istereo2: f0da8b2b61ec libs/libjpeg/jdmerge.c

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view libs/libjpeg/jdmerge.c @ 27:f0da8b2b61ec

removed iOS cpu restriction and bumped build number to 3 implemented android JNI calls to show/hide ads (untested)

author	John Tsiombikas <nuclear@member.fsf.org>
date	Mon, 05 Oct 2015 17:15:02 +0300
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1 /*

2 * jdmerge.c

3 *

5 * This file is part of the Independent JPEG Group's software.

6 * For conditions of distribution and use, see the accompanying README file.

7 *

8 * This file contains code for merged upsampling/color conversion.

9 *

10 * This file combines functions from jdsample.c and jdcolor.c;

11 * read those files first to understand what's going on.

12 *

13 * When the chroma components are to be upsampled by simple replication

14 * (ie, box filtering), we can save some work in color conversion by

15 * calculating all the output pixels corresponding to a pair of chroma

16 * samples at one time. In the conversion equations

17 * R = Y + K1 * Cr

18 * G = Y + K2 * Cb + K3 * Cr

19 * B = Y + K4 * Cb

20 * only the Y term varies among the group of pixels corresponding to a pair

21 * of chroma samples, so the rest of the terms can be calculated just once.

22 * At typical sampling ratios, this eliminates half or three-quarters of the

23 * multiplications needed for color conversion.

24 *

25 * This file currently provides implementations for the following cases:

26 * YCbCr => RGB color conversion only.

27 * Sampling ratios of 2h1v or 2h2v.

28 * No scaling needed at upsample time.

29 * Corner-aligned (non-CCIR601) sampling alignment.

30 * Other special cases could be added, but in most applications these are

31 * the only common cases. (For uncommon cases we fall back on the more

32 * general code in jdsample.c and jdcolor.c.)

33 */

35 #define JPEG_INTERNALS

36 #include "jinclude.h"

37 #include "jpeglib.h"

39 #ifdef UPSAMPLE_MERGING_SUPPORTED

42 /* Private subobject */

44 typedef struct {

45 struct jpeg_upsampler pub; /* public fields */

47 /* Pointer to routine to do actual upsampling/conversion of one row group */

48 JMETHOD(void, upmethod, (j_decompress_ptr cinfo,

49 JSAMPIMAGE input_buf, JDIMENSION in_row_group_ctr,

50 JSAMPARRAY output_buf));

52 /* Private state for YCC->RGB conversion */

53 int * Cr_r_tab; /* => table for Cr to R conversion */

54 int * Cb_b_tab; /* => table for Cb to B conversion */

55 INT32 * Cr_g_tab; /* => table for Cr to G conversion */

56 INT32 * Cb_g_tab; /* => table for Cb to G conversion */

58 /* For 2:1 vertical sampling, we produce two output rows at a time.

59 * We need a "spare" row buffer to hold the second output row if the

60 * application provides just a one-row buffer; we also use the spare

61 * to discard the dummy last row if the image height is odd.

62 */

63 JSAMPROW spare_row;

64 boolean spare_full; /* T if spare buffer is occupied */

66 JDIMENSION out_row_width; /* samples per output row */

67 JDIMENSION rows_to_go; /* counts rows remaining in image */

68 } my_upsampler;

70 typedef my_upsampler * my_upsample_ptr;

72 #define SCALEBITS 16 /* speediest right-shift on some machines */

73 #define ONE_HALF ((INT32) 1 << (SCALEBITS-1))

74 #define FIX(x) ((INT32) ((x) * (1L<<SCALEBITS) + 0.5))

77 /*

78 * Initialize tables for YCC->RGB colorspace conversion.

79 * This is taken directly from jdcolor.c; see that file for more info.

80 */

82 LOCAL(void)

83 build_ycc_rgb_table (j_decompress_ptr cinfo)

84 {

85 my_upsample_ptr upsample = (my_upsample_ptr) cinfo->upsample;

86 int i;

87 INT32 x;

88 SHIFT_TEMPS

90 upsample->Cr_r_tab = (int *)

91 (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,

92 (MAXJSAMPLE+1) * SIZEOF(int));

93 upsample->Cb_b_tab = (int *)

94 (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,

95 (MAXJSAMPLE+1) * SIZEOF(int));

96 upsample->Cr_g_tab = (INT32 *)

97 (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,

98 (MAXJSAMPLE+1) * SIZEOF(INT32));

99 upsample->Cb_g_tab = (INT32 *)

100 (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,

101 (MAXJSAMPLE+1) * SIZEOF(INT32));

102

103 for (i = 0, x = -CENTERJSAMPLE; i <= MAXJSAMPLE; i++, x++) {

104 /* i is the actual input pixel value, in the range 0..MAXJSAMPLE */

105 /* The Cb or Cr value we are thinking of is x = i - CENTERJSAMPLE */

106 /* Cr=>R value is nearest int to 1.40200 * x */

107 upsample->Cr_r_tab[i] = (int)

108 RIGHT_SHIFT(FIX(1.40200) * x + ONE_HALF, SCALEBITS);

109 /* Cb=>B value is nearest int to 1.77200 * x */

110 upsample->Cb_b_tab[i] = (int)

111 RIGHT_SHIFT(FIX(1.77200) * x + ONE_HALF, SCALEBITS);

112 /* Cr=>G value is scaled-up -0.71414 * x */

113 upsample->Cr_g_tab[i] = (- FIX(0.71414)) * x;

114 /* Cb=>G value is scaled-up -0.34414 * x */

115 /* We also add in ONE_HALF so that need not do it in inner loop */

116 upsample->Cb_g_tab[i] = (- FIX(0.34414)) * x + ONE_HALF;

117 }

118 }

119

120

121 /*

122 * Initialize for an upsampling pass.

123 */

124

125 METHODDEF(void)

126 start_pass_merged_upsample (j_decompress_ptr cinfo)

127 {

128 my_upsample_ptr upsample = (my_upsample_ptr) cinfo->upsample;

129

130 /* Mark the spare buffer empty */

131 upsample->spare_full = FALSE;

132 /* Initialize total-height counter for detecting bottom of image */

133 upsample->rows_to_go = cinfo->output_height;

134 }

135

136

137 /*

138 * Control routine to do upsampling (and color conversion).

139 *

140 * The control routine just handles the row buffering considerations.

141 */

142

143 METHODDEF(void)

144 merged_2v_upsample (j_decompress_ptr cinfo,

145 JSAMPIMAGE input_buf, JDIMENSION *in_row_group_ctr,

146 JDIMENSION in_row_groups_avail,

147 JSAMPARRAY output_buf, JDIMENSION *out_row_ctr,

148 JDIMENSION out_rows_avail)

149 /* 2:1 vertical sampling case: may need a spare row. */

150 {

151 my_upsample_ptr upsample = (my_upsample_ptr) cinfo->upsample;

152 JSAMPROW work_ptrs[2];

153 JDIMENSION num_rows; /* number of rows returned to caller */

154

155 if (upsample->spare_full) {

156 /* If we have a spare row saved from a previous cycle, just return it. */

157 jcopy_sample_rows(& upsample->spare_row, 0, output_buf + *out_row_ctr, 0,

158 1, upsample->out_row_width);

159 num_rows = 1;

160 upsample->spare_full = FALSE;

161 } else {

162 /* Figure number of rows to return to caller. */

163 num_rows = 2;

164 /* Not more than the distance to the end of the image. */

165 if (num_rows > upsample->rows_to_go)

166 num_rows = upsample->rows_to_go;

167 /* And not more than what the client can accept: */

168 out_rows_avail -= *out_row_ctr;

169 if (num_rows > out_rows_avail)

170 num_rows = out_rows_avail;

171 /* Create output pointer array for upsampler. */

172 work_ptrs[0] = output_buf[*out_row_ctr];

173 if (num_rows > 1) {

174 work_ptrs[1] = output_buf[*out_row_ctr + 1];

175 } else {

176 work_ptrs[1] = upsample->spare_row;

177 upsample->spare_full = TRUE;

178 }

179 /* Now do the upsampling. */

180 (*upsample->upmethod) (cinfo, input_buf, *in_row_group_ctr, work_ptrs);

181 }

182

183 /* Adjust counts */

184 *out_row_ctr += num_rows;

185 upsample->rows_to_go -= num_rows;

186 /* When the buffer is emptied, declare this input row group consumed */

187 if (! upsample->spare_full)

188 (*in_row_group_ctr)++;

189 }

190

191

192 METHODDEF(void)

193 merged_1v_upsample (j_decompress_ptr cinfo,

194 JSAMPIMAGE input_buf, JDIMENSION *in_row_group_ctr,

195 JDIMENSION in_row_groups_avail,

196 JSAMPARRAY output_buf, JDIMENSION *out_row_ctr,

197 JDIMENSION out_rows_avail)

198 /* 1:1 vertical sampling case: much easier, never need a spare row. */

199 {

200 my_upsample_ptr upsample = (my_upsample_ptr) cinfo->upsample;

201

202 /* Just do the upsampling. */

203 (*upsample->upmethod) (cinfo, input_buf, *in_row_group_ctr,

204 output_buf + *out_row_ctr);

205 /* Adjust counts */

206 (*out_row_ctr)++;

207 (*in_row_group_ctr)++;

208 }

209

210

211 /*

212 * These are the routines invoked by the control routines to do

213 * the actual upsampling/conversion. One row group is processed per call.

214 *

215 * Note: since we may be writing directly into application-supplied buffers,

216 * we have to be honest about the output width; we can't assume the buffer

217 * has been rounded up to an even width.

218 */

219

220

221 /*

222 * Upsample and color convert for the case of 2:1 horizontal and 1:1 vertical.

223 */

224

225 METHODDEF(void)

226 h2v1_merged_upsample (j_decompress_ptr cinfo,

227 JSAMPIMAGE input_buf, JDIMENSION in_row_group_ctr,

228 JSAMPARRAY output_buf)

229 {

230 my_upsample_ptr upsample = (my_upsample_ptr) cinfo->upsample;

231 register int y, cred, cgreen, cblue;

232 int cb, cr;

233 register JSAMPROW outptr;

234 JSAMPROW inptr0, inptr1, inptr2;

235 JDIMENSION col;

236 /* copy these pointers into registers if possible */

237 register JSAMPLE * range_limit = cinfo->sample_range_limit;

238 int * Crrtab = upsample->Cr_r_tab;

239 int * Cbbtab = upsample->Cb_b_tab;

240 INT32 * Crgtab = upsample->Cr_g_tab;

241 INT32 * Cbgtab = upsample->Cb_g_tab;

242 SHIFT_TEMPS

243

244 inptr0 = input_buf[0][in_row_group_ctr];

245 inptr1 = input_buf[1][in_row_group_ctr];

246 inptr2 = input_buf[2][in_row_group_ctr];

247 outptr = output_buf[0];

248 /* Loop for each pair of output pixels */

249 for (col = cinfo->output_width >> 1; col > 0; col--) {

250 /* Do the chroma part of the calculation */

251 cb = GETJSAMPLE(*inptr1++);

252 cr = GETJSAMPLE(*inptr2++);

253 cred = Crrtab[cr];

254 cgreen = (int) RIGHT_SHIFT(Cbgtab[cb] + Crgtab[cr], SCALEBITS);

255 cblue = Cbbtab[cb];

256 /* Fetch 2 Y values and emit 2 pixels */

257 y = GETJSAMPLE(*inptr0++);

258 outptr[RGB_RED] = range_limit[y + cred];

259 outptr[RGB_GREEN] = range_limit[y + cgreen];

260 outptr[RGB_BLUE] = range_limit[y + cblue];

261 outptr += RGB_PIXELSIZE;

262 y = GETJSAMPLE(*inptr0++);

263 outptr[RGB_RED] = range_limit[y + cred];

264 outptr[RGB_GREEN] = range_limit[y + cgreen];

265 outptr[RGB_BLUE] = range_limit[y + cblue];

266 outptr += RGB_PIXELSIZE;

267 }

268 /* If image width is odd, do the last output column separately */

269 if (cinfo->output_width & 1) {

270 cb = GETJSAMPLE(*inptr1);

271 cr = GETJSAMPLE(*inptr2);

272 cred = Crrtab[cr];

273 cgreen = (int) RIGHT_SHIFT(Cbgtab[cb] + Crgtab[cr], SCALEBITS);

274 cblue = Cbbtab[cb];

275 y = GETJSAMPLE(*inptr0);

276 outptr[RGB_RED] = range_limit[y + cred];

277 outptr[RGB_GREEN] = range_limit[y + cgreen];

278 outptr[RGB_BLUE] = range_limit[y + cblue];

279 }

280 }

281

282

283 /*

284 * Upsample and color convert for the case of 2:1 horizontal and 2:1 vertical.

285 */

286

287 METHODDEF(void)

288 h2v2_merged_upsample (j_decompress_ptr cinfo,

289 JSAMPIMAGE input_buf, JDIMENSION in_row_group_ctr,

290 JSAMPARRAY output_buf)

291 {

292 my_upsample_ptr upsample = (my_upsample_ptr) cinfo->upsample;

293 register int y, cred, cgreen, cblue;

294 int cb, cr;

295 register JSAMPROW outptr0, outptr1;

296 JSAMPROW inptr00, inptr01, inptr1, inptr2;

297 JDIMENSION col;

298 /* copy these pointers into registers if possible */

299 register JSAMPLE * range_limit = cinfo->sample_range_limit;

300 int * Crrtab = upsample->Cr_r_tab;

301 int * Cbbtab = upsample->Cb_b_tab;

302 INT32 * Crgtab = upsample->Cr_g_tab;

303 INT32 * Cbgtab = upsample->Cb_g_tab;

304 SHIFT_TEMPS

305

306 inptr00 = input_buf[0][in_row_group_ctr*2];

307 inptr01 = input_buf[0][in_row_group_ctr*2 + 1];

308 inptr1 = input_buf[1][in_row_group_ctr];

309 inptr2 = input_buf[2][in_row_group_ctr];

310 outptr0 = output_buf[0];

311 outptr1 = output_buf[1];

312 /* Loop for each group of output pixels */

313 for (col = cinfo->output_width >> 1; col > 0; col--) {

314 /* Do the chroma part of the calculation */

315 cb = GETJSAMPLE(*inptr1++);

316 cr = GETJSAMPLE(*inptr2++);

317 cred = Crrtab[cr];

318 cgreen = (int) RIGHT_SHIFT(Cbgtab[cb] + Crgtab[cr], SCALEBITS);

319 cblue = Cbbtab[cb];

320 /* Fetch 4 Y values and emit 4 pixels */

321 y = GETJSAMPLE(*inptr00++);

322 outptr0[RGB_RED] = range_limit[y + cred];

323 outptr0[RGB_GREEN] = range_limit[y + cgreen];

324 outptr0[RGB_BLUE] = range_limit[y + cblue];

325 outptr0 += RGB_PIXELSIZE;

326 y = GETJSAMPLE(*inptr00++);

327 outptr0[RGB_RED] = range_limit[y + cred];

328 outptr0[RGB_GREEN] = range_limit[y + cgreen];

329 outptr0[RGB_BLUE] = range_limit[y + cblue];

330 outptr0 += RGB_PIXELSIZE;

331 y = GETJSAMPLE(*inptr01++);

332 outptr1[RGB_RED] = range_limit[y + cred];

333 outptr1[RGB_GREEN] = range_limit[y + cgreen];

334 outptr1[RGB_BLUE] = range_limit[y + cblue];

335 outptr1 += RGB_PIXELSIZE;

336 y = GETJSAMPLE(*inptr01++);

337 outptr1[RGB_RED] = range_limit[y + cred];

338 outptr1[RGB_GREEN] = range_limit[y + cgreen];

339 outptr1[RGB_BLUE] = range_limit[y + cblue];

340 outptr1 += RGB_PIXELSIZE;

341 }

342 /* If image width is odd, do the last output column separately */

343 if (cinfo->output_width & 1) {

344 cb = GETJSAMPLE(*inptr1);

345 cr = GETJSAMPLE(*inptr2);

346 cred = Crrtab[cr];

347 cgreen = (int) RIGHT_SHIFT(Cbgtab[cb] + Crgtab[cr], SCALEBITS);

348 cblue = Cbbtab[cb];

349 y = GETJSAMPLE(*inptr00);

350 outptr0[RGB_RED] = range_limit[y + cred];

351 outptr0[RGB_GREEN] = range_limit[y + cgreen];

352 outptr0[RGB_BLUE] = range_limit[y + cblue];

353 y = GETJSAMPLE(*inptr01);

354 outptr1[RGB_RED] = range_limit[y + cred];

355 outptr1[RGB_GREEN] = range_limit[y + cgreen];

356 outptr1[RGB_BLUE] = range_limit[y + cblue];

357 }

358 }

359

360

361 /*

362 * Module initialization routine for merged upsampling/color conversion.

363 *

364 * NB: this is called under the conditions determined by use_merged_upsample()

365 * in jdmaster.c. That routine MUST correspond to the actual capabilities

366 * of this module; no safety checks are made here.

367 */

368

369 GLOBAL(void)

370 jinit_merged_upsampler (j_decompress_ptr cinfo)

371 {

372 my_upsample_ptr upsample;

373

374 upsample = (my_upsample_ptr)

375 (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,

376 SIZEOF(my_upsampler));

377 cinfo->upsample = (struct jpeg_upsampler *) upsample;

378 upsample->pub.start_pass = start_pass_merged_upsample;

379 upsample->pub.need_context_rows = FALSE;

380

381 upsample->out_row_width = cinfo->output_width * cinfo->out_color_components;

382

383 if (cinfo->max_v_samp_factor == 2) {

384 upsample->pub.upsample = merged_2v_upsample;

385 upsample->upmethod = h2v2_merged_upsample;

386 /* Allocate a spare row buffer */

387 upsample->spare_row = (JSAMPROW)

388 (*cinfo->mem->alloc_large) ((j_common_ptr) cinfo, JPOOL_IMAGE,

389 (size_t) (upsample->out_row_width * SIZEOF(JSAMPLE)));

390 } else {

391 upsample->pub.upsample = merged_1v_upsample;

392 upsample->upmethod = h2v1_merged_upsample;

393 /* No spare row needed */

394 upsample->spare_row = NULL;

395 }

396

397 build_ycc_rgb_table(cinfo);

398 }

399

400 #endif /* UPSAMPLE_MERGING_SUPPORTED */