/*
  * Copyright (c) 2017 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 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/imgutils.h"
 #include "libavutil/opt.h"
 #include "libavutil/pixdesc.h"
 #include "libavcodec/avfft.h"
 
 #include "avfilter.h"
 #include "formats.h"

 #include "framesync.h"

 #include "internal.h"
 #include "video.h"
 
 typedef struct ConvolveContext {
     const AVClass *class;
     FFFrameSync fs;
 
     FFTContext *fft[4];
     FFTContext *ifft[4];
 
     int fft_bits[4];
     int fft_len[4];
     int planewidth[4];
     int planeheight[4];
 
     FFTComplex *fft_hdata[4];
     FFTComplex *fft_vdata[4];
     FFTComplex *fft_hdata_impulse[4];
     FFTComplex *fft_vdata_impulse[4];
 
     int depth;
     int planes;
     int impulse;
     int nb_planes;
     int got_impulse[4];
 } ConvolveContext;
 
 #define OFFSET(x) offsetof(ConvolveContext, x)
 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
 
 static const AVOption convolve_options[] = {
     { "planes",  "set planes to convolve",                  OFFSET(planes),   AV_OPT_TYPE_INT,   {.i64=7}, 0, 15, FLAGS },
     { "impulse", "when to process impulses",                OFFSET(impulse),  AV_OPT_TYPE_INT,   {.i64=1}, 0,  1, FLAGS, "impulse" },
     {   "first", "process only first impulse, ignore rest", 0,                AV_OPT_TYPE_CONST, {.i64=0}, 0,  0, FLAGS, "impulse" },
     {   "all",   "process all impulses",                    0,                AV_OPT_TYPE_CONST, {.i64=1}, 0,  0, FLAGS, "impulse" },
     { NULL },
 };
 
 FRAMESYNC_DEFINE_CLASS(convolve, ConvolveContext, fs);
 
 static int query_formats(AVFilterContext *ctx)
 {
     static const enum AVPixelFormat pixel_fmts_fftfilt[] = {
         AV_PIX_FMT_YUVA444P, AV_PIX_FMT_YUV444P, AV_PIX_FMT_YUV440P,
         AV_PIX_FMT_YUVJ444P, AV_PIX_FMT_YUVJ440P,
         AV_PIX_FMT_YUVA422P, AV_PIX_FMT_YUV422P, AV_PIX_FMT_YUVA420P, AV_PIX_FMT_YUV420P,
         AV_PIX_FMT_YUVJ422P, AV_PIX_FMT_YUVJ420P,
         AV_PIX_FMT_YUVJ411P, AV_PIX_FMT_YUV411P, AV_PIX_FMT_YUV410P,
         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_YUV440P12,
         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_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_GBRAP10, AV_PIX_FMT_GBRAP12, AV_PIX_FMT_GBRAP16,
         AV_PIX_FMT_GRAY8, AV_PIX_FMT_GRAY9, AV_PIX_FMT_GRAY10, AV_PIX_FMT_GRAY12, AV_PIX_FMT_GRAY16,
         AV_PIX_FMT_NONE
     };
 
     AVFilterFormats *fmts_list = ff_make_format_list(pixel_fmts_fftfilt);
     if (!fmts_list)
         return AVERROR(ENOMEM);
     return ff_set_common_formats(ctx, fmts_list);
 }
 
 static int config_input_main(AVFilterLink *inlink)
 {
     ConvolveContext *s = inlink->dst->priv;
     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
     int fft_bits, i;
 
     s->planewidth[1] = s->planewidth[2] = AV_CEIL_RSHIFT(inlink->w, desc->log2_chroma_w);
     s->planewidth[0] = s->planewidth[3] = inlink->w;
     s->planeheight[1] = s->planeheight[2] = AV_CEIL_RSHIFT(inlink->h, desc->log2_chroma_h);
     s->planeheight[0] = s->planeheight[3] = inlink->h;
 
     s->nb_planes = desc->nb_components;
     s->depth = desc->comp[0].depth;
 
     for (i = 0; i < s->nb_planes; i++) {
         int w = s->planewidth[i];
         int h = s->planeheight[i];
         int n = FFMAX(w, h) * 10/9;
 
         for (fft_bits = 1; 1 << fft_bits < n; fft_bits++);
 
         s->fft_bits[i] = fft_bits;
         s->fft_len[i] = 1 << s->fft_bits[i];
 
         if (!(s->fft_hdata[i] = av_calloc(s->fft_len[i], s->fft_len[i] * sizeof(FFTComplex))))
             return AVERROR(ENOMEM);
 
         if (!(s->fft_vdata[i] = av_calloc(s->fft_len[i], s->fft_len[i] * sizeof(FFTComplex))))
             return AVERROR(ENOMEM);
 
         if (!(s->fft_hdata_impulse[i] = av_calloc(s->fft_len[i], s->fft_len[i] * sizeof(FFTComplex))))
             return AVERROR(ENOMEM);
 
         if (!(s->fft_vdata_impulse[i] = av_calloc(s->fft_len[i], s->fft_len[i] * sizeof(FFTComplex))))
             return AVERROR(ENOMEM);
     }
 
     return 0;
 }
 
 static int config_input_impulse(AVFilterLink *inlink)
 {
     AVFilterContext *ctx  = inlink->dst;
 
     if (ctx->inputs[0]->w != ctx->inputs[1]->w ||
         ctx->inputs[0]->h != ctx->inputs[1]->h) {
         av_log(ctx, AV_LOG_ERROR, "Width and height of input videos must be same.\n");
         return AVERROR(EINVAL);
     }
     if (ctx->inputs[0]->format != ctx->inputs[1]->format) {
         av_log(ctx, AV_LOG_ERROR, "Inputs must be of same pixel format.\n");
         return AVERROR(EINVAL);
     }
 
     return 0;
 }
 
 static void fft_horizontal(ConvolveContext *s, FFTComplex *fft_hdata,
                            AVFrame *in, int w, int h, int n, int plane, float scale)
 {
     int y, x;
 
     for (y = 0; y < h; y++) {
         if (s->depth == 8) {
             const uint8_t *src = in->data[plane] + in->linesize[plane] * y;
 
             for (x = 0; x < w; x++) {
                 fft_hdata[y * n + x].re = src[x] * scale;
                 fft_hdata[y * n + x].im = 0;
             }
         } else {
             const uint16_t *src = (const uint16_t *)(in->data[plane] + in->linesize[plane] * y);
 
             for (x = 0; x < w; x++) {
                 fft_hdata[y * n + x].re = src[x] * scale;
                 fft_hdata[y * n + x].im = 0;
             }
         }
         for (; x < n; x++) {
             fft_hdata[y * n + x].re = 0;
             fft_hdata[y * n + x].im = 0;
         }
     }
 
     for (; y < n; y++) {
         for (x = 0; x < n; x++) {
             fft_hdata[y * n + x].re = 0;
             fft_hdata[y * n + x].im = 0;
         }
     }
 
     for (y = 0; y < n; y++) {
         av_fft_permute(s->fft[plane], fft_hdata + y * n);
         av_fft_calc(s->fft[plane], fft_hdata + y * n);
     }
 }
 
 static void fft_vertical(ConvolveContext *s, FFTComplex *fft_hdata, FFTComplex *fft_vdata,
                          int n, int plane)
 {
     int y, x;
 
     for (y = 0; y < n; y++) {
         for (x = 0; x < n; x++) {
             fft_vdata[y * n + x].re = fft_hdata[x * n + y].re;
             fft_vdata[y * n + x].im = fft_hdata[x * n + y].im;
         }
         for (; x < n; x++) {
             fft_vdata[y * n + x].re = 0;
             fft_vdata[y * n + x].im = 0;
         }
         av_fft_permute(s->fft[plane], fft_vdata + y * n);
         av_fft_calc(s->fft[plane], fft_vdata + y * n);
     }
 }
 
 static void ifft_vertical(ConvolveContext *s, int n, int plane)
 {
     int y, x;
 
     for (y = 0; y < n; y++) {
         av_fft_permute(s->ifft[plane], s->fft_vdata[plane] + y * n);
         av_fft_calc(s->ifft[plane], s->fft_vdata[plane] + y * n);
         for (x = 0; x < n; x++) {
             s->fft_hdata[plane][x * n + y].re = s->fft_vdata[plane][y * n + x].re;
             s->fft_hdata[plane][x * n + y].im = s->fft_vdata[plane][y * n + x].im;
         }
     }
 }
 
 static void ifft_horizontal(ConvolveContext *s, AVFrame *out,
                             int w, int h, int n, int plane)
 {
     const float scale = 1.f / (n * n);
     const int max = (1 << s->depth) - 1;
     const int oh = h / 2;
     const int ow = w / 2;
     int y, x;
 
     for (y = 0; y < n; y++) {
         av_fft_permute(s->ifft[plane], s->fft_hdata[plane] + y * n);
         av_fft_calc(s->ifft[plane], s->fft_hdata[plane] + y * n);
     }
 
     if (s->depth == 8) {
         for (y = 0; y < h; y++) {
             uint8_t *dst = out->data[plane] + y * out->linesize[plane];
             for (x = 0; x < w; x++)

                 dst[x] = av_clip_uint8(s->fft_hdata[plane][(y+oh) * n + x+ow].re * scale);

         }
     } else {
         for (y = 0; y < h; y++) {
             uint16_t *dst = (uint16_t *)(out->data[plane] + y * out->linesize[plane]);
             for (x = 0; x < w; x++)
                 dst[x] = av_clip(s->fft_hdata[plane][(y+oh) * n + x+ow].re * scale, 0, max);
         }
     }
 }
 
 static int do_convolve(FFFrameSync *fs)
 {
     AVFilterContext *ctx = fs->parent;
     AVFilterLink *outlink = ctx->outputs[0];
     ConvolveContext *s = ctx->priv;
     AVFrame *mainpic = NULL, *impulsepic = NULL;
     int ret, y, x, plane;
 

     ret = ff_framesync_dualinput_get(fs, &mainpic, &impulsepic);

     if (ret < 0)
         return ret;
     if (!impulsepic)
         return ff_filter_frame(outlink, mainpic);
 
     for (plane = 0; plane < s->nb_planes; plane++) {
         const int n = s->fft_len[plane];
         const int w = s->planewidth[plane];
         const int h = s->planeheight[plane];
         float total = 0;
 
         if (!(s->planes & (1 << plane))) {
             continue;
         }
 
         fft_horizontal(s, s->fft_hdata[plane], mainpic, w, h, n, plane, 1.f);
         fft_vertical(s, s->fft_hdata[plane], s->fft_vdata[plane],
                      n, plane);
 
         if ((!s->impulse && !s->got_impulse[plane]) || s->impulse) {
             if (s->depth == 8) {
                 for (y = 0; y < h; y++) {
                     const uint8_t *src = (const uint8_t *)(impulsepic->data[plane] + y * impulsepic->linesize[plane]) ;
                     for (x = 0; x < w; x++) {
                         total += src[x];
                     }
                 }
             } else {
                 for (y = 0; y < h; y++) {
                     const uint16_t *src = (const uint16_t *)(impulsepic->data[plane] + y * impulsepic->linesize[plane]) ;
                     for (x = 0; x < w; x++) {
                         total += src[x];
                     }
                 }
             }
             total = FFMAX(1, total);
 
             fft_horizontal(s, s->fft_hdata_impulse[plane], impulsepic, w, h, n, plane, 1 / total);
             fft_vertical(s, s->fft_hdata_impulse[plane], s->fft_vdata_impulse[plane],
                          n, plane);
 
             s->got_impulse[plane] = 1;
         }
 
         for (y = 0; y < n; y++) {
             for (x = 0; x < n; x++) {
                 FFTSample re, im, ire, iim;
 
                 re = s->fft_vdata[plane][y*n + x].re;
                 im = s->fft_vdata[plane][y*n + x].im;
                 ire = s->fft_vdata_impulse[plane][y*n + x].re;
                 iim = s->fft_vdata_impulse[plane][y*n + x].im;
 
                 s->fft_vdata[plane][y*n + x].re = ire * re - iim * im;
                 s->fft_vdata[plane][y*n + x].im = iim * re + ire * im;
             }
         }
 
         ifft_vertical(s, n, plane);
         ifft_horizontal(s, mainpic, w, h, n, plane);
     }
 
     return ff_filter_frame(outlink, mainpic);
 }
 
 static int config_output(AVFilterLink *outlink)
 {
     AVFilterContext *ctx = outlink->src;
     ConvolveContext *s = ctx->priv;
     AVFilterLink *mainlink = ctx->inputs[0];
     int ret, i;
 
     s->fs.on_event = do_convolve;

     ret = ff_framesync_init_dualinput(&s->fs, ctx);

     if (ret < 0)
         return ret;
     outlink->w = mainlink->w;
     outlink->h = mainlink->h;
     outlink->time_base = mainlink->time_base;
     outlink->sample_aspect_ratio = mainlink->sample_aspect_ratio;
     outlink->frame_rate = mainlink->frame_rate;
 

     if ((ret = ff_framesync_configure(&s->fs)) < 0)

         return ret;
 
     for (i = 0; i < s->nb_planes; i++) {
         s->fft[i]  = av_fft_init(s->fft_bits[i], 0);
         s->ifft[i] = av_fft_init(s->fft_bits[i], 1);
         if (!s->fft[i] || !s->ifft[i])
             return AVERROR(ENOMEM);
     }
 
     return 0;
 }
 
 static int activate(AVFilterContext *ctx)
 {
     ConvolveContext *s = ctx->priv;

     return ff_framesync_activate(&s->fs);

 }
 
 static av_cold void uninit(AVFilterContext *ctx)
 {
     ConvolveContext *s = ctx->priv;
     int i;
 
     for (i = 0; i < 4; i++) {
         av_freep(&s->fft_hdata[i]);
         av_freep(&s->fft_vdata[i]);
         av_freep(&s->fft_hdata_impulse[i]);
         av_freep(&s->fft_vdata_impulse[i]);
         av_fft_end(s->fft[i]);
         av_fft_end(s->ifft[i]);
     }
 

     ff_framesync_uninit(&s->fs);

 }
 
 static const AVFilterPad convolve_inputs[] = {
     {
         .name          = "main",
         .type          = AVMEDIA_TYPE_VIDEO,
         .config_props  = config_input_main,
     },{
         .name          = "impulse",
         .type          = AVMEDIA_TYPE_VIDEO,
         .config_props  = config_input_impulse,
     },
     { NULL }
 };
 
 static const AVFilterPad convolve_outputs[] = {
     {
         .name          = "default",
         .type          = AVMEDIA_TYPE_VIDEO,
         .config_props  = config_output,
     },
     { NULL }
 };
 
 AVFilter ff_vf_convolve = {
     .name          = "convolve",
     .description   = NULL_IF_CONFIG_SMALL("Convolve first video stream with second video stream."),
     .preinit       = convolve_framesync_preinit,
     .uninit        = uninit,
     .query_formats = query_formats,
     .activate      = activate,
     .priv_size     = sizeof(ConvolveContext),
     .priv_class    = &convolve_class,
     .inputs        = convolve_inputs,
     .outputs       = convolve_outputs,
     .flags         = AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL,
 };