1 // Copyright 2011 Google Inc. All Rights Reserved.
2 //
3 // This code is licensed under the same terms as WebM:
4 // Software License Agreement: http://www.webmproject.org/license/software/
5 // Additional IP Rights Grant: http://www.webmproject.org/license/additional/
6 // -----------------------------------------------------------------------------
7 //
8 // YUV to RGB upsampling functions.
9 //
10 // Author: somnath@google.com (Somnath Banerjee)
11
12 #include "./dsp.h"
13 #include "./yuv.h"
14
15 #if defined(__cplusplus) || defined(c_plusplus)
16 extern "C" {
17 #endif
18
19 //------------------------------------------------------------------------------
20 // Fancy upsampler
21
22 #ifdef FANCY_UPSAMPLING
23
24 // Fancy upsampling functions to convert YUV to RGB
25 WebPUpsampleLinePairFunc WebPUpsamplers[MODE_LAST];
26
27 // Given samples laid out in a square as:
28 // [a b]
29 // [c d]
30 // we interpolate u/v as:
31 // ([9*a + 3*b + 3*c + d 3*a + 9*b + 3*c + d] + [8 8]) / 16
32 // ([3*a + b + 9*c + 3*d a + 3*b + 3*c + 9*d] [8 8]) / 16
33
34 // We process u and v together stashed into 32bit (16bit each).
35 #define LOAD_UV(u,v) ((u) | ((v) << 16))
36
37 #define UPSAMPLE_FUNC(FUNC_NAME, FUNC, XSTEP) \
38 static void FUNC_NAME(const uint8_t* top_y, const uint8_t* bottom_y, \
39 const uint8_t* top_u, const uint8_t* top_v, \
40 const uint8_t* cur_u, const uint8_t* cur_v, \
41 uint8_t* top_dst, uint8_t* bottom_dst, int len) { \
42 int x; \
43 const int last_pixel_pair = (len - 1) >> 1; \
44 uint32_t tl_uv = LOAD_UV(top_u[0], top_v[0]); /* top-left sample */ \
45 uint32_t l_uv = LOAD_UV(cur_u[0], cur_v[0]); /* left-sample */ \
46 if (top_y) { \
47 const uint32_t uv0 = (3 * tl_uv + l_uv + 0x00020002u) >> 2; \
48 FUNC(top_y[0], uv0 & 0xff, (uv0 >> 16), top_dst); \
49 } \
50 if (bottom_y) { \
51 const uint32_t uv0 = (3 * l_uv + tl_uv + 0x00020002u) >> 2; \
52 FUNC(bottom_y[0], uv0 & 0xff, (uv0 >> 16), bottom_dst); \
53 } \
54 for (x = 1; x <= last_pixel_pair; ++x) { \
55 const uint32_t t_uv = LOAD_UV(top_u[x], top_v[x]); /* top sample */ \
56 const uint32_t uv = LOAD_UV(cur_u[x], cur_v[x]); /* sample */ \
57 /* precompute invariant values associated with first and second diagonals*/\
58 const uint32_t avg = tl_uv + t_uv + l_uv + uv + 0x00080008u; \
59 const uint32_t diag_12 = (avg + 2 * (t_uv + l_uv)) >> 3; \
60 const uint32_t diag_03 = (avg + 2 * (tl_uv + uv)) >> 3; \
61 if (top_y) { \
62 const uint32_t uv0 = (diag_12 + tl_uv) >> 1; \
63 const uint32_t uv1 = (diag_03 + t_uv) >> 1; \
64 FUNC(top_y[2 * x - 1], uv0 & 0xff, (uv0 >> 16), \
65 top_dst + (2 * x - 1) * XSTEP); \
66 FUNC(top_y[2 * x - 0], uv1 & 0xff, (uv1 >> 16), \
67 top_dst + (2 * x - 0) * XSTEP); \
68 } \
69 if (bottom_y) { \
70 const uint32_t uv0 = (diag_03 + l_uv) >> 1; \
71 const uint32_t uv1 = (diag_12 + uv) >> 1; \
72 FUNC(bottom_y[2 * x - 1], uv0 & 0xff, (uv0 >> 16), \
73 bottom_dst + (2 * x - 1) * XSTEP); \
74 FUNC(bottom_y[2 * x + 0], uv1 & 0xff, (uv1 >> 16), \
75 bottom_dst + (2 * x + 0) * XSTEP); \
76 } \
77 tl_uv = t_uv; \
78 l_uv = uv; \
79 } \
80 if (!(len & 1)) { \
81 if (top_y) { \
82 const uint32_t uv0 = (3 * tl_uv + l_uv + 0x00020002u) >> 2; \
83 FUNC(top_y[len - 1], uv0 & 0xff, (uv0 >> 16), \
84 top_dst + (len - 1) * XSTEP); \
85 } \
86 if (bottom_y) { \
87 const uint32_t uv0 = (3 * l_uv + tl_uv + 0x00020002u) >> 2; \
88 FUNC(bottom_y[len - 1], uv0 & 0xff, (uv0 >> 16), \
89 bottom_dst + (len - 1) * XSTEP); \
90 } \
91 } \
92 }
93
94 // All variants implemented.
95 UPSAMPLE_FUNC(UpsampleRgbLinePair, VP8YuvToRgb, 3)
96 UPSAMPLE_FUNC(UpsampleBgrLinePair, VP8YuvToBgr, 3)
97 UPSAMPLE_FUNC(UpsampleRgbaLinePair, VP8YuvToRgba, 4)
98 UPSAMPLE_FUNC(UpsampleBgraLinePair, VP8YuvToBgra, 4)
99 UPSAMPLE_FUNC(UpsampleArgbLinePair, VP8YuvToArgb, 4)
100 UPSAMPLE_FUNC(UpsampleRgba4444LinePair, VP8YuvToRgba4444, 2)
101 UPSAMPLE_FUNC(UpsampleRgb565LinePair, VP8YuvToRgb565, 2)
102
103 #undef LOAD_UV
104 #undef UPSAMPLE_FUNC
105
106 #endif // FANCY_UPSAMPLING
107
108 //------------------------------------------------------------------------------
109 // simple point-sampling
110
111 #define SAMPLE_FUNC(FUNC_NAME, FUNC, XSTEP) \
112 static void FUNC_NAME(const uint8_t* top_y, const uint8_t* bottom_y, \
113 const uint8_t* u, const uint8_t* v, \
114 uint8_t* top_dst, uint8_t* bottom_dst, int len) { \
115 int i; \
116 for (i = 0; i < len - 1; i += 2) { \
117 FUNC(top_y[0], u[0], v[0], top_dst); \
118 FUNC(top_y[1], u[0], v[0], top_dst + XSTEP); \
119 FUNC(bottom_y[0], u[0], v[0], bottom_dst); \
120 FUNC(bottom_y[1], u[0], v[0], bottom_dst + XSTEP); \
121 top_y += 2; \
122 bottom_y += 2; \
123 u++; \
124 v++; \
125 top_dst += 2 * XSTEP; \
126 bottom_dst += 2 * XSTEP; \
127 } \
128 if (i == len - 1) { /* last one */ \
129 FUNC(top_y[0], u[0], v[0], top_dst); \
130 FUNC(bottom_y[0], u[0], v[0], bottom_dst); \
131 } \
132 }
133
134 // All variants implemented.
135 SAMPLE_FUNC(SampleRgbLinePair, VP8YuvToRgb, 3)
136 SAMPLE_FUNC(SampleBgrLinePair, VP8YuvToBgr, 3)
137 SAMPLE_FUNC(SampleRgbaLinePair, VP8YuvToRgba, 4)
138 SAMPLE_FUNC(SampleBgraLinePair, VP8YuvToBgra, 4)
139 SAMPLE_FUNC(SampleArgbLinePair, VP8YuvToArgb, 4)
140 SAMPLE_FUNC(SampleRgba4444LinePair, VP8YuvToRgba4444, 2)
141 SAMPLE_FUNC(SampleRgb565LinePair, VP8YuvToRgb565, 2)
142
143 #undef SAMPLE_FUNC
144
145 const WebPSampleLinePairFunc WebPSamplers[MODE_LAST] = {
146 SampleRgbLinePair, // MODE_RGB
147 SampleRgbaLinePair, // MODE_RGBA
148 SampleBgrLinePair, // MODE_BGR
149 SampleBgraLinePair, // MODE_BGRA
150 SampleArgbLinePair, // MODE_ARGB
151 SampleRgba4444LinePair, // MODE_RGBA_4444
152 SampleRgb565LinePair, // MODE_RGB_565
153 SampleRgbaLinePair, // MODE_rgbA
154 SampleBgraLinePair, // MODE_bgrA
155 SampleArgbLinePair, // MODE_Argb
156 SampleRgba4444LinePair // MODE_rgbA_4444
157 };
158
159 //------------------------------------------------------------------------------
160
161 #if !defined(FANCY_UPSAMPLING)
162 #define DUAL_SAMPLE_FUNC(FUNC_NAME, FUNC) \
163 static void FUNC_NAME(const uint8_t* top_y, const uint8_t* bot_y, \
164 const uint8_t* top_u, const uint8_t* top_v, \
165 const uint8_t* bot_u, const uint8_t* bot_v, \
166 uint8_t* top_dst, uint8_t* bot_dst, int len) { \
167 const int half_len = len >> 1; \
168 int x; \
169 if (top_dst != NULL) { \
170 for (x = 0; x < half_len; ++x) { \
171 FUNC(top_y[2 * x + 0], top_u[x], top_v[x], top_dst + 8 * x + 0); \
172 FUNC(top_y[2 * x + 1], top_u[x], top_v[x], top_dst + 8 * x + 4); \
173 } \
174 if (len & 1) FUNC(top_y[2 * x + 0], top_u[x], top_v[x], top_dst + 8 * x); \
175 } \
176 if (bot_dst != NULL) { \
177 for (x = 0; x < half_len; ++x) { \
178 FUNC(bot_y[2 * x + 0], bot_u[x], bot_v[x], bot_dst + 8 * x + 0); \
179 FUNC(bot_y[2 * x + 1], bot_u[x], bot_v[x], bot_dst + 8 * x + 4); \
180 } \
181 if (len & 1) FUNC(bot_y[2 * x + 0], bot_u[x], bot_v[x], bot_dst + 8 * x); \
182 } \
183 }
184
DUAL_SAMPLE_FUNC(DualLineSamplerBGRA,VP8YuvToBgra)185 DUAL_SAMPLE_FUNC(DualLineSamplerBGRA, VP8YuvToBgra)
186 DUAL_SAMPLE_FUNC(DualLineSamplerARGB, VP8YuvToArgb)
187 #undef DUAL_SAMPLE_FUNC
188
189 #endif // !FANCY_UPSAMPLING
190
191 WebPUpsampleLinePairFunc WebPGetLinePairConverter(int alpha_is_last) {
192 WebPInitUpsamplers();
193 VP8YUVInit();
194 #ifdef FANCY_UPSAMPLING
195 return WebPUpsamplers[alpha_is_last ? MODE_BGRA : MODE_ARGB];
196 #else
197 return (alpha_is_last ? DualLineSamplerBGRA : DualLineSamplerARGB);
198 #endif
199 }
200
201 //------------------------------------------------------------------------------
202 // YUV444 converter
203
204 #define YUV444_FUNC(FUNC_NAME, FUNC, XSTEP) \
205 static void FUNC_NAME(const uint8_t* y, const uint8_t* u, const uint8_t* v, \
206 uint8_t* dst, int len) { \
207 int i; \
208 for (i = 0; i < len; ++i) FUNC(y[i], u[i], v[i], &dst[i * XSTEP]); \
209 }
210
211 YUV444_FUNC(Yuv444ToRgb, VP8YuvToRgb, 3)
212 YUV444_FUNC(Yuv444ToBgr, VP8YuvToBgr, 3)
213 YUV444_FUNC(Yuv444ToRgba, VP8YuvToRgba, 4)
214 YUV444_FUNC(Yuv444ToBgra, VP8YuvToBgra, 4)
215 YUV444_FUNC(Yuv444ToArgb, VP8YuvToArgb, 4)
216 YUV444_FUNC(Yuv444ToRgba4444, VP8YuvToRgba4444, 2)
217 YUV444_FUNC(Yuv444ToRgb565, VP8YuvToRgb565, 2)
218
219 #undef YUV444_FUNC
220
221 const WebPYUV444Converter WebPYUV444Converters[MODE_LAST] = {
222 Yuv444ToRgb, // MODE_RGB
223 Yuv444ToRgba, // MODE_RGBA
224 Yuv444ToBgr, // MODE_BGR
225 Yuv444ToBgra, // MODE_BGRA
226 Yuv444ToArgb, // MODE_ARGB
227 Yuv444ToRgba4444, // MODE_RGBA_4444
228 Yuv444ToRgb565, // MODE_RGB_565
229 Yuv444ToRgba, // MODE_rgbA
230 Yuv444ToBgra, // MODE_bgrA
231 Yuv444ToArgb, // MODE_Argb
232 Yuv444ToRgba4444 // MODE_rgbA_4444
233 };
234
235 //------------------------------------------------------------------------------
236 // Premultiplied modes
237
238 // non dithered-modes
239
240 // (x * a * 32897) >> 23 is bit-wise equivalent to (int)(x * a / 255.)
241 // for all 8bit x or a. For bit-wise equivalence to (int)(x * a / 255. + .5),
242 // one can use instead: (x * a * 65793 + (1 << 23)) >> 24
243 #if 1 // (int)(x * a / 255.)
244 #define MULTIPLIER(a) ((a) * 32897UL)
245 #define PREMULTIPLY(x, m) (((x) * (m)) >> 23)
246 #else // (int)(x * a / 255. + .5)
247 #define MULTIPLIER(a) ((a) * 65793UL)
248 #define PREMULTIPLY(x, m) (((x) * (m) + (1UL << 23)) >> 24)
249 #endif
250
ApplyAlphaMultiply(uint8_t * rgba,int alpha_first,int w,int h,int stride)251 static void ApplyAlphaMultiply(uint8_t* rgba, int alpha_first,
252 int w, int h, int stride) {
253 while (h-- > 0) {
254 uint8_t* const rgb = rgba + (alpha_first ? 1 : 0);
255 const uint8_t* const alpha = rgba + (alpha_first ? 0 : 3);
256 int i;
257 for (i = 0; i < w; ++i) {
258 const uint32_t a = alpha[4 * i];
259 if (a != 0xff) {
260 const uint32_t mult = MULTIPLIER(a);
261 rgb[4 * i + 0] = PREMULTIPLY(rgb[4 * i + 0], mult);
262 rgb[4 * i + 1] = PREMULTIPLY(rgb[4 * i + 1], mult);
263 rgb[4 * i + 2] = PREMULTIPLY(rgb[4 * i + 2], mult);
264 }
265 }
266 rgba += stride;
267 }
268 }
269 #undef MULTIPLIER
270 #undef PREMULTIPLY
271
272 // rgbA4444
273
274 #define MULTIPLIER(a) ((a) * 0x1111) // 0x1111 ~= (1 << 16) / 15
275
dither_hi(uint8_t x)276 static WEBP_INLINE uint8_t dither_hi(uint8_t x) {
277 return (x & 0xf0) | (x >> 4);
278 }
279
dither_lo(uint8_t x)280 static WEBP_INLINE uint8_t dither_lo(uint8_t x) {
281 return (x & 0x0f) | (x << 4);
282 }
283
multiply(uint8_t x,uint32_t m)284 static WEBP_INLINE uint8_t multiply(uint8_t x, uint32_t m) {
285 return (x * m) >> 16;
286 }
287
ApplyAlphaMultiply4444(uint8_t * rgba4444,int w,int h,int stride)288 static void ApplyAlphaMultiply4444(uint8_t* rgba4444,
289 int w, int h, int stride) {
290 while (h-- > 0) {
291 int i;
292 for (i = 0; i < w; ++i) {
293 const uint8_t a = (rgba4444[2 * i + 1] & 0x0f);
294 const uint32_t mult = MULTIPLIER(a);
295 const uint8_t r = multiply(dither_hi(rgba4444[2 * i + 0]), mult);
296 const uint8_t g = multiply(dither_lo(rgba4444[2 * i + 0]), mult);
297 const uint8_t b = multiply(dither_hi(rgba4444[2 * i + 1]), mult);
298 rgba4444[2 * i + 0] = (r & 0xf0) | ((g >> 4) & 0x0f);
299 rgba4444[2 * i + 1] = (b & 0xf0) | a;
300 }
301 rgba4444 += stride;
302 }
303 }
304 #undef MULTIPLIER
305
306 void (*WebPApplyAlphaMultiply)(uint8_t*, int, int, int, int)
307 = ApplyAlphaMultiply;
308 void (*WebPApplyAlphaMultiply4444)(uint8_t*, int, int, int)
309 = ApplyAlphaMultiply4444;
310
311 //------------------------------------------------------------------------------
312 // Main call
313
WebPInitUpsamplers(void)314 void WebPInitUpsamplers(void) {
315 #ifdef FANCY_UPSAMPLING
316 WebPUpsamplers[MODE_RGB] = UpsampleRgbLinePair;
317 WebPUpsamplers[MODE_RGBA] = UpsampleRgbaLinePair;
318 WebPUpsamplers[MODE_BGR] = UpsampleBgrLinePair;
319 WebPUpsamplers[MODE_BGRA] = UpsampleBgraLinePair;
320 WebPUpsamplers[MODE_ARGB] = UpsampleArgbLinePair;
321 WebPUpsamplers[MODE_RGBA_4444] = UpsampleRgba4444LinePair;
322 WebPUpsamplers[MODE_RGB_565] = UpsampleRgb565LinePair;
323
324 // If defined, use CPUInfo() to overwrite some pointers with faster versions.
325 if (VP8GetCPUInfo != NULL) {
326 #if defined(WEBP_USE_SSE2)
327 if (VP8GetCPUInfo(kSSE2)) {
328 WebPInitUpsamplersSSE2();
329 }
330 #endif
331 }
332 #endif // FANCY_UPSAMPLING
333 }
334
WebPInitPremultiply(void)335 void WebPInitPremultiply(void) {
336 WebPApplyAlphaMultiply = ApplyAlphaMultiply;
337 WebPApplyAlphaMultiply4444 = ApplyAlphaMultiply4444;
338
339 #ifdef FANCY_UPSAMPLING
340 WebPUpsamplers[MODE_rgbA] = UpsampleRgbaLinePair;
341 WebPUpsamplers[MODE_bgrA] = UpsampleBgraLinePair;
342 WebPUpsamplers[MODE_Argb] = UpsampleArgbLinePair;
343 WebPUpsamplers[MODE_rgbA_4444] = UpsampleRgba4444LinePair;
344
345 if (VP8GetCPUInfo != NULL) {
346 #if defined(WEBP_USE_SSE2)
347 if (VP8GetCPUInfo(kSSE2)) {
348 WebPInitPremultiplySSE2();
349 }
350 #endif
351 }
352 #endif // FANCY_UPSAMPLING
353 }
354
355 #if defined(__cplusplus) || defined(c_plusplus)
356 } // extern "C"
357 #endif
358