1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
|
/*
* jdcolext-neon.c - colorspace conversion (Arm Neon)
*
* Copyright (C) 2020, Arm Limited. All Rights Reserved.
* Copyright (C) 2020, D. R. Commander. All Rights Reserved.
*
* This software is provided 'as-is', without any express or implied
* warranty. In no event will the authors be held liable for any damages
* arising from the use of this software.
*
* Permission is granted to anyone to use this software for any purpose,
* including commercial applications, and to alter it and redistribute it
* freely, subject to the following restrictions:
*
* 1. The origin of this software must not be misrepresented; you must not
* claim that you wrote the original software. If you use this software
* in a product, an acknowledgment in the product documentation would be
* appreciated but is not required.
* 2. Altered source versions must be plainly marked as such, and must not be
* misrepresented as being the original software.
* 3. This notice may not be removed or altered from any source distribution.
*/
/* This file is included by jdcolor-neon.c. */
/* YCbCr -> RGB conversion is defined by the following equations:
* R = Y + 1.40200 * (Cr - 128)
* G = Y - 0.34414 * (Cb - 128) - 0.71414 * (Cr - 128)
* B = Y + 1.77200 * (Cb - 128)
*
* Scaled integer constants are used to avoid floating-point arithmetic:
* 0.3441467 = 11277 * 2^-15
* 0.7141418 = 23401 * 2^-15
* 1.4020386 = 22971 * 2^-14
* 1.7720337 = 29033 * 2^-14
* These constants are defined in jdcolor-neon.c.
*
* To ensure correct results, rounding is used when descaling.
*/
/* Notes on safe memory access for YCbCr -> RGB conversion routines:
*
* Input memory buffers can be safely overread up to the next multiple of
* ALIGN_SIZE bytes, since they are always allocated by alloc_sarray() in
* jmemmgr.c.
*
* The output buffer cannot safely be written beyond output_width, since
* output_buf points to a possibly unpadded row in the decompressed image
* buffer allocated by the calling program.
*/
void jsimd_ycc_rgb_convert_neon(JDIMENSION output_width, JSAMPIMAGE input_buf,
JDIMENSION input_row, JSAMPARRAY output_buf,
int num_rows)
{
JSAMPROW outptr;
/* Pointers to Y, Cb, and Cr data */
JSAMPROW inptr0, inptr1, inptr2;
const int16x4_t consts = vld1_s16(jsimd_ycc_rgb_convert_neon_consts);
const int16x8_t neg_128 = vdupq_n_s16(-128);
while (--num_rows >= 0) {
inptr0 = input_buf[0][input_row];
inptr1 = input_buf[1][input_row];
inptr2 = input_buf[2][input_row];
input_row++;
outptr = *output_buf++;
int cols_remaining = output_width;
for (; cols_remaining >= 16; cols_remaining -= 16) {
uint8x16_t y = vld1q_u8(inptr0);
uint8x16_t cb = vld1q_u8(inptr1);
uint8x16_t cr = vld1q_u8(inptr2);
/* Subtract 128 from Cb and Cr. */
int16x8_t cr_128_l =
vreinterpretq_s16_u16(vaddw_u8(vreinterpretq_u16_s16(neg_128),
vget_low_u8(cr)));
int16x8_t cr_128_h =
vreinterpretq_s16_u16(vaddw_u8(vreinterpretq_u16_s16(neg_128),
vget_high_u8(cr)));
int16x8_t cb_128_l =
vreinterpretq_s16_u16(vaddw_u8(vreinterpretq_u16_s16(neg_128),
vget_low_u8(cb)));
int16x8_t cb_128_h =
vreinterpretq_s16_u16(vaddw_u8(vreinterpretq_u16_s16(neg_128),
vget_high_u8(cb)));
/* Compute G-Y: - 0.34414 * (Cb - 128) - 0.71414 * (Cr - 128) */
int32x4_t g_sub_y_ll = vmull_lane_s16(vget_low_s16(cb_128_l), consts, 0);
int32x4_t g_sub_y_lh = vmull_lane_s16(vget_high_s16(cb_128_l),
consts, 0);
int32x4_t g_sub_y_hl = vmull_lane_s16(vget_low_s16(cb_128_h), consts, 0);
int32x4_t g_sub_y_hh = vmull_lane_s16(vget_high_s16(cb_128_h),
consts, 0);
g_sub_y_ll = vmlsl_lane_s16(g_sub_y_ll, vget_low_s16(cr_128_l),
consts, 1);
g_sub_y_lh = vmlsl_lane_s16(g_sub_y_lh, vget_high_s16(cr_128_l),
consts, 1);
g_sub_y_hl = vmlsl_lane_s16(g_sub_y_hl, vget_low_s16(cr_128_h),
consts, 1);
g_sub_y_hh = vmlsl_lane_s16(g_sub_y_hh, vget_high_s16(cr_128_h),
consts, 1);
/* Descale G components: shift right 15, round, and narrow to 16-bit. */
int16x8_t g_sub_y_l = vcombine_s16(vrshrn_n_s32(g_sub_y_ll, 15),
vrshrn_n_s32(g_sub_y_lh, 15));
int16x8_t g_sub_y_h = vcombine_s16(vrshrn_n_s32(g_sub_y_hl, 15),
vrshrn_n_s32(g_sub_y_hh, 15));
/* Compute R-Y: 1.40200 * (Cr - 128) */
int16x8_t r_sub_y_l = vqrdmulhq_lane_s16(vshlq_n_s16(cr_128_l, 1),
consts, 2);
int16x8_t r_sub_y_h = vqrdmulhq_lane_s16(vshlq_n_s16(cr_128_h, 1),
consts, 2);
/* Compute B-Y: 1.77200 * (Cb - 128) */
int16x8_t b_sub_y_l = vqrdmulhq_lane_s16(vshlq_n_s16(cb_128_l, 1),
consts, 3);
int16x8_t b_sub_y_h = vqrdmulhq_lane_s16(vshlq_n_s16(cb_128_h, 1),
consts, 3);
/* Add Y. */
int16x8_t r_l =
vreinterpretq_s16_u16(vaddw_u8(vreinterpretq_u16_s16(r_sub_y_l),
vget_low_u8(y)));
int16x8_t r_h =
vreinterpretq_s16_u16(vaddw_u8(vreinterpretq_u16_s16(r_sub_y_h),
vget_high_u8(y)));
int16x8_t b_l =
vreinterpretq_s16_u16(vaddw_u8(vreinterpretq_u16_s16(b_sub_y_l),
vget_low_u8(y)));
int16x8_t b_h =
vreinterpretq_s16_u16(vaddw_u8(vreinterpretq_u16_s16(b_sub_y_h),
vget_high_u8(y)));
int16x8_t g_l =
vreinterpretq_s16_u16(vaddw_u8(vreinterpretq_u16_s16(g_sub_y_l),
vget_low_u8(y)));
int16x8_t g_h =
vreinterpretq_s16_u16(vaddw_u8(vreinterpretq_u16_s16(g_sub_y_h),
vget_high_u8(y)));
#if RGB_PIXELSIZE == 4
uint8x16x4_t rgba;
/* Convert each component to unsigned and narrow, clamping to [0-255]. */
rgba.val[RGB_RED] = vcombine_u8(vqmovun_s16(r_l), vqmovun_s16(r_h));
rgba.val[RGB_GREEN] = vcombine_u8(vqmovun_s16(g_l), vqmovun_s16(g_h));
rgba.val[RGB_BLUE] = vcombine_u8(vqmovun_s16(b_l), vqmovun_s16(b_h));
/* Set alpha channel to opaque (0xFF). */
rgba.val[RGB_ALPHA] = vdupq_n_u8(0xFF);
/* Store RGBA pixel data to memory. */
vst4q_u8(outptr, rgba);
#elif RGB_PIXELSIZE == 3
uint8x16x3_t rgb;
/* Convert each component to unsigned and narrow, clamping to [0-255]. */
rgb.val[RGB_RED] = vcombine_u8(vqmovun_s16(r_l), vqmovun_s16(r_h));
rgb.val[RGB_GREEN] = vcombine_u8(vqmovun_s16(g_l), vqmovun_s16(g_h));
rgb.val[RGB_BLUE] = vcombine_u8(vqmovun_s16(b_l), vqmovun_s16(b_h));
/* Store RGB pixel data to memory. */
vst3q_u8(outptr, rgb);
#else
/* Pack R, G, and B values in ratio 5:6:5. */
uint16x8_t rgb565_l = vqshluq_n_s16(r_l, 8);
rgb565_l = vsriq_n_u16(rgb565_l, vqshluq_n_s16(g_l, 8), 5);
rgb565_l = vsriq_n_u16(rgb565_l, vqshluq_n_s16(b_l, 8), 11);
uint16x8_t rgb565_h = vqshluq_n_s16(r_h, 8);
rgb565_h = vsriq_n_u16(rgb565_h, vqshluq_n_s16(g_h, 8), 5);
rgb565_h = vsriq_n_u16(rgb565_h, vqshluq_n_s16(b_h, 8), 11);
/* Store RGB pixel data to memory. */
vst1q_u16((uint16_t *)outptr, rgb565_l);
vst1q_u16(((uint16_t *)outptr) + 8, rgb565_h);
#endif
/* Increment pointers. */
inptr0 += 16;
inptr1 += 16;
inptr2 += 16;
outptr += (RGB_PIXELSIZE * 16);
}
if (cols_remaining >= 8) {
uint8x8_t y = vld1_u8(inptr0);
uint8x8_t cb = vld1_u8(inptr1);
uint8x8_t cr = vld1_u8(inptr2);
/* Subtract 128 from Cb and Cr. */
int16x8_t cr_128 =
vreinterpretq_s16_u16(vaddw_u8(vreinterpretq_u16_s16(neg_128), cr));
int16x8_t cb_128 =
vreinterpretq_s16_u16(vaddw_u8(vreinterpretq_u16_s16(neg_128), cb));
/* Compute G-Y: - 0.34414 * (Cb - 128) - 0.71414 * (Cr - 128) */
int32x4_t g_sub_y_l = vmull_lane_s16(vget_low_s16(cb_128), consts, 0);
int32x4_t g_sub_y_h = vmull_lane_s16(vget_high_s16(cb_128), consts, 0);
g_sub_y_l = vmlsl_lane_s16(g_sub_y_l, vget_low_s16(cr_128), consts, 1);
g_sub_y_h = vmlsl_lane_s16(g_sub_y_h, vget_high_s16(cr_128), consts, 1);
/* Descale G components: shift right 15, round, and narrow to 16-bit. */
int16x8_t g_sub_y = vcombine_s16(vrshrn_n_s32(g_sub_y_l, 15),
vrshrn_n_s32(g_sub_y_h, 15));
/* Compute R-Y: 1.40200 * (Cr - 128) */
int16x8_t r_sub_y = vqrdmulhq_lane_s16(vshlq_n_s16(cr_128, 1),
consts, 2);
/* Compute B-Y: 1.77200 * (Cb - 128) */
int16x8_t b_sub_y = vqrdmulhq_lane_s16(vshlq_n_s16(cb_128, 1),
consts, 3);
/* Add Y. */
int16x8_t r =
vreinterpretq_s16_u16(vaddw_u8(vreinterpretq_u16_s16(r_sub_y), y));
int16x8_t b =
vreinterpretq_s16_u16(vaddw_u8(vreinterpretq_u16_s16(b_sub_y), y));
int16x8_t g =
vreinterpretq_s16_u16(vaddw_u8(vreinterpretq_u16_s16(g_sub_y), y));
#if RGB_PIXELSIZE == 4
uint8x8x4_t rgba;
/* Convert each component to unsigned and narrow, clamping to [0-255]. */
rgba.val[RGB_RED] = vqmovun_s16(r);
rgba.val[RGB_GREEN] = vqmovun_s16(g);
rgba.val[RGB_BLUE] = vqmovun_s16(b);
/* Set alpha channel to opaque (0xFF). */
rgba.val[RGB_ALPHA] = vdup_n_u8(0xFF);
/* Store RGBA pixel data to memory. */
vst4_u8(outptr, rgba);
#elif RGB_PIXELSIZE == 3
uint8x8x3_t rgb;
/* Convert each component to unsigned and narrow, clamping to [0-255]. */
rgb.val[RGB_RED] = vqmovun_s16(r);
rgb.val[RGB_GREEN] = vqmovun_s16(g);
rgb.val[RGB_BLUE] = vqmovun_s16(b);
/* Store RGB pixel data to memory. */
vst3_u8(outptr, rgb);
#else
/* Pack R, G, and B values in ratio 5:6:5. */
uint16x8_t rgb565 = vqshluq_n_s16(r, 8);
rgb565 = vsriq_n_u16(rgb565, vqshluq_n_s16(g, 8), 5);
rgb565 = vsriq_n_u16(rgb565, vqshluq_n_s16(b, 8), 11);
/* Store RGB pixel data to memory. */
vst1q_u16((uint16_t *)outptr, rgb565);
#endif
/* Increment pointers. */
inptr0 += 8;
inptr1 += 8;
inptr2 += 8;
outptr += (RGB_PIXELSIZE * 8);
cols_remaining -= 8;
}
/* Handle the tail elements. */
if (cols_remaining > 0) {
uint8x8_t y = vld1_u8(inptr0);
uint8x8_t cb = vld1_u8(inptr1);
uint8x8_t cr = vld1_u8(inptr2);
/* Subtract 128 from Cb and Cr. */
int16x8_t cr_128 =
vreinterpretq_s16_u16(vaddw_u8(vreinterpretq_u16_s16(neg_128), cr));
int16x8_t cb_128 =
vreinterpretq_s16_u16(vaddw_u8(vreinterpretq_u16_s16(neg_128), cb));
/* Compute G-Y: - 0.34414 * (Cb - 128) - 0.71414 * (Cr - 128) */
int32x4_t g_sub_y_l = vmull_lane_s16(vget_low_s16(cb_128), consts, 0);
int32x4_t g_sub_y_h = vmull_lane_s16(vget_high_s16(cb_128), consts, 0);
g_sub_y_l = vmlsl_lane_s16(g_sub_y_l, vget_low_s16(cr_128), consts, 1);
g_sub_y_h = vmlsl_lane_s16(g_sub_y_h, vget_high_s16(cr_128), consts, 1);
/* Descale G components: shift right 15, round, and narrow to 16-bit. */
int16x8_t g_sub_y = vcombine_s16(vrshrn_n_s32(g_sub_y_l, 15),
vrshrn_n_s32(g_sub_y_h, 15));
/* Compute R-Y: 1.40200 * (Cr - 128) */
int16x8_t r_sub_y = vqrdmulhq_lane_s16(vshlq_n_s16(cr_128, 1),
consts, 2);
/* Compute B-Y: 1.77200 * (Cb - 128) */
int16x8_t b_sub_y = vqrdmulhq_lane_s16(vshlq_n_s16(cb_128, 1),
consts, 3);
/* Add Y. */
int16x8_t r =
vreinterpretq_s16_u16(vaddw_u8(vreinterpretq_u16_s16(r_sub_y), y));
int16x8_t b =
vreinterpretq_s16_u16(vaddw_u8(vreinterpretq_u16_s16(b_sub_y), y));
int16x8_t g =
vreinterpretq_s16_u16(vaddw_u8(vreinterpretq_u16_s16(g_sub_y), y));
#if RGB_PIXELSIZE == 4
uint8x8x4_t rgba;
/* Convert each component to unsigned and narrow, clamping to [0-255]. */
rgba.val[RGB_RED] = vqmovun_s16(r);
rgba.val[RGB_GREEN] = vqmovun_s16(g);
rgba.val[RGB_BLUE] = vqmovun_s16(b);
/* Set alpha channel to opaque (0xFF). */
rgba.val[RGB_ALPHA] = vdup_n_u8(0xFF);
/* Store RGBA pixel data to memory. */
switch (cols_remaining) {
case 7:
vst4_lane_u8(outptr + 6 * RGB_PIXELSIZE, rgba, 6);
FALLTHROUGH /*FALLTHROUGH*/
case 6:
vst4_lane_u8(outptr + 5 * RGB_PIXELSIZE, rgba, 5);
FALLTHROUGH /*FALLTHROUGH*/
case 5:
vst4_lane_u8(outptr + 4 * RGB_PIXELSIZE, rgba, 4);
FALLTHROUGH /*FALLTHROUGH*/
case 4:
vst4_lane_u8(outptr + 3 * RGB_PIXELSIZE, rgba, 3);
FALLTHROUGH /*FALLTHROUGH*/
case 3:
vst4_lane_u8(outptr + 2 * RGB_PIXELSIZE, rgba, 2);
FALLTHROUGH /*FALLTHROUGH*/
case 2:
vst4_lane_u8(outptr + RGB_PIXELSIZE, rgba, 1);
FALLTHROUGH /*FALLTHROUGH*/
case 1:
vst4_lane_u8(outptr, rgba, 0);
FALLTHROUGH /*FALLTHROUGH*/
default:
break;
}
#elif RGB_PIXELSIZE == 3
uint8x8x3_t rgb;
/* Convert each component to unsigned and narrow, clamping to [0-255]. */
rgb.val[RGB_RED] = vqmovun_s16(r);
rgb.val[RGB_GREEN] = vqmovun_s16(g);
rgb.val[RGB_BLUE] = vqmovun_s16(b);
/* Store RGB pixel data to memory. */
switch (cols_remaining) {
case 7:
vst3_lane_u8(outptr + 6 * RGB_PIXELSIZE, rgb, 6);
FALLTHROUGH /*FALLTHROUGH*/
case 6:
vst3_lane_u8(outptr + 5 * RGB_PIXELSIZE, rgb, 5);
FALLTHROUGH /*FALLTHROUGH*/
case 5:
vst3_lane_u8(outptr + 4 * RGB_PIXELSIZE, rgb, 4);
FALLTHROUGH /*FALLTHROUGH*/
case 4:
vst3_lane_u8(outptr + 3 * RGB_PIXELSIZE, rgb, 3);
FALLTHROUGH /*FALLTHROUGH*/
case 3:
vst3_lane_u8(outptr + 2 * RGB_PIXELSIZE, rgb, 2);
FALLTHROUGH /*FALLTHROUGH*/
case 2:
vst3_lane_u8(outptr + RGB_PIXELSIZE, rgb, 1);
FALLTHROUGH /*FALLTHROUGH*/
case 1:
vst3_lane_u8(outptr, rgb, 0);
FALLTHROUGH /*FALLTHROUGH*/
default:
break;
}
#else
/* Pack R, G, and B values in ratio 5:6:5. */
uint16x8_t rgb565 = vqshluq_n_s16(r, 8);
rgb565 = vsriq_n_u16(rgb565, vqshluq_n_s16(g, 8), 5);
rgb565 = vsriq_n_u16(rgb565, vqshluq_n_s16(b, 8), 11);
/* Store RGB565 pixel data to memory. */
switch (cols_remaining) {
case 7:
vst1q_lane_u16((uint16_t *)(outptr + 6 * RGB_PIXELSIZE), rgb565, 6);
FALLTHROUGH /*FALLTHROUGH*/
case 6:
vst1q_lane_u16((uint16_t *)(outptr + 5 * RGB_PIXELSIZE), rgb565, 5);
FALLTHROUGH /*FALLTHROUGH*/
case 5:
vst1q_lane_u16((uint16_t *)(outptr + 4 * RGB_PIXELSIZE), rgb565, 4);
FALLTHROUGH /*FALLTHROUGH*/
case 4:
vst1q_lane_u16((uint16_t *)(outptr + 3 * RGB_PIXELSIZE), rgb565, 3);
FALLTHROUGH /*FALLTHROUGH*/
case 3:
vst1q_lane_u16((uint16_t *)(outptr + 2 * RGB_PIXELSIZE), rgb565, 2);
FALLTHROUGH /*FALLTHROUGH*/
case 2:
vst1q_lane_u16((uint16_t *)(outptr + RGB_PIXELSIZE), rgb565, 1);
FALLTHROUGH /*FALLTHROUGH*/
case 1:
vst1q_lane_u16((uint16_t *)outptr, rgb565, 0);
FALLTHROUGH /*FALLTHROUGH*/
default:
break;
}
#endif
}
}
}
|
