1 | // Copyright 2015 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 variant of methods for lossless encoder |
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 <arm_neon.h> |
19 | |
20 | #include "src/dsp/lossless.h" |
21 | #include "src/dsp/neon.h" |
22 | |
23 | //------------------------------------------------------------------------------ |
24 | // Subtract-Green Transform |
25 | |
26 | // vtbl?_u8 are marked unavailable for iOS arm64 with Xcode < 6.3, use |
27 | // non-standard versions there. |
28 | #if defined(__APPLE__) && WEBP_AARCH64 && \ |
29 | defined(__apple_build_version__) && (__apple_build_version__< 6020037) |
30 | #define USE_VTBLQ |
31 | #endif |
32 | |
33 | #ifdef USE_VTBLQ |
34 | // 255 = byte will be zeroed |
35 | static const uint8_t kGreenShuffle[16] = { |
36 | 1, 255, 1, 255, 5, 255, 5, 255, 9, 255, 9, 255, 13, 255, 13, 255 |
37 | }; |
38 | |
39 | static WEBP_INLINE uint8x16_t DoGreenShuffle_NEON(const uint8x16_t argb, |
40 | const uint8x16_t shuffle) { |
41 | return vcombine_u8(vtbl1q_u8(argb, vget_low_u8(shuffle)), |
42 | vtbl1q_u8(argb, vget_high_u8(shuffle))); |
43 | } |
44 | #else // !USE_VTBLQ |
45 | // 255 = byte will be zeroed |
46 | static const uint8_t kGreenShuffle[8] = { 1, 255, 1, 255, 5, 255, 5, 255 }; |
47 | |
48 | static WEBP_INLINE uint8x16_t DoGreenShuffle_NEON(const uint8x16_t argb, |
49 | const uint8x8_t shuffle) { |
50 | return vcombine_u8(vtbl1_u8(vget_low_u8(argb), shuffle), |
51 | vtbl1_u8(vget_high_u8(argb), shuffle)); |
52 | } |
53 | #endif // USE_VTBLQ |
54 | |
55 | static void SubtractGreenFromBlueAndRed_NEON(uint32_t* argb_data, |
56 | int num_pixels) { |
57 | const uint32_t* const end = argb_data + (num_pixels & ~3); |
58 | #ifdef USE_VTBLQ |
59 | const uint8x16_t shuffle = vld1q_u8(kGreenShuffle); |
60 | #else |
61 | const uint8x8_t shuffle = vld1_u8(kGreenShuffle); |
62 | #endif |
63 | for (; argb_data < end; argb_data += 4) { |
64 | const uint8x16_t argb = vld1q_u8((uint8_t*)argb_data); |
65 | const uint8x16_t greens = DoGreenShuffle_NEON(argb, shuffle); |
66 | vst1q_u8((uint8_t*)argb_data, vsubq_u8(argb, greens)); |
67 | } |
68 | // fallthrough and finish off with plain-C |
69 | VP8LSubtractGreenFromBlueAndRed_C(argb_data, num_pixels & 3); |
70 | } |
71 | |
72 | //------------------------------------------------------------------------------ |
73 | // Color Transform |
74 | |
75 | static void TransformColor_NEON(const VP8LMultipliers* const m, |
76 | uint32_t* argb_data, int num_pixels) { |
77 | // sign-extended multiplying constants, pre-shifted by 6. |
78 | #define CST(X) (((int16_t)(m->X << 8)) >> 6) |
79 | const int16_t rb[8] = { |
80 | CST(green_to_blue_), CST(green_to_red_), |
81 | CST(green_to_blue_), CST(green_to_red_), |
82 | CST(green_to_blue_), CST(green_to_red_), |
83 | CST(green_to_blue_), CST(green_to_red_) |
84 | }; |
85 | const int16x8_t mults_rb = vld1q_s16(rb); |
86 | const int16_t b2[8] = { |
87 | 0, CST(red_to_blue_), 0, CST(red_to_blue_), |
88 | 0, CST(red_to_blue_), 0, CST(red_to_blue_), |
89 | }; |
90 | const int16x8_t mults_b2 = vld1q_s16(b2); |
91 | #undef CST |
92 | #ifdef USE_VTBLQ |
93 | static const uint8_t kg0g0[16] = { |
94 | 255, 1, 255, 1, 255, 5, 255, 5, 255, 9, 255, 9, 255, 13, 255, 13 |
95 | }; |
96 | const uint8x16_t shuffle = vld1q_u8(kg0g0); |
97 | #else |
98 | static const uint8_t k0g0g[8] = { 255, 1, 255, 1, 255, 5, 255, 5 }; |
99 | const uint8x8_t shuffle = vld1_u8(k0g0g); |
100 | #endif |
101 | const uint32x4_t mask_rb = vdupq_n_u32(0x00ff00ffu); // red-blue masks |
102 | int i; |
103 | for (i = 0; i + 4 <= num_pixels; i += 4) { |
104 | const uint8x16_t in = vld1q_u8((uint8_t*)(argb_data + i)); |
105 | // 0 g 0 g |
106 | const uint8x16_t greens = DoGreenShuffle_NEON(in, shuffle); |
107 | // x dr x db1 |
108 | const int16x8_t A = vqdmulhq_s16(vreinterpretq_s16_u8(greens), mults_rb); |
109 | // r 0 b 0 |
110 | const int16x8_t B = vshlq_n_s16(vreinterpretq_s16_u8(in), 8); |
111 | // x db2 0 0 |
112 | const int16x8_t C = vqdmulhq_s16(B, mults_b2); |
113 | // 0 0 x db2 |
114 | const uint32x4_t D = vshrq_n_u32(vreinterpretq_u32_s16(C), 16); |
115 | // x dr x db |
116 | const int8x16_t E = vaddq_s8(vreinterpretq_s8_u32(D), |
117 | vreinterpretq_s8_s16(A)); |
118 | // 0 dr 0 db |
119 | const uint32x4_t F = vandq_u32(vreinterpretq_u32_s8(E), mask_rb); |
120 | const int8x16_t out = vsubq_s8(vreinterpretq_s8_u8(in), |
121 | vreinterpretq_s8_u32(F)); |
122 | vst1q_s8((int8_t*)(argb_data + i), out); |
123 | } |
124 | // fallthrough and finish off with plain-C |
125 | VP8LTransformColor_C(m, argb_data + i, num_pixels - i); |
126 | } |
127 | |
128 | #undef USE_VTBLQ |
129 | |
130 | //------------------------------------------------------------------------------ |
131 | // Entry point |
132 | |
133 | extern void VP8LEncDspInitNEON(void); |
134 | |
135 | WEBP_TSAN_IGNORE_FUNCTION void VP8LEncDspInitNEON(void) { |
136 | VP8LSubtractGreenFromBlueAndRed = SubtractGreenFromBlueAndRed_NEON; |
137 | VP8LTransformColor = TransformColor_NEON; |
138 | } |
139 | |
140 | #else // !WEBP_USE_NEON |
141 | |
142 | WEBP_DSP_INIT_STUB(VP8LEncDspInitNEON) |
143 | |
144 | #endif // WEBP_USE_NEON |
145 | |