/*

  * Generate a synthetic YUV video sequence suitable for codec testing.

  *
  * copyright (c) Sebastien Bechet <s.bechet@av7.net>
  *
  * 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 <stdio.h>

 #include <inttypes.h>
 

 #define FIXP (1 << 16)

 #define MY_PI 205887 // (M_PI * FIX)

 static int64_t int_pow(int64_t a, int p)
 {
     int64_t v = FIXP;

     for (; p; p--) {
         v *= a;
         v /= FIXP;

     }
 
     return v;
 }
 

 static int64_t int_sin(int64_t a)
 {
     if (a < 0)
         a = MY_PI - a;  // 0..inf
     a %= 2 * MY_PI;     // 0..2PI

     if (a >= MY_PI * 3 / 2)
         a -= 2 * MY_PI; // -PI / 2 .. 3PI / 2

     if (a >= MY_PI / 2)

         a = MY_PI - a;  // -PI / 2 ..  PI / 2

     return a - int_pow(a, 3) / 6 + int_pow(a, 5) / 120 - int_pow(a, 7) / 5040;

 }

 
 #define SCALEBITS 8
 #define ONE_HALF  (1 << (SCALEBITS - 1))

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

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

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

     unsigned char *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

 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;
 }
 

 unsigned char tab_r[256 * 256];
 unsigned char tab_g[256 * 256];
 unsigned char tab_b[256 * 256];

 int h_cos[360];
 int h_sin[360];

 static int ipol(uint8_t *src, int x, int y)
 {
     int int_x  = x >> 16;
     int int_y  = y >> 16;
     int frac_x = x & 0xFFFF;
     int frac_y = y & 0xFFFF;
     int s00    = src[( int_x      & 255) + 256 * ( int_y      & 255)];
     int s01    = src[((int_x + 1) & 255) + 256 * ( int_y      & 255)];
     int s10    = src[( int_x      & 255) + 256 * ((int_y + 1) & 255)];
     int s11    = src[((int_x + 1) & 255) + 256 * ((int_y + 1) & 255)];
     int s0     = (((1 << 16) - frac_x) * s00 + frac_x * s01) >> 8;
     int s1     = (((1 << 16) - frac_x) * s10 + frac_x * s11) >> 8;
 
     return (((1 << 16) - frac_y) * s0 + frac_y * s1) >> 24;

 }
 

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

 {

     const int c = h_cos[num % 360];
     const int s = h_sin[num % 360];

     const int xi = -(w / 2) * c;
     const int yi =  (w / 2) * s;

     const int xj = -(h / 2) * s;
     const int yj = -(h / 2) * c;
     int i, j;

     int x, y;
     int xprime = xj;
     int yprime = yj;

     for (j = 0; j < h; j++) {

         x       = xprime + xi + FIXP * w / 2;

         xprime += s;

         y       = yprime + yi + FIXP * h / 2;

         yprime += c;

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

             x += c;
             y -= s;

             put_pixel(i, j,
                       ipol(tab_r, x, y),
                       ipol(tab_g, x, y),
                       ipol(tab_b, x, y));

         }

     }
 }
 

 #define W 256
 #define H 256
 

 static int init_demo(const char *filename)

 {
     int i, j;
     int h;
     int radian;
     char line[3 * W];
 

     FILE *input_file;

     input_file = fopen(filename, "rb");
     if (!input_file) {

         perror(filename);

         return 1;

     }

     if (fread(line, 1, 15, input_file) != 15)

         return 1;

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

         if (fread(line, 1, 3 * W, input_file) != 3 * W)

             return 1;

         for (j = 0; j < W; j++) {
             tab_r[W * i + j] = line[3 * j    ];
             tab_g[W * i + j] = line[3 * j + 1];
             tab_b[W * i + j] = line[3 * j + 2];
         }
     }

     fclose(input_file);

 
     /* tables sin/cos */
     for (i = 0; i < 360; i++) {

         radian   = 2 * i * MY_PI / 360;
         h        = 2 * FIXP + int_sin(radian);

         h_cos[i] = h * int_sin(radian + MY_PI / 2) / 2 / FIXP;
         h_sin[i] = h * int_sin(radian)             / 2 / FIXP;

     }

     return 0;

 }
 
 int main(int argc, char **argv)
 {
     int w, h, i;
     char buf[1024];
 

     if (argc != 3) {
         printf("usage: %s directory/ image.pnm\n"

                "generate a test video stream\n", argv[0]);

         return 1;

     }
 
     w = DEFAULT_WIDTH;
     h = DEFAULT_HEIGHT;
 
     rgb_tab = malloc(w * h * 3);

     wrap    = w * 3;
     width   = w;
     height  = h;

     if (init_demo(argv[2]))
         return 1;

     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;
 }