/*
  * Lossless video DSP utils
  *
  * 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 "avcodec.h"
 #include "lossless_videodsp.h"

 #include "libavcodec/mathops.h"

 // 0x7f7f7f7f or 0x7f7f7f7f7f7f7f7f or whatever, depending on the cpu's native arithmetic size
 #define pb_7f (~0UL / 255 * 0x7f)
 #define pb_80 (~0UL / 255 * 0x80)
 

 static void add_bytes_c(uint8_t *dst, uint8_t *src, ptrdiff_t w)

 {
     long i;
 
     for (i = 0; i <= w - (int) sizeof(long); i += sizeof(long)) {
         long a = *(long *) (src + i);
         long b = *(long *) (dst + i);
         *(long *) (dst + i) = ((a & pb_7f) + (b & pb_7f)) ^ ((a ^ b) & pb_80);
     }
     for (; i < w; i++)
         dst[i + 0] += src[i + 0];
 }
 
 static void add_median_pred_c(uint8_t *dst, const uint8_t *src1,

                               const uint8_t *diff, ptrdiff_t w,

                               int *left, int *left_top)
 {
     int i;
     uint8_t l, lt;
 
     l  = *left;
     lt = *left_top;
 
     for (i = 0; i < w; i++) {
         l      = mid_pred(l, src1[i], (l + src1[i] - lt) & 0xFF) + diff[i];
         lt     = src1[i];
         dst[i] = l;
     }
 
     *left     = l;
     *left_top = lt;
 }
 

 static int add_left_pred_c(uint8_t *dst, const uint8_t *src, ptrdiff_t w,

                            int acc)
 {
     int i;
 
     for (i = 0; i < w - 1; i++) {
         acc   += src[i];
         dst[i] = acc;
         i++;
         acc   += src[i];
         dst[i] = acc;
     }
 
     for (; i < w; i++) {
         acc   += src[i];
         dst[i] = acc;
     }
 
     return acc;
 }
 

 static int add_left_pred_int16_c(uint16_t *dst, const uint16_t *src, unsigned mask, ptrdiff_t w, unsigned acc){

     int i;
 
     for(i=0; i<w-1; i++){
         acc+= src[i];

         dst[i]= acc &= mask;

         i++;
         acc+= src[i];

         dst[i]= acc &= mask;

     }
 
     for(; i<w; i++){
         acc+= src[i];

         dst[i]= acc &= mask;

     }
 
     return acc;
 }
 
 

 void ff_llviddsp_init(LLVidDSPContext *c)

 {

     c->add_bytes                  = add_bytes_c;
     c->add_median_pred            = add_median_pred_c;
     c->add_left_pred              = add_left_pred_c;
 

     c->add_left_pred_int16        = add_left_pred_int16_c;

     if (ARCH_PPC)
         ff_llviddsp_init_ppc(c);

     if (ARCH_X86)

         ff_llviddsp_init_x86(c);

 }