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1 /*
2  * DVB subtitle decoding
3  * Copyright (c) 2005 Ian Caulfield
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 #include "avcodec.h"
23 #include "get_bits.h"
24 #include "bytestream.h"
25 #include "internal.h"
26 #include "libavutil/colorspace.h"
27 #include "libavutil/imgutils.h"
28 #include "libavutil/opt.h"
29 
30 #define DVBSUB_PAGE_SEGMENT     0x10
31 #define DVBSUB_REGION_SEGMENT   0x11
32 #define DVBSUB_CLUT_SEGMENT     0x12
33 #define DVBSUB_OBJECT_SEGMENT   0x13
34 #define DVBSUB_DISPLAYDEFINITION_SEGMENT 0x14
35 #define DVBSUB_DISPLAY_SEGMENT  0x80
36 
37 #define cm (ff_crop_tab + MAX_NEG_CROP)
38 
39 #define RGBA(r,g,b,a) (((unsigned)(a) << 24) | ((r) << 16) | ((g) << 8) | (b))
40 
41 typedef struct DVBSubCLUT {
42     int id;
43     int version;
44 
45     uint32_t clut4[4];
46     uint32_t clut16[16];
47     uint32_t clut256[256];
48 
49     struct DVBSubCLUT *next;
50 } DVBSubCLUT;
51 
52 static DVBSubCLUT default_clut;
53 
54 typedef struct DVBSubObjectDisplay {
55     int object_id;
56     int region_id;
57 
58     int x_pos;
59     int y_pos;
60 
61     int fgcolor;
62     int bgcolor;
63 
64     struct DVBSubObjectDisplay *region_list_next;
65     struct DVBSubObjectDisplay *object_list_next;
66 } DVBSubObjectDisplay;
67 
68 typedef struct DVBSubObject {
69     int id;
70     int version;
71 
72     int type;
73 
74     DVBSubObjectDisplay *display_list;
75 
76     struct DVBSubObject *next;
77 } DVBSubObject;
78 
79 typedef struct DVBSubRegionDisplay {
80     int region_id;
81 
82     int x_pos;
83     int y_pos;
84 
85     struct DVBSubRegionDisplay *next;
86 } DVBSubRegionDisplay;
87 
88 typedef struct DVBSubRegion {
89     int id;
90     int version;
91 
92     int width;
93     int height;
94     int depth;
95 
96     int clut;
97     int bgcolor;
98 
99     uint8_t computed_clut[4*256];
100     int has_computed_clut;
101 
102     uint8_t *pbuf;
103     int buf_size;
104     int dirty;
105 
106     DVBSubObjectDisplay *display_list;
107 
108     struct DVBSubRegion *next;
109 } DVBSubRegion;
110 
111 typedef struct DVBSubDisplayDefinition {
112     int version;
113 
114     int x;
115     int y;
116     int width;
117     int height;
118 } DVBSubDisplayDefinition;
119 
120 typedef struct DVBSubContext {
121     AVClass *class;
122     int composition_id;
123     int ancillary_id;
124 
125     int version;
126     int time_out;
127     int compute_edt; /**< if 1 end display time calculated using pts
128                           if 0 (Default) calculated using time out */
129     int compute_clut;
130     int clut_count2[257][256];
131     int substream;
132     int64_t prev_start;
133     DVBSubRegion *region_list;
134     DVBSubCLUT   *clut_list;
135     DVBSubObject *object_list;
136 
137     DVBSubRegionDisplay *display_list;
138     DVBSubDisplayDefinition *display_definition;
139 } DVBSubContext;
140 
141 
get_object(DVBSubContext * ctx,int object_id)142 static DVBSubObject* get_object(DVBSubContext *ctx, int object_id)
143 {
144     DVBSubObject *ptr = ctx->object_list;
145 
146     while (ptr && ptr->id != object_id) {
147         ptr = ptr->next;
148     }
149 
150     return ptr;
151 }
152 
get_clut(DVBSubContext * ctx,int clut_id)153 static DVBSubCLUT* get_clut(DVBSubContext *ctx, int clut_id)
154 {
155     DVBSubCLUT *ptr = ctx->clut_list;
156 
157     while (ptr && ptr->id != clut_id) {
158         ptr = ptr->next;
159     }
160 
161     return ptr;
162 }
163 
get_region(DVBSubContext * ctx,int region_id)164 static DVBSubRegion* get_region(DVBSubContext *ctx, int region_id)
165 {
166     DVBSubRegion *ptr = ctx->region_list;
167 
168     while (ptr && ptr->id != region_id) {
169         ptr = ptr->next;
170     }
171 
172     return ptr;
173 }
174 
delete_region_display_list(DVBSubContext * ctx,DVBSubRegion * region)175 static void delete_region_display_list(DVBSubContext *ctx, DVBSubRegion *region)
176 {
177     DVBSubObject *object, *obj2, **obj2_ptr;
178     DVBSubObjectDisplay *display, *obj_disp, **obj_disp_ptr;
179 
180     while (region->display_list) {
181         display = region->display_list;
182 
183         object = get_object(ctx, display->object_id);
184 
185         if (object) {
186             obj_disp_ptr = &object->display_list;
187             obj_disp = *obj_disp_ptr;
188 
189             while (obj_disp && obj_disp != display) {
190                 obj_disp_ptr = &obj_disp->object_list_next;
191                 obj_disp = *obj_disp_ptr;
192             }
193 
194             if (obj_disp) {
195                 *obj_disp_ptr = obj_disp->object_list_next;
196 
197                 if (!object->display_list) {
198                     obj2_ptr = &ctx->object_list;
199                     obj2 = *obj2_ptr;
200 
201                     while (obj2 != object) {
202                         av_assert0(obj2);
203                         obj2_ptr = &obj2->next;
204                         obj2 = *obj2_ptr;
205                     }
206 
207                     *obj2_ptr = obj2->next;
208 
209                     av_freep(&obj2);
210                 }
211             }
212         }
213 
214         region->display_list = display->region_list_next;
215 
216         av_freep(&display);
217     }
218 
219 }
220 
delete_cluts(DVBSubContext * ctx)221 static void delete_cluts(DVBSubContext *ctx)
222 {
223     while (ctx->clut_list) {
224         DVBSubCLUT *clut = ctx->clut_list;
225 
226         ctx->clut_list = clut->next;
227 
228         av_freep(&clut);
229     }
230 }
231 
delete_objects(DVBSubContext * ctx)232 static void delete_objects(DVBSubContext *ctx)
233 {
234     while (ctx->object_list) {
235         DVBSubObject *object = ctx->object_list;
236 
237         ctx->object_list = object->next;
238 
239         av_freep(&object);
240     }
241 }
242 
delete_regions(DVBSubContext * ctx)243 static void delete_regions(DVBSubContext *ctx)
244 {
245     while (ctx->region_list) {
246         DVBSubRegion *region = ctx->region_list;
247 
248         ctx->region_list = region->next;
249 
250         delete_region_display_list(ctx, region);
251 
252         av_freep(&region->pbuf);
253         av_freep(&region);
254     }
255 }
256 
dvbsub_init_decoder(AVCodecContext * avctx)257 static av_cold int dvbsub_init_decoder(AVCodecContext *avctx)
258 {
259     int i, r, g, b, a = 0;
260     DVBSubContext *ctx = avctx->priv_data;
261 
262     if (ctx->substream < 0) {
263         ctx->composition_id = -1;
264         ctx->ancillary_id   = -1;
265     } else if (!avctx->extradata || (avctx->extradata_size < 4) || ((avctx->extradata_size % 5 != 0) && (avctx->extradata_size != 4))) {
266         av_log(avctx, AV_LOG_WARNING, "Invalid DVB subtitles stream extradata!\n");
267         ctx->composition_id = -1;
268         ctx->ancillary_id   = -1;
269     } else {
270         if (avctx->extradata_size > 5*ctx->substream + 2) {
271             ctx->composition_id = AV_RB16(avctx->extradata + 5*ctx->substream);
272             ctx->ancillary_id   = AV_RB16(avctx->extradata + 5*ctx->substream + 2);
273         } else {
274             av_log(avctx, AV_LOG_WARNING, "Selected DVB subtitles sub-stream %d is not available\n", ctx->substream);
275             ctx->composition_id = AV_RB16(avctx->extradata);
276             ctx->ancillary_id   = AV_RB16(avctx->extradata + 2);
277         }
278     }
279 
280     ctx->version = -1;
281     ctx->prev_start = AV_NOPTS_VALUE;
282 
283     default_clut.id = -1;
284     default_clut.next = NULL;
285 
286     default_clut.clut4[0] = RGBA(  0,   0,   0,   0);
287     default_clut.clut4[1] = RGBA(255, 255, 255, 255);
288     default_clut.clut4[2] = RGBA(  0,   0,   0, 255);
289     default_clut.clut4[3] = RGBA(127, 127, 127, 255);
290 
291     default_clut.clut16[0] = RGBA(  0,   0,   0,   0);
292     for (i = 1; i < 16; i++) {
293         if (i < 8) {
294             r = (i & 1) ? 255 : 0;
295             g = (i & 2) ? 255 : 0;
296             b = (i & 4) ? 255 : 0;
297         } else {
298             r = (i & 1) ? 127 : 0;
299             g = (i & 2) ? 127 : 0;
300             b = (i & 4) ? 127 : 0;
301         }
302         default_clut.clut16[i] = RGBA(r, g, b, 255);
303     }
304 
305     default_clut.clut256[0] = RGBA(  0,   0,   0,   0);
306     for (i = 1; i < 256; i++) {
307         if (i < 8) {
308             r = (i & 1) ? 255 : 0;
309             g = (i & 2) ? 255 : 0;
310             b = (i & 4) ? 255 : 0;
311             a = 63;
312         } else {
313             switch (i & 0x88) {
314             case 0x00:
315                 r = ((i & 1) ? 85 : 0) + ((i & 0x10) ? 170 : 0);
316                 g = ((i & 2) ? 85 : 0) + ((i & 0x20) ? 170 : 0);
317                 b = ((i & 4) ? 85 : 0) + ((i & 0x40) ? 170 : 0);
318                 a = 255;
319                 break;
320             case 0x08:
321                 r = ((i & 1) ? 85 : 0) + ((i & 0x10) ? 170 : 0);
322                 g = ((i & 2) ? 85 : 0) + ((i & 0x20) ? 170 : 0);
323                 b = ((i & 4) ? 85 : 0) + ((i & 0x40) ? 170 : 0);
324                 a = 127;
325                 break;
326             case 0x80:
327                 r = 127 + ((i & 1) ? 43 : 0) + ((i & 0x10) ? 85 : 0);
328                 g = 127 + ((i & 2) ? 43 : 0) + ((i & 0x20) ? 85 : 0);
329                 b = 127 + ((i & 4) ? 43 : 0) + ((i & 0x40) ? 85 : 0);
330                 a = 255;
331                 break;
332             case 0x88:
333                 r = ((i & 1) ? 43 : 0) + ((i & 0x10) ? 85 : 0);
334                 g = ((i & 2) ? 43 : 0) + ((i & 0x20) ? 85 : 0);
335                 b = ((i & 4) ? 43 : 0) + ((i & 0x40) ? 85 : 0);
336                 a = 255;
337                 break;
338             }
339         }
340         default_clut.clut256[i] = RGBA(r, g, b, a);
341     }
342 
343     return 0;
344 }
345 
dvbsub_close_decoder(AVCodecContext * avctx)346 static av_cold int dvbsub_close_decoder(AVCodecContext *avctx)
347 {
348     DVBSubContext *ctx = avctx->priv_data;
349     DVBSubRegionDisplay *display;
350 
351     delete_regions(ctx);
352 
353     delete_objects(ctx);
354 
355     delete_cluts(ctx);
356 
357     av_freep(&ctx->display_definition);
358 
359     while (ctx->display_list) {
360         display = ctx->display_list;
361         ctx->display_list = display->next;
362 
363         av_freep(&display);
364     }
365 
366     return 0;
367 }
368 
dvbsub_read_2bit_string(AVCodecContext * avctx,uint8_t * destbuf,int dbuf_len,const uint8_t ** srcbuf,int buf_size,int non_mod,uint8_t * map_table,int x_pos)369 static int dvbsub_read_2bit_string(AVCodecContext *avctx,
370                                    uint8_t *destbuf, int dbuf_len,
371                                    const uint8_t **srcbuf, int buf_size,
372                                    int non_mod, uint8_t *map_table, int x_pos)
373 {
374     GetBitContext gb;
375 
376     int bits;
377     int run_length;
378     int pixels_read = x_pos;
379 
380     init_get_bits(&gb, *srcbuf, buf_size << 3);
381 
382     destbuf += x_pos;
383 
384     while (get_bits_count(&gb) < buf_size << 3 && pixels_read < dbuf_len) {
385         bits = get_bits(&gb, 2);
386 
387         if (bits) {
388             if (non_mod != 1 || bits != 1) {
389                 if (map_table)
390                     *destbuf++ = map_table[bits];
391                 else
392                     *destbuf++ = bits;
393             }
394             pixels_read++;
395         } else {
396             bits = get_bits1(&gb);
397             if (bits == 1) {
398                 run_length = get_bits(&gb, 3) + 3;
399                 bits = get_bits(&gb, 2);
400 
401                 if (non_mod == 1 && bits == 1)
402                     pixels_read += run_length;
403                 else {
404                     if (map_table)
405                         bits = map_table[bits];
406                     while (run_length-- > 0 && pixels_read < dbuf_len) {
407                         *destbuf++ = bits;
408                         pixels_read++;
409                     }
410                 }
411             } else {
412                 bits = get_bits1(&gb);
413                 if (bits == 0) {
414                     bits = get_bits(&gb, 2);
415                     if (bits == 2) {
416                         run_length = get_bits(&gb, 4) + 12;
417                         bits = get_bits(&gb, 2);
418 
419                         if (non_mod == 1 && bits == 1)
420                             pixels_read += run_length;
421                         else {
422                             if (map_table)
423                                 bits = map_table[bits];
424                             while (run_length-- > 0 && pixels_read < dbuf_len) {
425                                 *destbuf++ = bits;
426                                 pixels_read++;
427                             }
428                         }
429                     } else if (bits == 3) {
430                         run_length = get_bits(&gb, 8) + 29;
431                         bits = get_bits(&gb, 2);
432 
433                         if (non_mod == 1 && bits == 1)
434                             pixels_read += run_length;
435                         else {
436                             if (map_table)
437                                 bits = map_table[bits];
438                             while (run_length-- > 0 && pixels_read < dbuf_len) {
439                                 *destbuf++ = bits;
440                                 pixels_read++;
441                             }
442                         }
443                     } else if (bits == 1) {
444                         if (map_table)
445                             bits = map_table[0];
446                         else
447                             bits = 0;
448                         run_length = 2;
449                         while (run_length-- > 0 && pixels_read < dbuf_len) {
450                             *destbuf++ = bits;
451                             pixels_read++;
452                         }
453                     } else {
454                         (*srcbuf) += (get_bits_count(&gb) + 7) >> 3;
455                         return pixels_read;
456                     }
457                 } else {
458                     if (map_table)
459                         bits = map_table[0];
460                     else
461                         bits = 0;
462                     *destbuf++ = bits;
463                     pixels_read++;
464                 }
465             }
466         }
467     }
468 
469     if (get_bits(&gb, 6))
470         av_log(avctx, AV_LOG_ERROR, "line overflow\n");
471 
472     (*srcbuf) += (get_bits_count(&gb) + 7) >> 3;
473 
474     return pixels_read;
475 }
476 
dvbsub_read_4bit_string(AVCodecContext * avctx,uint8_t * destbuf,int dbuf_len,const uint8_t ** srcbuf,int buf_size,int non_mod,uint8_t * map_table,int x_pos)477 static int dvbsub_read_4bit_string(AVCodecContext *avctx, uint8_t *destbuf, int dbuf_len,
478                                    const uint8_t **srcbuf, int buf_size,
479                                    int non_mod, uint8_t *map_table, int x_pos)
480 {
481     GetBitContext gb;
482 
483     int bits;
484     int run_length;
485     int pixels_read = x_pos;
486 
487     init_get_bits(&gb, *srcbuf, buf_size << 3);
488 
489     destbuf += x_pos;
490 
491     while (get_bits_count(&gb) < buf_size << 3 && pixels_read < dbuf_len) {
492         bits = get_bits(&gb, 4);
493 
494         if (bits) {
495             if (non_mod != 1 || bits != 1) {
496                 if (map_table)
497                     *destbuf++ = map_table[bits];
498                 else
499                     *destbuf++ = bits;
500             }
501             pixels_read++;
502         } else {
503             bits = get_bits1(&gb);
504             if (bits == 0) {
505                 run_length = get_bits(&gb, 3);
506 
507                 if (run_length == 0) {
508                     (*srcbuf) += (get_bits_count(&gb) + 7) >> 3;
509                     return pixels_read;
510                 }
511 
512                 run_length += 2;
513 
514                 if (map_table)
515                     bits = map_table[0];
516                 else
517                     bits = 0;
518 
519                 while (run_length-- > 0 && pixels_read < dbuf_len) {
520                     *destbuf++ = bits;
521                     pixels_read++;
522                 }
523             } else {
524                 bits = get_bits1(&gb);
525                 if (bits == 0) {
526                     run_length = get_bits(&gb, 2) + 4;
527                     bits = get_bits(&gb, 4);
528 
529                     if (non_mod == 1 && bits == 1)
530                         pixels_read += run_length;
531                     else {
532                         if (map_table)
533                             bits = map_table[bits];
534                         while (run_length-- > 0 && pixels_read < dbuf_len) {
535                             *destbuf++ = bits;
536                             pixels_read++;
537                         }
538                     }
539                 } else {
540                     bits = get_bits(&gb, 2);
541                     if (bits == 2) {
542                         run_length = get_bits(&gb, 4) + 9;
543                         bits = get_bits(&gb, 4);
544 
545                         if (non_mod == 1 && bits == 1)
546                             pixels_read += run_length;
547                         else {
548                             if (map_table)
549                                 bits = map_table[bits];
550                             while (run_length-- > 0 && pixels_read < dbuf_len) {
551                                 *destbuf++ = bits;
552                                 pixels_read++;
553                             }
554                         }
555                     } else if (bits == 3) {
556                         run_length = get_bits(&gb, 8) + 25;
557                         bits = get_bits(&gb, 4);
558 
559                         if (non_mod == 1 && bits == 1)
560                             pixels_read += run_length;
561                         else {
562                             if (map_table)
563                                 bits = map_table[bits];
564                             while (run_length-- > 0 && pixels_read < dbuf_len) {
565                                 *destbuf++ = bits;
566                                 pixels_read++;
567                             }
568                         }
569                     } else if (bits == 1) {
570                         if (map_table)
571                             bits = map_table[0];
572                         else
573                             bits = 0;
574                         run_length = 2;
575                         while (run_length-- > 0 && pixels_read < dbuf_len) {
576                             *destbuf++ = bits;
577                             pixels_read++;
578                         }
579                     } else {
580                         if (map_table)
581                             bits = map_table[0];
582                         else
583                             bits = 0;
584                         *destbuf++ = bits;
585                         pixels_read ++;
586                     }
587                 }
588             }
589         }
590     }
591 
592     if (get_bits(&gb, 8))
593         av_log(avctx, AV_LOG_ERROR, "line overflow\n");
594 
595     (*srcbuf) += (get_bits_count(&gb) + 7) >> 3;
596 
597     return pixels_read;
598 }
599 
dvbsub_read_8bit_string(AVCodecContext * avctx,uint8_t * destbuf,int dbuf_len,const uint8_t ** srcbuf,int buf_size,int non_mod,uint8_t * map_table,int x_pos)600 static int dvbsub_read_8bit_string(AVCodecContext *avctx,
601                                    uint8_t *destbuf, int dbuf_len,
602                                     const uint8_t **srcbuf, int buf_size,
603                                     int non_mod, uint8_t *map_table, int x_pos)
604 {
605     const uint8_t *sbuf_end = (*srcbuf) + buf_size;
606     int bits;
607     int run_length;
608     int pixels_read = x_pos;
609 
610     destbuf += x_pos;
611 
612     while (*srcbuf < sbuf_end && pixels_read < dbuf_len) {
613         bits = *(*srcbuf)++;
614 
615         if (bits) {
616             if (non_mod != 1 || bits != 1) {
617                 if (map_table)
618                     *destbuf++ = map_table[bits];
619                 else
620                     *destbuf++ = bits;
621             }
622             pixels_read++;
623         } else {
624             bits = *(*srcbuf)++;
625             run_length = bits & 0x7f;
626             if ((bits & 0x80) == 0) {
627                 if (run_length == 0) {
628                     return pixels_read;
629                 }
630 
631                 bits = 0;
632             } else {
633                 bits = *(*srcbuf)++;
634             }
635             if (non_mod == 1 && bits == 1)
636                 pixels_read += run_length;
637             else {
638                 if (map_table)
639                     bits = map_table[bits];
640                 while (run_length-- > 0 && pixels_read < dbuf_len) {
641                     *destbuf++ = bits;
642                     pixels_read++;
643                 }
644             }
645         }
646     }
647 
648     if (*(*srcbuf)++)
649         av_log(avctx, AV_LOG_ERROR, "line overflow\n");
650 
651     return pixels_read;
652 }
653 
compute_default_clut(DVBSubContext * ctx,uint8_t * clut,AVSubtitleRect * rect,int w,int h)654 static void compute_default_clut(DVBSubContext *ctx, uint8_t *clut, AVSubtitleRect *rect, int w, int h)
655 {
656     uint8_t list[256] = {0};
657     uint8_t list_inv[256];
658     int counttab[256] = {0};
659     int (*counttab2)[256] = ctx->clut_count2;
660     int count, i, x, y;
661     ptrdiff_t stride = rect->linesize[0];
662 
663     memset(ctx->clut_count2, 0 , sizeof(ctx->clut_count2));
664 
665 #define V(x,y) rect->data[0][(x) + (y)*stride]
666     for (y = 0; y<h; y++) {
667         for (x = 0; x<w; x++) {
668             int v = V(x,y) + 1;
669             int vl = x     ? V(x-1,y) + 1 : 0;
670             int vr = x+1<w ? V(x+1,y) + 1 : 0;
671             int vt = y     ? V(x,y-1) + 1 : 0;
672             int vb = y+1<h ? V(x,y+1) + 1 : 0;
673             counttab[v-1] += !!((v!=vl) + (v!=vr) + (v!=vt) + (v!=vb));
674             counttab2[vl][v-1] ++;
675             counttab2[vr][v-1] ++;
676             counttab2[vt][v-1] ++;
677             counttab2[vb][v-1] ++;
678         }
679     }
680 #define L(x,y) list[d[(x) + (y)*stride]]
681 
682     for (i = 0; i<256; i++) {
683         counttab2[i+1][i] = 0;
684     }
685     for (i = 0; i<256; i++) {
686         int bestscore = 0;
687         int bestv = 0;
688 
689         for (x = 0; x < 256; x++) {
690             int scorev = 0;
691             if (list[x])
692                 continue;
693             scorev += counttab2[0][x];
694             for (y = 0; y < 256; y++) {
695                 scorev += list[y] * counttab2[y+1][x];
696             }
697 
698             if (scorev) {
699                 int score = 1024LL*scorev / counttab[x];
700                 if (score > bestscore) {
701                     bestscore = score;
702                     bestv = x;
703                 }
704             }
705         }
706         if (!bestscore)
707             break;
708         list    [ bestv ] = 1;
709         list_inv[     i ] = bestv;
710     }
711 
712     count = FFMAX(i - 1, 1);
713     for (i--; i >= 0; i--) {
714         int v = i * 255 / count;
715         AV_WN32(clut + 4*list_inv[i], RGBA(v/2,v,v/2,v));
716     }
717 }
718 
719 
save_subtitle_set(AVCodecContext * avctx,AVSubtitle * sub,int * got_output)720 static int save_subtitle_set(AVCodecContext *avctx, AVSubtitle *sub, int *got_output)
721 {
722     DVBSubContext *ctx = avctx->priv_data;
723     DVBSubRegionDisplay *display;
724     DVBSubDisplayDefinition *display_def = ctx->display_definition;
725     DVBSubRegion *region;
726     AVSubtitleRect *rect;
727     DVBSubCLUT *clut;
728     uint32_t *clut_table;
729     int i;
730     int offset_x=0, offset_y=0;
731     int ret = 0;
732 
733 
734     if (display_def) {
735         offset_x = display_def->x;
736         offset_y = display_def->y;
737     }
738 
739     /* Not touching AVSubtitles again*/
740     if (sub->num_rects) {
741         avpriv_request_sample(ctx, "Different Version of Segment asked Twice");
742         return AVERROR_PATCHWELCOME;
743     }
744     for (display = ctx->display_list; display; display = display->next) {
745         region = get_region(ctx, display->region_id);
746         if (region && region->dirty)
747             sub->num_rects++;
748     }
749 
750     if (ctx->compute_edt == 0) {
751         sub->end_display_time = ctx->time_out * 1000;
752         *got_output = 1;
753     } else if (ctx->prev_start != AV_NOPTS_VALUE) {
754         sub->end_display_time = av_rescale_q((sub->pts - ctx->prev_start ), AV_TIME_BASE_Q, (AVRational){ 1, 1000 }) - 1;
755         *got_output = 1;
756     }
757     if (sub->num_rects > 0) {
758 
759         sub->rects = av_mallocz_array(sizeof(*sub->rects), sub->num_rects);
760         if (!sub->rects) {
761             ret = AVERROR(ENOMEM);
762             goto fail;
763         }
764 
765         for (i = 0; i < sub->num_rects; i++) {
766             sub->rects[i] = av_mallocz(sizeof(*sub->rects[i]));
767             if (!sub->rects[i]) {
768                 ret = AVERROR(ENOMEM);
769                 goto fail;
770             }
771         }
772 
773         i = 0;
774 
775         for (display = ctx->display_list; display; display = display->next) {
776             region = get_region(ctx, display->region_id);
777 
778             if (!region)
779                 continue;
780 
781             if (!region->dirty)
782                 continue;
783 
784             rect = sub->rects[i];
785             rect->x = display->x_pos + offset_x;
786             rect->y = display->y_pos + offset_y;
787             rect->w = region->width;
788             rect->h = region->height;
789             rect->nb_colors = (1 << region->depth);
790             rect->type      = SUBTITLE_BITMAP;
791             rect->linesize[0] = region->width;
792 
793             clut = get_clut(ctx, region->clut);
794 
795             if (!clut)
796                 clut = &default_clut;
797 
798             switch (region->depth) {
799             case 2:
800                 clut_table = clut->clut4;
801                 break;
802             case 8:
803                 clut_table = clut->clut256;
804                 break;
805             case 4:
806             default:
807                 clut_table = clut->clut16;
808                 break;
809             }
810 
811             rect->data[1] = av_mallocz(AVPALETTE_SIZE);
812             if (!rect->data[1]) {
813                 ret = AVERROR(ENOMEM);
814                 goto fail;
815             }
816             memcpy(rect->data[1], clut_table, (1 << region->depth) * sizeof(*clut_table));
817 
818             rect->data[0] = av_malloc(region->buf_size);
819             if (!rect->data[0]) {
820                 ret = AVERROR(ENOMEM);
821                 goto fail;
822             }
823 
824             memcpy(rect->data[0], region->pbuf, region->buf_size);
825 
826             if ((clut == &default_clut && ctx->compute_clut == -1) || ctx->compute_clut == 1) {
827                 if (!region->has_computed_clut) {
828                     compute_default_clut(ctx, region->computed_clut, rect, rect->w, rect->h);
829                     region->has_computed_clut = 1;
830                 }
831 
832                 memcpy(rect->data[1], region->computed_clut, sizeof(region->computed_clut));
833             }
834 
835 #if FF_API_AVPICTURE
836 FF_DISABLE_DEPRECATION_WARNINGS
837 {
838             int j;
839             for (j = 0; j < 4; j++) {
840                 rect->pict.data[j] = rect->data[j];
841                 rect->pict.linesize[j] = rect->linesize[j];
842             }
843 }
844 FF_ENABLE_DEPRECATION_WARNINGS
845 #endif
846 
847             i++;
848         }
849     }
850 
851     return 0;
852 fail:
853     if (sub->rects) {
854         for (i=0; i < sub->num_rects; i++) {
855             rect = sub->rects[i];
856             if (rect) {
857                 av_freep(&rect->data[0]);
858                 av_freep(&rect->data[1]);
859             }
860             av_freep(&sub->rects[i]);
861         }
862         av_freep(&sub->rects);
863     }
864     sub->num_rects = 0;
865     return ret;
866 }
867 
dvbsub_parse_pixel_data_block(AVCodecContext * avctx,DVBSubObjectDisplay * display,const uint8_t * buf,int buf_size,int top_bottom,int non_mod)868 static void dvbsub_parse_pixel_data_block(AVCodecContext *avctx, DVBSubObjectDisplay *display,
869                                           const uint8_t *buf, int buf_size, int top_bottom, int non_mod)
870 {
871     DVBSubContext *ctx = avctx->priv_data;
872 
873     DVBSubRegion *region = get_region(ctx, display->region_id);
874     const uint8_t *buf_end = buf + buf_size;
875     uint8_t *pbuf;
876     int x_pos, y_pos;
877     int i;
878 
879     uint8_t map2to4[] = { 0x0,  0x7,  0x8,  0xf};
880     uint8_t map2to8[] = {0x00, 0x77, 0x88, 0xff};
881     uint8_t map4to8[] = {0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77,
882                          0x88, 0x99, 0xaa, 0xbb, 0xcc, 0xdd, 0xee, 0xff};
883     uint8_t *map_table;
884 
885 #if 0
886     ff_dlog(avctx, "DVB pixel block size %d, %s field:\n", buf_size,
887             top_bottom ? "bottom" : "top");
888 
889     for (i = 0; i < buf_size; i++) {
890         if (i % 16 == 0)
891             ff_dlog(avctx, "0x%8p: ", buf+i);
892 
893         ff_dlog(avctx, "%02x ", buf[i]);
894         if (i % 16 == 15)
895             ff_dlog(avctx, "\n");
896     }
897 
898     if (i % 16)
899         ff_dlog(avctx, "\n");
900 #endif
901 
902     if (!region)
903         return;
904 
905     pbuf = region->pbuf;
906     region->dirty = 1;
907 
908     x_pos = display->x_pos;
909     y_pos = display->y_pos;
910 
911     y_pos += top_bottom;
912 
913     while (buf < buf_end) {
914         if ((*buf!=0xf0 && x_pos >= region->width) || y_pos >= region->height) {
915             av_log(avctx, AV_LOG_ERROR, "Invalid object location! %d-%d %d-%d %02x\n", x_pos, region->width, y_pos, region->height, *buf);
916             return;
917         }
918 
919         switch (*buf++) {
920         case 0x10:
921             if (region->depth == 8)
922                 map_table = map2to8;
923             else if (region->depth == 4)
924                 map_table = map2to4;
925             else
926                 map_table = NULL;
927 
928             x_pos = dvbsub_read_2bit_string(avctx, pbuf + (y_pos * region->width),
929                                             region->width, &buf, buf_end - buf,
930                                             non_mod, map_table, x_pos);
931             break;
932         case 0x11:
933             if (region->depth < 4) {
934                 av_log(avctx, AV_LOG_ERROR, "4-bit pixel string in %d-bit region!\n", region->depth);
935                 return;
936             }
937 
938             if (region->depth == 8)
939                 map_table = map4to8;
940             else
941                 map_table = NULL;
942 
943             x_pos = dvbsub_read_4bit_string(avctx, pbuf + (y_pos * region->width),
944                                             region->width, &buf, buf_end - buf,
945                                             non_mod, map_table, x_pos);
946             break;
947         case 0x12:
948             if (region->depth < 8) {
949                 av_log(avctx, AV_LOG_ERROR, "8-bit pixel string in %d-bit region!\n", region->depth);
950                 return;
951             }
952 
953             x_pos = dvbsub_read_8bit_string(avctx, pbuf + (y_pos * region->width),
954                                             region->width, &buf, buf_end - buf,
955                                             non_mod, NULL, x_pos);
956             break;
957 
958         case 0x20:
959             map2to4[0] = (*buf) >> 4;
960             map2to4[1] = (*buf++) & 0xf;
961             map2to4[2] = (*buf) >> 4;
962             map2to4[3] = (*buf++) & 0xf;
963             break;
964         case 0x21:
965             for (i = 0; i < 4; i++)
966                 map2to8[i] = *buf++;
967             break;
968         case 0x22:
969             for (i = 0; i < 16; i++)
970                 map4to8[i] = *buf++;
971             break;
972 
973         case 0xf0:
974             x_pos = display->x_pos;
975             y_pos += 2;
976             break;
977         default:
978             av_log(avctx, AV_LOG_INFO, "Unknown/unsupported pixel block 0x%x\n", *(buf-1));
979         }
980     }
981 
982     region->has_computed_clut = 0;
983 }
984 
dvbsub_parse_object_segment(AVCodecContext * avctx,const uint8_t * buf,int buf_size)985 static int dvbsub_parse_object_segment(AVCodecContext *avctx,
986                                        const uint8_t *buf, int buf_size)
987 {
988     DVBSubContext *ctx = avctx->priv_data;
989 
990     const uint8_t *buf_end = buf + buf_size;
991     int object_id;
992     DVBSubObject *object;
993     DVBSubObjectDisplay *display;
994     int top_field_len, bottom_field_len;
995 
996     int coding_method, non_modifying_color;
997 
998     object_id = AV_RB16(buf);
999     buf += 2;
1000 
1001     object = get_object(ctx, object_id);
1002 
1003     if (!object)
1004         return AVERROR_INVALIDDATA;
1005 
1006     coding_method = ((*buf) >> 2) & 3;
1007     non_modifying_color = ((*buf++) >> 1) & 1;
1008 
1009     if (coding_method == 0) {
1010         top_field_len = AV_RB16(buf);
1011         buf += 2;
1012         bottom_field_len = AV_RB16(buf);
1013         buf += 2;
1014 
1015         if (buf + top_field_len + bottom_field_len > buf_end) {
1016             av_log(avctx, AV_LOG_ERROR, "Field data size %d+%d too large\n", top_field_len, bottom_field_len);
1017             return AVERROR_INVALIDDATA;
1018         }
1019 
1020         for (display = object->display_list; display; display = display->object_list_next) {
1021             const uint8_t *block = buf;
1022             int bfl = bottom_field_len;
1023 
1024             dvbsub_parse_pixel_data_block(avctx, display, block, top_field_len, 0,
1025                                             non_modifying_color);
1026 
1027             if (bottom_field_len > 0)
1028                 block = buf + top_field_len;
1029             else
1030                 bfl = top_field_len;
1031 
1032             dvbsub_parse_pixel_data_block(avctx, display, block, bfl, 1,
1033                                             non_modifying_color);
1034         }
1035     } else if (coding_method == 1) {
1036         avpriv_report_missing_feature(avctx, "coded as a string of characters");
1037         return AVERROR_PATCHWELCOME;
1038     } else if (coding_method == 2) {
1039         avpriv_report_missing_feature(avctx, "progressive coding of pixels");
1040         return AVERROR_PATCHWELCOME;
1041     } else {
1042         av_log(avctx, AV_LOG_ERROR, "Unknown object coding %d\n", coding_method);
1043         return AVERROR_INVALIDDATA;
1044     }
1045 
1046     return 0;
1047 }
1048 
dvbsub_parse_clut_segment(AVCodecContext * avctx,const uint8_t * buf,int buf_size)1049 static int dvbsub_parse_clut_segment(AVCodecContext *avctx,
1050                                      const uint8_t *buf, int buf_size)
1051 {
1052     DVBSubContext *ctx = avctx->priv_data;
1053 
1054     const uint8_t *buf_end = buf + buf_size;
1055     int i, clut_id;
1056     int version;
1057     DVBSubCLUT *clut;
1058     int entry_id, depth , full_range;
1059     int y, cr, cb, alpha;
1060     int r, g, b, r_add, g_add, b_add;
1061 
1062     ff_dlog(avctx, "DVB clut packet:\n");
1063 
1064     for (i=0; i < buf_size; i++) {
1065         ff_dlog(avctx, "%02x ", buf[i]);
1066         if (i % 16 == 15)
1067             ff_dlog(avctx, "\n");
1068     }
1069 
1070     if (i % 16)
1071         ff_dlog(avctx, "\n");
1072 
1073     clut_id = *buf++;
1074     version = ((*buf)>>4)&15;
1075     buf += 1;
1076 
1077     clut = get_clut(ctx, clut_id);
1078 
1079     if (!clut) {
1080         clut = av_malloc(sizeof(*clut));
1081         if (!clut)
1082             return AVERROR(ENOMEM);
1083 
1084         memcpy(clut, &default_clut, sizeof(*clut));
1085 
1086         clut->id = clut_id;
1087         clut->version = -1;
1088 
1089         clut->next = ctx->clut_list;
1090         ctx->clut_list = clut;
1091     }
1092 
1093     if (clut->version != version) {
1094 
1095         clut->version = version;
1096 
1097         while (buf + 4 < buf_end) {
1098             entry_id = *buf++;
1099 
1100             depth = (*buf) & 0xe0;
1101 
1102             if (depth == 0) {
1103                 av_log(avctx, AV_LOG_ERROR, "Invalid clut depth 0x%x!\n", *buf);
1104             }
1105 
1106             full_range = (*buf++) & 1;
1107 
1108             if (full_range) {
1109                 y     = *buf++;
1110                 cr    = *buf++;
1111                 cb    = *buf++;
1112                 alpha = *buf++;
1113             } else {
1114                 y     = buf[0] & 0xfc;
1115                 cr    = (((buf[0] & 3) << 2) | ((buf[1] >> 6) & 3)) << 4;
1116                 cb    = (buf[1] << 2) & 0xf0;
1117                 alpha = (buf[1] << 6) & 0xc0;
1118 
1119                 buf += 2;
1120             }
1121 
1122             if (y == 0)
1123                 alpha = 0xff;
1124 
1125             YUV_TO_RGB1_CCIR(cb, cr);
1126             YUV_TO_RGB2_CCIR(r, g, b, y);
1127 
1128             ff_dlog(avctx, "clut %d := (%d,%d,%d,%d)\n", entry_id, r, g, b, alpha);
1129             if (!!(depth & 0x80) + !!(depth & 0x40) + !!(depth & 0x20) > 1) {
1130                 ff_dlog(avctx, "More than one bit level marked: %x\n", depth);
1131                 if (avctx->strict_std_compliance > FF_COMPLIANCE_NORMAL)
1132                     return AVERROR_INVALIDDATA;
1133             }
1134 
1135             if (depth & 0x80 && entry_id < 4)
1136                 clut->clut4[entry_id] = RGBA(r,g,b,255 - alpha);
1137             else if (depth & 0x40 && entry_id < 16)
1138                 clut->clut16[entry_id] = RGBA(r,g,b,255 - alpha);
1139             else if (depth & 0x20)
1140                 clut->clut256[entry_id] = RGBA(r,g,b,255 - alpha);
1141         }
1142     }
1143 
1144     return 0;
1145 }
1146 
1147 
dvbsub_parse_region_segment(AVCodecContext * avctx,const uint8_t * buf,int buf_size)1148 static int dvbsub_parse_region_segment(AVCodecContext *avctx,
1149                                        const uint8_t *buf, int buf_size)
1150 {
1151     DVBSubContext *ctx = avctx->priv_data;
1152 
1153     const uint8_t *buf_end = buf + buf_size;
1154     int region_id, object_id;
1155     int av_unused version;
1156     DVBSubRegion *region;
1157     DVBSubObject *object;
1158     DVBSubObjectDisplay *display;
1159     int fill;
1160     int ret;
1161 
1162     if (buf_size < 10)
1163         return AVERROR_INVALIDDATA;
1164 
1165     region_id = *buf++;
1166 
1167     region = get_region(ctx, region_id);
1168 
1169     if (!region) {
1170         region = av_mallocz(sizeof(*region));
1171         if (!region)
1172             return AVERROR(ENOMEM);
1173 
1174         region->id = region_id;
1175         region->version = -1;
1176 
1177         region->next = ctx->region_list;
1178         ctx->region_list = region;
1179     }
1180 
1181     version = ((*buf)>>4) & 15;
1182     fill = ((*buf++) >> 3) & 1;
1183 
1184     region->width = AV_RB16(buf);
1185     buf += 2;
1186     region->height = AV_RB16(buf);
1187     buf += 2;
1188 
1189     ret = av_image_check_size2(region->width, region->height, avctx->max_pixels, AV_PIX_FMT_PAL8, 0, avctx);
1190     if (ret >= 0 && region->width * region->height * 2 > 320 * 1024 * 8) {
1191         ret = AVERROR_INVALIDDATA;
1192         av_log(avctx, AV_LOG_ERROR, "Pixel buffer memory constraint violated\n");
1193     }
1194     if (ret < 0) {
1195         region->width= region->height= 0;
1196         return ret;
1197     }
1198 
1199     if (region->width * region->height != region->buf_size) {
1200         av_free(region->pbuf);
1201 
1202         region->buf_size = region->width * region->height;
1203 
1204         region->pbuf = av_malloc(region->buf_size);
1205         if (!region->pbuf) {
1206             region->buf_size =
1207             region->width =
1208             region->height = 0;
1209             return AVERROR(ENOMEM);
1210         }
1211 
1212         fill = 1;
1213         region->dirty = 0;
1214     }
1215 
1216     region->depth = 1 << (((*buf++) >> 2) & 7);
1217     if (region->depth < 2 || region->depth > 8) {
1218         av_log(avctx, AV_LOG_ERROR, "region depth %d is invalid\n", region->depth);
1219         region->depth= 4;
1220     }
1221     region->clut = *buf++;
1222 
1223     if (region->depth == 8) {
1224         region->bgcolor = *buf++;
1225         buf += 1;
1226     } else {
1227         buf += 1;
1228 
1229         if (region->depth == 4)
1230             region->bgcolor = (((*buf++) >> 4) & 15);
1231         else
1232             region->bgcolor = (((*buf++) >> 2) & 3);
1233     }
1234 
1235     ff_dlog(avctx, "Region %d, (%dx%d)\n", region_id, region->width, region->height);
1236 
1237     if (fill) {
1238         memset(region->pbuf, region->bgcolor, region->buf_size);
1239         ff_dlog(avctx, "Fill region (%d)\n", region->bgcolor);
1240     }
1241 
1242     delete_region_display_list(ctx, region);
1243 
1244     while (buf + 5 < buf_end) {
1245         object_id = AV_RB16(buf);
1246         buf += 2;
1247 
1248         object = get_object(ctx, object_id);
1249 
1250         if (!object) {
1251             object = av_mallocz(sizeof(*object));
1252             if (!object)
1253                 return AVERROR(ENOMEM);
1254 
1255             object->id = object_id;
1256             object->next = ctx->object_list;
1257             ctx->object_list = object;
1258         }
1259 
1260         object->type = (*buf) >> 6;
1261 
1262         display = av_mallocz(sizeof(*display));
1263         if (!display)
1264             return AVERROR(ENOMEM);
1265 
1266         display->object_id = object_id;
1267         display->region_id = region_id;
1268 
1269         display->x_pos = AV_RB16(buf) & 0xfff;
1270         buf += 2;
1271         display->y_pos = AV_RB16(buf) & 0xfff;
1272         buf += 2;
1273 
1274         if (display->x_pos >= region->width ||
1275             display->y_pos >= region->height) {
1276             av_log(avctx, AV_LOG_ERROR, "Object outside region\n");
1277             av_free(display);
1278             return AVERROR_INVALIDDATA;
1279         }
1280 
1281         if ((object->type == 1 || object->type == 2) && buf+1 < buf_end) {
1282             display->fgcolor = *buf++;
1283             display->bgcolor = *buf++;
1284         }
1285 
1286         display->region_list_next = region->display_list;
1287         region->display_list = display;
1288 
1289         display->object_list_next = object->display_list;
1290         object->display_list = display;
1291     }
1292 
1293     return 0;
1294 }
1295 
dvbsub_parse_page_segment(AVCodecContext * avctx,const uint8_t * buf,int buf_size,AVSubtitle * sub,int * got_output)1296 static int dvbsub_parse_page_segment(AVCodecContext *avctx,
1297                                      const uint8_t *buf, int buf_size, AVSubtitle *sub, int *got_output)
1298 {
1299     DVBSubContext *ctx = avctx->priv_data;
1300     DVBSubRegionDisplay *display;
1301     DVBSubRegionDisplay *tmp_display_list, **tmp_ptr;
1302 
1303     const uint8_t *buf_end = buf + buf_size;
1304     int region_id;
1305     int page_state;
1306     int timeout;
1307     int version;
1308 
1309     if (buf_size < 1)
1310         return AVERROR_INVALIDDATA;
1311 
1312     timeout = *buf++;
1313     version = ((*buf)>>4) & 15;
1314     page_state = ((*buf++) >> 2) & 3;
1315 
1316     if (ctx->version == version) {
1317         return 0;
1318     }
1319 
1320     ctx->time_out = timeout;
1321     ctx->version = version;
1322 
1323     ff_dlog(avctx, "Page time out %ds, state %d\n", ctx->time_out, page_state);
1324 
1325     if (ctx->compute_edt == 1)
1326         save_subtitle_set(avctx, sub, got_output);
1327 
1328     if (page_state == 1 || page_state == 2) {
1329         delete_regions(ctx);
1330         delete_objects(ctx);
1331         delete_cluts(ctx);
1332     }
1333 
1334     tmp_display_list = ctx->display_list;
1335     ctx->display_list = NULL;
1336 
1337     while (buf + 5 < buf_end) {
1338         region_id = *buf++;
1339         buf += 1;
1340 
1341         display = ctx->display_list;
1342         while (display && display->region_id != region_id) {
1343             display = display->next;
1344         }
1345         if (display) {
1346             av_log(avctx, AV_LOG_ERROR, "duplicate region\n");
1347             break;
1348         }
1349 
1350         display = tmp_display_list;
1351         tmp_ptr = &tmp_display_list;
1352 
1353         while (display && display->region_id != region_id) {
1354             tmp_ptr = &display->next;
1355             display = display->next;
1356         }
1357 
1358         if (!display) {
1359             display = av_mallocz(sizeof(*display));
1360             if (!display)
1361                 return AVERROR(ENOMEM);
1362         }
1363 
1364         display->region_id = region_id;
1365 
1366         display->x_pos = AV_RB16(buf);
1367         buf += 2;
1368         display->y_pos = AV_RB16(buf);
1369         buf += 2;
1370 
1371         *tmp_ptr = display->next;
1372 
1373         display->next = ctx->display_list;
1374         ctx->display_list = display;
1375 
1376         ff_dlog(avctx, "Region %d, (%d,%d)\n", region_id, display->x_pos, display->y_pos);
1377     }
1378 
1379     while (tmp_display_list) {
1380         display = tmp_display_list;
1381 
1382         tmp_display_list = display->next;
1383 
1384         av_freep(&display);
1385     }
1386 
1387     return 0;
1388 }
1389 
1390 
1391 #ifdef DEBUG
png_save(DVBSubContext * ctx,const char * filename,uint32_t * bitmap,int w,int h)1392 static void png_save(DVBSubContext *ctx, const char *filename, uint32_t *bitmap, int w, int h)
1393 {
1394     int x, y, v;
1395     FILE *f;
1396     char fname[40], fname2[40];
1397     char command[1024];
1398 
1399     snprintf(fname, sizeof(fname), "%s.ppm", filename);
1400 
1401     f = fopen(fname, "w");
1402     if (!f) {
1403         perror(fname);
1404         return;
1405     }
1406     fprintf(f, "P6\n"
1407             "%d %d\n"
1408             "%d\n",
1409             w, h, 255);
1410     for(y = 0; y < h; y++) {
1411         for(x = 0; x < w; x++) {
1412             v = bitmap[y * w + x];
1413             putc((v >> 16) & 0xff, f);
1414             putc((v >> 8) & 0xff, f);
1415             putc((v >> 0) & 0xff, f);
1416         }
1417     }
1418     fclose(f);
1419 
1420 
1421     snprintf(fname2, sizeof(fname2), "%s-a.pgm", filename);
1422 
1423     f = fopen(fname2, "w");
1424     if (!f) {
1425         perror(fname2);
1426         return;
1427     }
1428     fprintf(f, "P5\n"
1429             "%d %d\n"
1430             "%d\n",
1431             w, h, 255);
1432     for(y = 0; y < h; y++) {
1433         for(x = 0; x < w; x++) {
1434             v = bitmap[y * w + x];
1435             putc((v >> 24) & 0xff, f);
1436         }
1437     }
1438     fclose(f);
1439 
1440     snprintf(command, sizeof(command), "pnmtopng -alpha %s %s > %s.png 2> /dev/null", fname2, fname, filename);
1441     if (system(command) != 0) {
1442         av_log(ctx, AV_LOG_ERROR, "Error running pnmtopng\n");
1443         return;
1444     }
1445 
1446     snprintf(command, sizeof(command), "rm %s %s", fname, fname2);
1447     if (system(command) != 0) {
1448         av_log(ctx, AV_LOG_ERROR, "Error removing %s and %s\n", fname, fname2);
1449         return;
1450     }
1451 }
1452 
save_display_set(DVBSubContext * ctx)1453 static int save_display_set(DVBSubContext *ctx)
1454 {
1455     DVBSubRegion *region;
1456     DVBSubRegionDisplay *display;
1457     DVBSubCLUT *clut;
1458     uint32_t *clut_table;
1459     int x_pos, y_pos, width, height;
1460     int x, y, y_off, x_off;
1461     uint32_t *pbuf;
1462     char filename[32];
1463     static int fileno_index = 0;
1464 
1465     x_pos = -1;
1466     y_pos = -1;
1467     width = 0;
1468     height = 0;
1469 
1470     for (display = ctx->display_list; display; display = display->next) {
1471         region = get_region(ctx, display->region_id);
1472 
1473         if (!region)
1474             return -1;
1475 
1476         if (x_pos == -1) {
1477             x_pos = display->x_pos;
1478             y_pos = display->y_pos;
1479             width = region->width;
1480             height = region->height;
1481         } else {
1482             if (display->x_pos < x_pos) {
1483                 width += (x_pos - display->x_pos);
1484                 x_pos = display->x_pos;
1485             }
1486 
1487             if (display->y_pos < y_pos) {
1488                 height += (y_pos - display->y_pos);
1489                 y_pos = display->y_pos;
1490             }
1491 
1492             if (display->x_pos + region->width > x_pos + width) {
1493                 width = display->x_pos + region->width - x_pos;
1494             }
1495 
1496             if (display->y_pos + region->height > y_pos + height) {
1497                 height = display->y_pos + region->height - y_pos;
1498             }
1499         }
1500     }
1501 
1502     if (x_pos >= 0) {
1503 
1504         pbuf = av_malloc(width * height * 4);
1505         if (!pbuf)
1506             return -1;
1507 
1508         for (display = ctx->display_list; display; display = display->next) {
1509             region = get_region(ctx, display->region_id);
1510 
1511             if (!region)
1512                 return -1;
1513 
1514             x_off = display->x_pos - x_pos;
1515             y_off = display->y_pos - y_pos;
1516 
1517             clut = get_clut(ctx, region->clut);
1518 
1519             if (!clut)
1520                 clut = &default_clut;
1521 
1522             switch (region->depth) {
1523             case 2:
1524                 clut_table = clut->clut4;
1525                 break;
1526             case 8:
1527                 clut_table = clut->clut256;
1528                 break;
1529             case 4:
1530             default:
1531                 clut_table = clut->clut16;
1532                 break;
1533             }
1534 
1535             for (y = 0; y < region->height; y++) {
1536                 for (x = 0; x < region->width; x++) {
1537                     pbuf[((y + y_off) * width) + x_off + x] =
1538                         clut_table[region->pbuf[y * region->width + x]];
1539                 }
1540             }
1541 
1542         }
1543 
1544         snprintf(filename, sizeof(filename), "dvbs.%d", fileno_index);
1545 
1546         png_save(ctx, filename, pbuf, width, height);
1547 
1548         av_freep(&pbuf);
1549     }
1550 
1551     fileno_index++;
1552     return 0;
1553 }
1554 #endif /* DEBUG */
1555 
dvbsub_parse_display_definition_segment(AVCodecContext * avctx,const uint8_t * buf,int buf_size)1556 static int dvbsub_parse_display_definition_segment(AVCodecContext *avctx,
1557                                                    const uint8_t *buf,
1558                                                    int buf_size)
1559 {
1560     DVBSubContext *ctx = avctx->priv_data;
1561     DVBSubDisplayDefinition *display_def = ctx->display_definition;
1562     int dds_version, info_byte;
1563 
1564     if (buf_size < 5)
1565         return AVERROR_INVALIDDATA;
1566 
1567     info_byte   = bytestream_get_byte(&buf);
1568     dds_version = info_byte >> 4;
1569     if (display_def && display_def->version == dds_version)
1570         return 0; // already have this display definition version
1571 
1572     if (!display_def) {
1573         display_def             = av_mallocz(sizeof(*display_def));
1574         if (!display_def)
1575             return AVERROR(ENOMEM);
1576         ctx->display_definition = display_def;
1577     }
1578 
1579     display_def->version = dds_version;
1580     display_def->x       = 0;
1581     display_def->y       = 0;
1582     display_def->width   = bytestream_get_be16(&buf) + 1;
1583     display_def->height  = bytestream_get_be16(&buf) + 1;
1584     if (!avctx->width || !avctx->height) {
1585         int ret = ff_set_dimensions(avctx, display_def->width, display_def->height);
1586         if (ret < 0)
1587             return ret;
1588     }
1589 
1590     if (info_byte & 1<<3) { // display_window_flag
1591         if (buf_size < 13)
1592             return AVERROR_INVALIDDATA;
1593 
1594         display_def->x = bytestream_get_be16(&buf);
1595         display_def->width  = bytestream_get_be16(&buf) - display_def->x + 1;
1596         display_def->y = bytestream_get_be16(&buf);
1597         display_def->height = bytestream_get_be16(&buf) - display_def->y + 1;
1598     }
1599 
1600     return 0;
1601 }
1602 
dvbsub_display_end_segment(AVCodecContext * avctx,const uint8_t * buf,int buf_size,AVSubtitle * sub,int * got_output)1603 static int dvbsub_display_end_segment(AVCodecContext *avctx, const uint8_t *buf,
1604                                       int buf_size, AVSubtitle *sub,int *got_output)
1605 {
1606     DVBSubContext *ctx = avctx->priv_data;
1607 
1608     if (ctx->compute_edt == 0)
1609         save_subtitle_set(avctx, sub, got_output);
1610 #ifdef DEBUG
1611     save_display_set(ctx);
1612 #endif
1613     return 0;
1614 }
1615 
dvbsub_decode(AVCodecContext * avctx,void * data,int * got_sub_ptr,AVPacket * avpkt)1616 static int dvbsub_decode(AVCodecContext *avctx,
1617                          void *data, int *got_sub_ptr,
1618                          AVPacket *avpkt)
1619 {
1620     const uint8_t *buf = avpkt->data;
1621     int buf_size = avpkt->size;
1622     DVBSubContext *ctx = avctx->priv_data;
1623     AVSubtitle *sub = data;
1624     const uint8_t *p, *p_end;
1625     int segment_type;
1626     int page_id;
1627     int segment_length;
1628     int i;
1629     int ret = 0;
1630     int got_segment = 0;
1631     int got_dds = 0;
1632 
1633     ff_dlog(avctx, "DVB sub packet:\n");
1634 
1635     for (i=0; i < buf_size; i++) {
1636         ff_dlog(avctx, "%02x ", buf[i]);
1637         if (i % 16 == 15)
1638             ff_dlog(avctx, "\n");
1639     }
1640 
1641     if (i % 16)
1642         ff_dlog(avctx, "\n");
1643 
1644     if (buf_size <= 6 || *buf != 0x0f) {
1645         ff_dlog(avctx, "incomplete or broken packet");
1646         return AVERROR_INVALIDDATA;
1647     }
1648 
1649     p = buf;
1650     p_end = buf + buf_size;
1651 
1652     while (p_end - p >= 6 && *p == 0x0f) {
1653         p += 1;
1654         segment_type = *p++;
1655         page_id = AV_RB16(p);
1656         p += 2;
1657         segment_length = AV_RB16(p);
1658         p += 2;
1659 
1660         if (avctx->debug & FF_DEBUG_STARTCODE) {
1661             av_log(avctx, AV_LOG_DEBUG, "segment_type:%d page_id:%d segment_length:%d\n", segment_type, page_id, segment_length);
1662         }
1663 
1664         if (p_end - p < segment_length) {
1665             ff_dlog(avctx, "incomplete or broken packet");
1666             ret = -1;
1667             goto end;
1668         }
1669 
1670         if (page_id == ctx->composition_id || page_id == ctx->ancillary_id ||
1671             ctx->composition_id == -1 || ctx->ancillary_id == -1) {
1672             int ret = 0;
1673             switch (segment_type) {
1674             case DVBSUB_PAGE_SEGMENT:
1675                 ret = dvbsub_parse_page_segment(avctx, p, segment_length, sub, got_sub_ptr);
1676                 got_segment |= 1;
1677                 break;
1678             case DVBSUB_REGION_SEGMENT:
1679                 ret = dvbsub_parse_region_segment(avctx, p, segment_length);
1680                 got_segment |= 2;
1681                 break;
1682             case DVBSUB_CLUT_SEGMENT:
1683                 ret = dvbsub_parse_clut_segment(avctx, p, segment_length);
1684                 if (ret < 0) goto end;
1685                 got_segment |= 4;
1686                 break;
1687             case DVBSUB_OBJECT_SEGMENT:
1688                 ret = dvbsub_parse_object_segment(avctx, p, segment_length);
1689                 got_segment |= 8;
1690                 break;
1691             case DVBSUB_DISPLAYDEFINITION_SEGMENT:
1692                 ret = dvbsub_parse_display_definition_segment(avctx, p,
1693                                                               segment_length);
1694                 got_dds = 1;
1695                 break;
1696             case DVBSUB_DISPLAY_SEGMENT:
1697                 ret = dvbsub_display_end_segment(avctx, p, segment_length, sub, got_sub_ptr);
1698                 if (got_segment == 15 && !got_dds && !avctx->width && !avctx->height) {
1699                     // Default from ETSI EN 300 743 V1.3.1 (7.2.1)
1700                     avctx->width  = 720;
1701                     avctx->height = 576;
1702                 }
1703                 got_segment |= 16;
1704                 break;
1705             default:
1706                 ff_dlog(avctx, "Subtitling segment type 0x%x, page id %d, length %d\n",
1707                         segment_type, page_id, segment_length);
1708                 break;
1709             }
1710             if (ret < 0)
1711                 goto end;
1712         }
1713 
1714         p += segment_length;
1715     }
1716     // Some streams do not send a display segment but if we have all the other
1717     // segments then we need no further data.
1718     if (got_segment == 15) {
1719         av_log(avctx, AV_LOG_DEBUG, "Missing display_end_segment, emulating\n");
1720         dvbsub_display_end_segment(avctx, p, 0, sub, got_sub_ptr);
1721     }
1722 
1723 end:
1724     if (ret < 0) {
1725         *got_sub_ptr = 0;
1726         avsubtitle_free(sub);
1727         return ret;
1728     } else {
1729         if (ctx->compute_edt == 1)
1730             FFSWAP(int64_t, ctx->prev_start, sub->pts);
1731     }
1732 
1733     return p - buf;
1734 }
1735 
1736 #define DS AV_OPT_FLAG_DECODING_PARAM | AV_OPT_FLAG_SUBTITLE_PARAM
1737 #define OFFSET(x) offsetof(DVBSubContext, x)
1738 static const AVOption options[] = {
1739     {"compute_edt", "compute end of time using pts or timeout", OFFSET(compute_edt), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, DS},
1740     {"compute_clut", "compute clut when not available(-1) or always(1) or never(0)", OFFSET(compute_clut), AV_OPT_TYPE_BOOL, {.i64 = -1}, -1, 1, DS},
1741     {"dvb_substream", "", OFFSET(substream), AV_OPT_TYPE_INT, {.i64 = -1}, -1, 63, DS},
1742     {NULL}
1743 };
1744 static const AVClass dvbsubdec_class = {
1745     .class_name = "DVB Sub Decoder",
1746     .item_name  = av_default_item_name,
1747     .option     = options,
1748     .version    = LIBAVUTIL_VERSION_INT,
1749 };
1750 
1751 AVCodec ff_dvbsub_decoder = {
1752     .name           = "dvbsub",
1753     .long_name      = NULL_IF_CONFIG_SMALL("DVB subtitles"),
1754     .type           = AVMEDIA_TYPE_SUBTITLE,
1755     .id             = AV_CODEC_ID_DVB_SUBTITLE,
1756     .priv_data_size = sizeof(DVBSubContext),
1757     .init           = dvbsub_init_decoder,
1758     .close          = dvbsub_close_decoder,
1759     .decode         = dvbsub_decode,
1760     .priv_class     = &dvbsubdec_class,
1761 };
1762