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@mansr.com (Mans Rullgard)
13 // Based on SSE code by: somnath@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
Upsample16Pixels_NEON(const uint8_t * r1,const uint8_t * r2,uint8_t * out)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 
WebPInitUpsamplersNEON(void)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