1// Copyright 2014 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 decoder
11//
12// Author: Skal (pascal.massimino@gmail.com)
13
14#include "./dsp.h"
15
16#if defined(WEBP_USE_NEON)
17
18#include <arm_neon.h>
19
20#include "./lossless.h"
21#include "./neon.h"
22
23//------------------------------------------------------------------------------
24// Colorspace conversion functions
25
26#if !defined(WORK_AROUND_GCC)
27// gcc 4.6.0 had some trouble (NDK-r9) with this code. We only use it for
28// gcc-4.8.x at least.
29static void ConvertBGRAToRGBA(const uint32_t* src,
30                              int num_pixels, uint8_t* dst) {
31  const uint32_t* const end = src + (num_pixels & ~15);
32  for (; src < end; src += 16) {
33    uint8x16x4_t pixel = vld4q_u8((uint8_t*)src);
34    // swap B and R. (VSWP d0,d2 has no intrinsics equivalent!)
35    const uint8x16_t tmp = pixel.val[0];
36    pixel.val[0] = pixel.val[2];
37    pixel.val[2] = tmp;
38    vst4q_u8(dst, pixel);
39    dst += 64;
40  }
41  VP8LConvertBGRAToRGBA_C(src, num_pixels & 15, dst);  // left-overs
42}
43
44static void ConvertBGRAToBGR(const uint32_t* src,
45                             int num_pixels, uint8_t* dst) {
46  const uint32_t* const end = src + (num_pixels & ~15);
47  for (; src < end; src += 16) {
48    const uint8x16x4_t pixel = vld4q_u8((uint8_t*)src);
49    const uint8x16x3_t tmp = { { pixel.val[0], pixel.val[1], pixel.val[2] } };
50    vst3q_u8(dst, tmp);
51    dst += 48;
52  }
53  VP8LConvertBGRAToBGR_C(src, num_pixels & 15, dst);  // left-overs
54}
55
56static void ConvertBGRAToRGB(const uint32_t* src,
57                             int num_pixels, uint8_t* dst) {
58  const uint32_t* const end = src + (num_pixels & ~15);
59  for (; src < end; src += 16) {
60    const uint8x16x4_t pixel = vld4q_u8((uint8_t*)src);
61    const uint8x16x3_t tmp = { { pixel.val[2], pixel.val[1], pixel.val[0] } };
62    vst3q_u8(dst, tmp);
63    dst += 48;
64  }
65  VP8LConvertBGRAToRGB_C(src, num_pixels & 15, dst);  // left-overs
66}
67
68#else  // WORK_AROUND_GCC
69
70// gcc-4.6.0 fallback
71
72static const uint8_t kRGBAShuffle[8] = { 2, 1, 0, 3, 6, 5, 4, 7 };
73
74static void ConvertBGRAToRGBA(const uint32_t* src,
75                              int num_pixels, uint8_t* dst) {
76  const uint32_t* const end = src + (num_pixels & ~1);
77  const uint8x8_t shuffle = vld1_u8(kRGBAShuffle);
78  for (; src < end; src += 2) {
79    const uint8x8_t pixels = vld1_u8((uint8_t*)src);
80    vst1_u8(dst, vtbl1_u8(pixels, shuffle));
81    dst += 8;
82  }
83  VP8LConvertBGRAToRGBA_C(src, num_pixels & 1, dst);  // left-overs
84}
85
86static const uint8_t kBGRShuffle[3][8] = {
87  {  0,  1,  2,  4,  5,  6,  8,  9 },
88  { 10, 12, 13, 14, 16, 17, 18, 20 },
89  { 21, 22, 24, 25, 26, 28, 29, 30 }
90};
91
92static void ConvertBGRAToBGR(const uint32_t* src,
93                             int num_pixels, uint8_t* dst) {
94  const uint32_t* const end = src + (num_pixels & ~7);
95  const uint8x8_t shuffle0 = vld1_u8(kBGRShuffle[0]);
96  const uint8x8_t shuffle1 = vld1_u8(kBGRShuffle[1]);
97  const uint8x8_t shuffle2 = vld1_u8(kBGRShuffle[2]);
98  for (; src < end; src += 8) {
99    uint8x8x4_t pixels;
100    INIT_VECTOR4(pixels,
101                 vld1_u8((const uint8_t*)(src + 0)),
102                 vld1_u8((const uint8_t*)(src + 2)),
103                 vld1_u8((const uint8_t*)(src + 4)),
104                 vld1_u8((const uint8_t*)(src + 6)));
105    vst1_u8(dst +  0, vtbl4_u8(pixels, shuffle0));
106    vst1_u8(dst +  8, vtbl4_u8(pixels, shuffle1));
107    vst1_u8(dst + 16, vtbl4_u8(pixels, shuffle2));
108    dst += 8 * 3;
109  }
110  VP8LConvertBGRAToBGR_C(src, num_pixels & 7, dst);  // left-overs
111}
112
113static const uint8_t kRGBShuffle[3][8] = {
114  {  2,  1,  0,  6,  5,  4, 10,  9 },
115  {  8, 14, 13, 12, 18, 17, 16, 22 },
116  { 21, 20, 26, 25, 24, 30, 29, 28 }
117};
118
119static void ConvertBGRAToRGB(const uint32_t* src,
120                             int num_pixels, uint8_t* dst) {
121  const uint32_t* const end = src + (num_pixels & ~7);
122  const uint8x8_t shuffle0 = vld1_u8(kRGBShuffle[0]);
123  const uint8x8_t shuffle1 = vld1_u8(kRGBShuffle[1]);
124  const uint8x8_t shuffle2 = vld1_u8(kRGBShuffle[2]);
125  for (; src < end; src += 8) {
126    uint8x8x4_t pixels;
127    INIT_VECTOR4(pixels,
128                 vld1_u8((const uint8_t*)(src + 0)),
129                 vld1_u8((const uint8_t*)(src + 2)),
130                 vld1_u8((const uint8_t*)(src + 4)),
131                 vld1_u8((const uint8_t*)(src + 6)));
132    vst1_u8(dst +  0, vtbl4_u8(pixels, shuffle0));
133    vst1_u8(dst +  8, vtbl4_u8(pixels, shuffle1));
134    vst1_u8(dst + 16, vtbl4_u8(pixels, shuffle2));
135    dst += 8 * 3;
136  }
137  VP8LConvertBGRAToRGB_C(src, num_pixels & 7, dst);  // left-overs
138}
139
140#endif   // !WORK_AROUND_GCC
141
142//------------------------------------------------------------------------------
143
144#ifdef USE_INTRINSICS
145
146static WEBP_INLINE uint32_t Average2(const uint32_t* const a,
147                                     const uint32_t* const b) {
148  const uint8x8_t a0 = vreinterpret_u8_u64(vcreate_u64(*a));
149  const uint8x8_t b0 = vreinterpret_u8_u64(vcreate_u64(*b));
150  const uint8x8_t avg = vhadd_u8(a0, b0);
151  return vget_lane_u32(vreinterpret_u32_u8(avg), 0);
152}
153
154static WEBP_INLINE uint32_t Average3(const uint32_t* const a,
155                                     const uint32_t* const b,
156                                     const uint32_t* const c) {
157  const uint8x8_t a0 = vreinterpret_u8_u64(vcreate_u64(*a));
158  const uint8x8_t b0 = vreinterpret_u8_u64(vcreate_u64(*b));
159  const uint8x8_t c0 = vreinterpret_u8_u64(vcreate_u64(*c));
160  const uint8x8_t avg1 = vhadd_u8(a0, c0);
161  const uint8x8_t avg2 = vhadd_u8(avg1, b0);
162  return vget_lane_u32(vreinterpret_u32_u8(avg2), 0);
163}
164
165static WEBP_INLINE uint32_t Average4(const uint32_t* const a,
166                                     const uint32_t* const b,
167                                     const uint32_t* const c,
168                                     const uint32_t* const d) {
169  const uint8x8_t a0 = vreinterpret_u8_u64(vcreate_u64(*a));
170  const uint8x8_t b0 = vreinterpret_u8_u64(vcreate_u64(*b));
171  const uint8x8_t c0 = vreinterpret_u8_u64(vcreate_u64(*c));
172  const uint8x8_t d0 = vreinterpret_u8_u64(vcreate_u64(*d));
173  const uint8x8_t avg1 = vhadd_u8(a0, b0);
174  const uint8x8_t avg2 = vhadd_u8(c0, d0);
175  const uint8x8_t avg3 = vhadd_u8(avg1, avg2);
176  return vget_lane_u32(vreinterpret_u32_u8(avg3), 0);
177}
178
179static uint32_t Predictor5(uint32_t left, const uint32_t* const top) {
180  return Average3(&left, top + 0, top + 1);
181}
182
183static uint32_t Predictor6(uint32_t left, const uint32_t* const top) {
184  return Average2(&left, top - 1);
185}
186
187static uint32_t Predictor7(uint32_t left, const uint32_t* const top) {
188  return Average2(&left, top + 0);
189}
190
191static uint32_t Predictor8(uint32_t left, const uint32_t* const top) {
192  (void)left;
193  return Average2(top - 1, top + 0);
194}
195
196static uint32_t Predictor9(uint32_t left, const uint32_t* const top) {
197  (void)left;
198  return Average2(top + 0, top + 1);
199}
200
201static uint32_t Predictor10(uint32_t left, const uint32_t* const top) {
202  return Average4(&left, top - 1, top + 0, top + 1);
203}
204
205//------------------------------------------------------------------------------
206
207static WEBP_INLINE uint32_t Select(const uint32_t* const c0,
208                                   const uint32_t* const c1,
209                                   const uint32_t* const c2) {
210  const uint8x8_t p0 = vreinterpret_u8_u64(vcreate_u64(*c0));
211  const uint8x8_t p1 = vreinterpret_u8_u64(vcreate_u64(*c1));
212  const uint8x8_t p2 = vreinterpret_u8_u64(vcreate_u64(*c2));
213  const uint8x8_t bc = vabd_u8(p1, p2);   // |b-c|
214  const uint8x8_t ac = vabd_u8(p0, p2);   // |a-c|
215  const int16x4_t sum_bc = vreinterpret_s16_u16(vpaddl_u8(bc));
216  const int16x4_t sum_ac = vreinterpret_s16_u16(vpaddl_u8(ac));
217  const int32x2_t diff = vpaddl_s16(vsub_s16(sum_bc, sum_ac));
218  const int32_t pa_minus_pb = vget_lane_s32(diff, 0);
219  return (pa_minus_pb <= 0) ? *c0 : *c1;
220}
221
222static uint32_t Predictor11(uint32_t left, const uint32_t* const top) {
223  return Select(top + 0, &left, top - 1);
224}
225
226static WEBP_INLINE uint32_t ClampedAddSubtractFull(const uint32_t* const c0,
227                                                   const uint32_t* const c1,
228                                                   const uint32_t* const c2) {
229  const uint8x8_t p0 = vreinterpret_u8_u64(vcreate_u64(*c0));
230  const uint8x8_t p1 = vreinterpret_u8_u64(vcreate_u64(*c1));
231  const uint8x8_t p2 = vreinterpret_u8_u64(vcreate_u64(*c2));
232  const uint16x8_t sum0 = vaddl_u8(p0, p1);                // add and widen
233  const uint16x8_t sum1 = vqsubq_u16(sum0, vmovl_u8(p2));  // widen and subtract
234  const uint8x8_t out = vqmovn_u16(sum1);                  // narrow and clamp
235  return vget_lane_u32(vreinterpret_u32_u8(out), 0);
236}
237
238static uint32_t Predictor12(uint32_t left, const uint32_t* const top) {
239  return ClampedAddSubtractFull(&left, top + 0, top - 1);
240}
241
242static WEBP_INLINE uint32_t ClampedAddSubtractHalf(const uint32_t* const c0,
243                                                   const uint32_t* const c1,
244                                                   const uint32_t* const c2) {
245  const uint8x8_t p0 = vreinterpret_u8_u64(vcreate_u64(*c0));
246  const uint8x8_t p1 = vreinterpret_u8_u64(vcreate_u64(*c1));
247  const uint8x8_t p2 = vreinterpret_u8_u64(vcreate_u64(*c2));
248  const uint8x8_t avg = vhadd_u8(p0, p1);                  // Average(c0,c1)
249  const uint8x8_t ab = vshr_n_u8(vqsub_u8(avg, p2), 1);    // (a-b)>>1 saturated
250  const uint8x8_t ba = vshr_n_u8(vqsub_u8(p2, avg), 1);    // (b-a)>>1 saturated
251  const uint8x8_t out = vqsub_u8(vqadd_u8(avg, ab), ba);
252  return vget_lane_u32(vreinterpret_u32_u8(out), 0);
253}
254
255static uint32_t Predictor13(uint32_t left, const uint32_t* const top) {
256  return ClampedAddSubtractHalf(&left, top + 0, top - 1);
257}
258
259//------------------------------------------------------------------------------
260// Subtract-Green Transform
261
262// vtbl? are unavailable in iOS/arm64 builds.
263#if !defined(__aarch64__)
264
265// 255 = byte will be zero'd
266static const uint8_t kGreenShuffle[8] = { 1, 255, 1, 255, 5, 255, 5, 255  };
267
268static void SubtractGreenFromBlueAndRed(uint32_t* argb_data, int num_pixels) {
269  const uint32_t* const end = argb_data + (num_pixels & ~3);
270  const uint8x8_t shuffle = vld1_u8(kGreenShuffle);
271  for (; argb_data < end; argb_data += 4) {
272    const uint8x16_t argb = vld1q_u8((uint8_t*)argb_data);
273    const uint8x16_t greens =
274        vcombine_u8(vtbl1_u8(vget_low_u8(argb), shuffle),
275                    vtbl1_u8(vget_high_u8(argb), shuffle));
276    vst1q_u8((uint8_t*)argb_data, vsubq_u8(argb, greens));
277  }
278  // fallthrough and finish off with plain-C
279  VP8LSubtractGreenFromBlueAndRed_C(argb_data, num_pixels & 3);
280}
281
282static void AddGreenToBlueAndRed(uint32_t* argb_data, int num_pixels) {
283  const uint32_t* const end = argb_data + (num_pixels & ~3);
284  const uint8x8_t shuffle = vld1_u8(kGreenShuffle);
285  for (; argb_data < end; argb_data += 4) {
286    const uint8x16_t argb = vld1q_u8((uint8_t*)argb_data);
287    const uint8x16_t greens =
288        vcombine_u8(vtbl1_u8(vget_low_u8(argb), shuffle),
289                    vtbl1_u8(vget_high_u8(argb), shuffle));
290    vst1q_u8((uint8_t*)argb_data, vaddq_u8(argb, greens));
291  }
292  // fallthrough and finish off with plain-C
293  VP8LAddGreenToBlueAndRed_C(argb_data, num_pixels & 3);
294}
295
296#endif   // !__aarch64__
297
298#endif   // USE_INTRINSICS
299
300#endif   // WEBP_USE_NEON
301
302//------------------------------------------------------------------------------
303
304extern void VP8LDspInitNEON(void);
305
306void VP8LDspInitNEON(void) {
307#if defined(WEBP_USE_NEON)
308  VP8LConvertBGRAToRGBA = ConvertBGRAToRGBA;
309  VP8LConvertBGRAToBGR = ConvertBGRAToBGR;
310  VP8LConvertBGRAToRGB = ConvertBGRAToRGB;
311
312#ifdef USE_INTRINSICS
313  VP8LPredictors[5] = Predictor5;
314  VP8LPredictors[6] = Predictor6;
315  VP8LPredictors[7] = Predictor7;
316  VP8LPredictors[8] = Predictor8;
317  VP8LPredictors[9] = Predictor9;
318  VP8LPredictors[10] = Predictor10;
319  VP8LPredictors[11] = Predictor11;
320  VP8LPredictors[12] = Predictor12;
321  VP8LPredictors[13] = Predictor13;
322
323#if !defined(__aarch64__)
324  VP8LSubtractGreenFromBlueAndRed = SubtractGreenFromBlueAndRed;
325  VP8LAddGreenToBlueAndRed = AddGreenToBlueAndRed;
326#endif
327#endif
328
329#endif   // WEBP_USE_NEON
330}
331
332//------------------------------------------------------------------------------
333