/*
  * Copyright (c) 2002 Michael Niedermayer <michaelni@gmx.at>
  * Copyright (c) 2013 Paul B Mahol
  *
  * This file is part of FFmpeg.
  *
  * FFmpeg is free software; you can redistribute it and/or

  * modify it under the terms of the GNU 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
  * noise generator
  */
 
 #include "libavutil/opt.h"
 #include "libavutil/imgutils.h"

 #include "libavutil/lfg.h"

 #include "libavutil/parseutils.h"
 #include "libavutil/pixdesc.h"
 #include "avfilter.h"
 #include "formats.h"
 #include "internal.h"

 #include "vf_noise.h"

 #include "video.h"
 

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

 #define OFFSET(x) offsetof(NoiseContext, x)
 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
 
 #define NOISE_PARAMS(name, x, param)                                                                                             \
     {#name"_seed", "set component #"#x" noise seed", OFFSET(param.seed), AV_OPT_TYPE_INT, {.i64=-1}, -1, INT_MAX, FLAGS},        \
     {#name"_strength", "set component #"#x" strength", OFFSET(param.strength), AV_OPT_TYPE_INT, {.i64=0}, 0, 100, FLAGS},        \
     {#name"s",         "set component #"#x" strength", OFFSET(param.strength), AV_OPT_TYPE_INT, {.i64=0}, 0, 100, FLAGS},        \
     {#name"_flags", "set component #"#x" flags", OFFSET(param.flags), AV_OPT_TYPE_FLAGS, {.i64=0}, 0, 31, FLAGS, #name"_flags"}, \
     {#name"f", "set component #"#x" flags", OFFSET(param.flags), AV_OPT_TYPE_FLAGS, {.i64=0}, 0, 31, FLAGS, #name"_flags"},      \
     {"a", "averaged noise", 0, AV_OPT_TYPE_CONST, {.i64=NOISE_AVERAGED}, 0, 0, FLAGS, #name"_flags"},                            \
     {"p", "(semi)regular pattern", 0, AV_OPT_TYPE_CONST, {.i64=NOISE_PATTERN},  0, 0, FLAGS, #name"_flags"},                     \
     {"t", "temporal noise", 0, AV_OPT_TYPE_CONST, {.i64=NOISE_TEMPORAL}, 0, 0, FLAGS, #name"_flags"},                            \
     {"u", "uniform noise",  0, AV_OPT_TYPE_CONST, {.i64=NOISE_UNIFORM},  0, 0, FLAGS, #name"_flags"},
 
 static const AVOption noise_options[] = {
     NOISE_PARAMS(all, 0, all)
     NOISE_PARAMS(c0,  0, param[0])
     NOISE_PARAMS(c1,  1, param[1])
     NOISE_PARAMS(c2,  2, param[2])
     NOISE_PARAMS(c3,  3, param[3])
     {NULL}
 };
 
 AVFILTER_DEFINE_CLASS(noise);
 
 static const int8_t patt[4] = { -1, 0, 1, 0 };
 

 #define RAND_N(range) ((int) ((double) range * av_lfg_get(lfg) / (UINT_MAX + 1.0)))

 static av_cold int init_noise(NoiseContext *n, int comp)

 {
     int8_t *noise = av_malloc(MAX_NOISE * sizeof(int8_t));
     FilterParams *fp = &n->param[comp];

     AVLFG *lfg = &n->param[comp].lfg;

     int strength = fp->strength;
     int flags = fp->flags;
     int i, j;
 
     if (!noise)
         return AVERROR(ENOMEM);
 

     av_lfg_init(&fp->lfg, fp->seed + comp*31415U);

 
     for (i = 0, j = 0; i < MAX_NOISE; i++, j++) {
         if (flags & NOISE_UNIFORM) {
             if (flags & NOISE_AVERAGED) {
                 if (flags & NOISE_PATTERN) {
                     noise[i] = (RAND_N(strength) - strength / 2) / 6
                         + patt[j % 4] * strength * 0.25 / 3;
                 } else {
                     noise[i] = (RAND_N(strength) - strength / 2) / 3;
                 }
             } else {
                 if (flags & NOISE_PATTERN) {
                     noise[i] = (RAND_N(strength) - strength / 2) / 2
                         + patt[j % 4] * strength * 0.25;
                 } else {
                     noise[i] = RAND_N(strength) - strength / 2;
                 }
             }
         } else {
             double x1, x2, w, y1;
             do {

                 x1 = 2.0 * av_lfg_get(lfg) / (float)UINT_MAX - 1.0;
                 x2 = 2.0 * av_lfg_get(lfg) / (float)UINT_MAX - 1.0;

                 w = x1 * x1 + x2 * x2;
             } while (w >= 1.0);
 
             w   = sqrt((-2.0 * log(w)) / w);
             y1  = x1 * w;
             y1 *= strength / sqrt(3.0);
             if (flags & NOISE_PATTERN) {
                 y1 /= 2;
                 y1 += patt[j % 4] * strength * 0.35;
             }
             y1 = av_clipf(y1, -128, 127);
             if (flags & NOISE_AVERAGED)
                 y1 /= 3.0;
             noise[i] = (int)y1;
         }
         if (RAND_N(6) == 0)
             j--;
     }
 
     for (i = 0; i < MAX_RES; i++)
         for (j = 0; j < 3; j++)

             fp->prev_shift[i][j] = noise + (av_lfg_get(lfg) & (MAX_SHIFT - 1));

 
     fp->noise = noise;
     return 0;
 }
 
 static int query_formats(AVFilterContext *ctx)
 {
     AVFilterFormats *formats = NULL;

     int fmt, ret;

     for (fmt = 0; av_pix_fmt_desc_get(fmt); fmt++) {

         const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(fmt);

         if (desc->flags & AV_PIX_FMT_FLAG_PLANAR && !(desc->comp[0].depth & 7)
             && (ret = ff_add_format(&formats, fmt)) < 0)
                 return ret;

     }
 

     return ff_set_common_formats(ctx, formats);

 }
 
 static int config_input(AVFilterLink *inlink)
 {
     NoiseContext *n = inlink->dst->priv;
     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);

     int ret;

     n->nb_planes = av_pix_fmt_count_planes(inlink->format);

     if ((ret = av_image_fill_linesizes(n->bytewidth, inlink->format, inlink->w)) < 0)

         return ret;
 

     n->height[1] = n->height[2] = AV_CEIL_RSHIFT(inlink->h, desc->log2_chroma_h);

     n->height[0] = n->height[3] = inlink->h;
 
     return 0;
 }
 

 void ff_line_noise_c(uint8_t *dst, const uint8_t *src, const int8_t *noise,
                      int len, int shift)

 {
     int i;
 
     noise += shift;
     for (i = 0; i < len; i++) {
         int v = src[i] + noise[i];
 
         dst[i] = av_clip_uint8(v);
     }
 }
 

 void ff_line_noise_avg_c(uint8_t *dst, const uint8_t *src,
                          int len, const int8_t * const *shift)

 {
     int i;

     const int8_t *src2 = (const int8_t*)src;

 
     for (i = 0; i < len; i++) {
         const int n = shift[0][i] + shift[1][i] + shift[2][i];
         dst[i] = src2[i] + ((n * src2[i]) >> 7);
     }
 }
 
 static void noise(uint8_t *dst, const uint8_t *src,
                   int dst_linesize, int src_linesize,

                   int width, int start, int end, NoiseContext *n, int comp)

 {

     FilterParams *p = &n->param[comp];
     int8_t *noise = p->noise;
     const int flags = p->flags;

     int y;

 
     if (!noise) {

         if (dst != src)

             av_image_copy_plane(dst, dst_linesize, src, src_linesize, width, end - start);

         return;
     }
 

     for (y = start; y < end; y++) {

         const int ix = y & (MAX_RES - 1);

         int x;
         for (x=0; x < width; x+= MAX_RES) {
             int w = FFMIN(width - x, MAX_RES);

             int shift = p->rand_shift[ix];

 
             if (flags & NOISE_AVERAGED) {
                 n->line_noise_avg(dst + x, src + x, w, (const int8_t**)p->prev_shift[ix]);
                 p->prev_shift[ix][shift & 3] = noise + shift;
             } else {
                 n->line_noise(dst + x, src + x, noise, w, shift);
             }

         }
         dst += dst_linesize;
         src += src_linesize;
     }

 }

 static int filter_slice(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs)
 {
     NoiseContext *s = ctx->priv;
     ThreadData *td = arg;
     int plane;
 
     for (plane = 0; plane < s->nb_planes; plane++) {
         const int height = s->height[plane];
         const int start  = (height *  jobnr   ) / nb_jobs;
         const int end    = (height * (jobnr+1)) / nb_jobs;
         noise(td->out->data[plane] + start * td->out->linesize[plane],
               td->in->data[plane]  + start * td->in->linesize[plane],
               td->out->linesize[plane], td->in->linesize[plane],

               s->bytewidth[plane], start, end, s, plane);

     }
     return 0;

 }
 

 static int filter_frame(AVFilterLink *inlink, AVFrame *inpicref)

 {

     AVFilterContext *ctx = inlink->dst;
     AVFilterLink *outlink = ctx->outputs[0];
     NoiseContext *n = ctx->priv;
     ThreadData td;

     AVFrame *out;

     int comp, i;

     if (av_frame_is_writable(inpicref)) {

         out = inpicref;
     } else {

         out = ff_get_video_buffer(outlink, outlink->w, outlink->h);

         if (!out) {

             av_frame_free(&inpicref);

             return AVERROR(ENOMEM);
         }

         av_frame_copy_props(out, inpicref);

     }
 

     for (comp = 0; comp < 4; comp++) {
         FilterParams *fp = &n->param[comp];
 

         if ((!fp->rand_shift_init || (fp->flags & NOISE_TEMPORAL)) && fp->strength) {

 
             for (i = 0; i < MAX_RES; i++) {

                 fp->rand_shift[i] = av_lfg_get(&fp->lfg) & (MAX_SHIFT - 1);

             }

             fp->rand_shift_init = 1;

         }
     }
 

     td.in = inpicref; td.out = out;

     ctx->internal->execute(ctx, filter_slice, &td, NULL, FFMIN(n->height[0], ff_filter_get_nb_threads(ctx)));

     emms_c();

 
     if (inpicref != out)

         av_frame_free(&inpicref);

     return ff_filter_frame(outlink, out);

 }
 

 static av_cold int init(AVFilterContext *ctx)

 {
     NoiseContext *n = ctx->priv;
     int ret, i;
 
     for (i = 0; i < 4; i++) {
         if (n->all.seed >= 0)
             n->param[i].seed = n->all.seed;
         else
             n->param[i].seed = 123457;
         if (n->all.strength)
             n->param[i].strength = n->all.strength;
         if (n->all.flags)
             n->param[i].flags = n->all.flags;
     }
 
     for (i = 0; i < 4; i++) {
         if (n->param[i].strength && ((ret = init_noise(n, i)) < 0))
             return ret;
     }
 

     n->line_noise     = ff_line_noise_c;
     n->line_noise_avg = ff_line_noise_avg_c;

     if (ARCH_X86)
         ff_noise_init_x86(n);

 
     return 0;
 }
 

 static av_cold void uninit(AVFilterContext *ctx)
 {
     NoiseContext *n = ctx->priv;
     int i;
 
     for (i = 0; i < 4; i++)
         av_freep(&n->param[i].noise);
 }
 
 static const AVFilterPad noise_inputs[] = {
     {

         .name         = "default",
         .type         = AVMEDIA_TYPE_VIDEO,
         .filter_frame = filter_frame,
         .config_props = config_input,

     },
     { NULL }
 };
 
 static const AVFilterPad noise_outputs[] = {
     {

         .name = "default",
         .type = AVMEDIA_TYPE_VIDEO,

     },
     { NULL }
 };
 

 AVFilter ff_vf_noise = {

     .name          = "noise",
     .description   = NULL_IF_CONFIG_SMALL("Add noise."),
     .priv_size     = sizeof(NoiseContext),
     .init          = init,
     .uninit        = uninit,
     .query_formats = query_formats,
     .inputs        = noise_inputs,
     .outputs       = noise_outputs,
     .priv_class    = &noise_class,

     .flags         = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC | AVFILTER_FLAG_SLICE_THREADS,

 };