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1 /*
2  * DVD subtitle decoding
3  * Copyright (c) 2005 Fabrice Bellard
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 "internal.h"
25 
26 #include "libavutil/attributes.h"
27 #include "libavutil/colorspace.h"
28 #include "libavutil/opt.h"
29 #include "libavutil/imgutils.h"
30 #include "libavutil/bswap.h"
31 
32 typedef struct DVDSubContext
33 {
34   AVClass *class;
35   uint32_t palette[16];
36   char    *palette_str;
37   char    *ifo_str;
38   int      has_palette;
39   uint8_t  colormap[4];
40   uint8_t  alpha[256];
41   uint8_t  buf[0x10000];
42   int      buf_size;
43   int      forced_subs_only;
44   uint8_t  used_color[256];
45 #ifdef DEBUG
46   int sub_id;
47 #endif
48 } DVDSubContext;
49 
yuv_a_to_rgba(const uint8_t * ycbcr,const uint8_t * alpha,uint32_t * rgba,int num_values)50 static void yuv_a_to_rgba(const uint8_t *ycbcr, const uint8_t *alpha, uint32_t *rgba, int num_values)
51 {
52     const uint8_t *cm = ff_crop_tab + MAX_NEG_CROP;
53     uint8_t r, g, b;
54     int i, y, cb, cr;
55     int r_add, g_add, b_add;
56 
57     for (i = num_values; i > 0; i--) {
58         y = *ycbcr++;
59         cr = *ycbcr++;
60         cb = *ycbcr++;
61         YUV_TO_RGB1_CCIR(cb, cr);
62         YUV_TO_RGB2_CCIR(r, g, b, y);
63         *rgba++ = ((unsigned)*alpha++ << 24) | (r << 16) | (g << 8) | b;
64     }
65 }
66 
decode_run_2bit(GetBitContext * gb,int * color)67 static int decode_run_2bit(GetBitContext *gb, int *color)
68 {
69     unsigned int v, t;
70 
71     v = 0;
72     for (t = 1; v < t && t <= 0x40; t <<= 2)
73         v = (v << 4) | get_bits(gb, 4);
74     *color = v & 3;
75     if (v < 4) { /* Code for fill rest of line */
76         return INT_MAX;
77     }
78     return v >> 2;
79 }
80 
decode_run_8bit(GetBitContext * gb,int * color)81 static int decode_run_8bit(GetBitContext *gb, int *color)
82 {
83     int len;
84     int has_run = get_bits1(gb);
85     *color = get_bits(gb, 2 + 6*get_bits1(gb));
86     if (has_run) {
87         if (get_bits1(gb)) {
88             len = get_bits(gb, 7);
89             if (len == 0)
90                 len = INT_MAX;
91             else
92                 len += 9;
93         } else
94             len = get_bits(gb, 3) + 2;
95     } else
96         len = 1;
97     return len;
98 }
99 
decode_rle(uint8_t * bitmap,int linesize,int w,int h,uint8_t used_color[256],const uint8_t * buf,int start,int buf_size,int is_8bit)100 static int decode_rle(uint8_t *bitmap, int linesize, int w, int h, uint8_t used_color[256],
101                       const uint8_t *buf, int start, int buf_size, int is_8bit)
102 {
103     GetBitContext gb;
104     int bit_len;
105     int x, y, len, color;
106     uint8_t *d;
107 
108     if (start >= buf_size)
109         return -1;
110 
111     if (w <= 0 || h <= 0)
112         return -1;
113 
114     bit_len = (buf_size - start) * 8;
115     init_get_bits(&gb, buf + start, bit_len);
116 
117     x = 0;
118     y = 0;
119     d = bitmap;
120     for(;;) {
121         if (get_bits_count(&gb) > bit_len)
122             return -1;
123         if (is_8bit)
124             len = decode_run_8bit(&gb, &color);
125         else
126             len = decode_run_2bit(&gb, &color);
127         if (len != INT_MAX && len > w - x)
128             return AVERROR_INVALIDDATA;
129         len = FFMIN(len, w - x);
130         memset(d + x, color, len);
131         used_color[color] = 1;
132         x += len;
133         if (x >= w) {
134             y++;
135             if (y >= h)
136                 break;
137             d += linesize;
138             x = 0;
139             /* byte align */
140             align_get_bits(&gb);
141         }
142     }
143     return 0;
144 }
145 
guess_palette(DVDSubContext * ctx,uint32_t * rgba_palette,uint32_t subtitle_color)146 static void guess_palette(DVDSubContext* ctx,
147                           uint32_t *rgba_palette,
148                           uint32_t subtitle_color)
149 {
150     static const uint8_t level_map[4][4] = {
151         // this configuration (full range, lowest to highest) in tests
152         // seemed most common, so assume this
153         {0xff},
154         {0x00, 0xff},
155         {0x00, 0x80, 0xff},
156         {0x00, 0x55, 0xaa, 0xff},
157     };
158     uint8_t color_used[16] = { 0 };
159     int nb_opaque_colors, i, level, j, r, g, b;
160     uint8_t *colormap = ctx->colormap, *alpha = ctx->alpha;
161 
162     if(ctx->has_palette) {
163         for(i = 0; i < 4; i++)
164             rgba_palette[i] = (ctx->palette[colormap[i]] & 0x00ffffff)
165                               | ((alpha[i] * 17U) << 24);
166         return;
167     }
168 
169     for(i = 0; i < 4; i++)
170         rgba_palette[i] = 0;
171 
172     nb_opaque_colors = 0;
173     for(i = 0; i < 4; i++) {
174         if (alpha[i] != 0 && !color_used[colormap[i]]) {
175             color_used[colormap[i]] = 1;
176             nb_opaque_colors++;
177         }
178     }
179 
180     if (nb_opaque_colors == 0)
181         return;
182 
183     j = 0;
184     memset(color_used, 0, 16);
185     for(i = 0; i < 4; i++) {
186         if (alpha[i] != 0) {
187             if (!color_used[colormap[i]])  {
188                 level = level_map[nb_opaque_colors - 1][j];
189                 r = (((subtitle_color >> 16) & 0xff) * level) >> 8;
190                 g = (((subtitle_color >> 8) & 0xff) * level) >> 8;
191                 b = (((subtitle_color >> 0) & 0xff) * level) >> 8;
192                 rgba_palette[i] = b | (g << 8) | (r << 16) | ((alpha[i] * 17U) << 24);
193                 color_used[colormap[i]] = (i + 1);
194                 j++;
195             } else {
196                 rgba_palette[i] = (rgba_palette[color_used[colormap[i]] - 1] & 0x00ffffff) |
197                                     ((alpha[i] * 17U) << 24);
198             }
199         }
200     }
201 }
202 
reset_rects(AVSubtitle * sub_header)203 static void reset_rects(AVSubtitle *sub_header)
204 {
205     int i;
206 
207     if (sub_header->rects) {
208         for (i = 0; i < sub_header->num_rects; i++) {
209             av_freep(&sub_header->rects[i]->data[0]);
210             av_freep(&sub_header->rects[i]->data[1]);
211             av_freep(&sub_header->rects[i]);
212         }
213         av_freep(&sub_header->rects);
214         sub_header->num_rects = 0;
215     }
216 }
217 
218 #define READ_OFFSET(a) (big_offsets ? AV_RB32(a) : AV_RB16(a))
219 
decode_dvd_subtitles(DVDSubContext * ctx,AVSubtitle * sub_header,const uint8_t * buf,int buf_size)220 static int decode_dvd_subtitles(DVDSubContext *ctx, AVSubtitle *sub_header,
221                                 const uint8_t *buf, int buf_size)
222 {
223     int cmd_pos, pos, cmd, x1, y1, x2, y2, next_cmd_pos;
224     int big_offsets, offset_size, is_8bit = 0;
225     const uint8_t *yuv_palette = NULL;
226     uint8_t *colormap = ctx->colormap, *alpha = ctx->alpha;
227     int date;
228     int i;
229     int is_menu = 0;
230     uint32_t size;
231     int64_t offset1, offset2;
232 
233     if (buf_size < 10)
234         return -1;
235 
236     if (AV_RB16(buf) == 0) {   /* HD subpicture with 4-byte offsets */
237         big_offsets = 1;
238         offset_size = 4;
239         cmd_pos = 6;
240     } else {
241         big_offsets = 0;
242         offset_size = 2;
243         cmd_pos = 2;
244     }
245 
246     size = READ_OFFSET(buf + (big_offsets ? 2 : 0));
247     cmd_pos = READ_OFFSET(buf + cmd_pos);
248 
249     if (cmd_pos < 0 || cmd_pos > buf_size - 2 - offset_size) {
250         if (cmd_pos > size) {
251             av_log(ctx, AV_LOG_ERROR, "Discarding invalid packet\n");
252             return 0;
253         }
254         return AVERROR(EAGAIN);
255     }
256 
257     while (cmd_pos > 0 && cmd_pos < buf_size - 2 - offset_size) {
258         date = AV_RB16(buf + cmd_pos);
259         next_cmd_pos = READ_OFFSET(buf + cmd_pos + 2);
260         ff_dlog(NULL, "cmd_pos=0x%04x next=0x%04x date=%d\n",
261                 cmd_pos, next_cmd_pos, date);
262         pos = cmd_pos + 2 + offset_size;
263         offset1 = -1;
264         offset2 = -1;
265         x1 = y1 = x2 = y2 = 0;
266         while (pos < buf_size) {
267             cmd = buf[pos++];
268             ff_dlog(NULL, "cmd=%02x\n", cmd);
269             switch(cmd) {
270             case 0x00:
271                 /* menu subpicture */
272                 is_menu = 1;
273                 break;
274             case 0x01:
275                 /* set start date */
276                 sub_header->start_display_time = (date << 10) / 90;
277                 break;
278             case 0x02:
279                 /* set end date */
280                 sub_header->end_display_time = (date << 10) / 90;
281                 break;
282             case 0x03:
283                 /* set colormap */
284                 if ((buf_size - pos) < 2)
285                     goto fail;
286                 colormap[3] = buf[pos] >> 4;
287                 colormap[2] = buf[pos] & 0x0f;
288                 colormap[1] = buf[pos + 1] >> 4;
289                 colormap[0] = buf[pos + 1] & 0x0f;
290                 pos += 2;
291                 break;
292             case 0x04:
293                 /* set alpha */
294                 if ((buf_size - pos) < 2)
295                     goto fail;
296                 alpha[3] = buf[pos] >> 4;
297                 alpha[2] = buf[pos] & 0x0f;
298                 alpha[1] = buf[pos + 1] >> 4;
299                 alpha[0] = buf[pos + 1] & 0x0f;
300                 pos += 2;
301                 ff_dlog(NULL, "alpha=%x%x%x%x\n", alpha[0],alpha[1],alpha[2],alpha[3]);
302                 break;
303             case 0x05:
304             case 0x85:
305                 if ((buf_size - pos) < 6)
306                     goto fail;
307                 x1 = (buf[pos] << 4) | (buf[pos + 1] >> 4);
308                 x2 = ((buf[pos + 1] & 0x0f) << 8) | buf[pos + 2];
309                 y1 = (buf[pos + 3] << 4) | (buf[pos + 4] >> 4);
310                 y2 = ((buf[pos + 4] & 0x0f) << 8) | buf[pos + 5];
311                 if (cmd & 0x80)
312                     is_8bit = 1;
313                 ff_dlog(NULL, "x1=%d x2=%d y1=%d y2=%d\n", x1, x2, y1, y2);
314                 pos += 6;
315                 break;
316             case 0x06:
317                 if ((buf_size - pos) < 4)
318                     goto fail;
319                 offset1 = AV_RB16(buf + pos);
320                 offset2 = AV_RB16(buf + pos + 2);
321                 ff_dlog(NULL, "offset1=0x%04"PRIx64" offset2=0x%04"PRIx64"\n", offset1, offset2);
322                 pos += 4;
323                 break;
324             case 0x86:
325                 if ((buf_size - pos) < 8)
326                     goto fail;
327                 offset1 = AV_RB32(buf + pos);
328                 offset2 = AV_RB32(buf + pos + 4);
329                 ff_dlog(NULL, "offset1=0x%04"PRIx64" offset2=0x%04"PRIx64"\n", offset1, offset2);
330                 pos += 8;
331                 break;
332 
333             case 0x83:
334                 /* HD set palette */
335                 if ((buf_size - pos) < 768)
336                     goto fail;
337                 yuv_palette = buf + pos;
338                 pos += 768;
339                 break;
340             case 0x84:
341                 /* HD set contrast (alpha) */
342                 if ((buf_size - pos) < 256)
343                     goto fail;
344                 for (i = 0; i < 256; i++)
345                     alpha[i] = 0xFF - buf[pos+i];
346                 pos += 256;
347                 break;
348 
349             case 0xff:
350                 goto the_end;
351             default:
352                 ff_dlog(NULL, "unrecognised subpicture command 0x%x\n", cmd);
353                 goto the_end;
354             }
355         }
356     the_end:
357         if (offset1 >= buf_size || offset2 >= buf_size)
358             goto fail;
359 
360         if (offset1 >= 0 && offset2 >= 0) {
361             int w, h;
362             uint8_t *bitmap;
363 
364             /* decode the bitmap */
365             w = x2 - x1 + 1;
366             if (w < 0)
367                 w = 0;
368             h = y2 - y1 + 1;
369             if (h < 0)
370                 h = 0;
371             if (w > 0 && h > 1) {
372                 reset_rects(sub_header);
373                 memset(ctx->used_color, 0, sizeof(ctx->used_color));
374                 sub_header->rects = av_mallocz(sizeof(*sub_header->rects));
375                 if (!sub_header->rects)
376                     goto fail;
377                 sub_header->rects[0] = av_mallocz(sizeof(AVSubtitleRect));
378                 if (!sub_header->rects[0])
379                     goto fail;
380                 sub_header->num_rects = 1;
381                 bitmap = sub_header->rects[0]->data[0] = av_malloc(w * h);
382                 if (!bitmap)
383                     goto fail;
384                 if (decode_rle(bitmap, w * 2, w, (h + 1) / 2, ctx->used_color,
385                                buf, offset1, buf_size, is_8bit) < 0)
386                     goto fail;
387                 if (decode_rle(bitmap + w, w * 2, w, h / 2, ctx->used_color,
388                                buf, offset2, buf_size, is_8bit) < 0)
389                     goto fail;
390                 sub_header->rects[0]->data[1] = av_mallocz(AVPALETTE_SIZE);
391                 if (!sub_header->rects[0]->data[1])
392                     goto fail;
393                 if (is_8bit) {
394                     if (!yuv_palette)
395                         goto fail;
396                     sub_header->rects[0]->nb_colors = 256;
397                     yuv_a_to_rgba(yuv_palette, alpha,
398                                   (uint32_t *)sub_header->rects[0]->data[1],
399                                   256);
400                 } else {
401                     sub_header->rects[0]->nb_colors = 4;
402                     guess_palette(ctx, (uint32_t*)sub_header->rects[0]->data[1],
403                                   0xffff00);
404                 }
405                 sub_header->rects[0]->x = x1;
406                 sub_header->rects[0]->y = y1;
407                 sub_header->rects[0]->w = w;
408                 sub_header->rects[0]->h = h;
409                 sub_header->rects[0]->type = SUBTITLE_BITMAP;
410                 sub_header->rects[0]->linesize[0] = w;
411                 sub_header->rects[0]->flags = is_menu ? AV_SUBTITLE_FLAG_FORCED : 0;
412 
413 #if FF_API_AVPICTURE
414 FF_DISABLE_DEPRECATION_WARNINGS
415                 for (i = 0; i < 4; i++) {
416                     sub_header->rects[0]->pict.data[i] = sub_header->rects[0]->data[i];
417                     sub_header->rects[0]->pict.linesize[i] = sub_header->rects[0]->linesize[i];
418                 }
419 FF_ENABLE_DEPRECATION_WARNINGS
420 #endif
421             }
422         }
423         if (next_cmd_pos < cmd_pos) {
424             av_log(ctx, AV_LOG_ERROR, "Invalid command offset\n");
425             break;
426         }
427         if (next_cmd_pos == cmd_pos)
428             break;
429         cmd_pos = next_cmd_pos;
430     }
431     if (sub_header->num_rects > 0)
432         return is_menu;
433  fail:
434     reset_rects(sub_header);
435     return -1;
436 }
437 
is_transp(const uint8_t * buf,int pitch,int n,const uint8_t * transp_color)438 static int is_transp(const uint8_t *buf, int pitch, int n,
439                      const uint8_t *transp_color)
440 {
441     int i;
442     for(i = 0; i < n; i++) {
443         if (!transp_color[*buf])
444             return 0;
445         buf += pitch;
446     }
447     return 1;
448 }
449 
450 /* return 0 if empty rectangle, 1 if non empty */
find_smallest_bounding_rectangle(DVDSubContext * ctx,AVSubtitle * s)451 static int find_smallest_bounding_rectangle(DVDSubContext *ctx, AVSubtitle *s)
452 {
453     uint8_t transp_color[256] = { 0 };
454     int y1, y2, x1, x2, y, w, h, i;
455     uint8_t *bitmap;
456     int transparent = 1;
457 
458     if (s->num_rects == 0 || !s->rects || s->rects[0]->w <= 0 || s->rects[0]->h <= 0)
459         return 0;
460 
461     for(i = 0; i < s->rects[0]->nb_colors; i++) {
462         if ((((uint32_t *)s->rects[0]->data[1])[i] >> 24) == 0) {
463             transp_color[i] = 1;
464         } else if (ctx->used_color[i])
465             transparent = 0;
466     }
467     if (transparent)
468         return 0;
469     y1 = 0;
470     while (y1 < s->rects[0]->h && is_transp(s->rects[0]->data[0] + y1 * s->rects[0]->linesize[0],
471                                   1, s->rects[0]->w, transp_color))
472         y1++;
473     if (y1 == s->rects[0]->h) {
474         av_freep(&s->rects[0]->data[0]);
475         s->rects[0]->w = s->rects[0]->h = 0;
476         return 0;
477     }
478 
479     y2 = s->rects[0]->h - 1;
480     while (y2 > 0 && is_transp(s->rects[0]->data[0] + y2 * s->rects[0]->linesize[0], 1,
481                                s->rects[0]->w, transp_color))
482         y2--;
483     x1 = 0;
484     while (x1 < (s->rects[0]->w - 1) && is_transp(s->rects[0]->data[0] + x1, s->rects[0]->linesize[0],
485                                         s->rects[0]->h, transp_color))
486         x1++;
487     x2 = s->rects[0]->w - 1;
488     while (x2 > 0 && is_transp(s->rects[0]->data[0] + x2, s->rects[0]->linesize[0], s->rects[0]->h,
489                                   transp_color))
490         x2--;
491     w = x2 - x1 + 1;
492     h = y2 - y1 + 1;
493     bitmap = av_malloc(w * h);
494     if (!bitmap)
495         return 1;
496     for(y = 0; y < h; y++) {
497         memcpy(bitmap + w * y, s->rects[0]->data[0] + x1 + (y1 + y) * s->rects[0]->linesize[0], w);
498     }
499     av_freep(&s->rects[0]->data[0]);
500     s->rects[0]->data[0] = bitmap;
501     s->rects[0]->linesize[0] = w;
502     s->rects[0]->w = w;
503     s->rects[0]->h = h;
504     s->rects[0]->x += x1;
505     s->rects[0]->y += y1;
506 
507 #if FF_API_AVPICTURE
508 FF_DISABLE_DEPRECATION_WARNINGS
509     for (i = 0; i < 4; i++) {
510         s->rects[0]->pict.data[i] = s->rects[0]->data[i];
511         s->rects[0]->pict.linesize[i] = s->rects[0]->linesize[i];
512     }
513 FF_ENABLE_DEPRECATION_WARNINGS
514 #endif
515 
516     return 1;
517 }
518 
519 #ifdef DEBUG
520 #define ALPHA_MIX(A,BACK,FORE) (((255-(A)) * (BACK) + (A) * (FORE)) / 255)
ppm_save(const char * filename,uint8_t * bitmap,int w,int h,uint32_t * rgba_palette)521 static void ppm_save(const char *filename, uint8_t *bitmap, int w, int h,
522                      uint32_t *rgba_palette)
523 {
524     int x, y, alpha;
525     uint32_t v;
526     int back[3] = {0, 255, 0};  /* green background */
527     FILE *f;
528 
529     f = fopen(filename, "w");
530     if (!f) {
531         perror(filename);
532         return;
533     }
534     fprintf(f, "P6\n"
535             "%d %d\n"
536             "%d\n",
537             w, h, 255);
538     for(y = 0; y < h; y++) {
539         for(x = 0; x < w; x++) {
540             v = rgba_palette[bitmap[y * w + x]];
541             alpha = v >> 24;
542             putc(ALPHA_MIX(alpha, back[0], (v >> 16) & 0xff), f);
543             putc(ALPHA_MIX(alpha, back[1], (v >> 8) & 0xff), f);
544             putc(ALPHA_MIX(alpha, back[2], (v >> 0) & 0xff), f);
545         }
546     }
547     fclose(f);
548 }
549 #endif
550 
append_to_cached_buf(AVCodecContext * avctx,const uint8_t * buf,int buf_size)551 static int append_to_cached_buf(AVCodecContext *avctx,
552                                 const uint8_t *buf, int buf_size)
553 {
554     DVDSubContext *ctx = avctx->priv_data;
555 
556     av_assert0(buf_size >= 0 && ctx->buf_size <= sizeof(ctx->buf));
557     if (buf_size >= sizeof(ctx->buf) - ctx->buf_size) {
558         av_log(avctx, AV_LOG_WARNING, "Attempt to reconstruct "
559                "too large SPU packets aborted.\n");
560         ctx->buf_size = 0;
561         return AVERROR_INVALIDDATA;
562     }
563     memcpy(ctx->buf + ctx->buf_size, buf, buf_size);
564     ctx->buf_size += buf_size;
565     return 0;
566 }
567 
dvdsub_decode(AVCodecContext * avctx,void * data,int * data_size,AVPacket * avpkt)568 static int dvdsub_decode(AVCodecContext *avctx,
569                          void *data, int *data_size,
570                          AVPacket *avpkt)
571 {
572     DVDSubContext *ctx = avctx->priv_data;
573     const uint8_t *buf = avpkt->data;
574     int buf_size = avpkt->size;
575     AVSubtitle *sub = data;
576     int appended = 0;
577     int is_menu;
578 
579     if (ctx->buf_size) {
580         int ret = append_to_cached_buf(avctx, buf, buf_size);
581         if (ret < 0) {
582             *data_size = 0;
583             return ret;
584         }
585         buf = ctx->buf;
586         buf_size = ctx->buf_size;
587         appended = 1;
588     }
589 
590     is_menu = decode_dvd_subtitles(ctx, sub, buf, buf_size);
591     if (is_menu == AVERROR(EAGAIN)) {
592         *data_size = 0;
593         return appended ? 0 : append_to_cached_buf(avctx, buf, buf_size);
594     }
595 
596     if (is_menu < 0) {
597         ctx->buf_size = 0;
598     no_subtitle:
599         reset_rects(sub);
600         *data_size = 0;
601 
602         return buf_size;
603     }
604     if (!is_menu && find_smallest_bounding_rectangle(ctx, sub) == 0)
605         goto no_subtitle;
606 
607     if (ctx->forced_subs_only && !(sub->rects[0]->flags & AV_SUBTITLE_FLAG_FORCED))
608         goto no_subtitle;
609 
610 #if defined(DEBUG)
611     {
612     char ppm_name[32];
613 
614     snprintf(ppm_name, sizeof(ppm_name), "/tmp/%05d.ppm", ctx->sub_id++);
615     ff_dlog(NULL, "start=%d ms end =%d ms\n",
616             sub->start_display_time,
617             sub->end_display_time);
618     ppm_save(ppm_name, sub->rects[0]->data[0],
619              sub->rects[0]->w, sub->rects[0]->h, (uint32_t*) sub->rects[0]->data[1]);
620     }
621 #endif
622 
623     ctx->buf_size = 0;
624     *data_size = 1;
625     return buf_size;
626 }
627 
parse_ifo_palette(DVDSubContext * ctx,char * p)628 static int parse_ifo_palette(DVDSubContext *ctx, char *p)
629 {
630     FILE *ifo;
631     char ifostr[12];
632     uint32_t sp_pgci, pgci, off_pgc, pgc;
633     uint8_t r, g, b, yuv[65], *buf;
634     int i, y, cb, cr, r_add, g_add, b_add;
635     int ret = 0;
636     const uint8_t *cm = ff_crop_tab + MAX_NEG_CROP;
637 
638     ctx->has_palette = 0;
639     if ((ifo = fopen(p, "r")) == NULL) {
640         av_log(ctx, AV_LOG_WARNING, "Unable to open IFO file \"%s\": %s\n", p, av_err2str(AVERROR(errno)));
641         return AVERROR_EOF;
642     }
643     if (fread(ifostr, 12, 1, ifo) != 1 || memcmp(ifostr, "DVDVIDEO-VTS", 12)) {
644         av_log(ctx, AV_LOG_WARNING, "\"%s\" is not a proper IFO file\n", p);
645         ret = AVERROR_INVALIDDATA;
646         goto end;
647     }
648     if (fseek(ifo, 0xCC, SEEK_SET) == -1) {
649         ret = AVERROR(errno);
650         goto end;
651     }
652     if (fread(&sp_pgci, 4, 1, ifo) == 1) {
653         pgci = av_be2ne32(sp_pgci) * 2048;
654         if (fseek(ifo, pgci + 0x0C, SEEK_SET) == -1) {
655             ret = AVERROR(errno);
656             goto end;
657         }
658         if (fread(&off_pgc, 4, 1, ifo) == 1) {
659             pgc = pgci + av_be2ne32(off_pgc);
660             if (fseek(ifo, pgc + 0xA4, SEEK_SET) == -1) {
661                 ret = AVERROR(errno);
662                 goto end;
663             }
664             if (fread(yuv, 64, 1, ifo) == 1) {
665                 buf = yuv;
666                 for(i=0; i<16; i++) {
667                     y  = *++buf;
668                     cr = *++buf;
669                     cb = *++buf;
670                     YUV_TO_RGB1_CCIR(cb, cr);
671                     YUV_TO_RGB2_CCIR(r, g, b, y);
672                     ctx->palette[i] = (r << 16) + (g << 8) + b;
673                     buf++;
674                 }
675                 ctx->has_palette = 1;
676             }
677         }
678     }
679     if (ctx->has_palette == 0) {
680         av_log(ctx, AV_LOG_WARNING, "Failed to read palette from IFO file \"%s\"\n", p);
681         ret = AVERROR_INVALIDDATA;
682     }
683 end:
684     fclose(ifo);
685     return ret;
686 }
687 
dvdsub_parse_extradata(AVCodecContext * avctx)688 static int dvdsub_parse_extradata(AVCodecContext *avctx)
689 {
690     DVDSubContext *ctx = (DVDSubContext*) avctx->priv_data;
691     char *dataorig, *data;
692     int ret = 1;
693 
694     if (!avctx->extradata || !avctx->extradata_size)
695         return 1;
696 
697     dataorig = data = av_malloc(avctx->extradata_size+1);
698     if (!data)
699         return AVERROR(ENOMEM);
700     memcpy(data, avctx->extradata, avctx->extradata_size);
701     data[avctx->extradata_size] = '\0';
702 
703     for(;;) {
704         int pos = strcspn(data, "\n\r");
705         if (pos==0 && *data==0)
706             break;
707 
708         if (strncmp("palette:", data, 8) == 0) {
709             ctx->has_palette = 1;
710             ff_dvdsub_parse_palette(ctx->palette, data + 8);
711         } else if (strncmp("size:", data, 5) == 0) {
712             int w, h;
713             if (sscanf(data + 5, "%dx%d", &w, &h) == 2) {
714                ret = ff_set_dimensions(avctx, w, h);
715                if (ret < 0)
716                    goto fail;
717             }
718         }
719 
720         data += pos;
721         data += strspn(data, "\n\r");
722     }
723 
724 fail:
725     av_free(dataorig);
726     return ret;
727 }
728 
dvdsub_init(AVCodecContext * avctx)729 static av_cold int dvdsub_init(AVCodecContext *avctx)
730 {
731     DVDSubContext *ctx = avctx->priv_data;
732     int ret;
733 
734     if ((ret = dvdsub_parse_extradata(avctx)) < 0)
735         return ret;
736 
737     if (ctx->ifo_str)
738         parse_ifo_palette(ctx, ctx->ifo_str);
739     if (ctx->palette_str) {
740         ctx->has_palette = 1;
741         ff_dvdsub_parse_palette(ctx->palette, ctx->palette_str);
742     }
743     if (ctx->has_palette) {
744         int i;
745         av_log(avctx, AV_LOG_DEBUG, "palette:");
746         for(i=0;i<16;i++)
747             av_log(avctx, AV_LOG_DEBUG, " 0x%06"PRIx32, ctx->palette[i]);
748         av_log(avctx, AV_LOG_DEBUG, "\n");
749     }
750 
751     return 1;
752 }
753 
dvdsub_flush(AVCodecContext * avctx)754 static void dvdsub_flush(AVCodecContext *avctx)
755 {
756     DVDSubContext *ctx = avctx->priv_data;
757     ctx->buf_size = 0;
758 }
759 
dvdsub_close(AVCodecContext * avctx)760 static av_cold int dvdsub_close(AVCodecContext *avctx)
761 {
762     dvdsub_flush(avctx);
763     return 0;
764 }
765 
766 #define OFFSET(field) offsetof(DVDSubContext, field)
767 #define SD AV_OPT_FLAG_SUBTITLE_PARAM | AV_OPT_FLAG_DECODING_PARAM
768 static const AVOption options[] = {
769     { "palette", "set the global palette", OFFSET(palette_str), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, SD },
770     { "ifo_palette", "obtain the global palette from .IFO file", OFFSET(ifo_str), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, SD },
771     { "forced_subs_only", "Only show forced subtitles", OFFSET(forced_subs_only), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, SD},
772     { NULL }
773 };
774 static const AVClass dvdsub_class = {
775     .class_name = "dvdsubdec",
776     .item_name  = av_default_item_name,
777     .option     = options,
778     .version    = LIBAVUTIL_VERSION_INT,
779 };
780 
781 AVCodec ff_dvdsub_decoder = {
782     .name           = "dvdsub",
783     .long_name      = NULL_IF_CONFIG_SMALL("DVD subtitles"),
784     .type           = AVMEDIA_TYPE_SUBTITLE,
785     .id             = AV_CODEC_ID_DVD_SUBTITLE,
786     .priv_data_size = sizeof(DVDSubContext),
787     .init           = dvdsub_init,
788     .decode         = dvdsub_decode,
789     .flush          = dvdsub_flush,
790     .close          = dvdsub_close,
791     .priv_class     = &dvdsub_class,
792 };
793