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// Utilities for processing transparent channel.
11//
12// Author: Skal (pascal.massimino@gmail.com)
13
14#include "src/dsp/dsp.h"
15
16#if defined(WEBP_USE_SSE2)
17#include <emmintrin.h>
18
19//------------------------------------------------------------------------------
20
21static int DispatchAlpha_SSE2(const uint8_t* WEBP_RESTRICT alpha,
22 int alpha_stride, int width, int height,
23 uint8_t* WEBP_RESTRICT dst, int dst_stride) {
24 // alpha_and stores an 'and' operation of all the alpha[] values. The final
25 // value is not 0xff if any of the alpha[] is not equal to 0xff.
26 uint32_t alpha_and = 0xff;
27 int i, j;
28 const __m128i zero = _mm_setzero_si128();
29 const __m128i rgb_mask = _mm_set1_epi32((int)0xffffff00); // to preserve RGB
30 const __m128i all_0xff = _mm_set_epi32(0, 0, ~0, ~0);
31 __m128i all_alphas = all_0xff;
32
33 // We must be able to access 3 extra bytes after the last written byte
34 // 'dst[4 * width - 4]', because we don't know if alpha is the first or the
35 // last byte of the quadruplet.
36 const int limit = (width - 1) & ~7;
37
38 for (j = 0; j < height; ++j) {
39 __m128i* out = (__m128i*)dst;
40 for (i = 0; i < limit; i += 8) {
41 // load 8 alpha bytes
42 const __m128i a0 = _mm_loadl_epi64((const __m128i*)&alpha[i]);
43 const __m128i a1 = _mm_unpacklo_epi8(a0, zero);
44 const __m128i a2_lo = _mm_unpacklo_epi16(a1, zero);
45 const __m128i a2_hi = _mm_unpackhi_epi16(a1, zero);
46 // load 8 dst pixels (32 bytes)
47 const __m128i b0_lo = _mm_loadu_si128(out + 0);
48 const __m128i b0_hi = _mm_loadu_si128(out + 1);
49 // mask dst alpha values
50 const __m128i b1_lo = _mm_and_si128(b0_lo, rgb_mask);
51 const __m128i b1_hi = _mm_and_si128(b0_hi, rgb_mask);
52 // combine
53 const __m128i b2_lo = _mm_or_si128(b1_lo, a2_lo);
54 const __m128i b2_hi = _mm_or_si128(b1_hi, a2_hi);
55 // store
56 _mm_storeu_si128(out + 0, b2_lo);
57 _mm_storeu_si128(out + 1, b2_hi);
58 // accumulate eight alpha 'and' in parallel
59 all_alphas = _mm_and_si128(all_alphas, a0);
60 out += 2;
61 }
62 for (; i < width; ++i) {
63 const uint32_t alpha_value = alpha[i];
64 dst[4 * i] = alpha_value;
65 alpha_and &= alpha_value;
66 }
67 alpha += alpha_stride;
68 dst += dst_stride;
69 }
70 // Combine the eight alpha 'and' into a 8-bit mask.
71 alpha_and &= _mm_movemask_epi8(_mm_cmpeq_epi8(all_alphas, all_0xff));
72 return (alpha_and != 0xff);
73}
74
75static void DispatchAlphaToGreen_SSE2(const uint8_t* WEBP_RESTRICT alpha,
76 int alpha_stride, int width, int height,
77 uint32_t* WEBP_RESTRICT dst,
78 int dst_stride) {
79 int i, j;
80 const __m128i zero = _mm_setzero_si128();
81 const int limit = width & ~15;
82 for (j = 0; j < height; ++j) {
83 for (i = 0; i < limit; i += 16) { // process 16 alpha bytes
84 const __m128i a0 = _mm_loadu_si128((const __m128i*)&alpha[i]);
85 const __m128i a1 = _mm_unpacklo_epi8(zero, a0); // note the 'zero' first!
86 const __m128i b1 = _mm_unpackhi_epi8(zero, a0);
87 const __m128i a2_lo = _mm_unpacklo_epi16(a1, zero);
88 const __m128i b2_lo = _mm_unpacklo_epi16(b1, zero);
89 const __m128i a2_hi = _mm_unpackhi_epi16(a1, zero);
90 const __m128i b2_hi = _mm_unpackhi_epi16(b1, zero);
91 _mm_storeu_si128((__m128i*)&dst[i + 0], a2_lo);
92 _mm_storeu_si128((__m128i*)&dst[i + 4], a2_hi);
93 _mm_storeu_si128((__m128i*)&dst[i + 8], b2_lo);
94 _mm_storeu_si128((__m128i*)&dst[i + 12], b2_hi);
95 }
96 for (; i < width; ++i) dst[i] = alpha[i] << 8;
97 alpha += alpha_stride;
98 dst += dst_stride;
99 }
100}
101
102static int ExtractAlpha_SSE2(const uint8_t* WEBP_RESTRICT argb, int argb_stride,
103 int width, int height,
104 uint8_t* WEBP_RESTRICT alpha, int alpha_stride) {
105 // alpha_and stores an 'and' operation of all the alpha[] values. The final
106 // value is not 0xff if any of the alpha[] is not equal to 0xff.
107 uint32_t alpha_and = 0xff;
108 int i, j;
109 const __m128i a_mask = _mm_set1_epi32(0xff); // to preserve alpha
110 const __m128i all_0xff = _mm_set_epi32(0, 0, ~0, ~0);
111 __m128i all_alphas = all_0xff;
112
113 // We must be able to access 3 extra bytes after the last written byte
114 // 'src[4 * width - 4]', because we don't know if alpha is the first or the
115 // last byte of the quadruplet.
116 const int limit = (width - 1) & ~7;
117
118 for (j = 0; j < height; ++j) {
119 const __m128i* src = (const __m128i*)argb;
120 for (i = 0; i < limit; i += 8) {
121 // load 32 argb bytes
122 const __m128i a0 = _mm_loadu_si128(src + 0);
123 const __m128i a1 = _mm_loadu_si128(src + 1);
124 const __m128i b0 = _mm_and_si128(a0, a_mask);
125 const __m128i b1 = _mm_and_si128(a1, a_mask);
126 const __m128i c0 = _mm_packs_epi32(b0, b1);
127 const __m128i d0 = _mm_packus_epi16(c0, c0);
128 // store
129 _mm_storel_epi64((__m128i*)&alpha[i], d0);
130 // accumulate eight alpha 'and' in parallel
131 all_alphas = _mm_and_si128(all_alphas, d0);
132 src += 2;
133 }
134 for (; i < width; ++i) {
135 const uint32_t alpha_value = argb[4 * i];
136 alpha[i] = alpha_value;
137 alpha_and &= alpha_value;
138 }
139 argb += argb_stride;
140 alpha += alpha_stride;
141 }
142 // Combine the eight alpha 'and' into a 8-bit mask.
143 alpha_and &= _mm_movemask_epi8(_mm_cmpeq_epi8(all_alphas, all_0xff));
144 return (alpha_and == 0xff);
145}
146
147//------------------------------------------------------------------------------
148// Non-dither premultiplied modes
149
150#define MULTIPLIER(a) ((a) * 0x8081)
151#define PREMULTIPLY(x, m) (((x) * (m)) >> 23)
152
153// We can't use a 'const int' for the SHUFFLE value, because it has to be an
154// immediate in the _mm_shufflexx_epi16() instruction. We really need a macro.
155// We use: v / 255 = (v * 0x8081) >> 23, where v = alpha * {r,g,b} is a 16bit
156// value.
157#define APPLY_ALPHA(RGBX, SHUFFLE) do { \
158 const __m128i argb0 = _mm_loadu_si128((const __m128i*)&(RGBX)); \
159 const __m128i argb1_lo = _mm_unpacklo_epi8(argb0, zero); \
160 const __m128i argb1_hi = _mm_unpackhi_epi8(argb0, zero); \
161 const __m128i alpha0_lo = _mm_or_si128(argb1_lo, kMask); \
162 const __m128i alpha0_hi = _mm_or_si128(argb1_hi, kMask); \
163 const __m128i alpha1_lo = _mm_shufflelo_epi16(alpha0_lo, SHUFFLE); \
164 const __m128i alpha1_hi = _mm_shufflelo_epi16(alpha0_hi, SHUFFLE); \
165 const __m128i alpha2_lo = _mm_shufflehi_epi16(alpha1_lo, SHUFFLE); \
166 const __m128i alpha2_hi = _mm_shufflehi_epi16(alpha1_hi, SHUFFLE); \
167 /* alpha2 = [ff a0 a0 a0][ff a1 a1 a1] */ \
168 const __m128i A0_lo = _mm_mullo_epi16(alpha2_lo, argb1_lo); \
169 const __m128i A0_hi = _mm_mullo_epi16(alpha2_hi, argb1_hi); \
170 const __m128i A1_lo = _mm_mulhi_epu16(A0_lo, kMult); \
171 const __m128i A1_hi = _mm_mulhi_epu16(A0_hi, kMult); \
172 const __m128i A2_lo = _mm_srli_epi16(A1_lo, 7); \
173 const __m128i A2_hi = _mm_srli_epi16(A1_hi, 7); \
174 const __m128i A3 = _mm_packus_epi16(A2_lo, A2_hi); \
175 _mm_storeu_si128((__m128i*)&(RGBX), A3); \
176} while (0)
177
178static void ApplyAlphaMultiply_SSE2(uint8_t* rgba, int alpha_first,
179 int w, int h, int stride) {
180 const __m128i zero = _mm_setzero_si128();
181 const __m128i kMult = _mm_set1_epi16((short)0x8081);
182 const __m128i kMask = _mm_set_epi16(0, 0xff, 0xff, 0, 0, 0xff, 0xff, 0);
183 const int kSpan = 4;
184 while (h-- > 0) {
185 uint32_t* const rgbx = (uint32_t*)rgba;
186 int i;
187 if (!alpha_first) {
188 for (i = 0; i + kSpan <= w; i += kSpan) {
189 APPLY_ALPHA(rgbx[i], _MM_SHUFFLE(2, 3, 3, 3));
190 }
191 } else {
192 for (i = 0; i + kSpan <= w; i += kSpan) {
193 APPLY_ALPHA(rgbx[i], _MM_SHUFFLE(0, 0, 0, 1));
194 }
195 }
196 // Finish with left-overs.
197 for (; i < w; ++i) {
198 uint8_t* const rgb = rgba + (alpha_first ? 1 : 0);
199 const uint8_t* const alpha = rgba + (alpha_first ? 0 : 3);
200 const uint32_t a = alpha[4 * i];
201 if (a != 0xff) {
202 const uint32_t mult = MULTIPLIER(a);
203 rgb[4 * i + 0] = PREMULTIPLY(rgb[4 * i + 0], mult);
204 rgb[4 * i + 1] = PREMULTIPLY(rgb[4 * i + 1], mult);
205 rgb[4 * i + 2] = PREMULTIPLY(rgb[4 * i + 2], mult);
206 }
207 }
208 rgba += stride;
209 }
210}
211#undef MULTIPLIER
212#undef PREMULTIPLY
213
214//------------------------------------------------------------------------------
215// Alpha detection
216
217static int HasAlpha8b_SSE2(const uint8_t* src, int length) {
218 const __m128i all_0xff = _mm_set1_epi8((char)0xff);
219 int i = 0;
220 for (; i + 16 <= length; i += 16) {
221 const __m128i v = _mm_loadu_si128((const __m128i*)(src + i));
222 const __m128i bits = _mm_cmpeq_epi8(v, all_0xff);
223 const int mask = _mm_movemask_epi8(bits);
224 if (mask != 0xffff) return 1;
225 }
226 for (; i < length; ++i) if (src[i] != 0xff) return 1;
227 return 0;
228}
229
230static int HasAlpha32b_SSE2(const uint8_t* src, int length) {
231 const __m128i alpha_mask = _mm_set1_epi32(0xff);
232 const __m128i all_0xff = _mm_set1_epi8((char)0xff);
233 int i = 0;
234 // We don't know if we can access the last 3 bytes after the last alpha
235 // value 'src[4 * length - 4]' (because we don't know if alpha is the first
236 // or the last byte of the quadruplet). Hence the '-3' protection below.
237 length = length * 4 - 3; // size in bytes
238 for (; i + 64 <= length; i += 64) {
239 const __m128i a0 = _mm_loadu_si128((const __m128i*)(src + i + 0));
240 const __m128i a1 = _mm_loadu_si128((const __m128i*)(src + i + 16));
241 const __m128i a2 = _mm_loadu_si128((const __m128i*)(src + i + 32));
242 const __m128i a3 = _mm_loadu_si128((const __m128i*)(src + i + 48));
243 const __m128i b0 = _mm_and_si128(a0, alpha_mask);
244 const __m128i b1 = _mm_and_si128(a1, alpha_mask);
245 const __m128i b2 = _mm_and_si128(a2, alpha_mask);
246 const __m128i b3 = _mm_and_si128(a3, alpha_mask);
247 const __m128i c0 = _mm_packs_epi32(b0, b1);
248 const __m128i c1 = _mm_packs_epi32(b2, b3);
249 const __m128i d = _mm_packus_epi16(c0, c1);
250 const __m128i bits = _mm_cmpeq_epi8(d, all_0xff);
251 const int mask = _mm_movemask_epi8(bits);
252 if (mask != 0xffff) return 1;
253 }
254 for (; i + 32 <= length; i += 32) {
255 const __m128i a0 = _mm_loadu_si128((const __m128i*)(src + i + 0));
256 const __m128i a1 = _mm_loadu_si128((const __m128i*)(src + i + 16));
257 const __m128i b0 = _mm_and_si128(a0, alpha_mask);
258 const __m128i b1 = _mm_and_si128(a1, alpha_mask);
259 const __m128i c = _mm_packs_epi32(b0, b1);
260 const __m128i d = _mm_packus_epi16(c, c);
261 const __m128i bits = _mm_cmpeq_epi8(d, all_0xff);
262 const int mask = _mm_movemask_epi8(bits);
263 if (mask != 0xffff) return 1;
264 }
265 for (; i <= length; i += 4) if (src[i] != 0xff) return 1;
266 return 0;
267}
268
269static void AlphaReplace_SSE2(uint32_t* src, int length, uint32_t color) {
270 const __m128i m_color = _mm_set1_epi32((int)color);
271 const __m128i zero = _mm_setzero_si128();
272 int i = 0;
273 for (; i + 8 <= length; i += 8) {
274 const __m128i a0 = _mm_loadu_si128((const __m128i*)(src + i + 0));
275 const __m128i a1 = _mm_loadu_si128((const __m128i*)(src + i + 4));
276 const __m128i b0 = _mm_srai_epi32(a0, 24);
277 const __m128i b1 = _mm_srai_epi32(a1, 24);
278 const __m128i c0 = _mm_cmpeq_epi32(b0, zero);
279 const __m128i c1 = _mm_cmpeq_epi32(b1, zero);
280 const __m128i d0 = _mm_and_si128(c0, m_color);
281 const __m128i d1 = _mm_and_si128(c1, m_color);
282 const __m128i e0 = _mm_andnot_si128(c0, a0);
283 const __m128i e1 = _mm_andnot_si128(c1, a1);
284 _mm_storeu_si128((__m128i*)(src + i + 0), _mm_or_si128(d0, e0));
285 _mm_storeu_si128((__m128i*)(src + i + 4), _mm_or_si128(d1, e1));
286 }
287 for (; i < length; ++i) if ((src[i] >> 24) == 0) src[i] = color;
288}
289
290// -----------------------------------------------------------------------------
291// Apply alpha value to rows
292
293static void MultARGBRow_SSE2(uint32_t* const ptr, int width, int inverse) {
294 int x = 0;
295 if (!inverse) {
296 const int kSpan = 2;
297 const __m128i zero = _mm_setzero_si128();
298 const __m128i k128 = _mm_set1_epi16(128);
299 const __m128i kMult = _mm_set1_epi16(0x0101);
300 const __m128i kMask = _mm_set_epi16(0, 0xff, 0, 0, 0, 0xff, 0, 0);
301 for (x = 0; x + kSpan <= width; x += kSpan) {
302 // To compute 'result = (int)(a * x / 255. + .5)', we use:
303 // tmp = a * v + 128, result = (tmp * 0x0101u) >> 16
304 const __m128i A0 = _mm_loadl_epi64((const __m128i*)&ptr[x]);
305 const __m128i A1 = _mm_unpacklo_epi8(A0, zero);
306 const __m128i A2 = _mm_or_si128(A1, kMask);
307 const __m128i A3 = _mm_shufflelo_epi16(A2, _MM_SHUFFLE(2, 3, 3, 3));
308 const __m128i A4 = _mm_shufflehi_epi16(A3, _MM_SHUFFLE(2, 3, 3, 3));
309 // here, A4 = [ff a0 a0 a0][ff a1 a1 a1]
310 const __m128i A5 = _mm_mullo_epi16(A4, A1);
311 const __m128i A6 = _mm_add_epi16(A5, k128);
312 const __m128i A7 = _mm_mulhi_epu16(A6, kMult);
313 const __m128i A10 = _mm_packus_epi16(A7, zero);
314 _mm_storel_epi64((__m128i*)&ptr[x], A10);
315 }
316 }
317 width -= x;
318 if (width > 0) WebPMultARGBRow_C(ptr + x, width, inverse);
319}
320
321static void MultRow_SSE2(uint8_t* WEBP_RESTRICT const ptr,
322 const uint8_t* WEBP_RESTRICT const alpha,
323 int width, int inverse) {
324 int x = 0;
325 if (!inverse) {
326 const __m128i zero = _mm_setzero_si128();
327 const __m128i k128 = _mm_set1_epi16(128);
328 const __m128i kMult = _mm_set1_epi16(0x0101);
329 for (x = 0; x + 8 <= width; x += 8) {
330 const __m128i v0 = _mm_loadl_epi64((__m128i*)&ptr[x]);
331 const __m128i a0 = _mm_loadl_epi64((const __m128i*)&alpha[x]);
332 const __m128i v1 = _mm_unpacklo_epi8(v0, zero);
333 const __m128i a1 = _mm_unpacklo_epi8(a0, zero);
334 const __m128i v2 = _mm_mullo_epi16(v1, a1);
335 const __m128i v3 = _mm_add_epi16(v2, k128);
336 const __m128i v4 = _mm_mulhi_epu16(v3, kMult);
337 const __m128i v5 = _mm_packus_epi16(v4, zero);
338 _mm_storel_epi64((__m128i*)&ptr[x], v5);
339 }
340 }
341 width -= x;
342 if (width > 0) WebPMultRow_C(ptr + x, alpha + x, width, inverse);
343}
344
345//------------------------------------------------------------------------------
346// Entry point
347
348extern void WebPInitAlphaProcessingSSE2(void);
349
350WEBP_TSAN_IGNORE_FUNCTION void WebPInitAlphaProcessingSSE2(void) {
351 WebPMultARGBRow = MultARGBRow_SSE2;
352 WebPMultRow = MultRow_SSE2;
353 WebPApplyAlphaMultiply = ApplyAlphaMultiply_SSE2;
354 WebPDispatchAlpha = DispatchAlpha_SSE2;
355 WebPDispatchAlphaToGreen = DispatchAlphaToGreen_SSE2;
356 WebPExtractAlpha = ExtractAlpha_SSE2;
357
358 WebPHasAlpha8b = HasAlpha8b_SSE2;
359 WebPHasAlpha32b = HasAlpha32b_SSE2;
360 WebPAlphaReplace = AlphaReplace_SSE2;
361}
362
363#else // !WEBP_USE_SSE2
364
365WEBP_DSP_INIT_STUB(WebPInitAlphaProcessingSSE2)
366
367#endif // WEBP_USE_SSE2
368