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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 "src/dsp/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 "src/dsp/neon.h"
     23 #include "src/dsp/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) do {                             \
     32   const uint8x8_t a = vld1_u8(r1 + 0);                                  \
     33   const uint8x8_t b = vld1_u8(r1 + 1);                                  \
     34   const uint8x8_t c = vld1_u8(r2 + 0);                                  \
     35   const uint8x8_t d = vld1_u8(r2 + 1);                                  \
     36   /* a + b + c + d */                                                   \
     37   const uint16x8_t ad = vaddl_u8(a,  d);                                \
     38   const uint16x8_t bc = vaddl_u8(b,  c);                                \
     39   const uint16x8_t abcd = vaddq_u16(ad, bc);                            \
     40   /* 3a +  b +  c + 3d */                                               \
     41   const uint16x8_t al = vaddq_u16(abcd, vshlq_n_u16(ad, 1));            \
     42   /*  a + 3b + 3c +  d */                                               \
     43   const uint16x8_t bl = vaddq_u16(abcd, vshlq_n_u16(bc, 1));            \
     44                                                                         \
     45   const uint8x8_t diag2 = vshrn_n_u16(al, 3);                           \
     46   const uint8x8_t diag1 = vshrn_n_u16(bl, 3);                           \
     47                                                                         \
     48   const uint8x8_t A = vrhadd_u8(a, diag1);                              \
     49   const uint8x8_t B = vrhadd_u8(b, diag2);                              \
     50   const uint8x8_t C = vrhadd_u8(c, diag2);                              \
     51   const uint8x8_t D = vrhadd_u8(d, diag1);                              \
     52                                                                         \
     53   uint8x8x2_t A_B, C_D;                                                 \
     54   INIT_VECTOR2(A_B, A, B);                                              \
     55   INIT_VECTOR2(C_D, C, D);                                              \
     56   vst2_u8(out +  0, A_B);                                               \
     57   vst2_u8(out + 32, C_D);                                               \
     58 } while (0)
     59 
     60 // Turn the macro into a function for reducing code-size when non-critical
     61 static void Upsample16Pixels_NEON(const uint8_t *r1, const uint8_t *r2,
     62                                   uint8_t *out) {
     63   UPSAMPLE_16PIXELS(r1, r2, out);
     64 }
     65 
     66 #define UPSAMPLE_LAST_BLOCK(tb, bb, num_pixels, out) {                  \
     67   uint8_t r1[9], r2[9];                                                 \
     68   memcpy(r1, (tb), (num_pixels));                                       \
     69   memcpy(r2, (bb), (num_pixels));                                       \
     70   /* replicate last byte */                                             \
     71   memset(r1 + (num_pixels), r1[(num_pixels) - 1], 9 - (num_pixels));    \
     72   memset(r2 + (num_pixels), r2[(num_pixels) - 1], 9 - (num_pixels));    \
     73   Upsample16Pixels_NEON(r1, r2, out);                                   \
     74 }
     75 
     76 //-----------------------------------------------------------------------------
     77 // YUV->RGB conversion
     78 
     79 // note: we represent the 33050 large constant as 32768 + 282
     80 static const int16_t kCoeffs1[4] = { 19077, 26149, 6419, 13320 };
     81 
     82 #define v255 vdup_n_u8(255)
     83 
     84 #define STORE_Rgb(out, r, g, b) do {                                    \
     85   uint8x8x3_t r_g_b;                                                    \
     86   INIT_VECTOR3(r_g_b, r, g, b);                                         \
     87   vst3_u8(out, r_g_b);                                                  \
     88 } while (0)
     89 
     90 #define STORE_Bgr(out, r, g, b) do {                                    \
     91   uint8x8x3_t b_g_r;                                                    \
     92   INIT_VECTOR3(b_g_r, b, g, r);                                         \
     93   vst3_u8(out, b_g_r);                                                  \
     94 } while (0)
     95 
     96 #define STORE_Rgba(out, r, g, b) do {                                   \
     97   uint8x8x4_t r_g_b_v255;                                               \
     98   INIT_VECTOR4(r_g_b_v255, r, g, b, v255);                              \
     99   vst4_u8(out, r_g_b_v255);                                             \
    100 } while (0)
    101 
    102 #define STORE_Bgra(out, r, g, b) do {                                   \
    103   uint8x8x4_t b_g_r_v255;                                               \
    104   INIT_VECTOR4(b_g_r_v255, b, g, r, v255);                              \
    105   vst4_u8(out, b_g_r_v255);                                             \
    106 } while (0)
    107 
    108 #define STORE_Argb(out, r, g, b) do {                                   \
    109   uint8x8x4_t v255_r_g_b;                                               \
    110   INIT_VECTOR4(v255_r_g_b, v255, r, g, b);                              \
    111   vst4_u8(out, v255_r_g_b);                                             \
    112 } while (0)
    113 
    114 #if !defined(WEBP_SWAP_16BIT_CSP)
    115 #define ZIP_U8(lo, hi) vzip_u8((lo), (hi))
    116 #else
    117 #define ZIP_U8(lo, hi) vzip_u8((hi), (lo))
    118 #endif
    119 
    120 #define STORE_Rgba4444(out, r, g, b) do {                               \
    121   const uint8x8_t rg = vsri_n_u8(r, g, 4);      /* shift g, insert r */ \
    122   const uint8x8_t ba = vsri_n_u8(b, v255, 4);   /* shift a, insert b */ \
    123   const uint8x8x2_t rgba4444 = ZIP_U8(rg, ba);                          \
    124   vst1q_u8(out, vcombine_u8(rgba4444.val[0], rgba4444.val[1]));         \
    125 } while (0)
    126 
    127 #define STORE_Rgb565(out, r, g, b) do {                                 \
    128   const uint8x8_t rg = vsri_n_u8(r, g, 5);   /* shift g and insert r */ \
    129   const uint8x8_t g1 = vshl_n_u8(g, 3);      /* pre-shift g: 3bits */   \
    130   const uint8x8_t gb = vsri_n_u8(g1, b, 3);  /* shift b and insert g */ \
    131   const uint8x8x2_t rgb565 = ZIP_U8(rg, gb);                            \
    132   vst1q_u8(out, vcombine_u8(rgb565.val[0], rgb565.val[1]));             \
    133 } while (0)
    134 
    135 #define CONVERT8(FMT, XSTEP, N, src_y, src_uv, out, cur_x) do {         \
    136   int i;                                                                \
    137   for (i = 0; i < N; i += 8) {                                          \
    138     const int off = ((cur_x) + i) * XSTEP;                              \
    139     const uint8x8_t y  = vld1_u8((src_y) + (cur_x)  + i);               \
    140     const uint8x8_t u  = vld1_u8((src_uv) + i +  0);                    \
    141     const uint8x8_t v  = vld1_u8((src_uv) + i + 16);                    \
    142     const int16x8_t Y0 = vreinterpretq_s16_u16(vshll_n_u8(y, 7));       \
    143     const int16x8_t U0 = vreinterpretq_s16_u16(vshll_n_u8(u, 7));       \
    144     const int16x8_t V0 = vreinterpretq_s16_u16(vshll_n_u8(v, 7));       \
    145     const int16x8_t Y1 = vqdmulhq_lane_s16(Y0, coeff1, 0);              \
    146     const int16x8_t R0 = vqdmulhq_lane_s16(V0, coeff1, 1);              \
    147     const int16x8_t G0 = vqdmulhq_lane_s16(U0, coeff1, 2);              \
    148     const int16x8_t G1 = vqdmulhq_lane_s16(V0, coeff1, 3);              \
    149     const int16x8_t B0 = vqdmulhq_n_s16(U0, 282);                       \
    150     const int16x8_t R1 = vqaddq_s16(Y1, R_Rounder);                     \
    151     const int16x8_t G2 = vqaddq_s16(Y1, G_Rounder);                     \
    152     const int16x8_t B1 = vqaddq_s16(Y1, B_Rounder);                     \
    153     const int16x8_t R2 = vqaddq_s16(R0, R1);                            \
    154     const int16x8_t G3 = vqaddq_s16(G0, G1);                            \
    155     const int16x8_t B2 = vqaddq_s16(B0, B1);                            \
    156     const int16x8_t G4 = vqsubq_s16(G2, G3);                            \
    157     const int16x8_t B3 = vqaddq_s16(B2, U0);                            \
    158     const uint8x8_t R = vqshrun_n_s16(R2, YUV_FIX2);                    \
    159     const uint8x8_t G = vqshrun_n_s16(G4, YUV_FIX2);                    \
    160     const uint8x8_t B = vqshrun_n_s16(B3, YUV_FIX2);                    \
    161     STORE_ ## FMT(out + off, R, G, B);                                  \
    162   }                                                                     \
    163 } while (0)
    164 
    165 #define CONVERT1(FUNC, XSTEP, N, src_y, src_uv, rgb, cur_x) {           \
    166   int i;                                                                \
    167   for (i = 0; i < N; i++) {                                             \
    168     const int off = ((cur_x) + i) * XSTEP;                              \
    169     const int y = src_y[(cur_x) + i];                                   \
    170     const int u = (src_uv)[i];                                          \
    171     const int v = (src_uv)[i + 16];                                     \
    172     FUNC(y, u, v, rgb + off);                                           \
    173   }                                                                     \
    174 }
    175 
    176 #define CONVERT2RGB_8(FMT, XSTEP, top_y, bottom_y, uv,                  \
    177                       top_dst, bottom_dst, cur_x, len) {                \
    178   CONVERT8(FMT, XSTEP, len, top_y, uv, top_dst, cur_x);                 \
    179   if (bottom_y != NULL) {                                               \
    180     CONVERT8(FMT, XSTEP, len, bottom_y, (uv) + 32, bottom_dst, cur_x);  \
    181   }                                                                     \
    182 }
    183 
    184 #define CONVERT2RGB_1(FUNC, XSTEP, top_y, bottom_y, uv,                 \
    185                       top_dst, bottom_dst, cur_x, len) {                \
    186   CONVERT1(FUNC, XSTEP, len, top_y, uv, top_dst, cur_x);                \
    187   if (bottom_y != NULL) {                                               \
    188     CONVERT1(FUNC, XSTEP, len, bottom_y, (uv) + 32, bottom_dst, cur_x); \
    189   }                                                                     \
    190 }
    191 
    192 #define NEON_UPSAMPLE_FUNC(FUNC_NAME, FMT, XSTEP)                       \
    193 static void FUNC_NAME(const uint8_t *top_y, const uint8_t *bottom_y,    \
    194                       const uint8_t *top_u, const uint8_t *top_v,       \
    195                       const uint8_t *cur_u, const uint8_t *cur_v,       \
    196                       uint8_t *top_dst, uint8_t *bottom_dst, int len) { \
    197   int block;                                                            \
    198   /* 16 byte aligned array to cache reconstructed u and v */            \
    199   uint8_t uv_buf[2 * 32 + 15];                                          \
    200   uint8_t *const r_uv = (uint8_t*)((uintptr_t)(uv_buf + 15) & ~15);     \
    201   const int uv_len = (len + 1) >> 1;                                    \
    202   /* 9 pixels must be read-able for each block */                       \
    203   const int num_blocks = (uv_len - 1) >> 3;                             \
    204   const int leftover = uv_len - num_blocks * 8;                         \
    205   const int last_pos = 1 + 16 * num_blocks;                             \
    206                                                                         \
    207   const int u_diag = ((top_u[0] + cur_u[0]) >> 1) + 1;                  \
    208   const int v_diag = ((top_v[0] + cur_v[0]) >> 1) + 1;                  \
    209                                                                         \
    210   const int16x4_t coeff1 = vld1_s16(kCoeffs1);                          \
    211   const int16x8_t R_Rounder = vdupq_n_s16(-14234);                      \
    212   const int16x8_t G_Rounder = vdupq_n_s16(8708);                        \
    213   const int16x8_t B_Rounder = vdupq_n_s16(-17685);                      \
    214                                                                         \
    215   /* Treat the first pixel in regular way */                            \
    216   assert(top_y != NULL);                                                \
    217   {                                                                     \
    218     const int u0 = (top_u[0] + u_diag) >> 1;                            \
    219     const int v0 = (top_v[0] + v_diag) >> 1;                            \
    220     VP8YuvTo ## FMT(top_y[0], u0, v0, top_dst);                         \
    221   }                                                                     \
    222   if (bottom_y != NULL) {                                               \
    223     const int u0 = (cur_u[0] + u_diag) >> 1;                            \
    224     const int v0 = (cur_v[0] + v_diag) >> 1;                            \
    225     VP8YuvTo ## FMT(bottom_y[0], u0, v0, bottom_dst);                   \
    226   }                                                                     \
    227                                                                         \
    228   for (block = 0; block < num_blocks; ++block) {                        \
    229     UPSAMPLE_16PIXELS(top_u, cur_u, r_uv);                              \
    230     UPSAMPLE_16PIXELS(top_v, cur_v, r_uv + 16);                         \
    231     CONVERT2RGB_8(FMT, XSTEP, top_y, bottom_y, r_uv,                    \
    232                   top_dst, bottom_dst, 16 * block + 1, 16);             \
    233     top_u += 8;                                                         \
    234     cur_u += 8;                                                         \
    235     top_v += 8;                                                         \
    236     cur_v += 8;                                                         \
    237   }                                                                     \
    238                                                                         \
    239   UPSAMPLE_LAST_BLOCK(top_u, cur_u, leftover, r_uv);                    \
    240   UPSAMPLE_LAST_BLOCK(top_v, cur_v, leftover, r_uv + 16);               \
    241   CONVERT2RGB_1(VP8YuvTo ## FMT, XSTEP, top_y, bottom_y, r_uv,          \
    242                 top_dst, bottom_dst, last_pos, len - last_pos);         \
    243 }
    244 
    245 // NEON variants of the fancy upsampler.
    246 NEON_UPSAMPLE_FUNC(UpsampleRgbaLinePair_NEON, Rgba, 4)
    247 NEON_UPSAMPLE_FUNC(UpsampleBgraLinePair_NEON, Bgra, 4)
    248 #if !defined(WEBP_REDUCE_CSP)
    249 NEON_UPSAMPLE_FUNC(UpsampleRgbLinePair_NEON,  Rgb,  3)
    250 NEON_UPSAMPLE_FUNC(UpsampleBgrLinePair_NEON,  Bgr,  3)
    251 NEON_UPSAMPLE_FUNC(UpsampleArgbLinePair_NEON, Argb, 4)
    252 NEON_UPSAMPLE_FUNC(UpsampleRgba4444LinePair_NEON, Rgba4444, 2)
    253 NEON_UPSAMPLE_FUNC(UpsampleRgb565LinePair_NEON, Rgb565, 2)
    254 #endif   // WEBP_REDUCE_CSP
    255 
    256 //------------------------------------------------------------------------------
    257 // Entry point
    258 
    259 extern WebPUpsampleLinePairFunc WebPUpsamplers[/* MODE_LAST */];
    260 
    261 extern void WebPInitUpsamplersNEON(void);
    262 
    263 WEBP_TSAN_IGNORE_FUNCTION void WebPInitUpsamplersNEON(void) {
    264   WebPUpsamplers[MODE_RGBA] = UpsampleRgbaLinePair_NEON;
    265   WebPUpsamplers[MODE_BGRA] = UpsampleBgraLinePair_NEON;
    266   WebPUpsamplers[MODE_rgbA] = UpsampleRgbaLinePair_NEON;
    267   WebPUpsamplers[MODE_bgrA] = UpsampleBgraLinePair_NEON;
    268 #if !defined(WEBP_REDUCE_CSP)
    269   WebPUpsamplers[MODE_RGB]  = UpsampleRgbLinePair_NEON;
    270   WebPUpsamplers[MODE_BGR]  = UpsampleBgrLinePair_NEON;
    271   WebPUpsamplers[MODE_ARGB] = UpsampleArgbLinePair_NEON;
    272   WebPUpsamplers[MODE_Argb] = UpsampleArgbLinePair_NEON;
    273   WebPUpsamplers[MODE_RGB_565] = UpsampleRgb565LinePair_NEON;
    274   WebPUpsamplers[MODE_RGBA_4444] = UpsampleRgba4444LinePair_NEON;
    275   WebPUpsamplers[MODE_rgbA_4444] = UpsampleRgba4444LinePair_NEON;
    276 #endif   // WEBP_REDUCE_CSP
    277 }
    278 
    279 #endif  // FANCY_UPSAMPLING
    280 
    281 #endif  // WEBP_USE_NEON
    282 
    283 #if !(defined(FANCY_UPSAMPLING) && defined(WEBP_USE_NEON))
    284 WEBP_DSP_INIT_STUB(WebPInitUpsamplersNEON)
    285 #endif
    286