/*
  * Canopus HQ/HQA decoder
  *

  * 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 <stdint.h>
 
 #include "libavutil/attributes.h"
 #include "libavutil/common.h"
 
 #include "hq_hqadsp.h"
 
 #define FIX_1_082 17734
 #define FIX_1_847 30274
 #define FIX_1_414 23170
 #define FIX_2_613 21407 // divided by two to fit the range
 

 #define IDCTMUL(a, b) ((int)((a) * (unsigned)(b)) >> 16)

 
 static inline void idct_row(int16_t *blk)
 {
     int tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7, tmp8, tmp9, tmpA;
     int tmpB, tmpC, tmpD, tmpE, tmpF, tmp10, tmp11, tmp12, tmp13, tmp14;
 
     tmp0 = blk[5] - blk[3];
     tmp1 = blk[5] + blk[3];
     tmp2 = blk[1] - blk[7];
     tmp3 = blk[1] + blk[7];
     tmp4 = tmp3 - tmp1;
     tmp5 = IDCTMUL(tmp0 + tmp2, FIX_1_847);
     tmp6 = IDCTMUL(tmp2,        FIX_1_082) - tmp5;
     tmp7 = tmp5 - IDCTMUL(tmp0, FIX_2_613) * 2;
     tmp8 = tmp3 + tmp1;
     tmp9 = tmp7 * 4 - tmp8;
     tmpA = IDCTMUL(tmp4, FIX_1_414) * 4 - tmp9;
     tmpB = tmp6 * 4 + tmpA;
     tmpC = blk[2] + blk[6];
     tmpD = blk[2] - blk[6];
     tmpE = blk[0] - blk[4];
     tmpF = blk[0] + blk[4];
 
     tmp10 = IDCTMUL(tmpD, FIX_1_414) * 4 - tmpC;
     tmp11 = tmpE - tmp10;
     tmp12 = tmpF - tmpC;
     tmp13 = tmpE + tmp10;
     tmp14 = tmpF + tmpC;
 
     blk[0] = tmp14 + tmp8;
     blk[1] = tmp13 + tmp9;
     blk[2] = tmp11 + tmpA;
     blk[3] = tmp12 - tmpB;
     blk[4] = tmp12 + tmpB;
     blk[5] = tmp11 - tmpA;
     blk[6] = tmp13 - tmp9;
     blk[7] = tmp14 - tmp8;
 }
 
 static inline void idct_col(int16_t *blk)
 {
     int tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7, tmp8, tmp9, tmpA;
     int tmpB, tmpC, tmpD, tmpE, tmpF, tmp10, tmp11, tmp12, tmp13, tmp14;
 
     tmp0 = blk[5 * 8] - blk[3 * 8];
     tmp1 = blk[5 * 8] + blk[3 * 8];
     tmp2 = blk[1 * 8] * 2 - (blk[7 * 8] >> 2);
     tmp3 = blk[1 * 8] * 2 + (blk[7 * 8] >> 2);
     tmp4 = tmp3 - tmp1;
     tmp5 = IDCTMUL(tmp0 + tmp2, FIX_1_847);
     tmp6 = IDCTMUL(tmp2,        FIX_1_082) - tmp5;
     tmp7 = tmp5 - IDCTMUL(tmp0, FIX_2_613) * 2;
     tmp8 = (tmp3 + tmp1) >> 1;
     tmp9 = tmp7 * 2 - tmp8;
     tmpA = IDCTMUL(tmp4, FIX_1_414) * 2 - tmp9;
     tmpB = tmp6 * 2 + tmpA;
     tmpC =  blk[2 * 8] + (blk[6 * 8] >> 1) >> 1;
     tmpD =  blk[2 * 8] - (blk[6 * 8] >> 1);
     tmpE = (blk[0 * 8] >> 1) - (blk[4 * 8] >> 1) + 0x2020;
     tmpF = (blk[0 * 8] >> 1) + (blk[4 * 8] >> 1) + 0x2020;
 
     tmp10 = IDCTMUL(tmpD, FIX_1_414) * 2 - tmpC;
     tmp11 = tmpE - tmp10;
     tmp12 = tmpF - tmpC;
     tmp13 = tmpE + tmp10;
     tmp14 = tmpF + tmpC;
 
     blk[0 * 8] = (tmp14 + tmp8) >> 6;
     blk[1 * 8] = (tmp13 + tmp9) >> 6;
     blk[2 * 8] = (tmp11 + tmpA) >> 6;
     blk[3 * 8] = (tmp12 - tmpB) >> 6;
     blk[4 * 8] = (tmp12 + tmpB) >> 6;
     blk[5 * 8] = (tmp11 - tmpA) >> 6;
     blk[6 * 8] = (tmp13 - tmp9) >> 6;
     blk[7 * 8] = (tmp14 - tmp8) >> 6;
 }
 
 static void hq_idct_put(uint8_t *dst, int stride, int16_t *block)
 {
     int i, j;
 
     for (i = 0; i < 8; i++)
         idct_row(block + i * 8);
     for (i = 0; i < 8; i++)
         idct_col(block + i);
 
     for (i = 0; i < 8; i++) {
         for (j = 0; j < 8; j++)
             dst[j] = av_clip_uint8(block[j + i * 8]);
         dst += stride;
     }
 }
 
 av_cold void ff_hqdsp_init(HQDSPContext *c)
 {
     c->idct_put = hq_idct_put;
 }