/*
  * Copyright (C) 2012 Mark Himsley
  *
  * get_scene_score() Copyright (c) 2011 Stefano Sabatini
  * taken from libavfilter/vf_select.c
  *
  * This file is part of FFmpeg.
  *
  * FFmpeg is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *
  * FFmpeg is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
  * License along with FFmpeg; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
 /**
  * @file
  * filter for upsampling or downsampling a progressive source
  */
 
 #define DEBUG
 
 #include "libavutil/avassert.h"
 #include "libavutil/imgutils.h"
 #include "libavutil/internal.h"
 #include "libavutil/opt.h"
 #include "libavutil/pixdesc.h"
 #include "libavutil/pixelutils.h"
 
 #include "avfilter.h"
 #include "internal.h"
 #include "video.h"

 #include "framerate.h"

 
 #define OFFSET(x) offsetof(FrameRateContext, x)
 #define V AV_OPT_FLAG_VIDEO_PARAM
 #define F AV_OPT_FLAG_FILTERING_PARAM
 #define FRAMERATE_FLAG_SCD 01
 
 static const AVOption framerate_options[] = {
     {"fps",                 "required output frames per second rate", OFFSET(dest_frame_rate), AV_OPT_TYPE_VIDEO_RATE, {.str="50"},             0,       INT_MAX, V|F },
 

     {"interp_start",        "point to start linear interpolation",    OFFSET(interp_start),    AV_OPT_TYPE_INT,      {.i64=15},                 0,       255,     V|F },
     {"interp_end",          "point to end linear interpolation",      OFFSET(interp_end),      AV_OPT_TYPE_INT,      {.i64=240},                0,       255,     V|F },

     {"scene",               "scene change level",                     OFFSET(scene_score),     AV_OPT_TYPE_DOUBLE,   {.dbl=8.2},                0,       INT_MAX, V|F },

 
     {"flags",               "set flags",                              OFFSET(flags),           AV_OPT_TYPE_FLAGS,    {.i64=1},                  0,       INT_MAX, V|F, "flags" },
     {"scene_change_detect", "enable scene change detection",          0,                       AV_OPT_TYPE_CONST,    {.i64=FRAMERATE_FLAG_SCD}, INT_MIN, INT_MAX, V|F, "flags" },
     {"scd",                 "enable scene change detection",          0,                       AV_OPT_TYPE_CONST,    {.i64=FRAMERATE_FLAG_SCD}, INT_MIN, INT_MAX, V|F, "flags" },
 
     {NULL}
 };
 
 AVFILTER_DEFINE_CLASS(framerate);
 

 static av_always_inline int64_t sad_8x8_16(const uint16_t *src1, ptrdiff_t stride1,
                                            const uint16_t *src2, ptrdiff_t stride2)
 {
     int sum = 0;
     int x, y;
 
     for (y = 0; y < 8; y++) {
         for (x = 0; x < 8; x++)
             sum += FFABS(src1[x] - src2[x]);
         src1 += stride1;
         src2 += stride2;
     }
     return sum;
 }
 

 static int64_t scene_sad16(FrameRateContext *s, const uint16_t *p1, int p1_linesize, const uint16_t* p2, int p2_linesize, const int width, const int height)

 {

     int64_t sad;
     int x, y;

     for (sad = y = 0; y < height - 7; y += 8) {
         for (x = 0; x < width - 7; x += 8) {

             sad += sad_8x8_16(p1 + y * p1_linesize + x,
                               p1_linesize,
                               p2 + y * p2_linesize + x,
                               p2_linesize);
         }
     }
     return sad;
 }

 static int64_t scene_sad8(FrameRateContext *s, uint8_t *p1, int p1_linesize, uint8_t* p2, int p2_linesize, const int width, const int height)

 {
     int64_t sad;
     int x, y;

     for (sad = y = 0; y < height - 7; y += 8) {
         for (x = 0; x < width - 7; x += 8) {

             sad += s->sad(p1 + y * p1_linesize + x,
                           p1_linesize,
                           p2 + y * p2_linesize + x,
                           p2_linesize);

         }
     }

     emms_c();
     return sad;

 }
 

 static double get_scene_score(AVFilterContext *ctx, AVFrame *crnt, AVFrame *next)
 {
     FrameRateContext *s = ctx->priv;
     double ret = 0;
 
     ff_dlog(ctx, "get_scene_score()\n");
 

     if (crnt->height == next->height &&

         crnt->width  == next->width) {
         int64_t sad;
         double mafd, diff;
 
         ff_dlog(ctx, "get_scene_score() process\n");

         if (s->bitdepth == 8)

             sad = scene_sad8(s, crnt->data[0], crnt->linesize[0], next->data[0], next->linesize[0], crnt->width, crnt->height);

         else

             sad = scene_sad16(s, (const uint16_t*)crnt->data[0], crnt->linesize[0] / 2, (const uint16_t*)next->data[0], next->linesize[0] / 2, crnt->width, crnt->height);

         mafd = (double)sad * 100.0 / FFMAX(1, (crnt->height & ~7) * (crnt->width & ~7)) / (1 << s->bitdepth);

         diff = fabs(mafd - s->prev_mafd);
         ret  = av_clipf(FFMIN(mafd, diff), 0, 100.0);
         s->prev_mafd = mafd;
     }

     ff_dlog(ctx, "get_scene_score() result is:%f\n", ret);

     return ret;
 }
 

 typedef struct ThreadData {
     AVFrame *copy_src1, *copy_src2;
     uint16_t src1_factor, src2_factor;
 } ThreadData;
 

 static int filter_slice(AVFilterContext *ctx, void *arg, int job, int nb_jobs)

 {
     FrameRateContext *s = ctx->priv;
     ThreadData *td = arg;
     uint16_t src1_factor = td->src1_factor;
     uint16_t src2_factor = td->src2_factor;

     int plane;

 
     for (plane = 0; plane < 4 && td->copy_src1->data[plane] && td->copy_src2->data[plane]; plane++) {
         int cpy_line_width = s->line_size[plane];
         uint8_t *cpy_src1_data = td->copy_src1->data[plane];
         int cpy_src1_line_size = td->copy_src1->linesize[plane];
         uint8_t *cpy_src2_data = td->copy_src2->data[plane];
         int cpy_src2_line_size = td->copy_src2->linesize[plane];
         int cpy_src_h = (plane > 0 && plane < 3) ? (td->copy_src1->height >> s->vsub) : (td->copy_src1->height);
         uint8_t *cpy_dst_data = s->work->data[plane];
         int cpy_dst_line_size = s->work->linesize[plane];
         const int start = (cpy_src_h *  job   ) / nb_jobs;
         const int end   = (cpy_src_h * (job+1)) / nb_jobs;
         cpy_src1_data += start * cpy_src1_line_size;
         cpy_src2_data += start * cpy_src2_line_size;
         cpy_dst_data += start * cpy_dst_line_size;
 

         s->blend(cpy_src1_data, cpy_src1_line_size,
                  cpy_src2_data, cpy_src2_line_size,
                  cpy_dst_data,  cpy_dst_line_size,
                  cpy_line_width, end - start,

                  src1_factor, src2_factor, s->blend_factor_max >> 1);

     }
 
     return 0;
 }
 

 static int blend_frames(AVFilterContext *ctx, int interpolate)

 {
     FrameRateContext *s = ctx->priv;
     AVFilterLink *outlink = ctx->outputs[0];
     double interpolate_scene_score = 0;
 

     if ((s->flags & FRAMERATE_FLAG_SCD)) {
         if (s->score >= 0.0)
             interpolate_scene_score = s->score;

         else

             interpolate_scene_score = s->score = get_scene_score(ctx, s->f0, s->f1);

         ff_dlog(ctx, "blend_frames() interpolate scene score:%f\n", interpolate_scene_score);

     }
     // decide if the shot-change detection allows us to blend two frames

     if (interpolate_scene_score < s->scene_score) {

         ThreadData td;

         td.copy_src1 = s->f0;
         td.copy_src2 = s->f1;
         td.src2_factor = interpolate;

         td.src1_factor = s->blend_factor_max - td.src2_factor;

 
         // get work-space for output frame
         s->work = ff_get_video_buffer(outlink, outlink->w, outlink->h);
         if (!s->work)
             return AVERROR(ENOMEM);
 

         av_frame_copy_props(s->work, s->f0);

         ff_dlog(ctx, "blend_frames() INTERPOLATE to create work frame\n");

         ctx->internal->execute(ctx, filter_slice, &td, NULL, FFMIN(FFMAX(1, outlink->h >> 2), ff_filter_get_nb_threads(ctx)));

         return 1;
     }
     return 0;
 }
 

 static int process_work_frame(AVFilterContext *ctx)

 {
     FrameRateContext *s = ctx->priv;

     int64_t work_pts;

     int64_t interpolate, interpolate8;

     int ret;

     if (!s->f1)

         return 0;

     if (!s->f0 && !s->flush)

         return 0;
 

     work_pts = s->start_pts + av_rescale_q(s->n, av_inv_q(s->dest_frame_rate), s->dest_time_base);
 
     if (work_pts >= s->pts1 && !s->flush)
         return 0;

     if (!s->f0) {
         s->work = av_frame_clone(s->f1);
     } else {
         if (work_pts >= s->pts1 + s->delta && s->flush)
             return 0;
 

         interpolate = av_rescale(work_pts - s->pts0, s->blend_factor_max, s->delta);
         interpolate8 = av_rescale(work_pts - s->pts0, 256, s->delta);
         ff_dlog(ctx, "process_work_frame() interpolate: %"PRId64"/256\n", interpolate8);
         if (interpolate >= s->blend_factor_max || interpolate8 > s->interp_end) {

             s->work = av_frame_clone(s->f1);

         } else if (interpolate <= 0 || interpolate8 < s->interp_start) {

             s->work = av_frame_clone(s->f0);

         } else {

             ret = blend_frames(ctx, interpolate);
             if (ret < 0)
                 return ret;
             if (ret == 0)

                 s->work = av_frame_clone(interpolate > (s->blend_factor_max >> 1) ? s->f1 : s->f0);

         }
     }
 

     if (!s->work)

         return AVERROR(ENOMEM);
 

     s->work->pts = work_pts;
     s->n++;

     return 1;

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

     s->start_pts = AV_NOPTS_VALUE;

     return 0;
 }
 
 static av_cold void uninit(AVFilterContext *ctx)
 {
     FrameRateContext *s = ctx->priv;

     av_frame_free(&s->f0);
     av_frame_free(&s->f1);

 }
 
 static int query_formats(AVFilterContext *ctx)
 {
     static const enum AVPixelFormat pix_fmts[] = {
         AV_PIX_FMT_YUV410P,
         AV_PIX_FMT_YUV411P, AV_PIX_FMT_YUVJ411P,
         AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUVJ420P,
         AV_PIX_FMT_YUV422P, AV_PIX_FMT_YUVJ422P,
         AV_PIX_FMT_YUV440P, AV_PIX_FMT_YUVJ440P,
         AV_PIX_FMT_YUV444P, AV_PIX_FMT_YUVJ444P,

         AV_PIX_FMT_YUV420P9, AV_PIX_FMT_YUV420P10, AV_PIX_FMT_YUV420P12,
         AV_PIX_FMT_YUV422P9, AV_PIX_FMT_YUV422P10, AV_PIX_FMT_YUV422P12,
         AV_PIX_FMT_YUV444P9, AV_PIX_FMT_YUV444P10, AV_PIX_FMT_YUV444P12,

         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 void blend_frames_c(BLEND_FUNC_PARAMS)
 {
     int line, pixel;
     for (line = 0; line < height; line++) {

         for (pixel = 0; pixel < width; pixel++)
             dst[pixel] = ((src1[pixel] * factor1) + (src2[pixel] * factor2) + half) >> BLEND_FACTOR_DEPTH8;

         src1 += src1_linesize;
         src2 += src2_linesize;
         dst  += dst_linesize;
     }
 }
 
 static void blend_frames16_c(BLEND_FUNC_PARAMS)
 {
     int line, pixel;
     uint16_t *dstw = (uint16_t *)dst;
     uint16_t *src1w = (uint16_t *)src1;
     uint16_t *src2w = (uint16_t *)src2;
     width /= 2;
     src1_linesize /= 2;
     src2_linesize /= 2;
     dst_linesize /= 2;
     for (line = 0; line < height; line++) {
         for (pixel = 0; pixel < width; pixel++)

             dstw[pixel] = ((src1w[pixel] * factor1) + (src2w[pixel] * factor2) + half) >> BLEND_FACTOR_DEPTH16;

         src1w += src1_linesize;
         src2w += src2_linesize;
         dstw  += dst_linesize;
     }
 }
 

 void ff_framerate_init(FrameRateContext *s)
 {
     if (s->bitdepth == 8) {
         s->blend_factor_max = 1 << BLEND_FACTOR_DEPTH8;
         s->blend = blend_frames_c;
     } else {
         s->blend_factor_max = 1 << BLEND_FACTOR_DEPTH16;
         s->blend = blend_frames16_c;
     }
     if (ARCH_X86)
         ff_framerate_init_x86(s);
 }
 

 static int config_input(AVFilterLink *inlink)
 {
     AVFilterContext *ctx = inlink->dst;
     FrameRateContext *s = ctx->priv;
     const AVPixFmtDescriptor *pix_desc = av_pix_fmt_desc_get(inlink->format);
     int plane;
 
     for (plane = 0; plane < 4; plane++) {
         s->line_size[plane] = av_image_get_linesize(inlink->format, inlink->w,
                                                     plane);
     }
 

     s->bitdepth = pix_desc->comp[0].depth;

     s->vsub = pix_desc->log2_chroma_h;
 
     s->sad = av_pixelutils_get_sad_fn(3, 3, 2, s); // 8x8 both sources aligned
     if (!s->sad)
         return AVERROR(EINVAL);
 
     s->srce_time_base = inlink->time_base;
 

     ff_framerate_init(s);

     return 0;
 }
 
 static int filter_frame(AVFilterLink *inlink, AVFrame *inpicref)
 {

     int ret;

     AVFilterContext *ctx = inlink->dst;
     FrameRateContext *s = ctx->priv;

     int64_t pts;

 
     if (inpicref->interlaced_frame)
         av_log(ctx, AV_LOG_WARNING, "Interlaced frame found - the output will not be correct.\n");
 

     if (inpicref->pts == AV_NOPTS_VALUE) {
         av_log(ctx, AV_LOG_WARNING, "Ignoring frame without PTS.\n");
         return 0;
     }

     pts = av_rescale_q(inpicref->pts, s->srce_time_base, s->dest_time_base);
     if (s->f1 && pts == s->pts1) {
         av_log(ctx, AV_LOG_WARNING, "Ignoring frame with same PTS.\n");
         return 0;

     }
 

     av_frame_free(&s->f0);
     s->f0 = s->f1;
     s->pts0 = s->pts1;
     s->f1 = inpicref;
     s->pts1 = pts;
     s->delta = s->pts1 - s->pts0;
     s->score = -1.0;
 
     if (s->delta < 0) {
         av_log(ctx, AV_LOG_WARNING, "PTS discontinuity.\n");
         s->start_pts = s->pts1;
         s->n = 0;
         av_frame_free(&s->f0);
     }
 
     if (s->start_pts == AV_NOPTS_VALUE)
         s->start_pts = s->pts1;
 
     do {
         ret = process_work_frame(ctx);
         if (ret <= 0)
             return ret;
         ret = ff_filter_frame(ctx->outputs[0], s->work);
     } while (ret >= 0);
 
     return ret;

 }
 
 static int config_output(AVFilterLink *outlink)
 {
     AVFilterContext *ctx = outlink->src;
     FrameRateContext *s = ctx->priv;
     int exact;
 
     ff_dlog(ctx, "config_output()\n");
 
     ff_dlog(ctx,
            "config_output() input time base:%u/%u (%f)\n",
            ctx->inputs[0]->time_base.num,ctx->inputs[0]->time_base.den,
            av_q2d(ctx->inputs[0]->time_base));
 
     // make sure timebase is small enough to hold the framerate
 
     exact = av_reduce(&s->dest_time_base.num, &s->dest_time_base.den,
                       av_gcd((int64_t)s->srce_time_base.num * s->dest_frame_rate.num,
                              (int64_t)s->srce_time_base.den * s->dest_frame_rate.den ),
                       (int64_t)s->srce_time_base.den * s->dest_frame_rate.num, INT_MAX);
 
     av_log(ctx, AV_LOG_INFO,
            "time base:%u/%u -> %u/%u exact:%d\n",
            s->srce_time_base.num, s->srce_time_base.den,
            s->dest_time_base.num, s->dest_time_base.den, exact);
     if (!exact) {
         av_log(ctx, AV_LOG_WARNING, "Timebase conversion is not exact\n");
     }
 
     outlink->frame_rate = s->dest_frame_rate;
     outlink->time_base = s->dest_time_base;
 
     ff_dlog(ctx,
            "config_output() output time base:%u/%u (%f) w:%d h:%d\n",
            outlink->time_base.num, outlink->time_base.den,
            av_q2d(outlink->time_base),
            outlink->w, outlink->h);
 
 
     av_log(ctx, AV_LOG_INFO, "fps -> fps:%u/%u scene score:%f interpolate start:%d end:%d\n",
             s->dest_frame_rate.num, s->dest_frame_rate.den,
             s->scene_score, s->interp_start, s->interp_end);
 
     return 0;
 }
 
 static int request_frame(AVFilterLink *outlink)
 {
     AVFilterContext *ctx = outlink->src;
     FrameRateContext *s = ctx->priv;

     int ret;

 
     ff_dlog(ctx, "request_frame()\n");
 

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

     if (ret == AVERROR_EOF && s->f1 && !s->flush) {

         s->flush = 1;

         ret = process_work_frame(ctx);
         if (ret < 0)
             return ret;
         ret = ret ? ff_filter_frame(ctx->outputs[0], s->work) : AVERROR_EOF;

     }

     ff_dlog(ctx, "request_frame() source's request_frame() returned:%d\n", ret);

     return ret;

 }
 
 static const AVFilterPad framerate_inputs[] = {
     {
         .name         = "default",
         .type         = AVMEDIA_TYPE_VIDEO,
         .config_props = config_input,
         .filter_frame = filter_frame,
     },
     { NULL }
 };
 
 static const AVFilterPad framerate_outputs[] = {
     {
         .name          = "default",
         .type          = AVMEDIA_TYPE_VIDEO,
         .request_frame = request_frame,
         .config_props  = config_output,
     },
     { NULL }
 };
 
 AVFilter ff_vf_framerate = {
     .name          = "framerate",
     .description   = NULL_IF_CONFIG_SMALL("Upsamples or downsamples progressive source between specified frame rates."),
     .priv_size     = sizeof(FrameRateContext),
     .priv_class    = &framerate_class,
     .init          = init,
     .uninit        = uninit,
     .query_formats = query_formats,
     .inputs        = framerate_inputs,
     .outputs       = framerate_outputs,

     .flags         = AVFILTER_FLAG_SLICE_THREADS,

 };