat = dst_sat->data[0] + slice_start * lsz_sat;
     uint8_t *p_hue = dst_hue->data[0] + slice_start * lsz_hue;

     for (j = slice_start; j < slice_end; j++) {

         for (i = 0; i < s->chromaw; i++) {
             const int yuvu = p_u[i];
             const int yuvv = p_v[i];
             p_sat[i] = hypot(yuvu - 128, yuvv - 128); // int or round?
             ((int16_t*)p_hue)[i] = floor((180 / M_PI) * atan2f(yuvu-128, yuvv-128) + 180);
         }
         p_u   += lsz_u;
         p_v   += lsz_v;
         p_sat += lsz_sat;
         p_hue += lsz_hue;
     }

 
     return 0;

 }
 

 static int compute_sat_hue_metrics16(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs)
 {
     int i, j;
     ThreadDataHueSatMetrics *td = arg;
     const SignalstatsContext *s = ctx->priv;
     const AVFrame *src = td->src;
     AVFrame *dst_sat = td->dst_sat;
     AVFrame *dst_hue = td->dst_hue;
     const int mid = 1 << (s->depth - 1);
 
     const int slice_start = (s->chromah *  jobnr   ) / nb_jobs;
     const int slice_end   = (s->chromah * (jobnr+1)) / nb_jobs;
 
     const int lsz_u = src->linesize[1] / 2;
     const int lsz_v = src->linesize[2] / 2;
     const uint16_t *p_u = (uint16_t*)src->data[1] + slice_start * lsz_u;
     const uint16_t *p_v = (uint16_t*)src->data[2] + slice_start * lsz_v;
 
     const int lsz_sat = dst_sat->linesize[0] / 2;
     const int lsz_hue = dst_hue->linesize[0] / 2;
     uint16_t *p_sat = (uint16_t*)dst_sat->data[0] + slice_start * lsz_sat;
     uint16_t *p_hue = (uint16_t*)dst_hue->data[0] + slice_start * lsz_hue;
 
     for (j = slice_start; j < slice_end; j++) {
         for (i = 0; i < s->chromaw; i++) {
             const int yuvu = p_u[i];
             const int yuvv = p_v[i];
             p_sat[i] = hypot(yuvu - mid, yuvv - mid); // int or round?
             ((int16_t*)p_hue)[i] = floor((180 / M_PI) * atan2f(yuvu-mid, yuvv-mid) + 180);
         }
         p_u   += lsz_u;
         p_v   += lsz_v;
         p_sat += lsz_sat;
         p_hue += lsz_hue;
     }
 
     return 0;
 }
 

 static unsigned compute_bit_depth(uint16_t mask)
 {
     return av_popcount(mask);
 }
 

 static int filter_frame8(AVFilterLink *link, AVFrame *in)

 {

     AVFilterContext *ctx = link->dst;
     SignalstatsContext *s = ctx->priv;
     AVFilterLink *outlink = ctx->outputs[0];

     AVFrame *out = in;
     int i, j;
     int  w = 0,  cw = 0, // in
         pw = 0, cpw = 0; // prev
     int fil;
     char metabuf[128];
     unsigned int histy[DEPTH] = {0},
                  histu[DEPTH] = {0},
                  histv[DEPTH] = {0},
                  histhue[360] = {0},
                  histsat[DEPTH] = {0}; // limited to 8 bit data.
     int miny  = -1, minu  = -1, minv  = -1;
     int maxy  = -1, maxu  = -1, maxv  = -1;
     int lowy  = -1, lowu  = -1, lowv  = -1;
     int highy = -1, highu = -1, highv = -1;
     int minsat = -1, maxsat = -1, lowsat = -1, highsat = -1;
     int lowp, highp, clowp, chighp;
     int accy, accu, accv;
     int accsat, acchue = 0;
     int medhue, maxhue;
     int toty = 0, totu = 0, totv = 0, totsat=0;
     int tothue = 0;
     int dify = 0, difu = 0, difv = 0;

     uint16_t masky = 0, masku = 0, maskv = 0;

 
     int filtot[FILT_NUMB] = {0};
     AVFrame *prev;
 

     AVFrame *sat = s->frame_sat;
     AVFrame *hue = s->frame_hue;
     const uint8_t *p_sat = sat->data[0];
     const uint8_t *p_hue = hue->data[0];
     const int lsz_sat = sat->linesize[0];
     const int lsz_hue = hue->linesize[0];

     ThreadDataHueSatMetrics td_huesat = {
         .src     = in,
         .dst_sat = sat,
         .dst_hue = hue,
     };

     if (!s->frame_prev)
         s->frame_prev = av_frame_clone(in);
 
     prev = s->frame_prev;
 

     if (s->outfilter != FILTER_NONE) {

         out = av_frame_clone(in);

         av_frame_make_writable(out);
     }

     ctx->internal->execute(ctx, compute_sat_hue_metrics8, &td_huesat,

                            NULL, FFMIN(s->chromah, ff_filter_get_nb_threads(ctx)));

     // Calculate luma histogram and difference with previous frame or field.
     for (j = 0; j < link->h; j++) {
         for (i = 0; i < link->w; i++) {

             const int yuv = in->data[0][w + i];

 
             masky |= yuv;

             histy[yuv]++;

             dify += abs(yuv - prev->data[0][pw + i]);

         }
         w  += in->linesize[0];
         pw += prev->linesize[0];
     }
 
     // Calculate chroma histogram and difference with previous frame or field.
     for (j = 0; j < s->chromah; j++) {
         for (i = 0; i < s->chromaw; i++) {

             const int yuvu = in->data[1][cw+i];
             const int yuvv = in->data[2][cw+i];

 
             masku |= yuvu;
             maskv |= yuvv;

             histu[yuvu]++;

             difu += abs(yuvu - prev->data[1][cpw+i]);

             histv[yuvv]++;

             difv += abs(yuvv - prev->data[2][cpw+i]);

             histsat[p_sat[i]]++;
             histhue[((int16_t*)p_hue)[i]]++;

         }
         cw  += in->linesize[1];
         cpw += prev->linesize[1];

         p_sat += lsz_sat;
         p_hue += lsz_hue;

     }
 

     for (fil = 0; fil < FILT_NUMB; fil ++) {
         if (s->filters & 1<<fil) {

             ThreadData td = {
                 .in = in,
                 .out = out != in && s->outfilter == fil ? out : NULL,
             };
             memset(s->jobs_rets, 0, s->nb_jobs * sizeof(*s->jobs_rets));

             ctx->internal->execute(ctx, filters_def[fil].process8,

                                    &td, s->jobs_rets, s->nb_jobs);
             for (i = 0; i < s->nb_jobs; i++)
                 filtot[fil] += s->jobs_rets[i];

         }

     }

 
     // find low / high based on histogram percentile
     // these only need to be calculated once.
 
     lowp   = lrint(s->fs  * 10 / 100.);
     highp  = lrint(s->fs  * 90 / 100.);
     clowp  = lrint(s->cfs * 10 / 100.);
     chighp = lrint(s->cfs * 90 / 100.);
 
     accy = accu = accv = accsat = 0;
     for (fil = 0; fil < DEPTH; fil++) {
         if (miny   < 0 && histy[fil])   miny = fil;
         if (minu   < 0 && histu[fil])   minu = fil;
         if (minv   < 0 && histv[fil])   minv = fil;
         if (minsat < 0 && histsat[fil]) minsat = fil;
 
         if (histy[fil])   maxy   = fil;
         if (histu[fil])   maxu   = fil;
         if (histv[fil])   maxv   = fil;
         if (histsat[fil]) maxsat = fil;
 
         toty   += histy[fil]   * fil;
         totu   += histu[fil]   * fil;
         totv   += histv[fil]   * fil;
         totsat += histsat[fil] * fil;
 
         accy   += histy[fil];
         accu   += histu[fil];
         accv   += histv[fil];
         accsat += histsat[fil];
 
         if (lowy   == -1 && accy   >=  lowp) lowy   = fil;
         if (lowu   == -1 && accu   >= clowp) lowu   = fil;
         if (lowv   == -1 && accv   >= clowp) lowv   = fil;
         if (lowsat == -1 && accsat >= clowp) lowsat = fil;
 
         if (highy   == -1 && accy   >=  highp) highy   = fil;
         if (highu   == -1 && accu   >= chighp) highu   = fil;
         if (highv   == -1 && accv   >= chighp) highv   = fil;
         if (highsat == -1 && accsat >= chighp) highsat = fil;
     }
 
     maxhue = histhue[0];
     medhue = -1;
     for (fil = 0; fil < 360; fil++) {
         tothue += histhue[fil] * fil;
         acchue += histhue[fil];
 
         if (medhue == -1 && acchue > s->cfs / 2)
             medhue = fil;
         if (histhue[fil] > maxhue) {
             maxhue = histhue[fil];
         }
     }
 
     av_frame_free(&s->frame_prev);
     s->frame_prev = av_frame_clone(in);
 
 #define SET_META(key, fmt, val) do {                                \
     snprintf(metabuf, sizeof(metabuf), fmt, val);                   \
     av_dict_set(&out->metadata, "lavfi.signalstats." key, metabuf, 0);   \
 } while (0)
 
     SET_META("YMIN",    "%d", miny);
     SET_META("YLOW",    "%d", lowy);
     SET_META("YAVG",    "%g", 1.0 * toty / s->fs);
     SET_META("YHIGH",   "%d", highy);
     SET_META("YMAX",    "%d", maxy);
 
     SET_META("UMIN",    "%d", minu);
     SET_META("ULOW",    "%d", lowu);
     SET_META("UAVG",    "%g", 1.0 * totu / s->cfs);
     SET_META("UHIGH",   "%d", highu);
     SET_META("UMAX",    "%d", maxu);
 
     SET_META("VMIN",    "%d", minv);
     SET_META("VLOW",    "%d", lowv);
     SET_META("VAVG",    "%g", 1.0 * totv / s->cfs);
     SET_META("VHIGH",   "%d", highv);
     SET_META("VMAX",    "%d", maxv);
 
     SET_META("SATMIN",  "%d", minsat);
     SET_META("SATLOW",  "%d", lowsat);
     SET_META("SATAVG",  "%g", 1.0 * totsat / s->cfs);
     SET_META("SATHIGH", "%d", highsat);
     SET_META("SATMAX",  "%d", maxsat);
 
     SET_META("HUEMED",  "%d", medhue);
     SET_META("HUEAVG",  "%g", 1.0 * tothue / s->cfs);
 
     SET_META("YDIF",    "%g", 1.0 * dify / s->fs);
     SET_META("UDIF",    "%g", 1.0 * difu / s->cfs);
     SET_META("VDIF",    "%g", 1.0 * difv / s->cfs);
 

     SET_META("YBITDEPTH", "%d", compute_bit_depth(masky));
     SET_META("UBITDEPTH", "%d", compute_bit_depth(masku));
     SET_META("VBITDEPTH", "%d", compute_bit_depth(maskv));
 

     for (fil = 0; fil < FILT_NUMB; fil ++) {
         if (s->filters & 1<<fil) {
             char metaname[128];
             snprintf(metabuf,  sizeof(metabuf),  "%g", 1.0 * filtot[fil] / s->fs);
             snprintf(metaname, sizeof(metaname), "lavfi.signalstats.%s", filters_def[fil].name);
             av_dict_set(&out->metadata, metaname, metabuf, 0);
         }
     }
 
     if (in != out)
         av_frame_free(&in);
     return ff_filter_frame(outlink, out);
 }
 

 static int filter_frame16(AVFilterLink *link, AVFrame *in)
 {
     AVFilterContext *ctx = link->dst;
     SignalstatsContext *s = ctx->priv;
     AVFilterLink *outlink = ctx->outputs[0];
     AVFrame *out = in;
     int i, j;
     int  w = 0,  cw = 0, // in
         pw = 0, cpw = 0; // prev
     int fil;
     char metabuf[128];
     unsigned int *histy = s->histy,
                  *histu = s->histu,
                  *histv = s->histv,
                  histhue[360] = {0},
                  *histsat = s->histsat;
     int miny  = -1, minu  = -1, minv  = -1;
     int maxy  = -1, maxu  = -1, maxv  = -1;
     int lowy  = -1, lowu  = -1, lowv  = -1;
     int highy = -1, highu = -1, highv = -1;
     int minsat = -1, maxsat = -1, lowsat = -1, highsat = -1;
     int lowp, highp, clowp, chighp;
     int accy, accu, accv;
     int accsat, acchue = 0;
     int medhue, maxhue;
     int64_t toty = 0, totu = 0, totv = 0, totsat=0;
     int64_t tothue = 0;
     int64_t dify = 0, difu = 0, difv = 0;

     uint16_t masky = 0, masku = 0, maskv = 0;

 
     int filtot[FILT_NUMB] = {0};
     AVFrame *prev;
 
     AVFrame *sat = s->frame_sat;
     AVFrame *hue = s->frame_hue;

     const uint16_t *p_sat = (uint16_t *)sat->data[0];
     const uint16_t *p_hue = (uint16_t *)hue->data[0];
     const int lsz_sat = sat->linesize[0] / 2;
     const int lsz_hue = hue->linesize[0] / 2;

     ThreadDataHueSatMetrics td_huesat = {
         .src     = in,
         .dst_sat = sat,
         .dst_hue = hue,
     };
 
     if (!s->frame_prev)
         s->frame_prev = av_frame_clone(in);
 
     prev = s->frame_prev;
 
     if (s->outfilter != FILTER_NONE) {
         out = av_frame_clone(in);
         av_frame_make_writable(out);
     }
 
     ctx->internal->execute(ctx, compute_sat_hue_metrics16, &td_huesat,

                            NULL, FFMIN(s->chromah, ff_filter_get_nb_threads(ctx)));

 
     // Calculate luma histogram and difference with previous frame or field.
     memset(s->histy, 0, (1 << s->depth) * sizeof(*s->histy));
     for (j = 0; j < link->h; j++) {
         for (i = 0; i < link->w; i++) {
             const int yuv = AV_RN16(in->data[0] + w + i * 2);

 
             masky |= yuv;

             histy[yuv]++;
             dify += abs(yuv - AV_RN16(prev->data[0] + pw + i * 2));
         }
         w  += in->linesize[0];
         pw += prev->linesize[0];
     }
 
     // Calculate chroma histogram and difference with previous frame or field.
     memset(s->histu, 0, (1 << s->depth) * sizeof(*s->histu));
     memset(s->histv, 0, (1 << s->depth) * sizeof(*s->histv));
     memset(s->histsat, 0, (1 << s->depth) * sizeof(*s->histsat));
     for (j = 0; j < s->chromah; j++) {
         for (i = 0; i < s->chromaw; i++) {
             const int yuvu = AV_RN16(in->data[1] + cw + i * 2);
             const int yuvv = AV_RN16(in->data[2] + cw + i * 2);

 
             masku |= yuvu;
             maskv |= yuvv;

             histu[yuvu]++;
             difu += abs(yuvu - AV_RN16(prev->data[1] + cpw + i * 2));
             histv[yuvv]++;
             difv += abs(yuvv - AV_RN16(prev->data[2] + cpw + i * 2));
 
             histsat[p_sat[i]]++;
             histhue[((int16_t*)p_hue)[i]]++;
         }
         cw  += in->linesize[1];
         cpw += prev->linesize[1];
         p_sat += lsz_sat;
         p_hue += lsz_hue;
     }
 
     for (fil = 0; fil < FILT_NUMB; fil ++) {
         if (s->filters & 1<<fil) {
             ThreadData td = {
                 .in = in,
                 .out = out != in && s->outfilter == fil ? out : NULL,
             };
             memset(s->jobs_rets, 0, s->nb_jobs * sizeof(*s->jobs_rets));
             ctx->internal->execute(ctx, filters_def[fil].process16,
                                    &td, s->jobs_rets, s->nb_jobs);
             for (i = 0; i < s->nb_jobs; i++)
                 filtot[fil] += s->jobs_rets[i];
         }
     }
 
     // find low / high based on histogram percentile
     // these only need to be calculated once.
 
     lowp   = lrint(s->fs  * 10 / 100.);
     highp  = lrint(s->fs  * 90 / 100.);
     clowp  = lrint(s->cfs * 10 / 100.);
     chighp = lrint(s->cfs * 90 / 100.);
 
     accy = accu = accv = accsat = 0;
     for (fil = 0; fil < 1 << s->depth; fil++) {
         if (miny   < 0 && histy[fil])   miny = fil;
         if (minu   < 0 && histu[fil])   minu = fil;
         if (minv   < 0 && histv[fil])   minv = fil;
         if (minsat < 0 && histsat[fil]) minsat = fil;
 
         if (histy[fil])   maxy   = fil;
         if (histu[fil])   maxu   = fil;
         if (histv[fil])   maxv   = fil;
         if (histsat[fil]) maxsat = fil;
 
         toty   += histy[fil]   * fil;
         totu   += histu[fil]   * fil;
         totv   += histv[fil]   * fil;
         totsat += histsat[fil] * fil;
 
         accy   += histy[fil];
         accu   += histu[fil];
         accv   += histv[fil];
         accsat += histsat[fil];
 
         if (lowy   == -1 && accy   >=  lowp) lowy   = fil;
         if (lowu   == -1 && accu   >= clowp) lowu   = fil;
         if (lowv   == -1 && accv   >= clowp) lowv   = fil;
         if (lowsat == -1 && accsat >= clowp) lowsat = fil;
 
         if (highy   == -1 && accy   >=  highp) highy   = fil;
         if (highu   == -1 && accu   >= chighp) highu   = fil;
         if (highv   == -1 && accv   >= chighp) highv   = fil;
         if (highsat == -1 && accsat >= chighp) highsat = fil;
     }
 
     maxhue = histhue[0];
     medhue = -1;
     for (fil = 0; fil < 360; fil++) {
         tothue += histhue[fil] * fil;
         acchue += histhue[fil];
 
         if (medhue == -1 && acchue > s->cfs / 2)
             medhue = fil;
         if (histhue[fil] > maxhue) {
             maxhue = histhue[fil];
         }
     }
 
     av_frame_free(&s->frame_prev);
     s->frame_prev = av_frame_clone(in);
 
     SET_META("YMIN",    "%d", miny);
     SET_META("YLOW",    "%d", lowy);
     SET_META("YAVG",    "%g", 1.0 * toty / s->fs);
     SET_META("YHIGH",   "%d", highy);
     SET_META("YMAX",    "%d", maxy);
 
     SET_META("UMIN",    "%d", minu);
     SET_META("ULOW",    "%d", lowu);
     SET_META("UAVG",    "%g", 1.0 * totu / s->cfs);
     SET_META("UHIGH",   "%d", highu);
     SET_META("UMAX",    "%d", maxu);
 
     SET_META("VMIN",    "%d", minv);
     SET_META("VLOW",    "%d", lowv);
     SET_META("VAVG",    "%g", 1.0 * totv / s->cfs);
     SET_META("VHIGH",   "%d", highv);
     SET_META("VMAX",    "%d", maxv);
 
     SET_META("SATMIN",  "%d", minsat);
     SET_META("SATLOW",  "%d", lowsat);
     SET_META("SATAVG",  "%g", 1.0 * totsat / s->cfs);
     SET_META("SATHIGH", "%d", highsat);
     SET_META("SATMAX",  "%d", maxsat);
 
     SET_META("HUEMED",  "%d", medhue);
     SET_META("HUEAVG",  "%g", 1.0 * tothue / s->cfs);
 
     SET_META("YDIF",    "%g", 1.0 * dify / s->fs);
     SET_META("UDIF",    "%g", 1.0 * difu / s->cfs);
     SET_META("VDIF",    "%g", 1.0 * difv / s->cfs);
 

     SET_META("YBITDEPTH", "%d", compute_bit_depth(masky));
     SET_META("UBITDEPTH", "%d", compute_bit_depth(masku));
     SET_META("VBITDEPTH", "%d", compute_bit_depth(maskv));
 

     for (fil = 0; fil < FILT_NUMB; fil ++) {
         if (s->filters & 1<<fil) {
             char metaname[128];
             snprintf(metabuf,  sizeof(metabuf),  "%g", 1.0 * filtot[fil] / s->fs);
             snprintf(metaname, sizeof(metaname), "lavfi.signalstats.%s", filters_def[fil].name);
             av_dict_set(&out->metadata, metaname, metabuf, 0);
         }
     }
 
     if (in != out)
         av_frame_free(&in);
     return ff_filter_frame(outlink, out);
 }
 
 static int filter_frame(AVFilterLink *link, AVFrame *in)
 {
     AVFilterContext *ctx = link->dst;
     SignalstatsContext *s = ctx->priv;
 
     if (s->depth > 8)
         return filter_frame16(link, in);
     else
         return filter_frame8(link, in);
 }
 

 static const AVFilterPad signalstats_inputs[] = {
     {
         .name           = "default",
         .type           = AVMEDIA_TYPE_VIDEO,
         .filter_frame   = filter_frame,
     },
     { NULL }
 };
 
 static const AVFilterPad signalstats_outputs[] = {
     {
         .name           = "default",
         .config_props   = config_props,
         .type           = AVMEDIA_TYPE_VIDEO,
     },
     { NULL }
 };
 
 AVFilter ff_vf_signalstats = {
     .name          = "signalstats",
     .description   = "Generate statistics from video analysis.",
     .init          = init,
     .uninit        = uninit,
     .query_formats = query_formats,
     .priv_size     = sizeof(SignalstatsContext),
     .inputs        = signalstats_inputs,
     .outputs       = signalstats_outputs,
     .priv_class    = &signalstats_class,

     .flags         = AVFILTER_FLAG_SLICE_THREADS,

 };