1 /*
2 **
3 ** Copyright 2008, The Android Open Source Project
4 **
5 ** Licensed under the Apache License, Version 2.0 (the "License");
6 ** you may not use this file except in compliance with the License.
7 ** You may obtain a copy of the License at
8 **
9 ** http://www.apache.org/licenses/LICENSE-2.0
10 **
11 ** Unless required by applicable law or agreed to in writing, software
12 ** distributed under the License is distributed on an "AS IS" BASIS,
13 ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 ** See the License for the specific language governing permissions and
15 ** limitations under the License.
16 */
17
18 #define LOG_TAG "FakeCamera"
19 #include <utils/Log.h>
20
21 #include <string.h>
22 #include <stdlib.h>
23 #include <utils/String8.h>
24
25 #include "FakeCamera.h"
26
27
28 namespace android {
29
30 // TODO: All this rgb to yuv should probably be in a util class.
31
32 // TODO: I think something is wrong in this class because the shadow is kBlue
33 // and the square color should alternate between kRed and kGreen. However on the
34 // emulator screen these are all shades of gray. Y seems ok but the U and V are
35 // probably not.
36
37 static int tables_initialized = 0;
38 uint8_t *gYTable, *gCbTable, *gCrTable;
39
40 static int
clamp(int x)41 clamp(int x)
42 {
43 if (x > 255) return 255;
44 if (x < 0) return 0;
45 return x;
46 }
47
48 /* the equation used by the video code to translate YUV to RGB looks like this
49 *
50 * Y = (Y0 - 16)*k0
51 * Cb = Cb0 - 128
52 * Cr = Cr0 - 128
53 *
54 * G = ( Y - k1*Cr - k2*Cb )
55 * R = ( Y + k3*Cr )
56 * B = ( Y + k4*Cb )
57 *
58 */
59
60 static const double k0 = 1.164;
61 static const double k1 = 0.813;
62 static const double k2 = 0.391;
63 static const double k3 = 1.596;
64 static const double k4 = 2.018;
65
66 /* let's try to extract the value of Y
67 *
68 * G + k1/k3*R + k2/k4*B = Y*( 1 + k1/k3 + k2/k4 )
69 *
70 * Y = ( G + k1/k3*R + k2/k4*B ) / (1 + k1/k3 + k2/k4)
71 * Y0 = ( G0 + k1/k3*R0 + k2/k4*B0 ) / ((1 + k1/k3 + k2/k4)*k0) + 16
72 *
73 * let define:
74 * kYr = k1/k3
75 * kYb = k2/k4
76 * kYy = k0 * ( 1 + kYr + kYb )
77 *
78 * we have:
79 * Y = ( G + kYr*R + kYb*B )
80 * Y0 = clamp[ Y/kYy + 16 ]
81 */
82
83 static const double kYr = k1/k3;
84 static const double kYb = k2/k4;
85 static const double kYy = k0*( 1. + kYr + kYb );
86
87 static void
initYtab(void)88 initYtab( void )
89 {
90 const int imax = (int)( (kYr + kYb)*(31 << 2) + (61 << 3) + 0.1 );
91 int i;
92
93 gYTable = (uint8_t *)malloc(imax);
94
95 for(i=0; i<imax; i++) {
96 int x = (int)(i/kYy + 16.5);
97 if (x < 16) x = 16;
98 else if (x > 235) x = 235;
99 gYTable[i] = (uint8_t) x;
100 }
101 }
102
103 /*
104 * the source is RGB565, so adjust for 8-bit range of input values:
105 *
106 * G = (pixels >> 3) & 0xFC;
107 * R = (pixels >> 8) & 0xF8;
108 * B = (pixels & 0x1f) << 3;
109 *
110 * R2 = (pixels >> 11) R = R2*8
111 * B2 = (pixels & 0x1f) B = B2*8
112 *
113 * kYr*R = kYr2*R2 => kYr2 = kYr*8
114 * kYb*B = kYb2*B2 => kYb2 = kYb*8
115 *
116 * we want to use integer multiplications:
117 *
118 * SHIFT1 = 9
119 *
120 * (ALPHA*R2) >> SHIFT1 == R*kYr => ALPHA = kYr*8*(1 << SHIFT1)
121 *
122 * ALPHA = kYr*(1 << (SHIFT1+3))
123 * BETA = kYb*(1 << (SHIFT1+3))
124 */
125
126 static const int SHIFT1 = 9;
127 static const int ALPHA = (int)( kYr*(1 << (SHIFT1+3)) + 0.5 );
128 static const int BETA = (int)( kYb*(1 << (SHIFT1+3)) + 0.5 );
129
130 /*
131 * now let's try to get the values of Cb and Cr
132 *
133 * R-B = (k3*Cr - k4*Cb)
134 *
135 * k3*Cr = k4*Cb + (R-B)
136 * k4*Cb = k3*Cr - (R-B)
137 *
138 * R-G = (k1+k3)*Cr + k2*Cb
139 * = (k1+k3)*Cr + k2/k4*(k3*Cr - (R-B)/k0)
140 * = (k1 + k3 + k2*k3/k4)*Cr - k2/k4*(R-B)
141 *
142 * kRr*Cr = (R-G) + kYb*(R-B)
143 *
144 * Cr = ((R-G) + kYb*(R-B))/kRr
145 * Cr0 = clamp(Cr + 128)
146 */
147
148 static const double kRr = (k1 + k3 + k2*k3/k4);
149
150 static void
initCrtab(void)151 initCrtab( void )
152 {
153 uint8_t *pTable;
154 int i;
155
156 gCrTable = (uint8_t *)malloc(768*2);
157
158 pTable = gCrTable + 384;
159 for(i=-384; i<384; i++)
160 pTable[i] = (uint8_t) clamp( i/kRr + 128.5 );
161 }
162
163 /*
164 * B-G = (k2 + k4)*Cb + k1*Cr
165 * = (k2 + k4)*Cb + k1/k3*(k4*Cb + (R-B))
166 * = (k2 + k4 + k1*k4/k3)*Cb + k1/k3*(R-B)
167 *
168 * kBb*Cb = (B-G) - kYr*(R-B)
169 *
170 * Cb = ((B-G) - kYr*(R-B))/kBb
171 * Cb0 = clamp(Cb + 128)
172 *
173 */
174
175 static const double kBb = (k2 + k4 + k1*k4/k3);
176
177 static void
initCbtab(void)178 initCbtab( void )
179 {
180 uint8_t *pTable;
181 int i;
182
183 gCbTable = (uint8_t *)malloc(768*2);
184
185 pTable = gCbTable + 384;
186 for(i=-384; i<384; i++)
187 pTable[i] = (uint8_t) clamp( i/kBb + 128.5 );
188 }
189
190 /*
191 * SHIFT2 = 16
192 *
193 * DELTA = kYb*(1 << SHIFT2)
194 * GAMMA = kYr*(1 << SHIFT2)
195 */
196
197 static const int SHIFT2 = 16;
198 static const int DELTA = kYb*(1 << SHIFT2);
199 static const int GAMMA = kYr*(1 << SHIFT2);
200
ccrgb16toyuv_wo_colorkey(uint8_t * rgb16,uint8_t * yuv420,uint32_t * param,uint8_t * table[])201 int32_t ccrgb16toyuv_wo_colorkey(uint8_t *rgb16, uint8_t *yuv420,
202 uint32_t *param, uint8_t *table[])
203 {
204 uint16_t *inputRGB = (uint16_t*)rgb16;
205 uint8_t *outYUV = yuv420;
206 int32_t width_dst = param[0];
207 int32_t height_dst = param[1];
208 int32_t pitch_dst = param[2];
209 int32_t mheight_dst = param[3];
210 int32_t pitch_src = param[4];
211 uint8_t *y_tab = table[0];
212 uint8_t *cb_tab = table[1];
213 uint8_t *cr_tab = table[2];
214
215 int32_t size16 = pitch_dst*mheight_dst;
216 int32_t i,j,count;
217 int32_t ilimit,jlimit;
218 uint8_t *tempY,*tempU,*tempV;
219 uint16_t pixels;
220 int tmp;
221 uint32_t temp;
222
223 tempY = outYUV;
224 tempU = outYUV + (height_dst * pitch_dst);
225 tempV = tempU + 1;
226
227 jlimit = height_dst;
228 ilimit = width_dst;
229
230 for(j=0; j<jlimit; j+=1)
231 {
232 for (i=0; i<ilimit; i+=2)
233 {
234 int32_t G_ds = 0, B_ds = 0, R_ds = 0;
235 uint8_t y0, y1, u, v;
236
237 pixels = inputRGB[i];
238 temp = (BETA*(pixels & 0x001F) + ALPHA*(pixels>>11) );
239 y0 = y_tab[(temp>>SHIFT1) + ((pixels>>3) & 0x00FC)];
240
241 G_ds += (pixels>>1) & 0x03E0;
242 B_ds += (pixels<<5) & 0x03E0;
243 R_ds += (pixels>>6) & 0x03E0;
244
245 pixels = inputRGB[i+1];
246 temp = (BETA*(pixels & 0x001F) + ALPHA*(pixels>>11) );
247 y1 = y_tab[(temp>>SHIFT1) + ((pixels>>3) & 0x00FC)];
248
249 G_ds += (pixels>>1) & 0x03E0;
250 B_ds += (pixels<<5) & 0x03E0;
251 R_ds += (pixels>>6) & 0x03E0;
252
253 R_ds >>= 1;
254 B_ds >>= 1;
255 G_ds >>= 1;
256
257 tmp = R_ds - B_ds;
258
259 u = cb_tab[(((B_ds-G_ds)<<SHIFT2) - GAMMA*tmp)>>(SHIFT2+2)];
260 v = cr_tab[(((R_ds-G_ds)<<SHIFT2) + DELTA*tmp)>>(SHIFT2+2)];
261
262 tempY[0] = y0;
263 tempY[1] = y1;
264 tempY += 2;
265
266 if ((j&1) == 0) {
267 tempU[0] = u;
268 tempV[0] = v;
269 tempU += 2;
270 tempV += 2;
271 }
272 }
273
274 inputRGB += pitch_src;
275 }
276
277 return 1;
278 }
279
280 #define min(a,b) ((a)<(b)?(a):(b))
281 #define max(a,b) ((a)>(b)?(a):(b))
282
convert_rgb16_to_yuv420(uint8_t * rgb,uint8_t * yuv,int width,int height)283 static void convert_rgb16_to_yuv420(uint8_t *rgb, uint8_t *yuv, int width, int height)
284 {
285 if (!tables_initialized) {
286 initYtab();
287 initCrtab();
288 initCbtab();
289 tables_initialized = 1;
290 }
291
292 uint32_t param[6];
293 param[0] = (uint32_t) width;
294 param[1] = (uint32_t) height;
295 param[2] = (uint32_t) width;
296 param[3] = (uint32_t) height;
297 param[4] = (uint32_t) width;
298 param[5] = (uint32_t) 0;
299
300 uint8_t *table[3];
301 table[0] = gYTable;
302 table[1] = gCbTable + 384;
303 table[2] = gCrTable + 384;
304
305 ccrgb16toyuv_wo_colorkey(rgb, yuv, param, table);
306 }
307
308 const int FakeCamera::kRed;
309 const int FakeCamera::kGreen;
310 const int FakeCamera::kBlue;
311
FakeCamera(int width,int height)312 FakeCamera::FakeCamera(int width, int height)
313 : mTmpRgb16Buffer(0)
314 {
315 setSize(width, height);
316 }
317
~FakeCamera()318 FakeCamera::~FakeCamera()
319 {
320 delete[] mTmpRgb16Buffer;
321 }
322
setSize(int width,int height)323 void FakeCamera::setSize(int width, int height)
324 {
325 mWidth = width;
326 mHeight = height;
327 mCounter = 0;
328 mCheckX = 0;
329 mCheckY = 0;
330
331 // This will cause it to be reallocated on the next call
332 // to getNextFrameAsYuv420().
333 delete[] mTmpRgb16Buffer;
334 mTmpRgb16Buffer = 0;
335 }
336
getNextFrameAsRgb565(uint16_t * buffer)337 void FakeCamera::getNextFrameAsRgb565(uint16_t *buffer)
338 {
339 int size = mWidth / 10;
340
341 drawCheckerboard(buffer, size);
342
343 int x = ((mCounter*3)&255);
344 if(x>128) x = 255 - x;
345 int y = ((mCounter*5)&255);
346 if(y>128) y = 255 - y;
347
348 drawSquare(buffer, x*size/32, y*size/32, (size*5)>>1, (mCounter&0x100)?kRed:kGreen, kBlue);
349
350 mCounter++;
351 }
352
getNextFrameAsYuv420(uint8_t * buffer)353 void FakeCamera::getNextFrameAsYuv420(uint8_t *buffer)
354 {
355 if (mTmpRgb16Buffer == 0)
356 mTmpRgb16Buffer = new uint16_t[mWidth * mHeight];
357
358 getNextFrameAsRgb565(mTmpRgb16Buffer);
359 convert_rgb16_to_yuv420((uint8_t*)mTmpRgb16Buffer, buffer, mWidth, mHeight);
360 }
361
drawSquare(uint16_t * dst,int x,int y,int size,int color,int shadow)362 void FakeCamera::drawSquare(uint16_t *dst, int x, int y, int size, int color, int shadow)
363 {
364 int square_xstop, square_ystop, shadow_xstop, shadow_ystop;
365
366 square_xstop = min(mWidth, x+size);
367 square_ystop = min(mHeight, y+size);
368 shadow_xstop = min(mWidth, x+size+(size/4));
369 shadow_ystop = min(mHeight, y+size+(size/4));
370
371 // Do the shadow.
372 uint16_t *sh = &dst[(y+(size/4))*mWidth];
373 for (int j = y + (size/4); j < shadow_ystop; j++) {
374 for (int i = x + (size/4); i < shadow_xstop; i++) {
375 sh[i] &= shadow;
376 }
377 sh += mWidth;
378 }
379
380 // Draw the square.
381 uint16_t *sq = &dst[y*mWidth];
382 for (int j = y; j < square_ystop; j++) {
383 for (int i = x; i < square_xstop; i++) {
384 sq[i] = color;
385 }
386 sq += mWidth;
387 }
388 }
389
drawCheckerboard(uint16_t * dst,int size)390 void FakeCamera::drawCheckerboard(uint16_t *dst, int size)
391 {
392 bool black = true;
393
394 if((mCheckX/size)&1)
395 black = false;
396 if((mCheckY/size)&1)
397 black = !black;
398
399 int county = mCheckY%size;
400 int checkxremainder = mCheckX%size;
401
402 for(int y=0;y<mHeight;y++) {
403 int countx = checkxremainder;
404 bool current = black;
405 for(int x=0;x<mWidth;x++) {
406 dst[y*mWidth+x] = current?0:0xffff;
407 if(countx++ >= size) {
408 countx=0;
409 current = !current;
410 }
411 }
412 if(county++ >= size) {
413 county=0;
414 black = !black;
415 }
416 }
417 mCheckX += 3;
418 mCheckY++;
419 }
420
421
dump(int fd) const422 void FakeCamera::dump(int fd) const
423 {
424 const size_t SIZE = 256;
425 char buffer[SIZE];
426 String8 result;
427 snprintf(buffer, 255, " width x height (%d x %d), counter (%d), check x-y coordinate(%d, %d)\n", mWidth, mHeight, mCounter, mCheckX, mCheckY);
428 result.append(buffer);
429 ::write(fd, result.string(), result.size());
430 }
431
432
433 }; // namespace android
434