FFmpeg: libavcodec/snowdec.c Source File

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libavcodec

snowdec.c

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1 /*

3 *

4 * This file is part of FFmpeg.

5 *

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

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

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

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

10 *

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

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

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

14 * Lesser General Public License for more details.

15 *

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

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

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

19 */

21 #include "libavutil/intmath.h"

22 #include "libavutil/log.h"

23 #include "libavutil/opt.h"

24 #include "avcodec.h"

25 #include "dsputil.h"

26 #include "dwt.h"

27 #include "internal.h"

28 #include "snow.h"

30 #include "rangecoder.h"

31 #include "mathops.h"

33 #include "mpegvideo.h"

34 #include "h263.h"

36 #undef NDEBUG

37 #include <assert.h>

39 static av_always_inline void predict_slice_buffered(SnowContext *s, slice_buffer * sb, IDWTELEM * old_buffer, int plane_index, int add, int mb_y){

40 Plane *p= &s->plane[plane_index];

41 const int mb_w= s->b_width << s->block_max_depth;

42 const int mb_h= s->b_height << s->block_max_depth;

43 int x, y, mb_x;

44 int block_size = MB_SIZE >> s->block_max_depth;

45 int block_w = plane_index ? block_size>>s->chroma_h_shift : block_size;

46 int block_h = plane_index ? block_size>>s->chroma_v_shift : block_size;

47 const uint8_t *obmc = plane_index ? ff_obmc_tab[s->block_max_depth+s->chroma_h_shift] : ff_obmc_tab[s->block_max_depth];

48 int obmc_stride= plane_index ? (2*block_size)>>s->chroma_h_shift : 2*block_size;

49 int ref_stride= s->current_picture.linesize[plane_index];

50 uint8_t *dst8= s->current_picture.data[plane_index];

51 int w= p->width;

52 int h= p->height;

54 if(s->keyframe || (s->avctx->debug&512)){

55 if(mb_y==mb_h)

56 return;

58 if(add){

59 for(y=block_h*mb_y; y<FFMIN(h,block_h*(mb_y+1)); y++){

60 // DWTELEM * line = slice_buffer_get_line(sb, y);

61 IDWTELEM * line = sb->line[y];

62 for(x=0; x<w; x++){

63 // int v= buf[x + y*w] + (128<<FRAC_BITS) + (1<<(FRAC_BITS-1));

64 int v= line[x] + (128<<FRAC_BITS) + (1<<(FRAC_BITS-1));

65 v >>= FRAC_BITS;

66 if(v&(~255)) v= ~(v>>31);

67 dst8[x + y*ref_stride]= v;

68 }

69 }

70 }else{

71 for(y=block_h*mb_y; y<FFMIN(h,block_h*(mb_y+1)); y++){

72 // DWTELEM * line = slice_buffer_get_line(sb, y);

73 IDWTELEM * line = sb->line[y];

74 for(x=0; x<w; x++){

75 line[x] -= 128 << FRAC_BITS;

76 // buf[x + y*w]-= 128<<FRAC_BITS;

77 }

78 }

79 }

81 return;

82 }

84 for(mb_x=0; mb_x<=mb_w; mb_x++){

85 add_yblock(s, 1, sb, old_buffer, dst8, obmc,

86 block_w*mb_x - block_w/2,

87 block_h*mb_y - block_h/2,

88 block_w, block_h,

89 w, h,

90 w, ref_stride, obmc_stride,

91 mb_x - 1, mb_y - 1,

92 add, 0, plane_index);

93 }

94 }

96 static inline void decode_subband_slice_buffered(SnowContext *s, SubBand *b, slice_buffer * sb, int start_y, int h, int save_state[1]){

97 const int w= b->width;

98 int y;

99 const int qlog= av_clip(s->qlog + b->qlog, 0, QROOT*16);

100 int qmul= ff_qexp[qlog&(QROOT-1)]<<(qlog>>QSHIFT);

101 int qadd= (s->qbias*qmul)>>QBIAS_SHIFT;

102 int new_index = 0;

103

104 if(b->ibuf == s->spatial_idwt_buffer || s->qlog == LOSSLESS_QLOG){

105 qadd= 0;

106 qmul= 1<<QEXPSHIFT;

107 }

108

109 /* If we are on the second or later slice, restore our index. */

110 if (start_y != 0)

111 new_index = save_state[0];

112

113

114 for(y=start_y; y<h; y++){

115 int x = 0;

116 int v;

117 IDWTELEM * line = slice_buffer_get_line(sb, y * b->stride_line + b->buf_y_offset) + b->buf_x_offset;

118 memset(line, 0, b->width*sizeof(IDWTELEM));

119 v = b->x_coeff[new_index].coeff;

120 x = b->x_coeff[new_index++].x;

121 while(x < w){

122 register int t= ( (v>>1)*qmul + qadd)>>QEXPSHIFT;

123 register int u= -(v&1);

124 line[x] = (t^u) - u;

125

126 v = b->x_coeff[new_index].coeff;

127 x = b->x_coeff[new_index++].x;

128 }

129 }

130

131 /* Save our variables for the next slice. */

132 save_state[0] = new_index;

133

134 return;

135 }

136

137 static int decode_q_branch(SnowContext *s, int level, int x, int y){

138 const int w= s->b_width << s->block_max_depth;

139 const int rem_depth= s->block_max_depth - level;

140 const int index= (x + y*w) << rem_depth;

141 int trx= (x+1)<<rem_depth;

142 const BlockNode *left = x ? &s->block[index-1] : &null_block;

143 const BlockNode *top = y ? &s->block[index-w] : &null_block;

144 const BlockNode *tl = y && x ? &s->block[index-w-1] : left;

145 const BlockNode *tr = y && trx<w && ((x&1)==0 || level==0) ? &s->block[index-w+(1<<rem_depth)] : tl; //FIXME use lt

146 int s_context= 2*left->level + 2*top->level + tl->level + tr->level;

147 int res;

148

149 if(s->keyframe){

150 set_blocks(s, level, x, y, null_block.color[0], null_block.color[1], null_block.color[2], null_block.mx, null_block.my, null_block.ref, BLOCK_INTRA);

151 return 0;

152 }

153

154 if(level==s->block_max_depth || get_rac(&s->c, &s->block_state[4 + s_context])){

155 int type, mx, my;

156 int l = left->color[0];

157 int cb= left->color[1];

158 int cr= left->color[2];

159 int ref = 0;

160 int ref_context= av_log2(2*left->ref) + av_log2(2*top->ref);

161 int mx_context= av_log2(2*FFABS(left->mx - top->mx)) + 0*av_log2(2*FFABS(tr->mx - top->mx));

162 int my_context= av_log2(2*FFABS(left->my - top->my)) + 0*av_log2(2*FFABS(tr->my - top->my));

163

164 type= get_rac(&s->c, &s->block_state[1 + left->type + top->type]) ? BLOCK_INTRA : 0;

165

166 if(type){

167 pred_mv(s, &mx, &my, 0, left, top, tr);

168 l += get_symbol(&s->c, &s->block_state[32], 1);

169 cb+= get_symbol(&s->c, &s->block_state[64], 1);

170 cr+= get_symbol(&s->c, &s->block_state[96], 1);

171 }else{

172 if(s->ref_frames > 1)

173 ref= get_symbol(&s->c, &s->block_state[128 + 1024 + 32*ref_context], 0);

174 if (ref >= s->ref_frames) {

175 av_log(s->avctx, AV_LOG_ERROR, "Invalid ref\n");

176 return AVERROR_INVALIDDATA;

177 }

178 pred_mv(s, &mx, &my, ref, left, top, tr);

179 mx+= get_symbol(&s->c, &s->block_state[128 + 32*(mx_context + 16*!!ref)], 1);

180 my+= get_symbol(&s->c, &s->block_state[128 + 32*(my_context + 16*!!ref)], 1);

181 }

182 set_blocks(s, level, x, y, l, cb, cr, mx, my, ref, type);

183 }else{

184 if ((res = decode_q_branch(s, level+1, 2*x+0, 2*y+0)) < 0 ||

185 (res = decode_q_branch(s, level+1, 2*x+1, 2*y+0)) < 0 ||

186 (res = decode_q_branch(s, level+1, 2*x+0, 2*y+1)) < 0 ||

187 (res = decode_q_branch(s, level+1, 2*x+1, 2*y+1)) < 0)

188 return res;

189 }

190 return 0;

191 }

192

193 static void dequantize_slice_buffered(SnowContext *s, slice_buffer * sb, SubBand *b, IDWTELEM *src, int stride, int start_y, int end_y){

194 const int w= b->width;

195 const int qlog= av_clip(s->qlog + b->qlog, 0, QROOT*16);

196 const int qmul= ff_qexp[qlog&(QROOT-1)]<<(qlog>>QSHIFT);

197 const int qadd= (s->qbias*qmul)>>QBIAS_SHIFT;

198 int x,y;

199

200 if(s->qlog == LOSSLESS_QLOG) return;

201

202 for(y=start_y; y<end_y; y++){

203 // DWTELEM * line = slice_buffer_get_line_from_address(sb, src + (y * stride));

204 IDWTELEM * line = slice_buffer_get_line(sb, (y * b->stride_line) + b->buf_y_offset) + b->buf_x_offset;

205 for(x=0; x<w; x++){

206 int i= line[x];

207 if(i<0){

208 line[x]= -((-i*qmul + qadd)>>(QEXPSHIFT)); //FIXME try different bias

209 }else if(i>0){

210 line[x]= (( i*qmul + qadd)>>(QEXPSHIFT));

211 }

212 }

213 }

214 }

215

216 static void correlate_slice_buffered(SnowContext *s, slice_buffer * sb, SubBand *b, IDWTELEM *src, int stride, int inverse, int use_median, int start_y, int end_y){

217 const int w= b->width;

218 int x,y;

219

220 IDWTELEM * line=0; // silence silly "could be used without having been initialized" warning

221 IDWTELEM * prev;

222

223 if (start_y != 0)

224 line = slice_buffer_get_line(sb, ((start_y - 1) * b->stride_line) + b->buf_y_offset) + b->buf_x_offset;

225

226 for(y=start_y; y<end_y; y++){

227 prev = line;

228 // line = slice_buffer_get_line_from_address(sb, src + (y * stride));

229 line = slice_buffer_get_line(sb, (y * b->stride_line) + b->buf_y_offset) + b->buf_x_offset;

230 for(x=0; x<w; x++){

231 if(x){

232 if(use_median){

233 if(y && x+1<w) line[x] += mid_pred(line[x - 1], prev[x], prev[x + 1]);

234 else line[x] += line[x - 1];

235 }else{

236 if(y) line[x] += mid_pred(line[x - 1], prev[x], line[x - 1] + prev[x] - prev[x - 1]);

237 else line[x] += line[x - 1];

238 }

239 }else{

240 if(y) line[x] += prev[x];

241 }

242 }

243 }

244 }

245

246 static void decode_qlogs(SnowContext *s){

247 int plane_index, level, orientation;

248

249 for(plane_index=0; plane_index<3; plane_index++){

250 for(level=0; level<s->spatial_decomposition_count; level++){

251 for(orientation=level ? 1:0; orientation<4; orientation++){

252 int q;

253 if (plane_index==2) q= s->plane[1].band[level][orientation].qlog;

254 else if(orientation==2) q= s->plane[plane_index].band[level][1].qlog;

255 else q= get_symbol(&s->c, s->header_state, 1);

256 s->plane[plane_index].band[level][orientation].qlog= q;

257 }

258 }

259 }

260 }

261

262 #define GET_S(dst, check) \

263 tmp= get_symbol(&s->c, s->header_state, 0);\

264 if(!(check)){\

265 av_log(s->avctx, AV_LOG_ERROR, "Error " #dst " is %d\n", tmp);\

266 return -1;\

267 }\

268 dst= tmp;

269

270 static int decode_header(SnowContext *s){

271 int plane_index, tmp;

272 uint8_t kstate[32];

273

274 memset(kstate, MID_STATE, sizeof(kstate));

275

276 s->keyframe= get_rac(&s->c, kstate);

277 if(s->keyframe || s->always_reset){

278 ff_snow_reset_contexts(s);

279 s->spatial_decomposition_type=

280 s->qlog=

281 s->qbias=

282 s->mv_scale=

283 s->block_max_depth= 0;

284 }

285 if(s->keyframe){

286 GET_S(s->version, tmp <= 0U)

287 s->always_reset= get_rac(&s->c, s->header_state);

288 s->temporal_decomposition_type= get_symbol(&s->c, s->header_state, 0);

289 s->temporal_decomposition_count= get_symbol(&s->c, s->header_state, 0);

290 GET_S(s->spatial_decomposition_count, 0 < tmp && tmp <= MAX_DECOMPOSITIONS)

291 s->colorspace_type= get_symbol(&s->c, s->header_state, 0);

292 s->chroma_h_shift= get_symbol(&s->c, s->header_state, 0);

293 s->chroma_v_shift= get_symbol(&s->c, s->header_state, 0);

294

295 if(s->chroma_h_shift == 1 && s->chroma_v_shift==1){

296 s->avctx->pix_fmt= AV_PIX_FMT_YUV420P;

297 }else if(s->chroma_h_shift == 0 && s->chroma_v_shift==0){

298 s->avctx->pix_fmt= AV_PIX_FMT_YUV444P;

299 }else if(s->chroma_h_shift == 2 && s->chroma_v_shift==2){

300 s->avctx->pix_fmt= AV_PIX_FMT_YUV410P;

301 } else {

302 av_log(s, AV_LOG_ERROR, "unsupported color subsample mode %d %d\n", s->chroma_h_shift, s->chroma_v_shift);

303 s->chroma_h_shift = s->chroma_v_shift = 1;

304 s->avctx->pix_fmt= AV_PIX_FMT_YUV420P;

305 return AVERROR_INVALIDDATA;

306 }

307

308 s->spatial_scalability= get_rac(&s->c, s->header_state);

309 // s->rate_scalability= get_rac(&s->c, s->header_state);

310 GET_S(s->max_ref_frames, tmp < (unsigned)MAX_REF_FRAMES)

311 s->max_ref_frames++;

312

313 decode_qlogs(s);

314 }

315

316 if(!s->keyframe){

317 if(get_rac(&s->c, s->header_state)){

318 for(plane_index=0; plane_index<2; plane_index++){

319 int htaps, i, sum=0;

320 Plane *p= &s->plane[plane_index];

321 p->diag_mc= get_rac(&s->c, s->header_state);

322 htaps= get_symbol(&s->c, s->header_state, 0)*2 + 2;

323 if((unsigned)htaps > HTAPS_MAX || htaps==0)

324 return -1;

325 p->htaps= htaps;

326 for(i= htaps/2; i; i--){

327 p->hcoeff[i]= get_symbol(&s->c, s->header_state, 0) * (1-2*(i&1));

328 sum += p->hcoeff[i];

329 }

330 p->hcoeff[0]= 32-sum;

331 }

332 s->plane[2].diag_mc= s->plane[1].diag_mc;

333 s->plane[2].htaps = s->plane[1].htaps;

334 memcpy(s->plane[2].hcoeff, s->plane[1].hcoeff, sizeof(s->plane[1].hcoeff));

335 }

336 if(get_rac(&s->c, s->header_state)){

337 GET_S(s->spatial_decomposition_count, 0 < tmp && tmp <= MAX_DECOMPOSITIONS)

338 decode_qlogs(s);

339 }

340 }

341

342 s->spatial_decomposition_type+= get_symbol(&s->c, s->header_state, 1);

343 if(s->spatial_decomposition_type > 1U){

344 av_log(s->avctx, AV_LOG_ERROR, "spatial_decomposition_type %d not supported\n", s->spatial_decomposition_type);

345 return -1;

346 }

347 if(FFMIN(s->avctx-> width>>s->chroma_h_shift,

348 s->avctx->height>>s->chroma_v_shift) >> (s->spatial_decomposition_count-1) <= 0){

349 av_log(s->avctx, AV_LOG_ERROR, "spatial_decomposition_count %d too large for size\n", s->spatial_decomposition_count);

350 return -1;

351 }

352

353

354 s->qlog += get_symbol(&s->c, s->header_state, 1);

355 s->mv_scale += get_symbol(&s->c, s->header_state, 1);

356 s->qbias += get_symbol(&s->c, s->header_state, 1);

357 s->block_max_depth+= get_symbol(&s->c, s->header_state, 1);

358 if(s->block_max_depth > 1 || s->block_max_depth < 0){

359 av_log(s->avctx, AV_LOG_ERROR, "block_max_depth= %d is too large\n", s->block_max_depth);

360 s->block_max_depth= 0;

361 return -1;

362 }

363

364 return 0;

365 }

366

367 static av_cold int decode_init(AVCodecContext *avctx)

368 {

369 int ret;

370

371 if ((ret = ff_snow_common_init(avctx)) < 0) {

372 ff_snow_common_end(avctx->priv_data);

373 return ret;

374 }

375

376 return 0;

377 }

378

379 static int decode_blocks(SnowContext *s){

380 int x, y;

381 int w= s->b_width;

382 int h= s->b_height;

383 int res;

384

385 for(y=0; y<h; y++){

386 for(x=0; x<w; x++){

387 if ((res = decode_q_branch(s, 0, x, y)) < 0)

388 return res;

389 }

390 }

391 return 0;

392 }

393

394 static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,

395 AVPacket *avpkt)

396 {

397 const uint8_t *buf = avpkt->data;

398 int buf_size = avpkt->size;

399 SnowContext *s = avctx->priv_data;

400 RangeCoder * const c= &s->c;

401 int bytes_read;

402 AVFrame *picture = data;

403 int level, orientation, plane_index;

404 int res;

405

406 ff_init_range_decoder(c, buf, buf_size);

407 ff_build_rac_states(c, 0.05*(1LL<<32), 256-8);

408

409 s->current_picture.pict_type= AV_PICTURE_TYPE_I; //FIXME I vs. P

410 if(decode_header(s)<0)

411 return -1;

412 if ((res=ff_snow_common_init_after_header(avctx)) < 0)

413 return res;

414

415 // realloc slice buffer for the case that spatial_decomposition_count changed

416 ff_slice_buffer_destroy(&s->sb);

417 if ((res = ff_slice_buffer_init(&s->sb, s->plane[0].height,

418 (MB_SIZE >> s->block_max_depth) +

419 s->spatial_decomposition_count * 11 + 1,

420 s->plane[0].width,

421 s->spatial_idwt_buffer)) < 0)

422 return res;

423

424 for(plane_index=0; plane_index<3; plane_index++){

425 Plane *p= &s->plane[plane_index];

426 p->fast_mc= p->diag_mc && p->htaps==6 && p->hcoeff[0]==40

427 && p->hcoeff[1]==-10

428 && p->hcoeff[2]==2;

429 }

430

431 ff_snow_alloc_blocks(s);

432

433 if(ff_snow_frame_start(s) < 0)

434 return -1;

435 //keyframe flag duplication mess FIXME

436 if(avctx->debug&FF_DEBUG_PICT_INFO)

437 av_log(avctx, AV_LOG_ERROR, "keyframe:%d qlog:%d\n", s->keyframe, s->qlog);

438

439 if ((res = decode_blocks(s)) < 0)

440 return res;

441

442 for(plane_index=0; plane_index<3; plane_index++){

443 Plane *p= &s->plane[plane_index];

444 int w= p->width;

445 int h= p->height;

446 int x, y;

447 int decode_state[MAX_DECOMPOSITIONS][4][1]; /* Stored state info for unpack_coeffs. 1 variable per instance. */

448

449 if(s->avctx->debug&2048){

450 memset(s->spatial_dwt_buffer, 0, sizeof(DWTELEM)*w*h);

451 predict_plane(s, s->spatial_idwt_buffer, plane_index, 1);

452

453 for(y=0; y<h; y++){

454 for(x=0; x<w; x++){

455 int v= s->current_picture.data[plane_index][y*s->current_picture.linesize[plane_index] + x];

456 s->mconly_picture.data[plane_index][y*s->mconly_picture.linesize[plane_index] + x]= v;

457 }

458 }

459 }

460

461 {

462 for(level=0; level<s->spatial_decomposition_count; level++){

463 for(orientation=level ? 1 : 0; orientation<4; orientation++){

464 SubBand *b= &p->band[level][orientation];

465 unpack_coeffs(s, b, b->parent, orientation);

466 }

467 }

468 }

469

470 {

471 const int mb_h= s->b_height << s->block_max_depth;

472 const int block_size = MB_SIZE >> s->block_max_depth;

473 const int block_h = plane_index ? block_size>>s->chroma_v_shift : block_size;

474 int mb_y;

475 DWTCompose cs[MAX_DECOMPOSITIONS];

476 int yd=0, yq=0;

477 int y;

478 int end_y;

479

480 ff_spatial_idwt_buffered_init(cs, &s->sb, w, h, 1, s->spatial_decomposition_type, s->spatial_decomposition_count);

481 for(mb_y=0; mb_y<=mb_h; mb_y++){

482

483 int slice_starty = block_h*mb_y;

484 int slice_h = block_h*(mb_y+1);

485

486 if (!(s->keyframe || s->avctx->debug&512)){

487 slice_starty = FFMAX(0, slice_starty - (block_h >> 1));

488 slice_h -= (block_h >> 1);

489 }

490

491 for(level=0; level<s->spatial_decomposition_count; level++){

492 for(orientation=level ? 1 : 0; orientation<4; orientation++){

493 SubBand *b= &p->band[level][orientation];

494 int start_y;

495 int end_y;

496 int our_mb_start = mb_y;

497 int our_mb_end = (mb_y + 1);

498 const int extra= 3;

499 start_y = (mb_y ? ((block_h * our_mb_start) >> (s->spatial_decomposition_count - level)) + s->spatial_decomposition_count - level + extra: 0);

500 end_y = (((block_h * our_mb_end) >> (s->spatial_decomposition_count - level)) + s->spatial_decomposition_count - level + extra);

501 if (!(s->keyframe || s->avctx->debug&512)){

502 start_y = FFMAX(0, start_y - (block_h >> (1+s->spatial_decomposition_count - level)));

503 end_y = FFMAX(0, end_y - (block_h >> (1+s->spatial_decomposition_count - level)));

504 }

505 start_y = FFMIN(b->height, start_y);

506 end_y = FFMIN(b->height, end_y);

507

508 if (start_y != end_y){

509 if (orientation == 0){

510 SubBand * correlate_band = &p->band[0][0];

511 int correlate_end_y = FFMIN(b->height, end_y + 1);

512 int correlate_start_y = FFMIN(b->height, (start_y ? start_y + 1 : 0));

513 decode_subband_slice_buffered(s, correlate_band, &s->sb, correlate_start_y, correlate_end_y, decode_state[0][0]);

514 correlate_slice_buffered(s, &s->sb, correlate_band, correlate_band->ibuf, correlate_band->stride, 1, 0, correlate_start_y, correlate_end_y);

515 dequantize_slice_buffered(s, &s->sb, correlate_band, correlate_band->ibuf, correlate_band->stride, start_y, end_y);

516 }

517 else

518 decode_subband_slice_buffered(s, b, &s->sb, start_y, end_y, decode_state[level][orientation]);

519 }

520 }

521 }

522

523 for(; yd<slice_h; yd+=4){

524 ff_spatial_idwt_buffered_slice(&s->dwt, cs, &s->sb, s->temp_idwt_buffer, w, h, 1, s->spatial_decomposition_type, s->spatial_decomposition_count, yd);

525 }

526

527 if(s->qlog == LOSSLESS_QLOG){

528 for(; yq<slice_h && yq<h; yq++){

529 IDWTELEM * line = slice_buffer_get_line(&s->sb, yq);

530 for(x=0; x<w; x++){

531 line[x] <<= FRAC_BITS;

532 }

533 }

534 }

535

536 predict_slice_buffered(s, &s->sb, s->spatial_idwt_buffer, plane_index, 1, mb_y);

537

538 y = FFMIN(p->height, slice_starty);

539 end_y = FFMIN(p->height, slice_h);

540 while(y < end_y)

541 ff_slice_buffer_release(&s->sb, y++);

542 }

543

544 ff_slice_buffer_flush(&s->sb);

545 }

546

547 }

548

549 emms_c();

550

551 ff_snow_release_buffer(avctx);

552

553 if(!(s->avctx->debug&2048))

554 *picture= s->current_picture;

555 else

556 *picture= s->mconly_picture;

557

558 *got_frame = 1;

559

560 bytes_read= c->bytestream - c->bytestream_start;

561 if(bytes_read ==0) av_log(s->avctx, AV_LOG_ERROR, "error at end of frame\n"); //FIXME

562

563 return bytes_read;

564 }

565

566 static av_cold int decode_end(AVCodecContext *avctx)

567 {

568 SnowContext *s = avctx->priv_data;

569

570 ff_slice_buffer_destroy(&s->sb);

571

572 ff_snow_common_end(s);

573

574 return 0;

575 }

576

577 AVCodec ff_snow_decoder = {

578 .name = "snow",

579 .type = AVMEDIA_TYPE_VIDEO,

580 .id = AV_CODEC_ID_SNOW,

581 .priv_data_size = sizeof(SnowContext),

582 .init = decode_init,

583 .close = decode_end,

584 .decode = decode_frame,

585 .capabilities = CODEC_CAP_DR1 /*| CODEC_CAP_DRAW_HORIZ_BAND*/,

586 .long_name = NULL_IF_CONFIG_SMALL("Snow"),

587 };

Generated on Sat May 25 2013 03:58:40 for FFmpeg by doxygen 1.8.2