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ffmpeg / libavcodec / dvdsubdec.c @ 7a886063

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1 240c1657 Fabrice Bellard
/*
2
 * DVD subtitle decoding for ffmpeg
3
 * Copyright (c) 2005 Fabrice Bellard.
4
 *
5 b78e7197 Diego Biurrun
 * This file is part of FFmpeg.
6
 *
7
 * FFmpeg is free software; you can redistribute it and/or
8 240c1657 Fabrice Bellard
 * modify it under the terms of the GNU Lesser General Public
9
 * License as published by the Free Software Foundation; either
10 b78e7197 Diego Biurrun
 * version 2.1 of the License, or (at your option) any later version.
11 240c1657 Fabrice Bellard
 *
12 b78e7197 Diego Biurrun
 * FFmpeg is distributed in the hope that it will be useful,
13 240c1657 Fabrice Bellard
 * 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 b78e7197 Diego Biurrun
 * License along with FFmpeg; if not, write to the Free Software
19 5509bffa Diego Biurrun
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 240c1657 Fabrice Bellard
 */
21
#include "avcodec.h"
22
23
//#define DEBUG
24
25
static int dvdsub_init_decoder(AVCodecContext *avctx)
26
{
27
    return 0;
28
}
29
30 ceaf1909 Dieter
static uint16_t getbe16(const uint8_t *p)
31 240c1657 Fabrice Bellard
{
32
    return (p[0] << 8) | p[1];
33
}
34
35 ceaf1909 Dieter
static int get_nibble(const uint8_t *buf, int nibble_offset)
36 240c1657 Fabrice Bellard
{
37
    return (buf[nibble_offset >> 1] >> ((1 - (nibble_offset & 1)) << 2)) & 0xf;
38
}
39
40 115329f1 Diego Biurrun
static int decode_rle(uint8_t *bitmap, int linesize, int w, int h,
41 240c1657 Fabrice Bellard
                      const uint8_t *buf, int nibble_offset, int buf_size)
42
{
43
    unsigned int v;
44
    int x, y, len, color, nibble_end;
45
    uint8_t *d;
46
47
    nibble_end = buf_size * 2;
48
    x = 0;
49
    y = 0;
50
    d = bitmap;
51
    for(;;) {
52
        if (nibble_offset >= nibble_end)
53
            return -1;
54
        v = get_nibble(buf, nibble_offset++);
55
        if (v < 0x4) {
56
            v = (v << 4) | get_nibble(buf, nibble_offset++);
57
            if (v < 0x10) {
58
                v = (v << 4) | get_nibble(buf, nibble_offset++);
59
                if (v < 0x040) {
60
                    v = (v << 4) | get_nibble(buf, nibble_offset++);
61
                    if (v < 4) {
62
                        v |= (w - x) << 2;
63
                    }
64
                }
65
            }
66
        }
67
        len = v >> 2;
68
        if (len > (w - x))
69
            len = (w - x);
70
        color = v & 0x03;
71
        memset(d + x, color, len);
72
        x += len;
73
        if (x >= w) {
74
            y++;
75
            if (y >= h)
76
                break;
77
            d += linesize;
78
            x = 0;
79
            /* byte align */
80
            nibble_offset += (nibble_offset & 1);
81
        }
82
    }
83
    return 0;
84
}
85
86
static void guess_palette(uint32_t *rgba_palette,
87
                          uint8_t *palette,
88
                          uint8_t *alpha,
89
                          uint32_t subtitle_color)
90
{
91
    uint8_t color_used[16];
92
    int nb_opaque_colors, i, level, j, r, g, b;
93 115329f1 Diego Biurrun
94 240c1657 Fabrice Bellard
    for(i = 0; i < 4; i++)
95
        rgba_palette[i] = 0;
96
97
    memset(color_used, 0, 16);
98
    nb_opaque_colors = 0;
99
    for(i = 0; i < 4; i++) {
100
        if (alpha[i] != 0 && !color_used[palette[i]]) {
101
            color_used[palette[i]] = 1;
102
            nb_opaque_colors++;
103
        }
104
    }
105 115329f1 Diego Biurrun
106 240c1657 Fabrice Bellard
    if (nb_opaque_colors == 0)
107
        return;
108 115329f1 Diego Biurrun
109 bf01fb69 Ian Caulfield
    j = nb_opaque_colors;
110 240c1657 Fabrice Bellard
    memset(color_used, 0, 16);
111
    for(i = 0; i < 4; i++) {
112
        if (alpha[i] != 0) {
113
            if (!color_used[palette[i]])  {
114 bf01fb69 Ian Caulfield
                level = (0xff * j) / nb_opaque_colors;
115 240c1657 Fabrice Bellard
                r = (((subtitle_color >> 16) & 0xff) * level) >> 8;
116
                g = (((subtitle_color >> 8) & 0xff) * level) >> 8;
117
                b = (((subtitle_color >> 0) & 0xff) * level) >> 8;
118 bf01fb69 Ian Caulfield
                rgba_palette[i] = b | (g << 8) | (r << 16) | ((alpha[i] * 17) << 24);
119 240c1657 Fabrice Bellard
                color_used[palette[i]] = (i + 1);
120 bf01fb69 Ian Caulfield
                j--;
121 240c1657 Fabrice Bellard
            } else {
122 bf01fb69 Ian Caulfield
                rgba_palette[i] = (rgba_palette[color_used[palette[i]] - 1] & 0x00ffffff) |
123
                                    ((alpha[i] * 17) << 24);
124 240c1657 Fabrice Bellard
            }
125
        }
126
    }
127
}
128
129 115329f1 Diego Biurrun
static int decode_dvd_subtitles(AVSubtitle *sub_header,
130 240c1657 Fabrice Bellard
                                const uint8_t *buf, int buf_size)
131
{
132
    int cmd_pos, pos, cmd, x1, y1, x2, y2, offset1, offset2, next_cmd_pos;
133
    uint8_t palette[4], alpha[4];
134
    int date;
135 50e2450b Michael Niedermayer
    int i;
136 bf01fb69 Ian Caulfield
    int is_menu = 0;
137 115329f1 Diego Biurrun
138 240c1657 Fabrice Bellard
    if (buf_size < 4)
139
        return -1;
140 50e2450b Michael Niedermayer
    sub_header->rects = NULL;
141
    sub_header->num_rects = 0;
142 240c1657 Fabrice Bellard
    sub_header->start_display_time = 0;
143
    sub_header->end_display_time = 0;
144
145
    cmd_pos = getbe16(buf + 2);
146
    while ((cmd_pos + 4) < buf_size) {
147
        date = getbe16(buf + cmd_pos);
148
        next_cmd_pos = getbe16(buf + cmd_pos + 2);
149
#ifdef DEBUG
150 115329f1 Diego Biurrun
        av_log(NULL, AV_LOG_INFO, "cmd_pos=0x%04x next=0x%04x date=%d\n",
151 240c1657 Fabrice Bellard
               cmd_pos, next_cmd_pos, date);
152
#endif
153
        pos = cmd_pos + 4;
154
        offset1 = -1;
155
        offset2 = -1;
156
        x1 = y1 = x2 = y2 = 0;
157
        while (pos < buf_size) {
158
            cmd = buf[pos++];
159
#ifdef DEBUG
160
            av_log(NULL, AV_LOG_INFO, "cmd=%02x\n", cmd);
161
#endif
162
            switch(cmd) {
163
            case 0x00:
164 bf01fb69 Ian Caulfield
                /* menu subpicture */
165
                is_menu = 1;
166 240c1657 Fabrice Bellard
                break;
167
            case 0x01:
168
                /* set start date */
169 bf01fb69 Ian Caulfield
                sub_header->start_display_time = (date << 10) / 90;
170 240c1657 Fabrice Bellard
                break;
171
            case 0x02:
172
                /* set end date */
173 bf01fb69 Ian Caulfield
                sub_header->end_display_time = (date << 10) / 90;
174 240c1657 Fabrice Bellard
                break;
175
            case 0x03:
176
                /* set palette */
177
                if ((buf_size - pos) < 2)
178
                    goto fail;
179 bf01fb69 Ian Caulfield
                palette[3] = buf[pos] >> 4;
180
                palette[2] = buf[pos] & 0x0f;
181
                palette[1] = buf[pos + 1] >> 4;
182
                palette[0] = buf[pos + 1] & 0x0f;
183 240c1657 Fabrice Bellard
                pos += 2;
184
                break;
185
            case 0x04:
186
                /* set alpha */
187
                if ((buf_size - pos) < 2)
188
                    goto fail;
189 bf01fb69 Ian Caulfield
                alpha[3] = buf[pos] >> 4;
190
                alpha[2] = buf[pos] & 0x0f;
191
                alpha[1] = buf[pos + 1] >> 4;
192
                alpha[0] = buf[pos + 1] & 0x0f;
193 240c1657 Fabrice Bellard
                pos += 2;
194 bf01fb69 Ian Caulfield
#ifdef DEBUG
195
            av_log(NULL, AV_LOG_INFO, "alpha=%x%x%x%x\n", alpha[0],alpha[1],alpha[2],alpha[3]);
196
#endif
197 240c1657 Fabrice Bellard
                break;
198
            case 0x05:
199
                if ((buf_size - pos) < 6)
200
                    goto fail;
201
                x1 = (buf[pos] << 4) | (buf[pos + 1] >> 4);
202
                x2 = ((buf[pos + 1] & 0x0f) << 8) | buf[pos + 2];
203
                y1 = (buf[pos + 3] << 4) | (buf[pos + 4] >> 4);
204
                y2 = ((buf[pos + 4] & 0x0f) << 8) | buf[pos + 5];
205
#ifdef DEBUG
206
                av_log(NULL, AV_LOG_INFO, "x1=%d x2=%d y1=%d y2=%d\n",
207
                       x1, x2, y1, y2);
208
#endif
209
                pos += 6;
210
                break;
211
            case 0x06:
212
                if ((buf_size - pos) < 4)
213
                    goto fail;
214
                offset1 = getbe16(buf + pos);
215
                offset2 = getbe16(buf + pos + 2);
216
#ifdef DEBUG
217
                av_log(NULL, AV_LOG_INFO, "offset1=0x%04x offset2=0x%04x\n", offset1, offset2);
218
#endif
219
                pos += 4;
220
                break;
221
            case 0xff:
222
            default:
223
                goto the_end;
224
            }
225
        }
226
    the_end:
227
        if (offset1 >= 0) {
228
            int w, h;
229
            uint8_t *bitmap;
230 115329f1 Diego Biurrun
231 240c1657 Fabrice Bellard
            /* decode the bitmap */
232
            w = x2 - x1 + 1;
233
            if (w < 0)
234
                w = 0;
235
            h = y2 - y1;
236
            if (h < 0)
237
                h = 0;
238
            if (w > 0 && h > 0) {
239 50e2450b Michael Niedermayer
                if (sub_header->rects != NULL) {
240
                    for (i = 0; i < sub_header->num_rects; i++) {
241
                        av_free(sub_header->rects[i].bitmap);
242
                        av_free(sub_header->rects[i].rgba_palette);
243
                    }
244
                    av_freep(&sub_header->rects);
245
                    sub_header->num_rects = 0;
246
                }
247
248 240c1657 Fabrice Bellard
                bitmap = av_malloc(w * h);
249 50e2450b Michael Niedermayer
                sub_header->rects = av_mallocz(sizeof(AVSubtitleRect));
250
                sub_header->num_rects = 1;
251
                sub_header->rects[0].rgba_palette = av_malloc(4 * 4);
252 240c1657 Fabrice Bellard
                decode_rle(bitmap, w * 2, w, h / 2,
253
                           buf, offset1 * 2, buf_size);
254
                decode_rle(bitmap + w, w * 2, w, h / 2,
255
                           buf, offset2 * 2, buf_size);
256 50e2450b Michael Niedermayer
                guess_palette(sub_header->rects[0].rgba_palette,
257 240c1657 Fabrice Bellard
                              palette, alpha, 0xffff00);
258 50e2450b Michael Niedermayer
                sub_header->rects[0].x = x1;
259
                sub_header->rects[0].y = y1;
260
                sub_header->rects[0].w = w;
261
                sub_header->rects[0].h = h;
262
                sub_header->rects[0].nb_colors = 4;
263
                sub_header->rects[0].linesize = w;
264
                sub_header->rects[0].bitmap = bitmap;
265 240c1657 Fabrice Bellard
            }
266
        }
267
        if (next_cmd_pos == cmd_pos)
268
            break;
269
        cmd_pos = next_cmd_pos;
270
    }
271 50e2450b Michael Niedermayer
    if (sub_header->num_rects > 0)
272 bf01fb69 Ian Caulfield
        return is_menu;
273 240c1657 Fabrice Bellard
 fail:
274
    return -1;
275
}
276
277 115329f1 Diego Biurrun
static int is_transp(const uint8_t *buf, int pitch, int n,
278 240c1657 Fabrice Bellard
                     const uint8_t *transp_color)
279
{
280
    int i;
281
    for(i = 0; i < n; i++) {
282
        if (!transp_color[*buf])
283
            return 0;
284
        buf += pitch;
285
    }
286
    return 1;
287
}
288
289
/* return 0 if empty rectangle, 1 if non empty */
290 bf01fb69 Ian Caulfield
static int find_smallest_bounding_rectangle(AVSubtitle *s)
291 240c1657 Fabrice Bellard
{
292
    uint8_t transp_color[256];
293
    int y1, y2, x1, x2, y, w, h, i;
294
    uint8_t *bitmap;
295
296 50e2450b Michael Niedermayer
    if (s->num_rects == 0 || s->rects == NULL || s->rects[0].w <= 0 || s->rects[0].h <= 0)
297 240c1657 Fabrice Bellard
        return 0;
298
299
    memset(transp_color, 0, 256);
300 50e2450b Michael Niedermayer
    for(i = 0; i < s->rects[0].nb_colors; i++) {
301
        if ((s->rects[0].rgba_palette[i] >> 24) == 0)
302 240c1657 Fabrice Bellard
            transp_color[i] = 1;
303
    }
304
    y1 = 0;
305 50e2450b Michael Niedermayer
    while (y1 < s->rects[0].h && is_transp(s->rects[0].bitmap + y1 * s->rects[0].linesize,
306
                                  1, s->rects[0].w, transp_color))
307 240c1657 Fabrice Bellard
        y1++;
308 50e2450b Michael Niedermayer
    if (y1 == s->rects[0].h) {
309
        av_freep(&s->rects[0].bitmap);
310
        s->rects[0].w = s->rects[0].h = 0;
311 240c1657 Fabrice Bellard
        return 0;
312
    }
313
314 50e2450b Michael Niedermayer
    y2 = s->rects[0].h - 1;
315
    while (y2 > 0 && is_transp(s->rects[0].bitmap + y2 * s->rects[0].linesize, 1,
316
                               s->rects[0].w, transp_color))
317 240c1657 Fabrice Bellard
        y2--;
318
    x1 = 0;
319 50e2450b Michael Niedermayer
    while (x1 < (s->rects[0].w - 1) && is_transp(s->rects[0].bitmap + x1, s->rects[0].linesize,
320
                                        s->rects[0].h, transp_color))
321 240c1657 Fabrice Bellard
        x1++;
322 50e2450b Michael Niedermayer
    x2 = s->rects[0].w - 1;
323
    while (x2 > 0 && is_transp(s->rects[0].bitmap + x2, s->rects[0].linesize, s->rects[0].h,
324 240c1657 Fabrice Bellard
                                  transp_color))
325
        x2--;
326
    w = x2 - x1 + 1;
327
    h = y2 - y1 + 1;
328
    bitmap = av_malloc(w * h);
329
    if (!bitmap)
330
        return 1;
331
    for(y = 0; y < h; y++) {
332 50e2450b Michael Niedermayer
        memcpy(bitmap + w * y, s->rects[0].bitmap + x1 + (y1 + y) * s->rects[0].linesize, w);
333 240c1657 Fabrice Bellard
    }
334 50e2450b Michael Niedermayer
    av_freep(&s->rects[0].bitmap);
335
    s->rects[0].bitmap = bitmap;
336
    s->rects[0].linesize = w;
337
    s->rects[0].w = w;
338
    s->rects[0].h = h;
339
    s->rects[0].x += x1;
340
    s->rects[0].y += y1;
341 240c1657 Fabrice Bellard
    return 1;
342
}
343
344
static int dvdsub_close_decoder(AVCodecContext *avctx)
345
{
346
    return 0;
347
}
348
349
#ifdef DEBUG
350
#undef fprintf
351
static void ppm_save(const char *filename, uint8_t *bitmap, int w, int h,
352
                     uint32_t *rgba_palette)
353
{
354
    int x, y, v;
355
    FILE *f;
356
357
    f = fopen(filename, "w");
358
    if (!f) {
359
        perror(filename);
360
        exit(1);
361
    }
362
    fprintf(f, "P6\n"
363
            "%d %d\n"
364
            "%d\n",
365
            w, h, 255);
366
    for(y = 0; y < h; y++) {
367
        for(x = 0; x < w; x++) {
368
            v = rgba_palette[bitmap[y * w + x]];
369
            putc((v >> 16) & 0xff, f);
370
            putc((v >> 8) & 0xff, f);
371
            putc((v >> 0) & 0xff, f);
372
        }
373
    }
374
    fclose(f);
375
}
376
#endif
377
378
static int dvdsub_decode(AVCodecContext *avctx,
379
                         void *data, int *data_size,
380
                         uint8_t *buf, int buf_size)
381
{
382
    AVSubtitle *sub = (void *)data;
383 bf01fb69 Ian Caulfield
    int is_menu;
384
385
    is_menu = decode_dvd_subtitles(sub, buf, buf_size);
386 240c1657 Fabrice Bellard
387 bf01fb69 Ian Caulfield
    if (is_menu < 0) {
388 240c1657 Fabrice Bellard
    no_subtitle:
389
        *data_size = 0;
390
391
        return buf_size;
392
    }
393 bf01fb69 Ian Caulfield
    if (!is_menu && find_smallest_bounding_rectangle(sub) == 0)
394 240c1657 Fabrice Bellard
        goto no_subtitle;
395
396
#if defined(DEBUG)
397 115329f1 Diego Biurrun
    av_log(NULL, AV_LOG_INFO, "start=%d ms end =%d ms\n",
398 240c1657 Fabrice Bellard
           sub->start_display_time,
399
           sub->end_display_time);
400 50e2450b Michael Niedermayer
    ppm_save("/tmp/a.ppm", sub->rects[0].bitmap,
401
             sub->rects[0].w, sub->rects[0].h, sub->rects[0].rgba_palette);
402 240c1657 Fabrice Bellard
#endif
403
404
    *data_size = 1;
405
    return buf_size;
406
}
407
408
AVCodec dvdsub_decoder = {
409
    "dvdsub",
410
    CODEC_TYPE_SUBTITLE,
411
    CODEC_ID_DVD_SUBTITLE,
412 8aaed74c Steve L'Homme
    0,
413 240c1657 Fabrice Bellard
    dvdsub_init_decoder,
414
    NULL,
415
    dvdsub_close_decoder,
416
    dvdsub_decode,
417
};
418
419
/* parser definition */
420
typedef struct DVDSubParseContext {
421
    uint8_t *packet;
422
    int packet_len;
423
    int packet_index;
424
} DVDSubParseContext;
425
426
static int dvdsub_parse_init(AVCodecParserContext *s)
427
{
428
    return 0;
429
}
430
431
static int dvdsub_parse(AVCodecParserContext *s,
432
                        AVCodecContext *avctx,
433 115329f1 Diego Biurrun
                        uint8_t **poutbuf, int *poutbuf_size,
434 240c1657 Fabrice Bellard
                        const uint8_t *buf, int buf_size)
435
{
436
    DVDSubParseContext *pc = s->priv_data;
437 115329f1 Diego Biurrun
438 240c1657 Fabrice Bellard
    if (pc->packet_index == 0) {
439
        if (buf_size < 2)
440
            return 0;
441
        pc->packet_len = (buf[0] << 8) | buf[1];
442
        av_freep(&pc->packet);
443
        pc->packet = av_malloc(pc->packet_len);
444
    }
445
    if (pc->packet) {
446
        if (pc->packet_index + buf_size <= pc->packet_len) {
447
            memcpy(pc->packet + pc->packet_index, buf, buf_size);
448
            pc->packet_index += buf_size;
449
            if (pc->packet_index >= pc->packet_len) {
450
                *poutbuf = pc->packet;
451
                *poutbuf_size = pc->packet_len;
452
                pc->packet_index = 0;
453
                return buf_size;
454
            }
455
        } else {
456
            /* erroneous size */
457
            pc->packet_index = 0;
458
        }
459
    }
460
    *poutbuf = NULL;
461
    *poutbuf_size = 0;
462
    return buf_size;
463
}
464
465
static void dvdsub_parse_close(AVCodecParserContext *s)
466
{
467
    DVDSubParseContext *pc = s->priv_data;
468
    av_freep(&pc->packet);
469
}
470
471
AVCodecParser dvdsub_parser = {
472
    { CODEC_ID_DVD_SUBTITLE },
473
    sizeof(DVDSubParseContext),
474
    dvdsub_parse_init,
475
    dvdsub_parse,
476
    dvdsub_parse_close,
477
};