GCC Code Coverage Report
Directory: ../../../ffmpeg/ Exec Total Coverage
File: src/libavcodec/pgssubdec.c Lines: 0 281 0.0 %
Date: 2019-11-20 04:07:19 Branches: 0 150 0.0 %

Line Branch Exec Source
1
/*
2
 * PGS subtitle decoder
3
 * Copyright (c) 2009 Stephen Backway
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
/**
23
 * @file
24
 * PGS subtitle decoder
25
 */
26
27
#include "avcodec.h"
28
#include "bytestream.h"
29
#include "internal.h"
30
#include "mathops.h"
31
32
#include "libavutil/colorspace.h"
33
#include "libavutil/imgutils.h"
34
#include "libavutil/opt.h"
35
36
#define RGBA(r,g,b,a) (((unsigned)(a) << 24) | ((r) << 16) | ((g) << 8) | (b))
37
#define MAX_EPOCH_PALETTES 8   // Max 8 allowed per PGS epoch
38
#define MAX_EPOCH_OBJECTS  64  // Max 64 allowed per PGS epoch
39
#define MAX_OBJECT_REFS    2   // Max objects per display set
40
41
enum SegmentType {
42
    PALETTE_SEGMENT      = 0x14,
43
    OBJECT_SEGMENT       = 0x15,
44
    PRESENTATION_SEGMENT = 0x16,
45
    WINDOW_SEGMENT       = 0x17,
46
    DISPLAY_SEGMENT      = 0x80,
47
};
48
49
typedef struct PGSSubObjectRef {
50
    int     id;
51
    int     window_id;
52
    uint8_t composition_flag;
53
    int     x;
54
    int     y;
55
    int     crop_x;
56
    int     crop_y;
57
    int     crop_w;
58
    int     crop_h;
59
} PGSSubObjectRef;
60
61
typedef struct PGSSubPresentation {
62
    int id_number;
63
    int palette_id;
64
    int object_count;
65
    PGSSubObjectRef objects[MAX_OBJECT_REFS];
66
    int64_t pts;
67
} PGSSubPresentation;
68
69
typedef struct PGSSubObject {
70
    int          id;
71
    int          w;
72
    int          h;
73
    uint8_t      *rle;
74
    unsigned int rle_buffer_size, rle_data_len;
75
    unsigned int rle_remaining_len;
76
} PGSSubObject;
77
78
typedef struct PGSSubObjects {
79
    int          count;
80
    PGSSubObject object[MAX_EPOCH_OBJECTS];
81
} PGSSubObjects;
82
83
typedef struct PGSSubPalette {
84
    int         id;
85
    uint32_t    clut[256];
86
} PGSSubPalette;
87
88
typedef struct PGSSubPalettes {
89
    int           count;
90
    PGSSubPalette palette[MAX_EPOCH_PALETTES];
91
} PGSSubPalettes;
92
93
typedef struct PGSSubContext {
94
    AVClass *class;
95
    PGSSubPresentation presentation;
96
    PGSSubPalettes     palettes;
97
    PGSSubObjects      objects;
98
    int forced_subs_only;
99
} PGSSubContext;
100
101
static void flush_cache(AVCodecContext *avctx)
102
{
103
    PGSSubContext *ctx = avctx->priv_data;
104
    int i;
105
106
    for (i = 0; i < ctx->objects.count; i++) {
107
        av_freep(&ctx->objects.object[i].rle);
108
        ctx->objects.object[i].rle_buffer_size  = 0;
109
        ctx->objects.object[i].rle_remaining_len  = 0;
110
    }
111
    ctx->objects.count = 0;
112
    ctx->palettes.count = 0;
113
}
114
115
static PGSSubObject * find_object(int id, PGSSubObjects *objects)
116
{
117
    int i;
118
119
    for (i = 0; i < objects->count; i++) {
120
        if (objects->object[i].id == id)
121
            return &objects->object[i];
122
    }
123
    return NULL;
124
}
125
126
static PGSSubPalette * find_palette(int id, PGSSubPalettes *palettes)
127
{
128
    int i;
129
130
    for (i = 0; i < palettes->count; i++) {
131
        if (palettes->palette[i].id == id)
132
            return &palettes->palette[i];
133
    }
134
    return NULL;
135
}
136
137
static av_cold int init_decoder(AVCodecContext *avctx)
138
{
139
    avctx->pix_fmt     = AV_PIX_FMT_PAL8;
140
141
    return 0;
142
}
143
144
static av_cold int close_decoder(AVCodecContext *avctx)
145
{
146
    flush_cache(avctx);
147
148
    return 0;
149
}
150
151
/**
152
 * Decode the RLE data.
153
 *
154
 * The subtitle is stored as a Run Length Encoded image.
155
 *
156
 * @param avctx contains the current codec context
157
 * @param sub pointer to the processed subtitle data
158
 * @param buf pointer to the RLE data to process
159
 * @param buf_size size of the RLE data to process
160
 */
161
static int decode_rle(AVCodecContext *avctx, AVSubtitleRect *rect,
162
                      const uint8_t *buf, unsigned int buf_size)
163
{
164
    const uint8_t *rle_bitmap_end;
165
    int pixel_count, line_count;
166
167
    rle_bitmap_end = buf + buf_size;
168
169
    rect->data[0] = av_malloc_array(rect->w, rect->h);
170
171
    if (!rect->data[0])
172
        return AVERROR(ENOMEM);
173
174
    pixel_count = 0;
175
    line_count  = 0;
176
177
    while (buf < rle_bitmap_end && line_count < rect->h) {
178
        uint8_t flags, color;
179
        int run;
180
181
        color = bytestream_get_byte(&buf);
182
        run   = 1;
183
184
        if (color == 0x00) {
185
            flags = bytestream_get_byte(&buf);
186
            run   = flags & 0x3f;
187
            if (flags & 0x40)
188
                run = (run << 8) + bytestream_get_byte(&buf);
189
            color = flags & 0x80 ? bytestream_get_byte(&buf) : 0;
190
        }
191
192
        if (run > 0 && pixel_count + run <= rect->w * rect->h) {
193
            memset(rect->data[0] + pixel_count, color, run);
194
            pixel_count += run;
195
        } else if (!run) {
196
            /*
197
             * New Line. Check if correct pixels decoded, if not display warning
198
             * and adjust bitmap pointer to correct new line position.
199
             */
200
            if (pixel_count % rect->w > 0) {
201
                av_log(avctx, AV_LOG_ERROR, "Decoded %d pixels, when line should be %d pixels\n",
202
                       pixel_count % rect->w, rect->w);
203
                if (avctx->err_recognition & AV_EF_EXPLODE) {
204
                    return AVERROR_INVALIDDATA;
205
                }
206
            }
207
            line_count++;
208
        }
209
    }
210
211
    if (pixel_count < rect->w * rect->h) {
212
        av_log(avctx, AV_LOG_ERROR, "Insufficient RLE data for subtitle\n");
213
        return AVERROR_INVALIDDATA;
214
    }
215
216
    ff_dlog(avctx, "Pixel Count = %d, Area = %d\n", pixel_count, rect->w * rect->h);
217
218
    return 0;
219
}
220
221
/**
222
 * Parse the picture segment packet.
223
 *
224
 * The picture segment contains details on the sequence id,
225
 * width, height and Run Length Encoded (RLE) bitmap data.
226
 *
227
 * @param avctx contains the current codec context
228
 * @param buf pointer to the packet to process
229
 * @param buf_size size of packet to process
230
 */
231
static int parse_object_segment(AVCodecContext *avctx,
232
                                  const uint8_t *buf, int buf_size)
233
{
234
    PGSSubContext *ctx = avctx->priv_data;
235
    PGSSubObject *object;
236
237
    uint8_t sequence_desc;
238
    unsigned int rle_bitmap_len, width, height;
239
    int id;
240
241
    if (buf_size <= 4)
242
        return AVERROR_INVALIDDATA;
243
    buf_size -= 4;
244
245
    id = bytestream_get_be16(&buf);
246
    object = find_object(id, &ctx->objects);
247
    if (!object) {
248
        if (ctx->objects.count >= MAX_EPOCH_OBJECTS) {
249
            av_log(avctx, AV_LOG_ERROR, "Too many objects in epoch\n");
250
            return AVERROR_INVALIDDATA;
251
        }
252
        object = &ctx->objects.object[ctx->objects.count++];
253
        object->id = id;
254
    }
255
256
    /* skip object version number */
257
    buf += 1;
258
259
    /* Read the Sequence Description to determine if start of RLE data or appended to previous RLE */
260
    sequence_desc = bytestream_get_byte(&buf);
261
262
    if (!(sequence_desc & 0x80)) {
263
        /* Additional RLE data */
264
        if (buf_size > object->rle_remaining_len)
265
            return AVERROR_INVALIDDATA;
266
267
        memcpy(object->rle + object->rle_data_len, buf, buf_size);
268
        object->rle_data_len += buf_size;
269
        object->rle_remaining_len -= buf_size;
270
271
        return 0;
272
    }
273
274
    if (buf_size <= 7)
275
        return AVERROR_INVALIDDATA;
276
    buf_size -= 7;
277
278
    /* Decode rle bitmap length, stored size includes width/height data */
279
    rle_bitmap_len = bytestream_get_be24(&buf) - 2*2;
280
281
    if (buf_size > rle_bitmap_len) {
282
        av_log(avctx, AV_LOG_ERROR,
283
               "Buffer dimension %d larger than the expected RLE data %d\n",
284
               buf_size, rle_bitmap_len);
285
        return AVERROR_INVALIDDATA;
286
    }
287
288
    /* Get bitmap dimensions from data */
289
    width  = bytestream_get_be16(&buf);
290
    height = bytestream_get_be16(&buf);
291
292
    /* Make sure the bitmap is not too large */
293
    if (avctx->width < width || avctx->height < height || !width || !height) {
294
        av_log(avctx, AV_LOG_ERROR, "Bitmap dimensions (%dx%d) invalid.\n", width, height);
295
        return AVERROR_INVALIDDATA;
296
    }
297
298
    object->w = width;
299
    object->h = height;
300
301
    av_fast_padded_malloc(&object->rle, &object->rle_buffer_size, rle_bitmap_len);
302
303
    if (!object->rle) {
304
        object->rle_data_len = 0;
305
        object->rle_remaining_len = 0;
306
        return AVERROR(ENOMEM);
307
    }
308
309
    memcpy(object->rle, buf, buf_size);
310
    object->rle_data_len = buf_size;
311
    object->rle_remaining_len = rle_bitmap_len - buf_size;
312
313
    return 0;
314
}
315
316
/**
317
 * Parse the palette segment packet.
318
 *
319
 * The palette segment contains details of the palette,
320
 * a maximum of 256 colors can be defined.
321
 *
322
 * @param avctx contains the current codec context
323
 * @param buf pointer to the packet to process
324
 * @param buf_size size of packet to process
325
 */
326
static int parse_palette_segment(AVCodecContext *avctx,
327
                                  const uint8_t *buf, int buf_size)
328
{
329
    PGSSubContext *ctx = avctx->priv_data;
330
    PGSSubPalette *palette;
331
332
    const uint8_t *buf_end = buf + buf_size;
333
    const uint8_t *cm      = ff_crop_tab + MAX_NEG_CROP;
334
    int color_id;
335
    int y, cb, cr, alpha;
336
    int r, g, b, r_add, g_add, b_add;
337
    int id;
338
339
    id  = bytestream_get_byte(&buf);
340
    palette = find_palette(id, &ctx->palettes);
341
    if (!palette) {
342
        if (ctx->palettes.count >= MAX_EPOCH_PALETTES) {
343
            av_log(avctx, AV_LOG_ERROR, "Too many palettes in epoch\n");
344
            return AVERROR_INVALIDDATA;
345
        }
346
        palette = &ctx->palettes.palette[ctx->palettes.count++];
347
        palette->id  = id;
348
    }
349
350
    /* Skip palette version */
351
    buf += 1;
352
353
    while (buf < buf_end) {
354
        color_id  = bytestream_get_byte(&buf);
355
        y         = bytestream_get_byte(&buf);
356
        cr        = bytestream_get_byte(&buf);
357
        cb        = bytestream_get_byte(&buf);
358
        alpha     = bytestream_get_byte(&buf);
359
360
        /* Default to BT.709 colorspace. In case of <= 576 height use BT.601 */
361
        if (avctx->height <= 0 || avctx->height > 576) {
362
            YUV_TO_RGB1_CCIR_BT709(cb, cr);
363
        } else {
364
            YUV_TO_RGB1_CCIR(cb, cr);
365
        }
366
367
        YUV_TO_RGB2_CCIR(r, g, b, y);
368
369
        ff_dlog(avctx, "Color %d := (%d,%d,%d,%d)\n", color_id, r, g, b, alpha);
370
371
        /* Store color in palette */
372
        palette->clut[color_id] = RGBA(r,g,b,alpha);
373
    }
374
    return 0;
375
}
376
377
/**
378
 * Parse the presentation segment packet.
379
 *
380
 * The presentation segment contains details on the video
381
 * width, video height, x & y subtitle position.
382
 *
383
 * @param avctx contains the current codec context
384
 * @param buf pointer to the packet to process
385
 * @param buf_size size of packet to process
386
 * @todo TODO: Implement cropping
387
 */
388
static int parse_presentation_segment(AVCodecContext *avctx,
389
                                      const uint8_t *buf, int buf_size,
390
                                      int64_t pts)
391
{
392
    PGSSubContext *ctx = avctx->priv_data;
393
    int i, state, ret;
394
    const uint8_t *buf_end = buf + buf_size;
395
396
    // Video descriptor
397
    int w = bytestream_get_be16(&buf);
398
    int h = bytestream_get_be16(&buf);
399
400
    ctx->presentation.pts = pts;
401
402
    ff_dlog(avctx, "Video Dimensions %dx%d\n",
403
            w, h);
404
    ret = ff_set_dimensions(avctx, w, h);
405
    if (ret < 0)
406
        return ret;
407
408
    /* Skip 1 bytes of unknown, frame rate */
409
    buf++;
410
411
    // Composition descriptor
412
    ctx->presentation.id_number = bytestream_get_be16(&buf);
413
    /*
414
     * state is a 2 bit field that defines pgs epoch boundaries
415
     * 00 - Normal, previously defined objects and palettes are still valid
416
     * 01 - Acquisition point, previous objects and palettes can be released
417
     * 10 - Epoch start, previous objects and palettes can be released
418
     * 11 - Epoch continue, previous objects and palettes can be released
419
     *
420
     * reserved 6 bits discarded
421
     */
422
    state = bytestream_get_byte(&buf) >> 6;
423
    if (state != 0) {
424
        flush_cache(avctx);
425
    }
426
427
    /*
428
     * skip palette_update_flag (0x80),
429
     */
430
    buf += 1;
431
    ctx->presentation.palette_id = bytestream_get_byte(&buf);
432
    ctx->presentation.object_count = bytestream_get_byte(&buf);
433
    if (ctx->presentation.object_count > MAX_OBJECT_REFS) {
434
        av_log(avctx, AV_LOG_ERROR,
435
               "Invalid number of presentation objects %d\n",
436
               ctx->presentation.object_count);
437
        ctx->presentation.object_count = 2;
438
        if (avctx->err_recognition & AV_EF_EXPLODE) {
439
            return AVERROR_INVALIDDATA;
440
        }
441
    }
442
443
444
    for (i = 0; i < ctx->presentation.object_count; i++)
445
    {
446
447
        if (buf_end - buf < 8) {
448
            av_log(avctx, AV_LOG_ERROR, "Insufficent space for object\n");
449
            ctx->presentation.object_count = i;
450
            return AVERROR_INVALIDDATA;
451
        }
452
453
        ctx->presentation.objects[i].id = bytestream_get_be16(&buf);
454
        ctx->presentation.objects[i].window_id = bytestream_get_byte(&buf);
455
        ctx->presentation.objects[i].composition_flag = bytestream_get_byte(&buf);
456
457
        ctx->presentation.objects[i].x = bytestream_get_be16(&buf);
458
        ctx->presentation.objects[i].y = bytestream_get_be16(&buf);
459
460
        // If cropping
461
        if (ctx->presentation.objects[i].composition_flag & 0x80) {
462
            ctx->presentation.objects[i].crop_x = bytestream_get_be16(&buf);
463
            ctx->presentation.objects[i].crop_y = bytestream_get_be16(&buf);
464
            ctx->presentation.objects[i].crop_w = bytestream_get_be16(&buf);
465
            ctx->presentation.objects[i].crop_h = bytestream_get_be16(&buf);
466
        }
467
468
        ff_dlog(avctx, "Subtitle Placement x=%d, y=%d\n",
469
                ctx->presentation.objects[i].x, ctx->presentation.objects[i].y);
470
471
        if (ctx->presentation.objects[i].x > avctx->width ||
472
            ctx->presentation.objects[i].y > avctx->height) {
473
            av_log(avctx, AV_LOG_ERROR, "Subtitle out of video bounds. x = %d, y = %d, video width = %d, video height = %d.\n",
474
                   ctx->presentation.objects[i].x,
475
                   ctx->presentation.objects[i].y,
476
                    avctx->width, avctx->height);
477
            ctx->presentation.objects[i].x = 0;
478
            ctx->presentation.objects[i].y = 0;
479
            if (avctx->err_recognition & AV_EF_EXPLODE) {
480
                return AVERROR_INVALIDDATA;
481
            }
482
        }
483
    }
484
485
    return 0;
486
}
487
488
/**
489
 * Parse the display segment packet.
490
 *
491
 * The display segment controls the updating of the display.
492
 *
493
 * @param avctx contains the current codec context
494
 * @param data pointer to the data pertaining the subtitle to display
495
 * @param buf pointer to the packet to process
496
 * @param buf_size size of packet to process
497
 */
498
static int display_end_segment(AVCodecContext *avctx, void *data,
499
                               const uint8_t *buf, int buf_size)
500
{
501
    AVSubtitle    *sub = data;
502
    PGSSubContext *ctx = avctx->priv_data;
503
    int64_t pts;
504
    PGSSubPalette *palette;
505
    int i, ret;
506
507
    pts = ctx->presentation.pts != AV_NOPTS_VALUE ? ctx->presentation.pts : sub->pts;
508
    memset(sub, 0, sizeof(*sub));
509
    sub->pts = pts;
510
    ctx->presentation.pts = AV_NOPTS_VALUE;
511
    sub->start_display_time = 0;
512
    // There is no explicit end time for PGS subtitles.  The end time
513
    // is defined by the start of the next sub which may contain no
514
    // objects (i.e. clears the previous sub)
515
    sub->end_display_time   = UINT32_MAX;
516
    sub->format             = 0;
517
518
    // Blank if last object_count was 0.
519
    if (!ctx->presentation.object_count)
520
        return 1;
521
    sub->rects = av_mallocz_array(ctx->presentation.object_count, sizeof(*sub->rects));
522
    if (!sub->rects) {
523
        return AVERROR(ENOMEM);
524
    }
525
    palette = find_palette(ctx->presentation.palette_id, &ctx->palettes);
526
    if (!palette) {
527
        // Missing palette.  Should only happen with damaged streams.
528
        av_log(avctx, AV_LOG_ERROR, "Invalid palette id %d\n",
529
               ctx->presentation.palette_id);
530
        avsubtitle_free(sub);
531
        return AVERROR_INVALIDDATA;
532
    }
533
    for (i = 0; i < ctx->presentation.object_count; i++) {
534
        PGSSubObject *object;
535
536
        sub->rects[i]  = av_mallocz(sizeof(*sub->rects[0]));
537
        if (!sub->rects[i]) {
538
            avsubtitle_free(sub);
539
            return AVERROR(ENOMEM);
540
        }
541
        sub->num_rects++;
542
        sub->rects[i]->type = SUBTITLE_BITMAP;
543
544
        /* Process bitmap */
545
        object = find_object(ctx->presentation.objects[i].id, &ctx->objects);
546
        if (!object) {
547
            // Missing object.  Should only happen with damaged streams.
548
            av_log(avctx, AV_LOG_ERROR, "Invalid object id %d\n",
549
                   ctx->presentation.objects[i].id);
550
            if (avctx->err_recognition & AV_EF_EXPLODE) {
551
                avsubtitle_free(sub);
552
                return AVERROR_INVALIDDATA;
553
            }
554
            // Leaves rect empty with 0 width and height.
555
            continue;
556
        }
557
        if (ctx->presentation.objects[i].composition_flag & 0x40)
558
            sub->rects[i]->flags |= AV_SUBTITLE_FLAG_FORCED;
559
560
        sub->rects[i]->x    = ctx->presentation.objects[i].x;
561
        sub->rects[i]->y    = ctx->presentation.objects[i].y;
562
563
        if (object->rle) {
564
            sub->rects[i]->w    = object->w;
565
            sub->rects[i]->h    = object->h;
566
567
            sub->rects[i]->linesize[0] = object->w;
568
569
            if (object->rle_remaining_len) {
570
                av_log(avctx, AV_LOG_ERROR, "RLE data length %u is %u bytes shorter than expected\n",
571
                       object->rle_data_len, object->rle_remaining_len);
572
                if (avctx->err_recognition & AV_EF_EXPLODE) {
573
                    avsubtitle_free(sub);
574
                    return AVERROR_INVALIDDATA;
575
                }
576
            }
577
            ret = decode_rle(avctx, sub->rects[i], object->rle, object->rle_data_len);
578
            if (ret < 0) {
579
                if ((avctx->err_recognition & AV_EF_EXPLODE) ||
580
                    ret == AVERROR(ENOMEM)) {
581
                    avsubtitle_free(sub);
582
                    return ret;
583
                }
584
                sub->rects[i]->w = 0;
585
                sub->rects[i]->h = 0;
586
                continue;
587
            }
588
        }
589
        /* Allocate memory for colors */
590
        sub->rects[i]->nb_colors    = 256;
591
        sub->rects[i]->data[1] = av_mallocz(AVPALETTE_SIZE);
592
        if (!sub->rects[i]->data[1]) {
593
            avsubtitle_free(sub);
594
            return AVERROR(ENOMEM);
595
        }
596
597
        if (!ctx->forced_subs_only || ctx->presentation.objects[i].composition_flag & 0x40)
598
        memcpy(sub->rects[i]->data[1], palette->clut, sub->rects[i]->nb_colors * sizeof(uint32_t));
599
600
#if FF_API_AVPICTURE
601
FF_DISABLE_DEPRECATION_WARNINGS
602
{
603
        AVSubtitleRect *rect;
604
        int j;
605
        rect = sub->rects[i];
606
        for (j = 0; j < 4; j++) {
607
            rect->pict.data[j] = rect->data[j];
608
            rect->pict.linesize[j] = rect->linesize[j];
609
        }
610
}
611
FF_ENABLE_DEPRECATION_WARNINGS
612
#endif
613
    }
614
    return 1;
615
}
616
617
static int decode(AVCodecContext *avctx, void *data, int *data_size,
618
                  AVPacket *avpkt)
619
{
620
    const uint8_t *buf = avpkt->data;
621
    int buf_size       = avpkt->size;
622
623
    const uint8_t *buf_end;
624
    uint8_t       segment_type;
625
    int           segment_length;
626
    int i, ret;
627
628
    ff_dlog(avctx, "PGS sub packet:\n");
629
630
    for (i = 0; i < buf_size; i++) {
631
        ff_dlog(avctx, "%02x ", buf[i]);
632
        if (i % 16 == 15)
633
            ff_dlog(avctx, "\n");
634
    }
635
636
    if (i & 15)
637
        ff_dlog(avctx, "\n");
638
639
    *data_size = 0;
640
641
    /* Ensure that we have received at a least a segment code and segment length */
642
    if (buf_size < 3)
643
        return -1;
644
645
    buf_end = buf + buf_size;
646
647
    /* Step through buffer to identify segments */
648
    while (buf < buf_end) {
649
        segment_type   = bytestream_get_byte(&buf);
650
        segment_length = bytestream_get_be16(&buf);
651
652
        ff_dlog(avctx, "Segment Length %d, Segment Type %x\n", segment_length, segment_type);
653
654
        if (segment_type != DISPLAY_SEGMENT && segment_length > buf_end - buf)
655
            break;
656
657
        ret = 0;
658
        switch (segment_type) {
659
        case PALETTE_SEGMENT:
660
            ret = parse_palette_segment(avctx, buf, segment_length);
661
            break;
662
        case OBJECT_SEGMENT:
663
            ret = parse_object_segment(avctx, buf, segment_length);
664
            break;
665
        case PRESENTATION_SEGMENT:
666
            ret = parse_presentation_segment(avctx, buf, segment_length, ((AVSubtitle*)(data))->pts);
667
            break;
668
        case WINDOW_SEGMENT:
669
            /*
670
             * Window Segment Structure (No new information provided):
671
             *     2 bytes: Unknown,
672
             *     2 bytes: X position of subtitle,
673
             *     2 bytes: Y position of subtitle,
674
             *     2 bytes: Width of subtitle,
675
             *     2 bytes: Height of subtitle.
676
             */
677
            break;
678
        case DISPLAY_SEGMENT:
679
            if (*data_size) {
680
                av_log(avctx, AV_LOG_ERROR, "Duplicate display segment\n");
681
                ret = AVERROR_INVALIDDATA;
682
                break;
683
            }
684
            ret = display_end_segment(avctx, data, buf, segment_length);
685
            if (ret >= 0)
686
                *data_size = ret;
687
            break;
688
        default:
689
            av_log(avctx, AV_LOG_ERROR, "Unknown subtitle segment type 0x%x, length %d\n",
690
                   segment_type, segment_length);
691
            ret = AVERROR_INVALIDDATA;
692
            break;
693
        }
694
        if (ret < 0 && (avctx->err_recognition & AV_EF_EXPLODE))
695
            return ret;
696
697
        buf += segment_length;
698
    }
699
700
    return buf_size;
701
}
702
703
#define OFFSET(x) offsetof(PGSSubContext, x)
704
#define SD AV_OPT_FLAG_SUBTITLE_PARAM | AV_OPT_FLAG_DECODING_PARAM
705
static const AVOption options[] = {
706
    {"forced_subs_only", "Only show forced subtitles", OFFSET(forced_subs_only), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, SD},
707
    { NULL },
708
};
709
710
static const AVClass pgsdec_class = {
711
    .class_name = "PGS subtitle decoder",
712
    .item_name  = av_default_item_name,
713
    .option     = options,
714
    .version    = LIBAVUTIL_VERSION_INT,
715
};
716
717
AVCodec ff_pgssub_decoder = {
718
    .name           = "pgssub",
719
    .long_name      = NULL_IF_CONFIG_SMALL("HDMV Presentation Graphic Stream subtitles"),
720
    .type           = AVMEDIA_TYPE_SUBTITLE,
721
    .id             = AV_CODEC_ID_HDMV_PGS_SUBTITLE,
722
    .priv_data_size = sizeof(PGSSubContext),
723
    .init           = init_decoder,
724
    .close          = close_decoder,
725
    .decode         = decode,
726
    .priv_class     = &pgsdec_class,
727
};