1 | // Copyright 2017 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 | // Utilities for processing transparent channel, NEON version. |
11 | // |
12 | // Author: Skal (pascal.massimino@gmail.com) |
13 | |
14 | #include "src/dsp/dsp.h" |
15 | |
16 | #if defined(WEBP_USE_NEON) |
17 | |
18 | #include "src/dsp/neon.h" |
19 | |
20 | //------------------------------------------------------------------------------ |
21 | |
22 | #define MULTIPLIER(a) ((a) * 0x8081) |
23 | #define PREMULTIPLY(x, m) (((x) * (m)) >> 23) |
24 | |
25 | #define MULTIPLY_BY_ALPHA(V, ALPHA, OTHER) do { \ |
26 | const uint8x8_t alpha = (V).val[(ALPHA)]; \ |
27 | const uint16x8_t r1 = vmull_u8((V).val[1], alpha); \ |
28 | const uint16x8_t g1 = vmull_u8((V).val[2], alpha); \ |
29 | const uint16x8_t b1 = vmull_u8((V).val[(OTHER)], alpha); \ |
30 | /* we use: v / 255 = (v + 1 + (v >> 8)) >> 8 */ \ |
31 | const uint16x8_t r2 = vsraq_n_u16(r1, r1, 8); \ |
32 | const uint16x8_t g2 = vsraq_n_u16(g1, g1, 8); \ |
33 | const uint16x8_t b2 = vsraq_n_u16(b1, b1, 8); \ |
34 | const uint16x8_t r3 = vaddq_u16(r2, kOne); \ |
35 | const uint16x8_t g3 = vaddq_u16(g2, kOne); \ |
36 | const uint16x8_t b3 = vaddq_u16(b2, kOne); \ |
37 | (V).val[1] = vshrn_n_u16(r3, 8); \ |
38 | (V).val[2] = vshrn_n_u16(g3, 8); \ |
39 | (V).val[(OTHER)] = vshrn_n_u16(b3, 8); \ |
40 | } while (0) |
41 | |
42 | static void ApplyAlphaMultiply_NEON(uint8_t* rgba, int alpha_first, |
43 | int w, int h, int stride) { |
44 | const uint16x8_t kOne = vdupq_n_u16(1u); |
45 | while (h-- > 0) { |
46 | uint32_t* const rgbx = (uint32_t*)rgba; |
47 | int i = 0; |
48 | if (alpha_first) { |
49 | for (; i + 8 <= w; i += 8) { |
50 | // load aaaa...|rrrr...|gggg...|bbbb... |
51 | uint8x8x4_t RGBX = vld4_u8((const uint8_t*)(rgbx + i)); |
52 | MULTIPLY_BY_ALPHA(RGBX, 0, 3); |
53 | vst4_u8((uint8_t*)(rgbx + i), RGBX); |
54 | } |
55 | } else { |
56 | for (; i + 8 <= w; i += 8) { |
57 | uint8x8x4_t RGBX = vld4_u8((const uint8_t*)(rgbx + i)); |
58 | MULTIPLY_BY_ALPHA(RGBX, 3, 0); |
59 | vst4_u8((uint8_t*)(rgbx + i), RGBX); |
60 | } |
61 | } |
62 | // Finish with left-overs. |
63 | for (; i < w; ++i) { |
64 | uint8_t* const rgb = rgba + (alpha_first ? 1 : 0); |
65 | const uint8_t* const alpha = rgba + (alpha_first ? 0 : 3); |
66 | const uint32_t a = alpha[4 * i]; |
67 | if (a != 0xff) { |
68 | const uint32_t mult = MULTIPLIER(a); |
69 | rgb[4 * i + 0] = PREMULTIPLY(rgb[4 * i + 0], mult); |
70 | rgb[4 * i + 1] = PREMULTIPLY(rgb[4 * i + 1], mult); |
71 | rgb[4 * i + 2] = PREMULTIPLY(rgb[4 * i + 2], mult); |
72 | } |
73 | } |
74 | rgba += stride; |
75 | } |
76 | } |
77 | #undef MULTIPLY_BY_ALPHA |
78 | #undef MULTIPLIER |
79 | #undef PREMULTIPLY |
80 | |
81 | //------------------------------------------------------------------------------ |
82 | |
83 | static int DispatchAlpha_NEON(const uint8_t* alpha, int alpha_stride, |
84 | int width, int height, |
85 | uint8_t* dst, int dst_stride) { |
86 | uint32_t alpha_mask = 0xffffffffu; |
87 | uint8x8_t mask8 = vdup_n_u8(0xff); |
88 | uint32_t tmp[2]; |
89 | int i, j; |
90 | for (j = 0; j < height; ++j) { |
91 | // We don't know if alpha is first or last in dst[] (depending on rgbA/Argb |
92 | // mode). So we must be sure dst[4*i + 8 - 1] is writable for the store. |
93 | // Hence the test with 'width - 1' instead of just 'width'. |
94 | for (i = 0; i + 8 <= width - 1; i += 8) { |
95 | uint8x8x4_t rgbX = vld4_u8((const uint8_t*)(dst + 4 * i)); |
96 | const uint8x8_t alphas = vld1_u8(alpha + i); |
97 | rgbX.val[0] = alphas; |
98 | vst4_u8((uint8_t*)(dst + 4 * i), rgbX); |
99 | mask8 = vand_u8(mask8, alphas); |
100 | } |
101 | for (; i < width; ++i) { |
102 | const uint32_t alpha_value = alpha[i]; |
103 | dst[4 * i] = alpha_value; |
104 | alpha_mask &= alpha_value; |
105 | } |
106 | alpha += alpha_stride; |
107 | dst += dst_stride; |
108 | } |
109 | vst1_u8((uint8_t*)tmp, mask8); |
110 | alpha_mask &= tmp[0]; |
111 | alpha_mask &= tmp[1]; |
112 | return (alpha_mask != 0xffffffffu); |
113 | } |
114 | |
115 | static void DispatchAlphaToGreen_NEON(const uint8_t* alpha, int alpha_stride, |
116 | int width, int height, |
117 | uint32_t* dst, int dst_stride) { |
118 | int i, j; |
119 | uint8x8x4_t greens; // leave A/R/B channels zero'd. |
120 | greens.val[0] = vdup_n_u8(0); |
121 | greens.val[2] = vdup_n_u8(0); |
122 | greens.val[3] = vdup_n_u8(0); |
123 | for (j = 0; j < height; ++j) { |
124 | for (i = 0; i + 8 <= width; i += 8) { |
125 | greens.val[1] = vld1_u8(alpha + i); |
126 | vst4_u8((uint8_t*)(dst + i), greens); |
127 | } |
128 | for (; i < width; ++i) dst[i] = alpha[i] << 8; |
129 | alpha += alpha_stride; |
130 | dst += dst_stride; |
131 | } |
132 | } |
133 | |
134 | static int ExtractAlpha_NEON(const uint8_t* argb, int argb_stride, |
135 | int width, int height, |
136 | uint8_t* alpha, int alpha_stride) { |
137 | uint32_t alpha_mask = 0xffffffffu; |
138 | uint8x8_t mask8 = vdup_n_u8(0xff); |
139 | uint32_t tmp[2]; |
140 | int i, j; |
141 | for (j = 0; j < height; ++j) { |
142 | // We don't know if alpha is first or last in dst[] (depending on rgbA/Argb |
143 | // mode). So we must be sure dst[4*i + 8 - 1] is writable for the store. |
144 | // Hence the test with 'width - 1' instead of just 'width'. |
145 | for (i = 0; i + 8 <= width - 1; i += 8) { |
146 | const uint8x8x4_t rgbX = vld4_u8((const uint8_t*)(argb + 4 * i)); |
147 | const uint8x8_t alphas = rgbX.val[0]; |
148 | vst1_u8((uint8_t*)(alpha + i), alphas); |
149 | mask8 = vand_u8(mask8, alphas); |
150 | } |
151 | for (; i < width; ++i) { |
152 | alpha[i] = argb[4 * i]; |
153 | alpha_mask &= alpha[i]; |
154 | } |
155 | argb += argb_stride; |
156 | alpha += alpha_stride; |
157 | } |
158 | vst1_u8((uint8_t*)tmp, mask8); |
159 | alpha_mask &= tmp[0]; |
160 | alpha_mask &= tmp[1]; |
161 | return (alpha_mask == 0xffffffffu); |
162 | } |
163 | |
164 | static void ExtractGreen_NEON(const uint32_t* argb, |
165 | uint8_t* alpha, int size) { |
166 | int i; |
167 | for (i = 0; i + 16 <= size; i += 16) { |
168 | const uint8x16x4_t rgbX = vld4q_u8((const uint8_t*)(argb + i)); |
169 | const uint8x16_t greens = rgbX.val[1]; |
170 | vst1q_u8(alpha + i, greens); |
171 | } |
172 | for (; i < size; ++i) alpha[i] = (argb[i] >> 8) & 0xff; |
173 | } |
174 | |
175 | //------------------------------------------------------------------------------ |
176 | |
177 | extern void WebPInitAlphaProcessingNEON(void); |
178 | |
179 | WEBP_TSAN_IGNORE_FUNCTION void WebPInitAlphaProcessingNEON(void) { |
180 | WebPApplyAlphaMultiply = ApplyAlphaMultiply_NEON; |
181 | WebPDispatchAlpha = DispatchAlpha_NEON; |
182 | WebPDispatchAlphaToGreen = DispatchAlphaToGreen_NEON; |
183 | WebPExtractAlpha = ExtractAlpha_NEON; |
184 | WebPExtractGreen = ExtractGreen_NEON; |
185 | } |
186 | |
187 | #else // !WEBP_USE_NEON |
188 | |
189 | WEBP_DSP_INIT_STUB(WebPInitAlphaProcessingNEON) |
190 | |
191 | #endif // WEBP_USE_NEON |
192 | |