FFmpeg: libavcodec/jpeglsdec.c Source File

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libavcodec

jpeglsdec.c

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1 /*

2 * JPEG-LS decoder

5 *

6 * This file is part of FFmpeg.

7 *

8 * FFmpeg is free software; you can redistribute it and/or

9 * modify it under the terms of the GNU Lesser General Public

10 * License as published by the Free Software Foundation; either

11 * version 2.1 of the License, or (at your option) any later version.

12 *

13 * FFmpeg is distributed in the hope that it will be useful,

14 * but WITHOUT ANY WARRANTY; without even the implied warranty of

15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU

16 * Lesser General Public License for more details.

17 *

18 * You should have received a copy of the GNU Lesser General Public

19 * License along with FFmpeg; if not, write to the Free Software

20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

21 */

23 /**

24 * @file

25 * JPEG-LS decoder.

26 */

28 #include "avcodec.h"

29 #include "get_bits.h"

30 #include "golomb.h"

31 #include "mathops.h"

32 #include "mjpeg.h"

33 #include "mjpegdec.h"

34 #include "jpegls.h"

35 #include "jpeglsdec.h"

37 /*

38 * Uncomment this to significantly speed up decoding of broken JPEG-LS

39 * (or test broken JPEG-LS decoder) and slow down ordinary decoding a bit.

40 *

41 * There is no Golomb code with length >= 32 bits possible, so check and

42 * avoid situation of 32 zeros, FFmpeg Golomb decoder is painfully slow

43 * on this errors.

44 */

45 //#define JLS_BROKEN

47 /**

48 * Decode LSE block with initialization parameters

49 */

50 int ff_jpegls_decode_lse(MJpegDecodeContext *s)

51 {

52 int id;

54 skip_bits(&s->gb, 16); /* length: FIXME: verify field validity */

55 id = get_bits(&s->gb, 8);

57 switch (id) {

58 case 1:

59 s->maxval = get_bits(&s->gb, 16);

60 s->t1 = get_bits(&s->gb, 16);

61 s->t2 = get_bits(&s->gb, 16);

62 s->t3 = get_bits(&s->gb, 16);

63 s->reset = get_bits(&s->gb, 16);

65 // ff_jpegls_reset_coding_parameters(s, 0);

66 //FIXME quant table?

67 break;

68 case 2:

69 case 3:

70 av_log(s->avctx, AV_LOG_ERROR, "palette not supported\n");

71 return AVERROR(ENOSYS);

72 case 4:

73 av_log(s->avctx, AV_LOG_ERROR, "oversize image not supported\n");

74 return AVERROR(ENOSYS);

75 default:

76 av_log(s->avctx, AV_LOG_ERROR, "invalid id %d\n", id);

77 return AVERROR_INVALIDDATA;

78 }

79 av_dlog(s->avctx, "ID=%i, T=%i,%i,%i\n", id, s->t1, s->t2, s->t3);

81 return 0;

82 }

84 /**

85 * Get context-dependent Golomb code, decode it and update context

86 */

87 static inline int ls_get_code_regular(GetBitContext *gb, JLSState *state, int Q)

88 {

89 int k, ret;

91 for (k = 0; (state->N[Q] << k) < state->A[Q]; k++)

92 ;

94 #ifdef JLS_BROKEN

95 if (!show_bits_long(gb, 32))

96 return -1;

97 #endif

98 ret = get_ur_golomb_jpegls(gb, k, state->limit, state->qbpp);

100 /* decode mapped error */

101 if (ret & 1)

102 ret = -(ret + 1 >> 1);

103 else

104 ret >>= 1;

105

106 /* for NEAR=0, k=0 and 2*B[Q] <= - N[Q] mapping is reversed */

107 if (!state->near && !k && (2 * state->B[Q] <= -state->N[Q]))

108 ret = -(ret + 1);

109

110 ret = ff_jpegls_update_state_regular(state, Q, ret);

111

112 return ret;

113 }

114

115 /**

116 * Get Golomb code, decode it and update state for run termination

117 */

118 static inline int ls_get_code_runterm(GetBitContext *gb, JLSState *state,

119 int RItype, int limit_add)

120 {

121 int k, ret, temp, map;

122 int Q = 365 + RItype;

123

124 temp = state->A[Q];

125 if (RItype)

126 temp += state->N[Q] >> 1;

127

128 for (k = 0; (state->N[Q] << k) < temp; k++)

129 ;

130

131 #ifdef JLS_BROKEN

132 if (!show_bits_long(gb, 32))

133 return -1;

134 #endif

135 ret = get_ur_golomb_jpegls(gb, k, state->limit - limit_add - 1,

136 state->qbpp);

137

138 /* decode mapped error */

139 map = 0;

140 if (!k && (RItype || ret) && (2 * state->B[Q] < state->N[Q]))

141 map = 1;

142 ret += RItype + map;

143

144 if (ret & 1) {

145 ret = map - (ret + 1 >> 1);

146 state->B[Q]++;

147 } else {

148 ret = ret >> 1;

149 }

150

151 /* update state */

152 state->A[Q] += FFABS(ret) - RItype;

153 ret *= state->twonear;

154 ff_jpegls_downscale_state(state, Q);

155

156 return ret;

157 }

158

159 /**

160 * Decode one line of image

161 */

162 static inline void ls_decode_line(JLSState *state, MJpegDecodeContext *s,

163 void *last, void *dst, int last2, int w,

164 int stride, int comp, int bits)

165 {

166 int i, x = 0;

167 int Ra, Rb, Rc, Rd;

168 int D0, D1, D2;

169

170 while (x < w) {

171 int err, pred;

172

173 /* compute gradients */

174 Ra = x ? R(dst, x - stride) : R(last, x);

175 Rb = R(last, x);

176 Rc = x ? R(last, x - stride) : last2;

177 Rd = (x >= w - stride) ? R(last, x) : R(last, x + stride);

178 D0 = Rd - Rb;

179 D1 = Rb - Rc;

180 D2 = Rc - Ra;

181 /* run mode */

182 if ((FFABS(D0) <= state->near) &&

183 (FFABS(D1) <= state->near) &&

184 (FFABS(D2) <= state->near)) {

185 int r;

186 int RItype;

187

188 /* decode full runs while available */

189 while (get_bits1(&s->gb)) {

190 int r;

191 r = 1 << ff_log2_run[state->run_index[comp]];

192 if (x + r * stride > w)

193 r = (w - x) / stride;

194 for (i = 0; i < r; i++) {

195 W(dst, x, Ra);

196 x += stride;

197 }

198 /* if EOL reached, we stop decoding */

199 if (r != 1 << ff_log2_run[state->run_index[comp]])

200 return;

201 if (state->run_index[comp] < 31)

202 state->run_index[comp]++;

203 if (x + stride > w)

204 return;

205 }

206 /* decode aborted run */

207 r = ff_log2_run[state->run_index[comp]];

208 if (r)

209 r = get_bits_long(&s->gb, r);

210 if (x + r * stride > w) {

211 r = (w - x) / stride;

212 }

213 for (i = 0; i < r; i++) {

214 W(dst, x, Ra);

215 x += stride;

216 }

217

218 /* decode run termination value */

219 Rb = R(last, x);

220 RItype = (FFABS(Ra - Rb) <= state->near) ? 1 : 0;

221 err = ls_get_code_runterm(&s->gb, state, RItype,

222 ff_log2_run[state->run_index[comp]]);

223 if (state->run_index[comp])

224 state->run_index[comp]--;

225

226 if (state->near && RItype) {

227 pred = Ra + err;

228 } else {

229 if (Rb < Ra)

230 pred = Rb - err;

231 else

232 pred = Rb + err;

233 }

234 } else { /* regular mode */

235 int context, sign;

236

237 context = ff_jpegls_quantize(state, D0) * 81 +

238 ff_jpegls_quantize(state, D1) * 9 +

239 ff_jpegls_quantize(state, D2);

240 pred = mid_pred(Ra, Ra + Rb - Rc, Rb);

241

242 if (context < 0) {

243 context = -context;

244 sign = 1;

245 } else {

246 sign = 0;

247 }

248

249 if (sign) {

250 pred = av_clip(pred - state->C[context], 0, state->maxval);

251 err = -ls_get_code_regular(&s->gb, state, context);

252 } else {

253 pred = av_clip(pred + state->C[context], 0, state->maxval);

254 err = ls_get_code_regular(&s->gb, state, context);

255 }

256

257 /* we have to do something more for near-lossless coding */

258 pred += err;

259 }

260 if (state->near) {

261 if (pred < -state->near)

262 pred += state->range * state->twonear;

263 else if (pred > state->maxval + state->near)

264 pred -= state->range * state->twonear;

265 pred = av_clip(pred, 0, state->maxval);

266 }

267

268 pred &= state->maxval;

269 W(dst, x, pred);

270 x += stride;

271 }

272 }

273

274 int ff_jpegls_decode_picture(MJpegDecodeContext *s, int near,

275 int point_transform, int ilv)

276 {

277 int i, t = 0;

278 uint8_t *zero, *last, *cur;

279 JLSState *state;

280 int off = 0, stride = 1, width, shift, ret = 0;

281

282 zero = av_mallocz(s->picture.linesize[0]);

283 last = zero;

284 cur = s->picture.data[0];

285

286 state = av_mallocz(sizeof(JLSState));

287 /* initialize JPEG-LS state from JPEG parameters */

288 state->near = near;

289 state->bpp = (s->bits < 2) ? 2 : s->bits;

290 state->maxval = s->maxval;

291 state->T1 = s->t1;

292 state->T2 = s->t2;

293 state->T3 = s->t3;

294 state->reset = s->reset;

295 ff_jpegls_reset_coding_parameters(state, 0);

296 ff_jpegls_init_state(state);

297

298 if (s->bits <= 8)

299 shift = point_transform + (8 - s->bits);

300 else

301 shift = point_transform + (16 - s->bits);

302

303 if (s->avctx->debug & FF_DEBUG_PICT_INFO) {

304 av_log(s->avctx, AV_LOG_DEBUG,

305 "JPEG-LS params: %ix%i NEAR=%i MV=%i T(%i,%i,%i) "

306 "RESET=%i, LIMIT=%i, qbpp=%i, RANGE=%i\n",

307 s->width, s->height, state->near, state->maxval,

308 state->T1, state->T2, state->T3,

309 state->reset, state->limit, state->qbpp, state->range);

310 av_log(s->avctx, AV_LOG_DEBUG, "JPEG params: ILV=%i Pt=%i BPP=%i, scan = %i\n",

311 ilv, point_transform, s->bits, s->cur_scan);

312 }

313 if (ilv == 0) { /* separate planes */

314 if (s->cur_scan > s->nb_components) {

315 ret = AVERROR_INVALIDDATA;

316 goto end;

317 }

318 stride = (s->nb_components > 1) ? 3 : 1;

319 off = av_clip(s->cur_scan - 1, 0, stride - 1);

320 width = s->width * stride;

321 cur += off;

322 for (i = 0; i < s->height; i++) {

323 if (s->bits <= 8) {

324 ls_decode_line(state, s, last, cur, t, width, stride, off, 8);

325 t = last[0];

326 } else {

327 ls_decode_line(state, s, last, cur, t, width, stride, off, 16);

328 t = *((uint16_t *)last);

329 }

330 last = cur;

331 cur += s->picture.linesize[0];

332

333 if (s->restart_interval && !--s->restart_count) {

334 align_get_bits(&s->gb);

335 skip_bits(&s->gb, 16); /* skip RSTn */

336 }

337 }

338 } else if (ilv == 1) { /* line interleaving */

339 int j;

340 int Rc[3] = { 0, 0, 0 };

341 stride = (s->nb_components > 1) ? 3 : 1;

342 memset(cur, 0, s->picture.linesize[0]);

343 width = s->width * stride;

344 for (i = 0; i < s->height; i++) {

345 for (j = 0; j < stride; j++) {

346 ls_decode_line(state, s, last + j, cur + j,

347 Rc[j], width, stride, j, 8);

348 Rc[j] = last[j];

349

350 if (s->restart_interval && !--s->restart_count) {

351 align_get_bits(&s->gb);

352 skip_bits(&s->gb, 16); /* skip RSTn */

353 }

354 }

355 last = cur;

356 cur += s->picture.linesize[0];

357 }

358 } else if (ilv == 2) { /* sample interleaving */

359 avpriv_report_missing_feature(s->avctx, "Sample interleaved images");

360 ret = AVERROR_PATCHWELCOME;

361 goto end;

362 }

363

364 if (shift) { /* we need to do point transform or normalize samples */

365 int x, w;

366

367 w = s->width * s->nb_components;

368

369 if (s->bits <= 8) {

370 uint8_t *src = s->picture.data[0];

371

372 for (i = 0; i < s->height; i++) {

373 for (x = off; x < w; x += stride)

374 src[x] <<= shift;

375 src += s->picture.linesize[0];

376 }

377 } else {

378 uint16_t *src = (uint16_t *)s->picture.data[0];

379

380 for (i = 0; i < s->height; i++) {

381 for (x = 0; x < w; x++)

382 src[x] <<= shift;

383 src += s->picture.linesize[0] / 2;

384 }

385 }

386 }

387

388 end:

389 av_free(state);

390 av_free(zero);

391

392 return ret;

393 }

394

395 AVCodec ff_jpegls_decoder = {

396 .name = "jpegls",

397 .long_name = NULL_IF_CONFIG_SMALL("JPEG-LS"),

398 .type = AVMEDIA_TYPE_VIDEO,

399 .id = AV_CODEC_ID_JPEGLS,

400 .priv_data_size = sizeof(MJpegDecodeContext),

401 .init = ff_mjpeg_decode_init,

402 .close = ff_mjpeg_decode_end,

403 .decode = ff_mjpeg_decode_frame,

404 .capabilities = CODEC_CAP_DR1,

405 };

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