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((__m128i*)&(r1)[0]); \
64 const __m128i b = _mm_loadu_si128((__m128i*)&(r1)[1]); \
65 const __m128i c = _mm_loadu_si128((__m128i*)&(r2)[0]); \
66 const __m128i d = _mm_loadu_si128((__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
177 #undef GET_M
178 #undef PACK_AND_STORE
179 #undef UPSAMPLE_32PIXELS
180 #undef UPSAMPLE_LAST_BLOCK
181 #undef CONVERT2RGB
182 #undef CONVERT2RGB_32
183 #undef SSE2_UPSAMPLE_FUNC
184
185 #endif // FANCY_UPSAMPLING
186
187 #endif // WEBP_USE_SSE2
188
189 //------------------------------------------------------------------------------
190
191 extern void WebPInitUpsamplersSSE2(void);
192
193 #ifdef FANCY_UPSAMPLING
194
195 extern WebPUpsampleLinePairFunc WebPUpsamplers[/* MODE_LAST */];
196
WebPInitUpsamplersSSE2(void)197 void WebPInitUpsamplersSSE2(void) {
198 #if defined(WEBP_USE_SSE2)
199 VP8YUVInitSSE2();
200 WebPUpsamplers[MODE_RGB] = UpsampleRgbLinePair;
201 WebPUpsamplers[MODE_RGBA] = UpsampleRgbaLinePair;
202 WebPUpsamplers[MODE_BGR] = UpsampleBgrLinePair;
203 WebPUpsamplers[MODE_BGRA] = UpsampleBgraLinePair;
204 WebPUpsamplers[MODE_rgbA] = UpsampleRgbaLinePair;
205 WebPUpsamplers[MODE_bgrA] = UpsampleBgraLinePair;
206 #endif // WEBP_USE_SSE2
207 }
208
209 #else
210
211 // this empty function is to avoid an empty .o
WebPInitUpsamplersSSE2(void)212 void WebPInitUpsamplersSSE2(void) {}
213
214 #endif // FANCY_UPSAMPLING
215