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      1 // Copyright 2011 Google Inc. All Rights Reserved.
      2 //
      3 // Use of this source code is governed by a BSD-style license
      4 // that can be found in the COPYING file in the root of the source
      5 // tree. An additional intellectual property rights grant can be found
      6 // in the file PATENTS. All contributing project authors may
      7 // be found in the AUTHORS file in the root of the source tree.
      8 // -----------------------------------------------------------------------------
      9 //
     10 // NEON version of YUV to RGB upsampling functions.
     11 //
     12 // Author: mans (at) mansr.com (Mans Rullgard)
     13 // Based on SSE code by: somnath (at) google.com (Somnath Banerjee)
     14 
     15 #include "./dsp.h"
     16 
     17 #if defined(WEBP_USE_NEON)
     18 
     19 #include <assert.h>
     20 #include <arm_neon.h>
     21 #include <string.h>
     22 #include "./neon.h"
     23 #include "./yuv.h"
     24 
     25 #ifdef FANCY_UPSAMPLING
     26 
     27 //-----------------------------------------------------------------------------
     28 // U/V upsampling
     29 
     30 // Loads 9 pixels each from rows r1 and r2 and generates 16 pixels.
     31 #define UPSAMPLE_16PIXELS(r1, r2, out) {                                \
     32   uint8x8_t a = vld1_u8(r1);                                            \
     33   uint8x8_t b = vld1_u8(r1 + 1);                                        \
     34   uint8x8_t c = vld1_u8(r2);                                            \
     35   uint8x8_t d = vld1_u8(r2 + 1);                                        \
     36                                                                         \
     37   uint16x8_t al = vshll_n_u8(a, 1);                                     \
     38   uint16x8_t bl = vshll_n_u8(b, 1);                                     \
     39   uint16x8_t cl = vshll_n_u8(c, 1);                                     \
     40   uint16x8_t dl = vshll_n_u8(d, 1);                                     \
     41                                                                         \
     42   uint8x8_t diag1, diag2;                                               \
     43   uint16x8_t sl;                                                        \
     44                                                                         \
     45   /* a + b + c + d */                                                   \
     46   sl = vaddl_u8(a,  b);                                                 \
     47   sl = vaddw_u8(sl, c);                                                 \
     48   sl = vaddw_u8(sl, d);                                                 \
     49                                                                         \
     50   al = vaddq_u16(sl, al); /* 3a +  b +  c +  d */                       \
     51   bl = vaddq_u16(sl, bl); /*  a + 3b +  c +  d */                       \
     52                                                                         \
     53   al = vaddq_u16(al, dl); /* 3a +  b +  c + 3d */                       \
     54   bl = vaddq_u16(bl, cl); /*  a + 3b + 3c +  d */                       \
     55                                                                         \
     56   diag2 = vshrn_n_u16(al, 3);                                           \
     57   diag1 = vshrn_n_u16(bl, 3);                                           \
     58                                                                         \
     59   a = vrhadd_u8(a, diag1);                                              \
     60   b = vrhadd_u8(b, diag2);                                              \
     61   c = vrhadd_u8(c, diag2);                                              \
     62   d = vrhadd_u8(d, diag1);                                              \
     63                                                                         \
     64   {                                                                     \
     65     uint8x8x2_t a_b, c_d;                                               \
     66     INIT_VECTOR2(a_b, a, b);                                            \
     67     INIT_VECTOR2(c_d, c, d);                                            \
     68     vst2_u8(out,      a_b);                                             \
     69     vst2_u8(out + 32, c_d);                                             \
     70   }                                                                     \
     71 }
     72 
     73 // Turn the macro into a function for reducing code-size when non-critical
     74 static void Upsample16Pixels(const uint8_t *r1, const uint8_t *r2,
     75                              uint8_t *out) {
     76   UPSAMPLE_16PIXELS(r1, r2, out);
     77 }
     78 
     79 #define UPSAMPLE_LAST_BLOCK(tb, bb, num_pixels, out) {                  \
     80   uint8_t r1[9], r2[9];                                                 \
     81   memcpy(r1, (tb), (num_pixels));                                       \
     82   memcpy(r2, (bb), (num_pixels));                                       \
     83   /* replicate last byte */                                             \
     84   memset(r1 + (num_pixels), r1[(num_pixels) - 1], 9 - (num_pixels));    \
     85   memset(r2 + (num_pixels), r2[(num_pixels) - 1], 9 - (num_pixels));    \
     86   Upsample16Pixels(r1, r2, out);                                        \
     87 }
     88 
     89 //-----------------------------------------------------------------------------
     90 // YUV->RGB conversion
     91 
     92 static const int16_t kCoeffs[4] = { kYScale, kVToR, kUToG, kVToG };
     93 
     94 #define v255 vdup_n_u8(255)
     95 
     96 #define STORE_Rgb(out, r, g, b) do {                                    \
     97   uint8x8x3_t r_g_b;                                                    \
     98   INIT_VECTOR3(r_g_b, r, g, b);                                         \
     99   vst3_u8(out, r_g_b);                                                  \
    100 } while (0)
    101 
    102 #define STORE_Bgr(out, r, g, b) do {                                    \
    103   uint8x8x3_t b_g_r;                                                    \
    104   INIT_VECTOR3(b_g_r, b, g, r);                                         \
    105   vst3_u8(out, b_g_r);                                                  \
    106 } while (0)
    107 
    108 #define STORE_Rgba(out, r, g, b) do {                                   \
    109   uint8x8x4_t r_g_b_v255;                                               \
    110   INIT_VECTOR4(r_g_b_v255, r, g, b, v255);                              \
    111   vst4_u8(out, r_g_b_v255);                                             \
    112 } while (0)
    113 
    114 #define STORE_Bgra(out, r, g, b) do {                                   \
    115   uint8x8x4_t b_g_r_v255;                                               \
    116   INIT_VECTOR4(b_g_r_v255, b, g, r, v255);                              \
    117   vst4_u8(out, b_g_r_v255);                                             \
    118 } while (0)
    119 
    120 #define CONVERT8(FMT, XSTEP, N, src_y, src_uv, out, cur_x) {            \
    121   int i;                                                                \
    122   for (i = 0; i < N; i += 8) {                                          \
    123     const int off = ((cur_x) + i) * XSTEP;                              \
    124     uint8x8_t y  = vld1_u8((src_y) + (cur_x)  + i);                     \
    125     uint8x8_t u  = vld1_u8((src_uv) + i);                               \
    126     uint8x8_t v  = vld1_u8((src_uv) + i + 16);                          \
    127     const int16x8_t yy = vreinterpretq_s16_u16(vsubl_u8(y, u16));       \
    128     const int16x8_t uu = vreinterpretq_s16_u16(vsubl_u8(u, u128));      \
    129     const int16x8_t vv = vreinterpretq_s16_u16(vsubl_u8(v, u128));      \
    130     int32x4_t yl = vmull_lane_s16(vget_low_s16(yy),  cf16, 0);          \
    131     int32x4_t yh = vmull_lane_s16(vget_high_s16(yy), cf16, 0);          \
    132     const int32x4_t rl = vmlal_lane_s16(yl, vget_low_s16(vv),  cf16, 1);\
    133     const int32x4_t rh = vmlal_lane_s16(yh, vget_high_s16(vv), cf16, 1);\
    134     int32x4_t gl = vmlsl_lane_s16(yl, vget_low_s16(uu),  cf16, 2);      \
    135     int32x4_t gh = vmlsl_lane_s16(yh, vget_high_s16(uu), cf16, 2);      \
    136     const int32x4_t bl = vmovl_s16(vget_low_s16(uu));                   \
    137     const int32x4_t bh = vmovl_s16(vget_high_s16(uu));                  \
    138     gl = vmlsl_lane_s16(gl, vget_low_s16(vv),  cf16, 3);                \
    139     gh = vmlsl_lane_s16(gh, vget_high_s16(vv), cf16, 3);                \
    140     yl = vmlaq_lane_s32(yl, bl, cf32, 0);                               \
    141     yh = vmlaq_lane_s32(yh, bh, cf32, 0);                               \
    142     /* vrshrn_n_s32() already incorporates the rounding constant */     \
    143     y = vqmovun_s16(vcombine_s16(vrshrn_n_s32(rl, YUV_FIX2),            \
    144                                  vrshrn_n_s32(rh, YUV_FIX2)));          \
    145     u = vqmovun_s16(vcombine_s16(vrshrn_n_s32(gl, YUV_FIX2),            \
    146                                  vrshrn_n_s32(gh, YUV_FIX2)));          \
    147     v = vqmovun_s16(vcombine_s16(vrshrn_n_s32(yl, YUV_FIX2),            \
    148                                  vrshrn_n_s32(yh, YUV_FIX2)));          \
    149     STORE_ ## FMT(out + off, y, u, v);                                  \
    150   }                                                                     \
    151 }
    152 
    153 #define CONVERT1(FUNC, XSTEP, N, src_y, src_uv, rgb, cur_x) {           \
    154   int i;                                                                \
    155   for (i = 0; i < N; i++) {                                             \
    156     const int off = ((cur_x) + i) * XSTEP;                              \
    157     const int y = src_y[(cur_x) + i];                                   \
    158     const int u = (src_uv)[i];                                          \
    159     const int v = (src_uv)[i + 16];                                     \
    160     FUNC(y, u, v, rgb + off);                                           \
    161   }                                                                     \
    162 }
    163 
    164 #define CONVERT2RGB_8(FMT, XSTEP, top_y, bottom_y, uv,                  \
    165                       top_dst, bottom_dst, cur_x, len) {                \
    166   CONVERT8(FMT, XSTEP, len, top_y, uv, top_dst, cur_x)                  \
    167   if (bottom_y != NULL) {                                               \
    168     CONVERT8(FMT, XSTEP, len, bottom_y, (uv) + 32, bottom_dst, cur_x)   \
    169   }                                                                     \
    170 }
    171 
    172 #define CONVERT2RGB_1(FUNC, XSTEP, top_y, bottom_y, uv,                 \
    173                       top_dst, bottom_dst, cur_x, len) {                \
    174   CONVERT1(FUNC, XSTEP, len, top_y, uv, top_dst, cur_x);                \
    175   if (bottom_y != NULL) {                                               \
    176     CONVERT1(FUNC, XSTEP, len, bottom_y, (uv) + 32, bottom_dst, cur_x); \
    177   }                                                                     \
    178 }
    179 
    180 #define NEON_UPSAMPLE_FUNC(FUNC_NAME, FMT, XSTEP)                       \
    181 static void FUNC_NAME(const uint8_t *top_y, const uint8_t *bottom_y,    \
    182                       const uint8_t *top_u, const uint8_t *top_v,       \
    183                       const uint8_t *cur_u, const uint8_t *cur_v,       \
    184                       uint8_t *top_dst, uint8_t *bottom_dst, int len) { \
    185   int block;                                                            \
    186   /* 16 byte aligned array to cache reconstructed u and v */            \
    187   uint8_t uv_buf[2 * 32 + 15];                                          \
    188   uint8_t *const r_uv = (uint8_t*)((uintptr_t)(uv_buf + 15) & ~15);     \
    189   const int uv_len = (len + 1) >> 1;                                    \
    190   /* 9 pixels must be read-able for each block */                       \
    191   const int num_blocks = (uv_len - 1) >> 3;                             \
    192   const int leftover = uv_len - num_blocks * 8;                         \
    193   const int last_pos = 1 + 16 * num_blocks;                             \
    194                                                                         \
    195   const int u_diag = ((top_u[0] + cur_u[0]) >> 1) + 1;                  \
    196   const int v_diag = ((top_v[0] + cur_v[0]) >> 1) + 1;                  \
    197                                                                         \
    198   const int16x4_t cf16 = vld1_s16(kCoeffs);                             \
    199   const int32x2_t cf32 = vdup_n_s32(kUToB);                             \
    200   const uint8x8_t u16  = vdup_n_u8(16);                                 \
    201   const uint8x8_t u128 = vdup_n_u8(128);                                \
    202                                                                         \
    203   /* Treat the first pixel in regular way */                            \
    204   assert(top_y != NULL);                                                \
    205   {                                                                     \
    206     const int u0 = (top_u[0] + u_diag) >> 1;                            \
    207     const int v0 = (top_v[0] + v_diag) >> 1;                            \
    208     VP8YuvTo ## FMT(top_y[0], u0, v0, top_dst);                         \
    209   }                                                                     \
    210   if (bottom_y != NULL) {                                               \
    211     const int u0 = (cur_u[0] + u_diag) >> 1;                            \
    212     const int v0 = (cur_v[0] + v_diag) >> 1;                            \
    213     VP8YuvTo ## FMT(bottom_y[0], u0, v0, bottom_dst);                   \
    214   }                                                                     \
    215                                                                         \
    216   for (block = 0; block < num_blocks; ++block) {                        \
    217     UPSAMPLE_16PIXELS(top_u, cur_u, r_uv);                              \
    218     UPSAMPLE_16PIXELS(top_v, cur_v, r_uv + 16);                         \
    219     CONVERT2RGB_8(FMT, XSTEP, top_y, bottom_y, r_uv,                    \
    220                   top_dst, bottom_dst, 16 * block + 1, 16);             \
    221     top_u += 8;                                                         \
    222     cur_u += 8;                                                         \
    223     top_v += 8;                                                         \
    224     cur_v += 8;                                                         \
    225   }                                                                     \
    226                                                                         \
    227   UPSAMPLE_LAST_BLOCK(top_u, cur_u, leftover, r_uv);                    \
    228   UPSAMPLE_LAST_BLOCK(top_v, cur_v, leftover, r_uv + 16);               \
    229   CONVERT2RGB_1(VP8YuvTo ## FMT, XSTEP, top_y, bottom_y, r_uv,          \
    230                 top_dst, bottom_dst, last_pos, len - last_pos);         \
    231 }
    232 
    233 // NEON variants of the fancy upsampler.
    234 NEON_UPSAMPLE_FUNC(UpsampleRgbLinePair,  Rgb,  3)
    235 NEON_UPSAMPLE_FUNC(UpsampleBgrLinePair,  Bgr,  3)
    236 NEON_UPSAMPLE_FUNC(UpsampleRgbaLinePair, Rgba, 4)
    237 NEON_UPSAMPLE_FUNC(UpsampleBgraLinePair, Bgra, 4)
    238 
    239 #endif  // FANCY_UPSAMPLING
    240 
    241 #endif   // WEBP_USE_NEON
    242 
    243 //------------------------------------------------------------------------------
    244 
    245 extern void WebPInitUpsamplersNEON(void);
    246 
    247 #ifdef FANCY_UPSAMPLING
    248 
    249 extern WebPUpsampleLinePairFunc WebPUpsamplers[/* MODE_LAST */];
    250 
    251 void WebPInitUpsamplersNEON(void) {
    252 #if defined(WEBP_USE_NEON)
    253   WebPUpsamplers[MODE_RGB]  = UpsampleRgbLinePair;
    254   WebPUpsamplers[MODE_RGBA] = UpsampleRgbaLinePair;
    255   WebPUpsamplers[MODE_BGR]  = UpsampleBgrLinePair;
    256   WebPUpsamplers[MODE_BGRA] = UpsampleBgraLinePair;
    257   WebPUpsamplers[MODE_rgbA] = UpsampleRgbaLinePair;
    258   WebPUpsamplers[MODE_bgrA] = UpsampleBgraLinePair;
    259 #endif   // WEBP_USE_NEON
    260 }
    261 
    262 #else
    263 
    264 // this empty function is to avoid an empty .o
    265 void WebPInitUpsamplersNEON(void) {}
    266 
    267 #endif  // FANCY_UPSAMPLING
    268