/*
  * Generates a synthetic YUV video sequence suitable for codec testing.

  * NOTE: No floats are used to guarantee a bit exact output.

  *
  * Copyright (c) 2002 Fabrice Bellard
  *
  * 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 <stdlib.h>

 #include <stdint.h>

 #include <stdio.h>
 
 #define SCALEBITS 8
 #define ONE_HALF  (1 << (SCALEBITS - 1))

 #define FIX(x)    ((int) ((x) * (1L<<SCALEBITS) + 0.5))

 static void rgb24_to_yuv420p(uint8_t *lum, uint8_t *cb, uint8_t *cr,
                               uint8_t *src, int width, int height)

 {
     int wrap, wrap3, x, y;
     int r, g, b, r1, g1, b1;

     uint8_t *p;

 
     wrap = width;
     wrap3 = width * 3;
     p = src;
     for(y=0;y<height;y+=2) {
         for(x=0;x<width;x+=2) {
             r = p[0];
             g = p[1];
             b = p[2];
             r1 = r;
             g1 = g;
             b1 = b;

             lum[0] = (FIX(0.29900) * r + FIX(0.58700) * g +

                       FIX(0.11400) * b + ONE_HALF) >> SCALEBITS;
             r = p[3];
             g = p[4];
             b = p[5];
             r1 += r;
             g1 += g;
             b1 += b;

             lum[1] = (FIX(0.29900) * r + FIX(0.58700) * g +

                       FIX(0.11400) * b + ONE_HALF) >> SCALEBITS;
             p += wrap3;
             lum += wrap;
 
             r = p[0];
             g = p[1];
             b = p[2];
             r1 += r;
             g1 += g;
             b1 += b;

             lum[0] = (FIX(0.29900) * r + FIX(0.58700) * g +

                       FIX(0.11400) * b + ONE_HALF) >> SCALEBITS;
             r = p[3];
             g = p[4];
             b = p[5];
             r1 += r;
             g1 += g;
             b1 += b;

             lum[1] = (FIX(0.29900) * r + FIX(0.58700) * g +

                       FIX(0.11400) * b + ONE_HALF) >> SCALEBITS;

 
             cb[0] = ((- FIX(0.16874) * r1 - FIX(0.33126) * g1 +

                       FIX(0.50000) * b1 + 4 * ONE_HALF - 1) >> (SCALEBITS + 2)) + 128;

             cr[0] = ((FIX(0.50000) * r1 - FIX(0.41869) * g1 -

                      FIX(0.08131) * b1 + 4 * ONE_HALF - 1) >> (SCALEBITS + 2)) + 128;
 
             cb++;
             cr++;
             p += -wrap3 + 2 * 3;
             lum += -wrap + 2;
         }
         p += wrap3;
         lum += wrap;
     }
 }
 
 /* cif format */
 #define DEFAULT_WIDTH   352
 #define DEFAULT_HEIGHT  288

 #define DEFAULT_NB_PICT 50 /* 2 seconds */

 static void pgmyuv_save(const char *filename, int w, int h,
                         unsigned char *rgb_tab)

 {
     FILE *f;
     int i, h2, w2;
     unsigned char *cb, *cr;
     unsigned char *lum_tab, *cb_tab, *cr_tab;
 
     lum_tab = malloc(w * h);
     cb_tab = malloc((w * h) / 4);
     cr_tab = malloc((w * h) / 4);
 
     rgb24_to_yuv420p(lum_tab, cb_tab, cr_tab, rgb_tab, w, h);
 

     f = fopen(filename,"wb");

     fprintf(f, "P5\n%d %d\n%d\n", w, (h * 3) / 2, 255);
     fwrite(lum_tab, 1, w * h, f);
     h2 = h / 2;
     w2 = w / 2;
     cb = cb_tab;
     cr = cr_tab;
     for(i=0;i<h2;i++) {
         fwrite(cb, 1, w2, f);
         fwrite(cr, 1, w2, f);
         cb += w2;
         cr += w2;
     }
     fclose(f);
 
     free(lum_tab);
     free(cb_tab);
     free(cr_tab);
 }
 
 unsigned char *rgb_tab;
 int width, height, wrap;
 

 static void put_pixel(int x, int y, int r, int g, int b)

 {
     unsigned char *p;
 
     if (x < 0 || x >= width ||
         y < 0 || y >= height)
         return;
 
     p = rgb_tab + y * wrap + x * 3;
     p[0] = r;
     p[1] = g;
     p[2] = b;
 }
 
 static unsigned int myrnd(unsigned int *seed_ptr, int n)
 {
     unsigned int seed, val;
 
     seed = *seed_ptr;
     seed = (seed * 314159) + 1;
     if (n == 256) {
         val = seed >> 24;
     } else {
         val = seed % n;
     }
     *seed_ptr = seed;
     return val;
 }
 
 #define NOISE_X  10
 #define NOISE_Y  30
 #define NOISE_W  26
 
 #define FRAC_BITS 8
 #define FRAC_ONE (1 << FRAC_BITS)
 
 /* cosine approximate with 1-x^2 */

 static int int_cos(int a)

 {
     int v, neg;
     a = a & (FRAC_ONE - 1);
     if (a >= (FRAC_ONE / 2))
         a = FRAC_ONE - a;
     neg = 0;
     if (a > (FRAC_ONE / 4)) {
         neg = -1;
         a = (FRAC_ONE / 2) - a;
     }
     v = FRAC_ONE - ((a * a) >> 4);
     v = (v ^ neg) - neg;
     return v;
 }
 
 #define NB_OBJS  10
 
 typedef struct VObj {
     int x, y, w, h;
     int r, g, b;
 } VObj;
 
 VObj objs[NB_OBJS];
 
 unsigned int seed = 1;
 

 static void gen_image(int num, int w, int h)

 {
     int r, g, b, x, y, i, dx, dy, x1, y1;
     unsigned int seed1;
 
     if (num == 0) {
         for(i=0;i<NB_OBJS;i++) {
             objs[i].x = myrnd(&seed, w);
             objs[i].y = myrnd(&seed, h);
             objs[i].w = myrnd(&seed, w / 4) + 10;
             objs[i].h = myrnd(&seed, h / 4) + 10;
             objs[i].r = myrnd(&seed, 256);
             objs[i].g = myrnd(&seed, 256);
             objs[i].b = myrnd(&seed, 256);
         }
     }
 
     /* first a moving background with gradients */
     /* test motion estimation */
     dx = int_cos(num * FRAC_ONE / 50) * 35;
     dy = int_cos(num * FRAC_ONE / 50 + FRAC_ONE / 10) * 30;
     for(y=0;y<h;y++) {
         for(x=0;x<w;x++) {
             x1 = (x << FRAC_BITS) + dx;

             y1 = (y << FRAC_BITS) + dy;

             r = ((y1 * 7) >> FRAC_BITS) & 0xff;
             g = (((x1 + y1) * 9) >> FRAC_BITS) & 0xff;
             b = ((x1 * 5) >> FRAC_BITS) & 0xff;
             put_pixel(x, y, r, g, b);
         }
     }
 
     /* then some noise with very high intensity to test saturation */
     seed1 = num;
     for(y=0;y<NOISE_W;y++) {
         for(x=0;x<NOISE_W;x++) {
             r = myrnd(&seed1, 256);
             g = myrnd(&seed1, 256);
             b = myrnd(&seed1, 256);
             put_pixel(x + NOISE_X, y + NOISE_Y, r, g, b);
         }
     }

     /* then moving objects */
     for(i=0;i<NB_OBJS;i++) {
         VObj *p = &objs[i];
         seed1 = i;
         for(y=0;y<p->h;y++) {
             for(x=0;x<p->w;x++) {
                 r = p->r;
                 g = p->g;
                 b = p->b;
                 /* add a per object noise */
                 r += myrnd(&seed1, 50);
                 g += myrnd(&seed1, 50);
                 b += myrnd(&seed1, 50);
                 put_pixel(x + p->x, y + p->y, r, g, b);
             }
         }
         p->x += myrnd(&seed, 21) - 10;
         p->y += myrnd(&seed, 21) - 10;
     }
 }
 
 int main(int argc, char **argv)
 {
     int w, h, i;
     char buf[1024];
 
     if (argc != 2) {
         printf("usage: %s file\n"
                "generate a test video stream\n", argv[0]);
         exit(1);
     }
 
     w = DEFAULT_WIDTH;
     h = DEFAULT_HEIGHT;
 
     rgb_tab = malloc(w * h * 3);
     wrap = w * 3;
     width = w;
     height = h;
 
     for(i=0;i<DEFAULT_NB_PICT;i++) {

         snprintf(buf, sizeof(buf), "%s%02d.pgm", argv[1], i);

         gen_image(i, w, h);
         pgmyuv_save(buf, w, h, rgb_tab);
     }

     free(rgb_tab);
     return 0;
 }