xref: /third_party/ffmpeg/libavcodec/dvdsubdec.c (revision cabdff1a)
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 "codec_internal.h"
24#include "get_bits.h"
25#include "internal.h"
26
27#include "libavutil/attributes.h"
28#include "libavutil/colorspace.h"
29#include "libavutil/opt.h"
30#include "libavutil/imgutils.h"
31#include "libavutil/bswap.h"
32
33typedef struct DVDSubContext
34{
35  AVClass *class;
36  uint32_t palette[16];
37  char    *palette_str;
38  char    *ifo_str;
39  int      has_palette;
40  uint8_t  colormap[4];
41  uint8_t  alpha[256];
42  uint8_t  buf[0x10000];
43  int      buf_size;
44  int      forced_subs_only;
45  uint8_t  used_color[256];
46} DVDSubContext;
47
48static void yuv_a_to_rgba(const uint8_t *ycbcr, const uint8_t *alpha, uint32_t *rgba, int num_values)
49{
50    const uint8_t *cm = ff_crop_tab + MAX_NEG_CROP;
51    uint8_t r, g, b;
52    int i, y, cb, cr;
53    int r_add, g_add, b_add;
54
55    for (i = num_values; i > 0; i--) {
56        y = *ycbcr++;
57        cr = *ycbcr++;
58        cb = *ycbcr++;
59        YUV_TO_RGB1_CCIR(cb, cr);
60        YUV_TO_RGB2_CCIR(r, g, b, y);
61        *rgba++ = ((unsigned)*alpha++ << 24) | (r << 16) | (g << 8) | b;
62    }
63}
64
65static int decode_run_2bit(GetBitContext *gb, int *color)
66{
67    unsigned int v, t;
68
69    v = 0;
70    for (t = 1; v < t && t <= 0x40; t <<= 2)
71        v = (v << 4) | get_bits(gb, 4);
72    *color = v & 3;
73    if (v < 4) { /* Code for fill rest of line */
74        return INT_MAX;
75    }
76    return v >> 2;
77}
78
79static int decode_run_8bit(GetBitContext *gb, int *color)
80{
81    int len;
82    int has_run = get_bits1(gb);
83    *color = get_bits(gb, 2 + 6*get_bits1(gb));
84    if (has_run) {
85        if (get_bits1(gb)) {
86            len = get_bits(gb, 7);
87            if (len == 0)
88                len = INT_MAX;
89            else
90                len += 9;
91        } else
92            len = get_bits(gb, 3) + 2;
93    } else
94        len = 1;
95    return len;
96}
97
98static int decode_rle(uint8_t *bitmap, int linesize, int w, int h, uint8_t used_color[256],
99                      const uint8_t *buf, int start, int buf_size, int is_8bit)
100{
101    GetBitContext gb;
102    int bit_len;
103    int x, y, len, color;
104    uint8_t *d;
105
106    if (start >= buf_size)
107        return -1;
108
109    if (w <= 0 || h <= 0)
110        return -1;
111
112    bit_len = (buf_size - start) * 8;
113    init_get_bits(&gb, buf + start, bit_len);
114
115    x = 0;
116    y = 0;
117    d = bitmap;
118    for(;;) {
119        if (get_bits_count(&gb) > bit_len)
120            return -1;
121        if (is_8bit)
122            len = decode_run_8bit(&gb, &color);
123        else
124            len = decode_run_2bit(&gb, &color);
125        if (len != INT_MAX && len > w - x)
126            return AVERROR_INVALIDDATA;
127        len = FFMIN(len, w - x);
128        memset(d + x, color, len);
129        used_color[color] = 1;
130        x += len;
131        if (x >= w) {
132            y++;
133            if (y >= h)
134                break;
135            d += linesize;
136            x = 0;
137            /* byte align */
138            align_get_bits(&gb);
139        }
140    }
141    return 0;
142}
143
144static void guess_palette(DVDSubContext* ctx,
145                          uint32_t *rgba_palette,
146                          uint32_t subtitle_color)
147{
148    static const uint8_t level_map[4][4] = {
149        // this configuration (full range, lowest to highest) in tests
150        // seemed most common, so assume this
151        {0xff},
152        {0x00, 0xff},
153        {0x00, 0x80, 0xff},
154        {0x00, 0x55, 0xaa, 0xff},
155    };
156    uint8_t color_used[16] = { 0 };
157    int nb_opaque_colors, i, level, j, r, g, b;
158    uint8_t *colormap = ctx->colormap, *alpha = ctx->alpha;
159
160    if(ctx->has_palette) {
161        for(i = 0; i < 4; i++)
162            rgba_palette[i] = (ctx->palette[colormap[i]] & 0x00ffffff)
163                              | ((alpha[i] * 17U) << 24);
164        return;
165    }
166
167    for(i = 0; i < 4; i++)
168        rgba_palette[i] = 0;
169
170    nb_opaque_colors = 0;
171    for(i = 0; i < 4; i++) {
172        if (alpha[i] != 0 && !color_used[colormap[i]]) {
173            color_used[colormap[i]] = 1;
174            nb_opaque_colors++;
175        }
176    }
177
178    if (nb_opaque_colors == 0)
179        return;
180
181    j = 0;
182    memset(color_used, 0, 16);
183    for(i = 0; i < 4; i++) {
184        if (alpha[i] != 0) {
185            if (!color_used[colormap[i]])  {
186                level = level_map[nb_opaque_colors - 1][j];
187                r = (((subtitle_color >> 16) & 0xff) * level) >> 8;
188                g = (((subtitle_color >> 8) & 0xff) * level) >> 8;
189                b = (((subtitle_color >> 0) & 0xff) * level) >> 8;
190                rgba_palette[i] = b | (g << 8) | (r << 16) | ((alpha[i] * 17U) << 24);
191                color_used[colormap[i]] = (i + 1);
192                j++;
193            } else {
194                rgba_palette[i] = (rgba_palette[color_used[colormap[i]] - 1] & 0x00ffffff) |
195                                    ((alpha[i] * 17U) << 24);
196            }
197        }
198    }
199}
200
201static void reset_rects(AVSubtitle *sub_header)
202{
203    int i;
204
205    if (sub_header->rects) {
206        for (i = 0; i < sub_header->num_rects; i++) {
207            av_freep(&sub_header->rects[i]->data[0]);
208            av_freep(&sub_header->rects[i]->data[1]);
209            av_freep(&sub_header->rects[i]);
210        }
211        av_freep(&sub_header->rects);
212        sub_header->num_rects = 0;
213    }
214}
215
216#define READ_OFFSET(a) (big_offsets ? AV_RB32(a) : AV_RB16(a))
217
218static int decode_dvd_subtitles(DVDSubContext *ctx, AVSubtitle *sub_header,
219                                const uint8_t *buf, int buf_size)
220{
221    int cmd_pos, pos, cmd, x1, y1, x2, y2, next_cmd_pos;
222    int big_offsets, offset_size, is_8bit = 0;
223    const uint8_t *yuv_palette = NULL;
224    uint8_t *colormap = ctx->colormap, *alpha = ctx->alpha;
225    int date;
226    int i;
227    int is_menu = 0;
228    uint32_t size;
229    int64_t offset1, offset2;
230
231    if (buf_size < 10)
232        return -1;
233
234    if (AV_RB16(buf) == 0) {   /* HD subpicture with 4-byte offsets */
235        big_offsets = 1;
236        offset_size = 4;
237        cmd_pos = 6;
238    } else {
239        big_offsets = 0;
240        offset_size = 2;
241        cmd_pos = 2;
242    }
243
244    size = READ_OFFSET(buf + (big_offsets ? 2 : 0));
245    cmd_pos = READ_OFFSET(buf + cmd_pos);
246
247    if (cmd_pos < 0 || cmd_pos > buf_size - 2 - offset_size) {
248        if (cmd_pos > size) {
249            av_log(ctx, AV_LOG_ERROR, "Discarding invalid packet\n");
250            return 0;
251        }
252        return AVERROR(EAGAIN);
253    }
254
255    while (cmd_pos > 0 && cmd_pos < buf_size - 2 - offset_size) {
256        date = AV_RB16(buf + cmd_pos);
257        next_cmd_pos = READ_OFFSET(buf + cmd_pos + 2);
258        ff_dlog(NULL, "cmd_pos=0x%04x next=0x%04x date=%d\n",
259                cmd_pos, next_cmd_pos, date);
260        pos = cmd_pos + 2 + offset_size;
261        offset1 = -1;
262        offset2 = -1;
263        x1 = y1 = x2 = y2 = 0;
264        while (pos < buf_size) {
265            cmd = buf[pos++];
266            ff_dlog(NULL, "cmd=%02x\n", cmd);
267            switch(cmd) {
268            case 0x00:
269                /* menu subpicture */
270                is_menu = 1;
271                break;
272            case 0x01:
273                /* set start date */
274                sub_header->start_display_time = (date << 10) / 90;
275                break;
276            case 0x02:
277                /* set end date */
278                sub_header->end_display_time = (date << 10) / 90;
279                break;
280            case 0x03:
281                /* set colormap */
282                if ((buf_size - pos) < 2)
283                    goto fail;
284                colormap[3] = buf[pos] >> 4;
285                colormap[2] = buf[pos] & 0x0f;
286                colormap[1] = buf[pos + 1] >> 4;
287                colormap[0] = buf[pos + 1] & 0x0f;
288                pos += 2;
289                break;
290            case 0x04:
291                /* set alpha */
292                if ((buf_size - pos) < 2)
293                    goto fail;
294                alpha[3] = buf[pos] >> 4;
295                alpha[2] = buf[pos] & 0x0f;
296                alpha[1] = buf[pos + 1] >> 4;
297                alpha[0] = buf[pos + 1] & 0x0f;
298                pos += 2;
299                ff_dlog(NULL, "alpha=%x%x%x%x\n", alpha[0],alpha[1],alpha[2],alpha[3]);
300                break;
301            case 0x05:
302            case 0x85:
303                if ((buf_size - pos) < 6)
304                    goto fail;
305                x1 = (buf[pos] << 4) | (buf[pos + 1] >> 4);
306                x2 = ((buf[pos + 1] & 0x0f) << 8) | buf[pos + 2];
307                y1 = (buf[pos + 3] << 4) | (buf[pos + 4] >> 4);
308                y2 = ((buf[pos + 4] & 0x0f) << 8) | buf[pos + 5];
309                if (cmd & 0x80)
310                    is_8bit = 1;
311                ff_dlog(NULL, "x1=%d x2=%d y1=%d y2=%d\n", x1, x2, y1, y2);
312                pos += 6;
313                break;
314            case 0x06:
315                if ((buf_size - pos) < 4)
316                    goto fail;
317                offset1 = AV_RB16(buf + pos);
318                offset2 = AV_RB16(buf + pos + 2);
319                ff_dlog(NULL, "offset1=0x%04"PRIx64" offset2=0x%04"PRIx64"\n", offset1, offset2);
320                pos += 4;
321                break;
322            case 0x86:
323                if ((buf_size - pos) < 8)
324                    goto fail;
325                offset1 = AV_RB32(buf + pos);
326                offset2 = AV_RB32(buf + pos + 4);
327                ff_dlog(NULL, "offset1=0x%04"PRIx64" offset2=0x%04"PRIx64"\n", offset1, offset2);
328                pos += 8;
329                break;
330
331            case 0x83:
332                /* HD set palette */
333                if ((buf_size - pos) < 768)
334                    goto fail;
335                yuv_palette = buf + pos;
336                pos += 768;
337                break;
338            case 0x84:
339                /* HD set contrast (alpha) */
340                if ((buf_size - pos) < 256)
341                    goto fail;
342                for (i = 0; i < 256; i++)
343                    alpha[i] = 0xFF - buf[pos+i];
344                pos += 256;
345                break;
346
347            case 0xff:
348                goto the_end;
349            default:
350                ff_dlog(NULL, "unrecognised subpicture command 0x%x\n", cmd);
351                goto the_end;
352            }
353        }
354    the_end:
355        if (offset1 >= buf_size || offset2 >= buf_size)
356            goto fail;
357
358        if (offset1 >= 0 && offset2 >= 0) {
359            int w, h;
360            uint8_t *bitmap;
361
362            /* decode the bitmap */
363            w = x2 - x1 + 1;
364            if (w < 0)
365                w = 0;
366            h = y2 - y1 + 1;
367            if (h < 0)
368                h = 0;
369            if (w > 0 && h > 1) {
370                reset_rects(sub_header);
371                memset(ctx->used_color, 0, sizeof(ctx->used_color));
372                sub_header->rects = av_mallocz(sizeof(*sub_header->rects));
373                if (!sub_header->rects)
374                    goto fail;
375                sub_header->rects[0] = av_mallocz(sizeof(AVSubtitleRect));
376                if (!sub_header->rects[0])
377                    goto fail;
378                sub_header->num_rects = 1;
379                bitmap = sub_header->rects[0]->data[0] = av_malloc(w * h);
380                if (!bitmap)
381                    goto fail;
382                if (decode_rle(bitmap, w * 2, w, (h + 1) / 2, ctx->used_color,
383                               buf, offset1, buf_size, is_8bit) < 0)
384                    goto fail;
385                if (decode_rle(bitmap + w, w * 2, w, h / 2, ctx->used_color,
386                               buf, offset2, buf_size, is_8bit) < 0)
387                    goto fail;
388                sub_header->rects[0]->data[1] = av_mallocz(AVPALETTE_SIZE);
389                if (!sub_header->rects[0]->data[1])
390                    goto fail;
391                if (is_8bit) {
392                    if (!yuv_palette)
393                        goto fail;
394                    sub_header->rects[0]->nb_colors = 256;
395                    yuv_a_to_rgba(yuv_palette, alpha,
396                                  (uint32_t *)sub_header->rects[0]->data[1],
397                                  256);
398                } else {
399                    sub_header->rects[0]->nb_colors = 4;
400                    guess_palette(ctx, (uint32_t*)sub_header->rects[0]->data[1],
401                                  0xffffff);
402                }
403                sub_header->rects[0]->x = x1;
404                sub_header->rects[0]->y = y1;
405                sub_header->rects[0]->w = w;
406                sub_header->rects[0]->h = h;
407                sub_header->rects[0]->type = SUBTITLE_BITMAP;
408                sub_header->rects[0]->linesize[0] = w;
409                sub_header->rects[0]->flags = is_menu ? AV_SUBTITLE_FLAG_FORCED : 0;
410            }
411        }
412        if (next_cmd_pos < cmd_pos) {
413            av_log(ctx, AV_LOG_ERROR, "Invalid command offset\n");
414            break;
415        }
416        if (next_cmd_pos == cmd_pos)
417            break;
418        cmd_pos = next_cmd_pos;
419    }
420    if (sub_header->num_rects > 0)
421        return is_menu;
422 fail:
423    reset_rects(sub_header);
424    return -1;
425}
426
427static int is_transp(const uint8_t *buf, int pitch, int n,
428                     const uint8_t *transp_color)
429{
430    int i;
431    for(i = 0; i < n; i++) {
432        if (!transp_color[*buf])
433            return 0;
434        buf += pitch;
435    }
436    return 1;
437}
438
439/* return 0 if empty rectangle, 1 if non empty */
440static int find_smallest_bounding_rectangle(DVDSubContext *ctx, AVSubtitle *s)
441{
442    uint8_t transp_color[256] = { 0 };
443    int y1, y2, x1, x2, y, w, h, i;
444    uint8_t *bitmap;
445    int transparent = 1;
446
447    if (s->num_rects == 0 || !s->rects || s->rects[0]->w <= 0 || s->rects[0]->h <= 0)
448        return 0;
449
450    for(i = 0; i < s->rects[0]->nb_colors; i++) {
451        if ((((uint32_t *)s->rects[0]->data[1])[i] >> 24) == 0) {
452            transp_color[i] = 1;
453        } else if (ctx->used_color[i])
454            transparent = 0;
455    }
456    if (transparent)
457        return 0;
458    y1 = 0;
459    while (y1 < s->rects[0]->h && is_transp(s->rects[0]->data[0] + y1 * s->rects[0]->linesize[0],
460                                  1, s->rects[0]->w, transp_color))
461        y1++;
462    if (y1 == s->rects[0]->h) {
463        av_freep(&s->rects[0]->data[0]);
464        s->rects[0]->w = s->rects[0]->h = 0;
465        return 0;
466    }
467
468    y2 = s->rects[0]->h - 1;
469    while (y2 > 0 && is_transp(s->rects[0]->data[0] + y2 * s->rects[0]->linesize[0], 1,
470                               s->rects[0]->w, transp_color))
471        y2--;
472    x1 = 0;
473    while (x1 < (s->rects[0]->w - 1) && is_transp(s->rects[0]->data[0] + x1, s->rects[0]->linesize[0],
474                                        s->rects[0]->h, transp_color))
475        x1++;
476    x2 = s->rects[0]->w - 1;
477    while (x2 > 0 && is_transp(s->rects[0]->data[0] + x2, s->rects[0]->linesize[0], s->rects[0]->h,
478                                  transp_color))
479        x2--;
480    w = x2 - x1 + 1;
481    h = y2 - y1 + 1;
482    bitmap = av_malloc(w * h);
483    if (!bitmap)
484        return 1;
485    for(y = 0; y < h; y++) {
486        memcpy(bitmap + w * y, s->rects[0]->data[0] + x1 + (y1 + y) * s->rects[0]->linesize[0], w);
487    }
488    av_freep(&s->rects[0]->data[0]);
489    s->rects[0]->data[0] = bitmap;
490    s->rects[0]->linesize[0] = w;
491    s->rects[0]->w = w;
492    s->rects[0]->h = h;
493    s->rects[0]->x += x1;
494    s->rects[0]->y += y1;
495
496    return 1;
497}
498
499static int append_to_cached_buf(AVCodecContext *avctx,
500                                const uint8_t *buf, int buf_size)
501{
502    DVDSubContext *ctx = avctx->priv_data;
503
504    av_assert0(buf_size >= 0 && ctx->buf_size <= sizeof(ctx->buf));
505    if (buf_size >= sizeof(ctx->buf) - ctx->buf_size) {
506        av_log(avctx, AV_LOG_WARNING, "Attempt to reconstruct "
507               "too large SPU packets aborted.\n");
508        ctx->buf_size = 0;
509        return AVERROR_INVALIDDATA;
510    }
511    memcpy(ctx->buf + ctx->buf_size, buf, buf_size);
512    ctx->buf_size += buf_size;
513    return 0;
514}
515
516static int dvdsub_decode(AVCodecContext *avctx, AVSubtitle *sub,
517                         int *data_size, const AVPacket *avpkt)
518{
519    DVDSubContext *ctx = avctx->priv_data;
520    const uint8_t *buf = avpkt->data;
521    int buf_size = avpkt->size;
522    int appended = 0;
523    int is_menu;
524
525    if (ctx->buf_size) {
526        int ret = append_to_cached_buf(avctx, buf, buf_size);
527        if (ret < 0) {
528            *data_size = 0;
529            return ret;
530        }
531        buf = ctx->buf;
532        buf_size = ctx->buf_size;
533        appended = 1;
534    }
535
536    is_menu = decode_dvd_subtitles(ctx, sub, buf, buf_size);
537    if (is_menu == AVERROR(EAGAIN)) {
538        *data_size = 0;
539        return appended ? 0 : append_to_cached_buf(avctx, buf, buf_size);
540    }
541
542    if (is_menu < 0) {
543        ctx->buf_size = 0;
544    no_subtitle:
545        reset_rects(sub);
546        *data_size = 0;
547
548        return buf_size;
549    }
550    if (!is_menu && find_smallest_bounding_rectangle(ctx, sub) == 0)
551        goto no_subtitle;
552
553    if (ctx->forced_subs_only && !(sub->rects[0]->flags & AV_SUBTITLE_FLAG_FORCED))
554        goto no_subtitle;
555
556    ctx->buf_size = 0;
557    *data_size = 1;
558    return buf_size;
559}
560
561static int parse_ifo_palette(DVDSubContext *ctx, char *p)
562{
563    FILE *ifo;
564    char ifostr[12];
565    uint32_t sp_pgci, pgci, off_pgc, pgc;
566    uint8_t r, g, b, yuv[65], *buf;
567    int i, y, cb, cr, r_add, g_add, b_add;
568    int ret = 0;
569    const uint8_t *cm = ff_crop_tab + MAX_NEG_CROP;
570
571    ctx->has_palette = 0;
572    if ((ifo = avpriv_fopen_utf8(p, "r")) == NULL) {
573        av_log(ctx, AV_LOG_WARNING, "Unable to open IFO file \"%s\": %s\n", p, av_err2str(AVERROR(errno)));
574        return AVERROR_EOF;
575    }
576    if (fread(ifostr, 12, 1, ifo) != 1 || memcmp(ifostr, "DVDVIDEO-VTS", 12)) {
577        av_log(ctx, AV_LOG_WARNING, "\"%s\" is not a proper IFO file\n", p);
578        ret = AVERROR_INVALIDDATA;
579        goto end;
580    }
581    if (fseek(ifo, 0xCC, SEEK_SET) == -1) {
582        ret = AVERROR(errno);
583        goto end;
584    }
585    if (fread(&sp_pgci, 4, 1, ifo) == 1) {
586        pgci = av_be2ne32(sp_pgci) * 2048;
587        if (fseek(ifo, pgci + 0x0C, SEEK_SET) == -1) {
588            ret = AVERROR(errno);
589            goto end;
590        }
591        if (fread(&off_pgc, 4, 1, ifo) == 1) {
592            pgc = pgci + av_be2ne32(off_pgc);
593            if (fseek(ifo, pgc + 0xA4, SEEK_SET) == -1) {
594                ret = AVERROR(errno);
595                goto end;
596            }
597            if (fread(yuv, 64, 1, ifo) == 1) {
598                buf = yuv;
599                for(i=0; i<16; i++) {
600                    y  = *++buf;
601                    cr = *++buf;
602                    cb = *++buf;
603                    YUV_TO_RGB1_CCIR(cb, cr);
604                    YUV_TO_RGB2_CCIR(r, g, b, y);
605                    ctx->palette[i] = (r << 16) + (g << 8) + b;
606                    buf++;
607                }
608                ctx->has_palette = 1;
609            }
610        }
611    }
612    if (ctx->has_palette == 0) {
613        av_log(ctx, AV_LOG_WARNING, "Failed to read palette from IFO file \"%s\"\n", p);
614        ret = AVERROR_INVALIDDATA;
615    }
616end:
617    fclose(ifo);
618    return ret;
619}
620
621static int dvdsub_parse_extradata(AVCodecContext *avctx)
622{
623    DVDSubContext *ctx = (DVDSubContext*) avctx->priv_data;
624    char *dataorig, *data;
625    int ret = 1;
626
627    if (!avctx->extradata || !avctx->extradata_size)
628        return 1;
629
630    dataorig = data = av_malloc(avctx->extradata_size+1);
631    if (!data)
632        return AVERROR(ENOMEM);
633    memcpy(data, avctx->extradata, avctx->extradata_size);
634    data[avctx->extradata_size] = '\0';
635
636    for(;;) {
637        int pos = strcspn(data, "\n\r");
638        if (pos==0 && *data==0)
639            break;
640
641        if (strncmp("palette:", data, 8) == 0) {
642            ctx->has_palette = 1;
643            ff_dvdsub_parse_palette(ctx->palette, data + 8);
644        } else if (strncmp("size:", data, 5) == 0) {
645            int w, h;
646            if (sscanf(data + 5, "%dx%d", &w, &h) == 2) {
647               ret = ff_set_dimensions(avctx, w, h);
648               if (ret < 0)
649                   goto fail;
650            }
651        }
652
653        data += pos;
654        data += strspn(data, "\n\r");
655    }
656
657fail:
658    av_free(dataorig);
659    return ret;
660}
661
662static av_cold int dvdsub_init(AVCodecContext *avctx)
663{
664    DVDSubContext *ctx = avctx->priv_data;
665    int ret;
666
667    if ((ret = dvdsub_parse_extradata(avctx)) < 0)
668        return ret;
669
670    if (ctx->ifo_str)
671        parse_ifo_palette(ctx, ctx->ifo_str);
672    if (ctx->palette_str) {
673        ctx->has_palette = 1;
674        ff_dvdsub_parse_palette(ctx->palette, ctx->palette_str);
675    }
676    if (ctx->has_palette) {
677        int i;
678        av_log(avctx, AV_LOG_DEBUG, "palette:");
679        for(i=0;i<16;i++)
680            av_log(avctx, AV_LOG_DEBUG, " 0x%06"PRIx32, ctx->palette[i]);
681        av_log(avctx, AV_LOG_DEBUG, "\n");
682    }
683
684    return 1;
685}
686
687static void dvdsub_flush(AVCodecContext *avctx)
688{
689    DVDSubContext *ctx = avctx->priv_data;
690    ctx->buf_size = 0;
691}
692
693#define OFFSET(field) offsetof(DVDSubContext, field)
694#define SD AV_OPT_FLAG_SUBTITLE_PARAM | AV_OPT_FLAG_DECODING_PARAM
695static const AVOption options[] = {
696    { "palette", "set the global palette", OFFSET(palette_str), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, SD },
697    { "ifo_palette", "obtain the global palette from .IFO file", OFFSET(ifo_str), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, SD },
698    { "forced_subs_only", "Only show forced subtitles", OFFSET(forced_subs_only), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, SD},
699    { NULL }
700};
701static const AVClass dvdsub_class = {
702    .class_name = "dvdsubdec",
703    .item_name  = av_default_item_name,
704    .option     = options,
705    .version    = LIBAVUTIL_VERSION_INT,
706};
707
708const FFCodec ff_dvdsub_decoder = {
709    .p.name         = "dvdsub",
710    .p.long_name    = NULL_IF_CONFIG_SMALL("DVD subtitles"),
711    .p.type         = AVMEDIA_TYPE_SUBTITLE,
712    .p.id           = AV_CODEC_ID_DVD_SUBTITLE,
713    .priv_data_size = sizeof(DVDSubContext),
714    .init           = dvdsub_init,
715    FF_CODEC_DECODE_SUB_CB(dvdsub_decode),
716    .flush          = dvdsub_flush,
717    .p.priv_class   = &dvdsub_class,
718    .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE,
719};
720