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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 // SSE2 version of YUV to RGB upsampling functions.
11 //
12 // Author: somnath@google.com (Somnath Banerjee)
13 
14 #include "./dsp.h"
15 
16 #if defined(WEBP_USE_SSE2)
17 
18 #include <assert.h>
19 #include <emmintrin.h>
20 #include <string.h>
21 #include "./yuv.h"
22 
23 #ifdef FANCY_UPSAMPLING
24 
25 // We compute (9*a + 3*b + 3*c + d + 8) / 16 as follows
26 // u = (9*a + 3*b + 3*c + d + 8) / 16
27 //   = (a + (a + 3*b + 3*c + d) / 8 + 1) / 2
28 //   = (a + m + 1) / 2
29 // where m = (a + 3*b + 3*c + d) / 8
30 //         = ((a + b + c + d) / 2 + b + c) / 4
31 //
32 // Let's say  k = (a + b + c + d) / 4.
33 // We can compute k as
34 // k = (s + t + 1) / 2 - ((a^d) | (b^c) | (s^t)) & 1
35 // where s = (a + d + 1) / 2 and t = (b + c + 1) / 2
36 //
37 // Then m can be written as
38 // m = (k + t + 1) / 2 - (((b^c) & (s^t)) | (k^t)) & 1
39 
40 // Computes out = (k + in + 1) / 2 - ((ij & (s^t)) | (k^in)) & 1
41 #define GET_M(ij, in, out) do {                                                \
42   const __m128i tmp0 = _mm_avg_epu8(k, (in));     /* (k + in + 1) / 2 */       \
43   const __m128i tmp1 = _mm_and_si128((ij), st);   /* (ij) & (s^t) */           \
44   const __m128i tmp2 = _mm_xor_si128(k, (in));    /* (k^in) */                 \
45   const __m128i tmp3 = _mm_or_si128(tmp1, tmp2);  /* ((ij) & (s^t)) | (k^in) */\
46   const __m128i tmp4 = _mm_and_si128(tmp3, one);  /* & 1 -> lsb_correction */  \
47   (out) = _mm_sub_epi8(tmp0, tmp4);    /* (k + in + 1) / 2 - lsb_correction */ \
48 } while (0)
49 
50 // pack and store two alternating pixel rows
51 #define PACK_AND_STORE(a, b, da, db, out) do {                                 \
52   const __m128i t_a = _mm_avg_epu8(a, da);  /* (9a + 3b + 3c +  d + 8) / 16 */ \
53   const __m128i t_b = _mm_avg_epu8(b, db);  /* (3a + 9b +  c + 3d + 8) / 16 */ \
54   const __m128i t_1 = _mm_unpacklo_epi8(t_a, t_b);                             \
55   const __m128i t_2 = _mm_unpackhi_epi8(t_a, t_b);                             \
56   _mm_store_si128(((__m128i*)(out)) + 0, t_1);                                 \
57   _mm_store_si128(((__m128i*)(out)) + 1, t_2);                                 \
58 } while (0)
59 
60 // Loads 17 pixels each from rows r1 and r2 and generates 32 pixels.
61 #define UPSAMPLE_32PIXELS(r1, r2, out) {                                       \
62   const __m128i one = _mm_set1_epi8(1);                                        \
63   const __m128i a = _mm_loadu_si128((const __m128i*)&(r1)[0]);                 \
64   const __m128i b = _mm_loadu_si128((const __m128i*)&(r1)[1]);                 \
65   const __m128i c = _mm_loadu_si128((const __m128i*)&(r2)[0]);                 \
66   const __m128i d = _mm_loadu_si128((const __m128i*)&(r2)[1]);                 \
67                                                                                \
68   const __m128i s = _mm_avg_epu8(a, d);        /* s = (a + d + 1) / 2 */       \
69   const __m128i t = _mm_avg_epu8(b, c);        /* t = (b + c + 1) / 2 */       \
70   const __m128i st = _mm_xor_si128(s, t);      /* st = s^t */                  \
71                                                                                \
72   const __m128i ad = _mm_xor_si128(a, d);      /* ad = a^d */                  \
73   const __m128i bc = _mm_xor_si128(b, c);      /* bc = b^c */                  \
74                                                                                \
75   const __m128i t1 = _mm_or_si128(ad, bc);     /* (a^d) | (b^c) */             \
76   const __m128i t2 = _mm_or_si128(t1, st);     /* (a^d) | (b^c) | (s^t) */     \
77   const __m128i t3 = _mm_and_si128(t2, one);   /* (a^d) | (b^c) | (s^t) & 1 */ \
78   const __m128i t4 = _mm_avg_epu8(s, t);                                       \
79   const __m128i k = _mm_sub_epi8(t4, t3);      /* k = (a + b + c + d) / 4 */   \
80   __m128i diag1, diag2;                                                        \
81                                                                                \
82   GET_M(bc, t, diag1);                  /* diag1 = (a + 3b + 3c + d) / 8 */    \
83   GET_M(ad, s, diag2);                  /* diag2 = (3a + b + c + 3d) / 8 */    \
84                                                                                \
85   /* pack the alternate pixels */                                              \
86   PACK_AND_STORE(a, b, diag1, diag2, out +      0);  /* store top */           \
87   PACK_AND_STORE(c, d, diag2, diag1, out + 2 * 32);  /* store bottom */        \
88 }
89 
90 // Turn the macro into a function for reducing code-size when non-critical
Upsample32Pixels(const uint8_t r1[],const uint8_t r2[],uint8_t * const out)91 static void Upsample32Pixels(const uint8_t r1[], const uint8_t r2[],
92                              uint8_t* const out) {
93   UPSAMPLE_32PIXELS(r1, r2, out);
94 }
95 
96 #define UPSAMPLE_LAST_BLOCK(tb, bb, num_pixels, out) {                         \
97   uint8_t r1[17], r2[17];                                                      \
98   memcpy(r1, (tb), (num_pixels));                                              \
99   memcpy(r2, (bb), (num_pixels));                                              \
100   /* replicate last byte */                                                    \
101   memset(r1 + (num_pixels), r1[(num_pixels) - 1], 17 - (num_pixels));          \
102   memset(r2 + (num_pixels), r2[(num_pixels) - 1], 17 - (num_pixels));          \
103   /* using the shared function instead of the macro saves ~3k code size */     \
104   Upsample32Pixels(r1, r2, out);                                               \
105 }
106 
107 #define CONVERT2RGB(FUNC, XSTEP, top_y, bottom_y,                              \
108                     top_dst, bottom_dst, cur_x, num_pixels) {                  \
109   int n;                                                                       \
110   for (n = 0; n < (num_pixels); ++n) {                                         \
111     FUNC(top_y[(cur_x) + n], r_u[n], r_v[n],                                   \
112          top_dst + ((cur_x) + n) * XSTEP);                                     \
113   }                                                                            \
114   if (bottom_y != NULL) {                                                      \
115     for (n = 0; n < (num_pixels); ++n) {                                       \
116       FUNC(bottom_y[(cur_x) + n], r_u[64 + n], r_v[64 + n],                    \
117            bottom_dst + ((cur_x) + n) * XSTEP);                                \
118     }                                                                          \
119   }                                                                            \
120 }
121 
122 #define CONVERT2RGB_32(FUNC, XSTEP, top_y, bottom_y,                           \
123                        top_dst, bottom_dst, cur_x) do {                        \
124   FUNC##32(top_y + (cur_x), r_u, r_v, top_dst + (cur_x) * XSTEP);              \
125   if (bottom_y != NULL) {                                                      \
126     FUNC##32(bottom_y + (cur_x), r_u + 64, r_v + 64,                           \
127              bottom_dst + (cur_x) * XSTEP);                                    \
128   }                                                                            \
129 } while (0)
130 
131 #define SSE2_UPSAMPLE_FUNC(FUNC_NAME, FUNC, XSTEP)                             \
132 static void FUNC_NAME(const uint8_t* top_y, const uint8_t* bottom_y,           \
133                       const uint8_t* top_u, const uint8_t* top_v,              \
134                       const uint8_t* cur_u, const uint8_t* cur_v,              \
135                       uint8_t* top_dst, uint8_t* bottom_dst, int len) {        \
136   int uv_pos, pos;                                                             \
137   /* 16byte-aligned array to cache reconstructed u and v */                    \
138   uint8_t uv_buf[4 * 32 + 15];                                                 \
139   uint8_t* const r_u = (uint8_t*)((uintptr_t)(uv_buf + 15) & ~15);             \
140   uint8_t* const r_v = r_u + 32;                                               \
141                                                                                \
142   assert(top_y != NULL);                                                       \
143   {   /* Treat the first pixel in regular way */                               \
144     const int u_diag = ((top_u[0] + cur_u[0]) >> 1) + 1;                       \
145     const int v_diag = ((top_v[0] + cur_v[0]) >> 1) + 1;                       \
146     const int u0_t = (top_u[0] + u_diag) >> 1;                                 \
147     const int v0_t = (top_v[0] + v_diag) >> 1;                                 \
148     FUNC(top_y[0], u0_t, v0_t, top_dst);                                       \
149     if (bottom_y != NULL) {                                                    \
150       const int u0_b = (cur_u[0] + u_diag) >> 1;                               \
151       const int v0_b = (cur_v[0] + v_diag) >> 1;                               \
152       FUNC(bottom_y[0], u0_b, v0_b, bottom_dst);                               \
153     }                                                                          \
154   }                                                                            \
155   /* For UPSAMPLE_32PIXELS, 17 u/v values must be read-able for each block */  \
156   for (pos = 1, uv_pos = 0; pos + 32 + 1 <= len; pos += 32, uv_pos += 16) {    \
157     UPSAMPLE_32PIXELS(top_u + uv_pos, cur_u + uv_pos, r_u);                    \
158     UPSAMPLE_32PIXELS(top_v + uv_pos, cur_v + uv_pos, r_v);                    \
159     CONVERT2RGB_32(FUNC, XSTEP, top_y, bottom_y, top_dst, bottom_dst, pos);    \
160   }                                                                            \
161   if (len > 1) {                                                               \
162     const int left_over = ((len + 1) >> 1) - (pos >> 1);                       \
163     assert(left_over > 0);                                                     \
164     UPSAMPLE_LAST_BLOCK(top_u + uv_pos, cur_u + uv_pos, left_over, r_u);       \
165     UPSAMPLE_LAST_BLOCK(top_v + uv_pos, cur_v + uv_pos, left_over, r_v);       \
166     CONVERT2RGB(FUNC, XSTEP, top_y, bottom_y, top_dst, bottom_dst,             \
167                 pos, len - pos);                                               \
168   }                                                                            \
169 }
170 
171 // SSE2 variants of the fancy upsampler.
172 SSE2_UPSAMPLE_FUNC(UpsampleRgbLinePair,  VP8YuvToRgb,  3)
173 SSE2_UPSAMPLE_FUNC(UpsampleBgrLinePair,  VP8YuvToBgr,  3)
174 SSE2_UPSAMPLE_FUNC(UpsampleRgbaLinePair, VP8YuvToRgba, 4)
175 SSE2_UPSAMPLE_FUNC(UpsampleBgraLinePair, VP8YuvToBgra, 4)
176 SSE2_UPSAMPLE_FUNC(UpsampleArgbLinePair, VP8YuvToArgb, 4)
177 SSE2_UPSAMPLE_FUNC(UpsampleRgba4444LinePair, VP8YuvToRgba4444, 2)
178 SSE2_UPSAMPLE_FUNC(UpsampleRgb565LinePair, VP8YuvToRgb565, 2)
179 
180 #undef GET_M
181 #undef PACK_AND_STORE
182 #undef UPSAMPLE_32PIXELS
183 #undef UPSAMPLE_LAST_BLOCK
184 #undef CONVERT2RGB
185 #undef CONVERT2RGB_32
186 #undef SSE2_UPSAMPLE_FUNC
187 
188 //------------------------------------------------------------------------------
189 // Entry point
190 
191 extern WebPUpsampleLinePairFunc WebPUpsamplers[/* MODE_LAST */];
192 
193 extern void WebPInitUpsamplersSSE2(void);
194 
WebPInitUpsamplersSSE2(void)195 WEBP_TSAN_IGNORE_FUNCTION void WebPInitUpsamplersSSE2(void) {
196   WebPUpsamplers[MODE_RGB]  = UpsampleRgbLinePair;
197   WebPUpsamplers[MODE_RGBA] = UpsampleRgbaLinePair;
198   WebPUpsamplers[MODE_BGR]  = UpsampleBgrLinePair;
199   WebPUpsamplers[MODE_BGRA] = UpsampleBgraLinePair;
200   WebPUpsamplers[MODE_ARGB] = UpsampleArgbLinePair;
201   WebPUpsamplers[MODE_rgbA] = UpsampleRgbaLinePair;
202   WebPUpsamplers[MODE_bgrA] = UpsampleBgraLinePair;
203   WebPUpsamplers[MODE_Argb] = UpsampleArgbLinePair;
204   WebPUpsamplers[MODE_RGB_565] = UpsampleRgb565LinePair;
205   WebPUpsamplers[MODE_RGBA_4444] = UpsampleRgba4444LinePair;
206   WebPUpsamplers[MODE_rgbA_4444] = UpsampleRgba4444LinePair;
207 }
208 
209 #endif  // FANCY_UPSAMPLING
210 
211 //------------------------------------------------------------------------------
212 
213 extern WebPYUV444Converter WebPYUV444Converters[/* MODE_LAST */];
214 extern void WebPInitYUV444ConvertersSSE2(void);
215 
216 #define YUV444_FUNC(FUNC_NAME, CALL, XSTEP) \
217 extern void WebP##FUNC_NAME##C(const uint8_t* y, const uint8_t* u,             \
218                                const uint8_t* v, uint8_t* dst, int len);       \
219 static void FUNC_NAME(const uint8_t* y, const uint8_t* u, const uint8_t* v,    \
220                       uint8_t* dst, int len) {                                 \
221   int i;                                                                       \
222   const int max_len = len & ~31;                                               \
223   for (i = 0; i < max_len; i += 32) CALL(y + i, u + i, v + i, dst + i * XSTEP);\
224   if (i < len) {  /* C-fallback */                                             \
225     WebP##FUNC_NAME##C(y + i, u + i, v + i, dst + i * XSTEP, len - i);         \
226   }                                                                            \
227 }
228 
229 YUV444_FUNC(Yuv444ToRgba, VP8YuvToRgba32, 4);
230 YUV444_FUNC(Yuv444ToBgra, VP8YuvToBgra32, 4);
231 YUV444_FUNC(Yuv444ToRgb, VP8YuvToRgb32, 3);
232 YUV444_FUNC(Yuv444ToBgr, VP8YuvToBgr32, 3);
233 
WebPInitYUV444ConvertersSSE2(void)234 WEBP_TSAN_IGNORE_FUNCTION void WebPInitYUV444ConvertersSSE2(void) {
235   WebPYUV444Converters[MODE_RGBA] = Yuv444ToRgba;
236   WebPYUV444Converters[MODE_BGRA] = Yuv444ToBgra;
237   WebPYUV444Converters[MODE_RGB]  = Yuv444ToRgb;
238   WebPYUV444Converters[MODE_BGR]  = Yuv444ToBgr;
239 }
240 
241 #else
242 
243 WEBP_DSP_INIT_STUB(WebPInitYUV444ConvertersSSE2)
244 
245 #endif  // WEBP_USE_SSE2
246 
247 #if !(defined(FANCY_UPSAMPLING) && defined(WEBP_USE_SSE2))
248 WEBP_DSP_INIT_STUB(WebPInitUpsamplersSSE2)
249 #endif
250