text: /*
   * AltiVec-enhanced yuv2yuvX
   *
   * Copyright (C) 2004 Romain Dolbeau <romain@dolbeau.org>
   * based on the equivalent C code in swscale.c
   *
   * 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 <inttypes.h>
  
  #include "config.h"
  #include "libswscale/swscale.h"
  #include "libswscale/swscale_internal.h"
  #include "libavutil/attributes.h"
  #include "libavutil/cpu.h"
  #include "yuv2rgb_altivec.h"
  
  #if HAVE_ALTIVEC
  #define vzero vec_splat_s32(0)
  
  #define yuv2planeX_8(d1, d2, l1, src, x, perm, filter) do {     \
          vector signed short l2  = vec_ld(((x) << 1) + 16, src); \
          vector signed short ls  = vec_perm(l1, l2, perm);       \
          vector signed int   i1  = vec_mule(filter, ls);         \
          vector signed int   i2  = vec_mulo(filter, ls);         \
          vector signed int   vf1 = vec_mergeh(i1, i2);           \
          vector signed int   vf2 = vec_mergel(i1, i2);           \
          d1 = vec_add(d1, vf1);                                  \
          d2 = vec_add(d2, vf2);                                  \
          l1 = l2;                                                \
      } while (0)
  
  static void yuv2planeX_16_altivec(const int16_t *filter, int filterSize,
                                    const int16_t **src, uint8_t *dest,
                                    const uint8_t *dither, int offset, int x)
  {
      register int i, j;
      DECLARE_ALIGNED(16, int, val)[16];
      vector signed int vo1, vo2, vo3, vo4;
      vector unsigned short vs1, vs2;
      vector unsigned char vf;
      vector unsigned int altivec_vectorShiftInt19 =
          vec_add(vec_splat_u32(10), vec_splat_u32(9));
  
      for (i = 0; i < 16; i++)
          val[i] = dither[(x + i + offset) & 7] << 12;
  
      vo1 = vec_ld(0,  val);
      vo2 = vec_ld(16, val);
      vo3 = vec_ld(32, val);
      vo4 = vec_ld(48, val);
  
      for (j = 0; j < filterSize; j++) {
          vector signed short l1, vLumFilter = vec_ld(j << 1, filter);
          vector unsigned char perm, perm0 = vec_lvsl(j << 1, filter);
          vLumFilter = vec_perm(vLumFilter, vLumFilter, perm0);
          vLumFilter = vec_splat(vLumFilter, 0); // lumFilter[j] is loaded 8 times in vLumFilter
  
          perm = vec_lvsl(x << 1, src[j]);
          l1   = vec_ld(x << 1, src[j]);
  
          yuv2planeX_8(vo1, vo2, l1, src[j], x,     perm, vLumFilter);
          yuv2planeX_8(vo3, vo4, l1, src[j], x + 8, perm, vLumFilter);
      }
  
      vo1 = vec_sra(vo1, altivec_vectorShiftInt19);
      vo2 = vec_sra(vo2, altivec_vectorShiftInt19);
      vo3 = vec_sra(vo3, altivec_vectorShiftInt19);
      vo4 = vec_sra(vo4, altivec_vectorShiftInt19);
      vs1 = vec_packsu(vo1, vo2);
      vs2 = vec_packsu(vo3, vo4);
      vf  = vec_packsu(vs1, vs2);
      vec_st(vf, 0, dest);
  }
  
  static inline void yuv2planeX_u(const int16_t *filter, int filterSize,
                                  const int16_t **src, uint8_t *dest, int dstW,
                                  const uint8_t *dither, int offset, int x)
  {
      int i, j;
  
      for (i = x; i < dstW; i++) {
          int t = dither[(i + offset) & 7] << 12;
          for (j = 0; j < filterSize; j++)
              t += src[j][i] * filter[j];
          dest[i] = av_clip_uint8(t >> 19);
      }
  }
  
  static void yuv2planeX_altivec(const int16_t *filter, int filterSize,
                                 const int16_t **src, uint8_t *dest, int dstW,
                                 const uint8_t *dither, int offset)
  {
      int dst_u = -(uintptr_t)dest & 15;
      int i;
  
      yuv2planeX_u(filter, filterSize, src, dest, dst_u, dither, offset, 0);
  
      for (i = dst_u; i < dstW - 15; i += 16)
          yuv2planeX_16_altivec(filter, filterSize, src, dest + i, dither,
                                offset, i);
  
      yuv2planeX_u(filter, filterSize, src, dest, dstW, dither, offset, i);
  }
  
  static void hScale_altivec_real(SwsContext *c, int16_t *dst, int dstW,
                                  const uint8_t *src, const int16_t *filter,
                                  const int32_t *filterPos, int filterSize)
  {
      register int i;
      DECLARE_ALIGNED(16, int, tempo)[4];
  
      if (filterSize % 4) {
          for (i = 0; i < dstW; i++) {
              register int j;
              register int srcPos = filterPos[i];
              register int val    = 0;
              for (j = 0; j < filterSize; j++)
                  val += ((int)src[srcPos + j]) * filter[filterSize * i + j];
              dst[i] = FFMIN(val >> 7, (1 << 15) - 1);
          }
      } else
          switch (filterSize) {
          case 4:
              for (i = 0; i < dstW; i++) {
                  register int srcPos = filterPos[i];
  
                  vector unsigned char src_v0 = vec_ld(srcPos, src);
                  vector unsigned char src_v1, src_vF;
                  vector signed short src_v, filter_v;
                  vector signed int val_vEven, val_s;
                  if ((((uintptr_t)src + srcPos) % 16) > 12) {
                      src_v1 = vec_ld(srcPos + 16, src);
                  }
                  src_vF = vec_perm(src_v0, src_v1, vec_lvsl(srcPos, src));
  
                  src_v = // vec_unpackh sign-extends...
                          (vector signed short)(vec_mergeh((vector unsigned char)vzero, src_vF));
                  // now put our elements in the even slots
                  src_v = vec_mergeh(src_v, (vector signed short)vzero);
  
                  filter_v = vec_ld(i << 3, filter);
                  // The 3 above is 2 (filterSize == 4) + 1 (sizeof(short) == 2).
  
                  // The neat trick: We only care for half the elements,
                  // high or low depending on (i<<3)%16 (it's 0 or 8 here),
                  // and we're going to use vec_mule, so we choose
                  // carefully how to "unpack" the elements into the even slots.
                  if ((i << 3) % 16)
                      filter_v = vec_mergel(filter_v, (vector signed short)vzero);
                  else
                      filter_v = vec_mergeh(filter_v, (vector signed short)vzero);
  
                  val_vEven = vec_mule(src_v, filter_v);
                  val_s     = vec_sums(val_vEven, vzero);
                  vec_st(val_s, 0, tempo);
                  dst[i] = FFMIN(tempo[3] >> 7, (1 << 15) - 1);
              }
          break;
  
          case 8:
              for (i = 0; i < dstW; i++) {
                  register int srcPos = filterPos[i];
  
                  vector unsigned char src_v0 = vec_ld(srcPos, src);
                  vector unsigned char src_v1, src_vF;
                  vector signed short src_v, filter_v;
                  vector signed int val_v, val_s;
                  if ((((uintptr_t)src + srcPos) % 16) > 8) {
                      src_v1 = vec_ld(srcPos + 16, src);
                  }
                  src_vF = vec_perm(src_v0, src_v1, vec_lvsl(srcPos, src));
  
                  src_v = // vec_unpackh sign-extends...
                          (vector signed short)(vec_mergeh((vector unsigned char)vzero, src_vF));
                  filter_v = vec_ld(i << 4, filter);
                  // the 4 above is 3 (filterSize == 8) + 1 (sizeof(short) == 2)
  
                  val_v = vec_msums(src_v, filter_v, (vector signed int)vzero);
                  val_s = vec_sums(val_v, vzero);
                  vec_st(val_s, 0, tempo);
                  dst[i] = FFMIN(tempo[3] >> 7, (1 << 15) - 1);
              }
          break;
  
          case 16:
              for (i = 0; i < dstW; i++) {
                  register int srcPos = filterPos[i];
  
                  vector unsigned char src_v0 = vec_ld(srcPos, src);
                  vector unsigned char src_v1 = vec_ld(srcPos + 16, src);
                  vector unsigned char src_vF = vec_perm(src_v0, src_v1, vec_lvsl(srcPos, src));
  
                  vector signed short src_vA = // vec_unpackh sign-extends...
                                               (vector signed short)(vec_mergeh((vector unsigned char)vzero, src_vF));
                  vector signed short src_vB = // vec_unpackh sign-extends...
                                               (vector signed short)(vec_mergel((vector unsigned char)vzero, src_vF));
  
                  vector signed short filter_v0 = vec_ld(i << 5, filter);
                  vector signed short filter_v1 = vec_ld((i << 5) + 16, filter);
                  // the 5 above are 4 (filterSize == 16) + 1 (sizeof(short) == 2)
  
                  vector signed int val_acc = vec_msums(src_vA, filter_v0, (vector signed int)vzero);
                  vector signed int val_v   = vec_msums(src_vB, filter_v1, val_acc);
  
                  vector signed int val_s = vec_sums(val_v, vzero);
  
                  vec_st(val_s, 0, tempo);
                  dst[i] = FFMIN(tempo[3] >> 7, (1 << 15) - 1);
              }
          break;
  
          default:
              for (i = 0; i < dstW; i++) {
                  register int j;
                  register int srcPos = filterPos[i];
  
                  vector signed int val_s, val_v = (vector signed int)vzero;
                  vector signed short filter_v0R = vec_ld(i * 2 * filterSize, filter);
                  vector unsigned char permF     = vec_lvsl((i * 2 * filterSize), filter);
  
                  vector unsigned char src_v0 = vec_ld(srcPos, src);
                  vector unsigned char permS  = vec_lvsl(srcPos, src);
  
                  for (j = 0; j < filterSize - 15; j += 16) {
                      vector unsigned char src_v1 = vec_ld(srcPos + j + 16, src);
                      vector unsigned char src_vF = vec_perm(src_v0, src_v1, permS);
  
                      vector signed short src_vA = // vec_unpackh sign-extends...
                                                   (vector signed short)(vec_mergeh((vector unsigned char)vzero, src_vF));
                      vector signed short src_vB = // vec_unpackh sign-extends...
                                                   (vector signed short)(vec_mergel((vector unsigned char)vzero, src_vF));
  
                      vector signed short filter_v1R = vec_ld((i * 2 * filterSize) + (j * 2) + 16, filter);
                      vector signed short filter_v2R = vec_ld((i * 2 * filterSize) + (j * 2) + 32, filter);
                      vector signed short filter_v0  = vec_perm(filter_v0R, filter_v1R, permF);
                      vector signed short filter_v1  = vec_perm(filter_v1R, filter_v2R, permF);
  
                      vector signed int val_acc = vec_msums(src_vA, filter_v0, val_v);
                      val_v = vec_msums(src_vB, filter_v1, val_acc);
  
                      filter_v0R = filter_v2R;
                      src_v0     = src_v1;
                  }
  
                  if (j < filterSize - 7) {
                      // loading src_v0 is useless, it's already done above
                      // vector unsigned char src_v0 = vec_ld(srcPos + j, src);
                      vector unsigned char src_v1, src_vF;
                      vector signed short src_v, filter_v1R, filter_v;
                      if ((((uintptr_t)src + srcPos) % 16) > 8) {
                          src_v1 = vec_ld(srcPos + j + 16, src);
                      }
                      src_vF = vec_perm(src_v0, src_v1, permS);
  
                      src_v = // vec_unpackh sign-extends...
                              (vector signed short)(vec_mergeh((vector unsigned char)vzero, src_vF));
                      // loading filter_v0R is useless, it's already done above
                      // vector signed short filter_v0R = vec_ld((i * 2 * filterSize) + j, filter);
                      filter_v1R = vec_ld((i * 2 * filterSize) + (j * 2) + 16, filter);
                      filter_v   = vec_perm(filter_v0R, filter_v1R, permF);
  
                      val_v = vec_msums(src_v, filter_v, val_v);
                  }
  
                  val_s = vec_sums(val_v, vzero);
  
                  vec_st(val_s, 0, tempo);
                  dst[i] = FFMIN(tempo[3] >> 7, (1 << 15) - 1);
              }
          }
  }
  #endif /* HAVE_ALTIVEC */
  
  av_cold void ff_sws_init_swscale_ppc(SwsContext *c)
  {
  #if HAVE_ALTIVEC
      enum AVPixelFormat dstFormat = c->dstFormat;
  
      if (!(av_get_cpu_flags() & AV_CPU_FLAG_ALTIVEC))
          return;
  
      if (c->srcBpc == 8 && c->dstBpc <= 14) {
          c->hyScale = c->hcScale = hScale_altivec_real;
      }
      if (!is16BPS(dstFormat) && !is9_OR_10BPS(dstFormat) &&
          dstFormat != AV_PIX_FMT_NV12 && dstFormat != AV_PIX_FMT_NV21 &&
          !c->alpPixBuf) {
          c->yuv2planeX = yuv2planeX_altivec;
      }
  
      /* The following list of supported dstFormat values should
       * match what's found in the body of ff_yuv2packedX_altivec() */
      if (!(c->flags & (SWS_BITEXACT | SWS_FULL_CHR_H_INT)) && !c->alpPixBuf) {
          switch (c->dstFormat) {
          case AV_PIX_FMT_ABGR:
              c->yuv2packedX = ff_yuv2abgr_X_altivec;
              break;
          case AV_PIX_FMT_BGRA:
              c->yuv2packedX = ff_yuv2bgra_X_altivec;
              break;
          case AV_PIX_FMT_ARGB:
              c->yuv2packedX = ff_yuv2argb_X_altivec;
              break;
          case AV_PIX_FMT_RGBA:
              c->yuv2packedX = ff_yuv2rgba_X_altivec;
              break;
          case AV_PIX_FMT_BGR24:
              c->yuv2packedX = ff_yuv2bgr24_X_altivec;
              break;
          case AV_PIX_FMT_RGB24:
              c->yuv2packedX = ff_yuv2rgb24_X_altivec;
              break;
          }
      }
  #endif /* HAVE_ALTIVEC */
  }
  