2 * DVD subtitle decoding
3 * Copyright (c) 2005 Fabrice Bellard
5 * This file is part of FFmpeg.
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.
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.
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
26 #include "libavutil/attributes.h"
27 #include "libavutil/colorspace.h"
28 #include "libavutil/opt.h"
29 #include "libavutil/imgutils.h"
30 #include "libavutil/avstring.h"
32 typedef struct DVDSubContext
47 static void yuv_a_to_rgba(const uint8_t *ycbcr
, const uint8_t *alpha
, uint32_t *rgba
, int num_values
)
49 const uint8_t *cm
= ff_crop_tab
+ MAX_NEG_CROP
;
52 int r_add
, g_add
, b_add
;
54 for (i
= num_values
; i
> 0; i
--) {
58 YUV_TO_RGB1_CCIR(cb
, cr
);
59 YUV_TO_RGB2_CCIR(r
, g
, b
, y
);
60 *rgba
++ = (*alpha
++ << 24) | (r
<< 16) | (g
<< 8) | b
;
64 static int decode_run_2bit(GetBitContext
*gb
, int *color
)
69 for (t
= 1; v
< t
&& t
<= 0x40; t
<<= 2)
70 v
= (v
<< 4) | get_bits(gb
, 4);
72 if (v
< 4) { /* Code for fill rest of line */
78 static int decode_run_8bit(GetBitContext
*gb
, int *color
)
81 int has_run
= get_bits1(gb
);
83 *color
= get_bits(gb
, 8);
85 *color
= get_bits(gb
, 2);
88 len
= get_bits(gb
, 7);
94 len
= get_bits(gb
, 3) + 2;
100 static int decode_rle(uint8_t *bitmap
, int linesize
, int w
, int h
,
101 const uint8_t *buf
, int start
, int buf_size
, int is_8bit
)
105 int x
, y
, len
, color
;
108 bit_len
= (buf_size
- start
) * 8;
109 init_get_bits(&gb
, buf
+ start
, bit_len
);
115 if (get_bits_count(&gb
) > bit_len
)
118 len
= decode_run_8bit(&gb
, &color
);
120 len
= decode_run_2bit(&gb
, &color
);
121 len
= FFMIN(len
, w
- x
);
122 memset(d
+ x
, color
, len
);
137 static void guess_palette(DVDSubContext
* ctx
,
138 uint32_t *rgba_palette
,
139 uint32_t subtitle_color
)
141 static const uint8_t level_map
[4][4] = {
142 // this configuration (full range, lowest to highest) in tests
143 // seemed most common, so assume this
147 {0x00, 0x55, 0xaa, 0xff},
149 uint8_t color_used
[16] = { 0 };
150 int nb_opaque_colors
, i
, level
, j
, r
, g
, b
;
151 uint8_t *colormap
= ctx
->colormap
, *alpha
= ctx
->alpha
;
153 if(ctx
->has_palette
) {
154 for(i
= 0; i
< 4; i
++)
155 rgba_palette
[i
] = (ctx
->palette
[colormap
[i
]] & 0x00ffffff)
156 | ((alpha
[i
] * 17U) << 24);
160 for(i
= 0; i
< 4; i
++)
163 nb_opaque_colors
= 0;
164 for(i
= 0; i
< 4; i
++) {
165 if (alpha
[i
] != 0 && !color_used
[colormap
[i
]]) {
166 color_used
[colormap
[i
]] = 1;
171 if (nb_opaque_colors
== 0)
175 memset(color_used
, 0, 16);
176 for(i
= 0; i
< 4; i
++) {
178 if (!color_used
[colormap
[i
]]) {
179 level
= level_map
[nb_opaque_colors
][j
];
180 r
= (((subtitle_color
>> 16) & 0xff) * level
) >> 8;
181 g
= (((subtitle_color
>> 8) & 0xff) * level
) >> 8;
182 b
= (((subtitle_color
>> 0) & 0xff) * level
) >> 8;
183 rgba_palette
[i
] = b
| (g
<< 8) | (r
<< 16) | ((alpha
[i
] * 17) << 24);
184 color_used
[colormap
[i
]] = (i
+ 1);
187 rgba_palette
[i
] = (rgba_palette
[color_used
[colormap
[i
]] - 1] & 0x00ffffff) |
188 ((alpha
[i
] * 17) << 24);
194 static void reset_rects(AVSubtitle
*sub_header
)
198 if (sub_header
->rects
) {
199 for (i
= 0; i
< sub_header
->num_rects
; i
++) {
200 av_freep(&sub_header
->rects
[i
]->pict
.data
[0]);
201 av_freep(&sub_header
->rects
[i
]->pict
.data
[1]);
202 av_freep(&sub_header
->rects
[i
]);
204 av_freep(&sub_header
->rects
);
205 sub_header
->num_rects
= 0;
209 #define READ_OFFSET(a) (big_offsets ? AV_RB32(a) : AV_RB16(a))
211 static int decode_dvd_subtitles(DVDSubContext
*ctx
, AVSubtitle
*sub_header
,
212 const uint8_t *buf
, int buf_size
)
214 int cmd_pos
, pos
, cmd
, x1
, y1
, x2
, y2
, offset1
, offset2
, next_cmd_pos
;
215 int big_offsets
, offset_size
, is_8bit
= 0;
216 const uint8_t *yuv_palette
= NULL
;
217 uint8_t *colormap
= ctx
->colormap
, *alpha
= ctx
->alpha
;
225 if (AV_RB16(buf
) == 0) { /* HD subpicture with 4-byte offsets */
235 cmd_pos
= READ_OFFSET(buf
+ cmd_pos
);
237 if (cmd_pos
< 0 || cmd_pos
> buf_size
- 2 - offset_size
)
238 return AVERROR(EAGAIN
);
240 while (cmd_pos
> 0 && cmd_pos
< buf_size
- 2 - offset_size
) {
241 date
= AV_RB16(buf
+ cmd_pos
);
242 next_cmd_pos
= READ_OFFSET(buf
+ cmd_pos
+ 2);
243 av_dlog(NULL
, "cmd_pos=0x%04x next=0x%04x date=%d\n",
244 cmd_pos
, next_cmd_pos
, date
);
245 pos
= cmd_pos
+ 2 + offset_size
;
248 x1
= y1
= x2
= y2
= 0;
249 while (pos
< buf_size
) {
251 av_dlog(NULL
, "cmd=%02x\n", cmd
);
254 /* menu subpicture */
259 sub_header
->start_display_time
= (date
<< 10) / 90;
263 sub_header
->end_display_time
= (date
<< 10) / 90;
267 if ((buf_size
- pos
) < 2)
269 colormap
[3] = buf
[pos
] >> 4;
270 colormap
[2] = buf
[pos
] & 0x0f;
271 colormap
[1] = buf
[pos
+ 1] >> 4;
272 colormap
[0] = buf
[pos
+ 1] & 0x0f;
277 if ((buf_size
- pos
) < 2)
279 alpha
[3] = buf
[pos
] >> 4;
280 alpha
[2] = buf
[pos
] & 0x0f;
281 alpha
[1] = buf
[pos
+ 1] >> 4;
282 alpha
[0] = buf
[pos
+ 1] & 0x0f;
284 av_dlog(NULL
, "alpha=%x%x%x%x\n", alpha
[0],alpha
[1],alpha
[2],alpha
[3]);
288 if ((buf_size
- pos
) < 6)
290 x1
= (buf
[pos
] << 4) | (buf
[pos
+ 1] >> 4);
291 x2
= ((buf
[pos
+ 1] & 0x0f) << 8) | buf
[pos
+ 2];
292 y1
= (buf
[pos
+ 3] << 4) | (buf
[pos
+ 4] >> 4);
293 y2
= ((buf
[pos
+ 4] & 0x0f) << 8) | buf
[pos
+ 5];
296 av_dlog(NULL
, "x1=%d x2=%d y1=%d y2=%d\n", x1
, x2
, y1
, y2
);
300 if ((buf_size
- pos
) < 4)
302 offset1
= AV_RB16(buf
+ pos
);
303 offset2
= AV_RB16(buf
+ pos
+ 2);
304 av_dlog(NULL
, "offset1=0x%04x offset2=0x%04x\n", offset1
, offset2
);
308 if ((buf_size
- pos
) < 8)
310 offset1
= AV_RB32(buf
+ pos
);
311 offset2
= AV_RB32(buf
+ pos
+ 4);
312 av_dlog(NULL
, "offset1=0x%04x offset2=0x%04x\n", offset1
, offset2
);
318 if ((buf_size
- pos
) < 768)
320 yuv_palette
= buf
+ pos
;
324 /* HD set contrast (alpha) */
325 if ((buf_size
- pos
) < 256)
327 for (i
= 0; i
< 256; i
++)
328 alpha
[i
] = 0xFF - buf
[pos
+i
];
335 av_dlog(NULL
, "unrecognised subpicture command 0x%x\n", cmd
);
344 /* decode the bitmap */
351 if (w
> 0 && h
> 0) {
352 reset_rects(sub_header
);
354 bitmap
= av_malloc(w
* h
);
355 sub_header
->rects
= av_mallocz(sizeof(*sub_header
->rects
));
356 sub_header
->rects
[0] = av_mallocz(sizeof(AVSubtitleRect
));
357 sub_header
->num_rects
= 1;
358 sub_header
->rects
[0]->pict
.data
[0] = bitmap
;
359 decode_rle(bitmap
, w
* 2, w
, (h
+ 1) / 2,
360 buf
, offset1
, buf_size
, is_8bit
);
361 decode_rle(bitmap
+ w
, w
* 2, w
, h
/ 2,
362 buf
, offset2
, buf_size
, is_8bit
);
363 sub_header
->rects
[0]->pict
.data
[1] = av_mallocz(AVPALETTE_SIZE
);
367 sub_header
->rects
[0]->nb_colors
= 256;
368 yuv_a_to_rgba(yuv_palette
, alpha
, (uint32_t*)sub_header
->rects
[0]->pict
.data
[1], 256);
370 sub_header
->rects
[0]->nb_colors
= 4;
371 guess_palette(ctx
, (uint32_t*)sub_header
->rects
[0]->pict
.data
[1],
374 sub_header
->rects
[0]->x
= x1
;
375 sub_header
->rects
[0]->y
= y1
;
376 sub_header
->rects
[0]->w
= w
;
377 sub_header
->rects
[0]->h
= h
;
378 sub_header
->rects
[0]->type
= SUBTITLE_BITMAP
;
379 sub_header
->rects
[0]->pict
.linesize
[0] = w
;
380 sub_header
->rects
[0]->flags
= is_menu
? AV_SUBTITLE_FLAG_FORCED
: 0;
383 if (next_cmd_pos
< cmd_pos
) {
384 av_log(NULL
, AV_LOG_ERROR
, "Invalid command offset\n");
387 if (next_cmd_pos
== cmd_pos
)
389 cmd_pos
= next_cmd_pos
;
391 if (sub_header
->num_rects
> 0)
394 reset_rects(sub_header
);
398 static int is_transp(const uint8_t *buf
, int pitch
, int n
,
399 const uint8_t *transp_color
)
402 for(i
= 0; i
< n
; i
++) {
403 if (!transp_color
[*buf
])
410 /* return 0 if empty rectangle, 1 if non empty */
411 static int find_smallest_bounding_rectangle(AVSubtitle
*s
)
413 uint8_t transp_color
[256] = { 0 };
414 int y1
, y2
, x1
, x2
, y
, w
, h
, i
;
417 if (s
->num_rects
== 0 || !s
->rects
|| s
->rects
[0]->w
<= 0 || s
->rects
[0]->h
<= 0)
420 for(i
= 0; i
< s
->rects
[0]->nb_colors
; i
++) {
421 if ((((uint32_t*)s
->rects
[0]->pict
.data
[1])[i
] >> 24) == 0)
425 while (y1
< s
->rects
[0]->h
&& is_transp(s
->rects
[0]->pict
.data
[0] + y1
* s
->rects
[0]->pict
.linesize
[0],
426 1, s
->rects
[0]->w
, transp_color
))
428 if (y1
== s
->rects
[0]->h
) {
429 av_freep(&s
->rects
[0]->pict
.data
[0]);
430 s
->rects
[0]->w
= s
->rects
[0]->h
= 0;
434 y2
= s
->rects
[0]->h
- 1;
435 while (y2
> 0 && is_transp(s
->rects
[0]->pict
.data
[0] + y2
* s
->rects
[0]->pict
.linesize
[0], 1,
436 s
->rects
[0]->w
, transp_color
))
439 while (x1
< (s
->rects
[0]->w
- 1) && is_transp(s
->rects
[0]->pict
.data
[0] + x1
, s
->rects
[0]->pict
.linesize
[0],
440 s
->rects
[0]->h
, transp_color
))
442 x2
= s
->rects
[0]->w
- 1;
443 while (x2
> 0 && is_transp(s
->rects
[0]->pict
.data
[0] + x2
, s
->rects
[0]->pict
.linesize
[0], s
->rects
[0]->h
,
448 bitmap
= av_malloc(w
* h
);
451 for(y
= 0; y
< h
; y
++) {
452 memcpy(bitmap
+ w
* y
, s
->rects
[0]->pict
.data
[0] + x1
+ (y1
+ y
) * s
->rects
[0]->pict
.linesize
[0], w
);
454 av_freep(&s
->rects
[0]->pict
.data
[0]);
455 s
->rects
[0]->pict
.data
[0] = bitmap
;
456 s
->rects
[0]->pict
.linesize
[0] = w
;
459 s
->rects
[0]->x
+= x1
;
460 s
->rects
[0]->y
+= y1
;
465 #define ALPHA_MIX(A,BACK,FORE) (((255-(A)) * (BACK) + (A) * (FORE)) / 255)
466 static void ppm_save(const char *filename
, uint8_t *bitmap
, int w
, int h
,
467 uint32_t *rgba_palette
)
471 int back
[3] = {0, 255, 0}; /* green background */
474 f
= fopen(filename
, "w");
483 for(y
= 0; y
< h
; y
++) {
484 for(x
= 0; x
< w
; x
++) {
485 v
= rgba_palette
[bitmap
[y
* w
+ x
]];
487 putc(ALPHA_MIX(alpha
, back
[0], (v
>> 16) & 0xff), f
);
488 putc(ALPHA_MIX(alpha
, back
[1], (v
>> 8) & 0xff), f
);
489 putc(ALPHA_MIX(alpha
, back
[2], (v
>> 0) & 0xff), f
);
496 static int append_to_cached_buf(AVCodecContext
*avctx
,
497 const uint8_t *buf
, int buf_size
)
499 DVDSubContext
*ctx
= avctx
->priv_data
;
501 if (ctx
->buf_size
> 0xffff - buf_size
) {
502 av_log(avctx
, AV_LOG_WARNING
, "Attempt to reconstruct "
503 "too large SPU packets aborted.\n");
505 return AVERROR_INVALIDDATA
;
507 ctx
->buf
= av_realloc(ctx
->buf
, ctx
->buf_size
+ buf_size
);
509 return AVERROR(ENOMEM
);
510 memcpy(ctx
->buf
+ ctx
->buf_size
, buf
, buf_size
);
511 ctx
->buf_size
+= buf_size
;
515 static int dvdsub_decode(AVCodecContext
*avctx
,
516 void *data
, int *data_size
,
519 DVDSubContext
*ctx
= avctx
->priv_data
;
520 const uint8_t *buf
= avpkt
->data
;
521 int buf_size
= avpkt
->size
;
522 AVSubtitle
*sub
= data
;
526 int ret
= append_to_cached_buf(avctx
, buf
, buf_size
);
532 buf_size
= ctx
->buf_size
;
535 is_menu
= decode_dvd_subtitles(ctx
, sub
, buf
, buf_size
);
536 if (is_menu
== AVERROR(EAGAIN
)) {
538 return append_to_cached_buf(avctx
, buf
, buf_size
);
548 if (!is_menu
&& find_smallest_bounding_rectangle(sub
) == 0)
555 snprintf(ppm_name
, sizeof(ppm_name
), "/tmp/%05d.ppm", ctx
->sub_id
++);
556 av_dlog(NULL
, "start=%d ms end =%d ms\n",
557 sub
->start_display_time
,
558 sub
->end_display_time
);
559 ppm_save(ppm_name
, sub
->rects
[0]->pict
.data
[0],
560 sub
->rects
[0]->w
, sub
->rects
[0]->h
, (uint32_t*) sub
->rects
[0]->pict
.data
[1]);
570 static void parse_palette(DVDSubContext
*ctx
, char *p
)
574 ctx
->has_palette
= 1;
576 ctx
->palette
[i
] = strtoul(p
, &p
, 16);
577 while(*p
== ',' || av_isspace(*p
))
582 static int dvdsub_parse_extradata(AVCodecContext
*avctx
)
584 DVDSubContext
*ctx
= (DVDSubContext
*) avctx
->priv_data
;
585 char *dataorig
, *data
;
587 if (!avctx
->extradata
|| !avctx
->extradata_size
)
590 dataorig
= data
= av_malloc(avctx
->extradata_size
+1);
592 return AVERROR(ENOMEM
);
593 memcpy(data
, avctx
->extradata
, avctx
->extradata_size
);
594 data
[avctx
->extradata_size
] = '\0';
597 int pos
= strcspn(data
, "\n\r");
598 if (pos
==0 && *data
==0)
601 if (strncmp("palette:", data
, 8) == 0) {
602 parse_palette(ctx
, data
+ 8);
603 } else if (strncmp("size:", data
, 5) == 0) {
605 if (sscanf(data
+ 5, "%dx%d", &w
, &h
) == 2) {
606 int ret
= ff_set_dimensions(avctx
, w
, h
);
615 data
+= strspn(data
, "\n\r");
622 static av_cold
int dvdsub_init(AVCodecContext
*avctx
)
624 DVDSubContext
*ctx
= avctx
->priv_data
;
627 if ((ret
= dvdsub_parse_extradata(avctx
)) < 0)
630 if (ctx
->palette_str
)
631 parse_palette(ctx
, ctx
->palette_str
);
632 if (ctx
->has_palette
) {
634 av_log(avctx
, AV_LOG_DEBUG
, "palette:");
636 av_log(avctx
, AV_LOG_DEBUG
, " 0x%06x", ctx
->palette
[i
]);
637 av_log(avctx
, AV_LOG_DEBUG
, "\n");
643 static av_cold
int dvdsub_close(AVCodecContext
*avctx
)
645 DVDSubContext
*ctx
= avctx
->priv_data
;
651 #define OFFSET(field) offsetof(DVDSubContext, field)
652 #define VD AV_OPT_FLAG_SUBTITLE_PARAM | AV_OPT_FLAG_DECODING_PARAM
653 static const AVOption options
[] = {
654 { "palette", "set the global palette", OFFSET(palette_str
), AV_OPT_TYPE_STRING
, { .str
= NULL
}, 0, 0, VD
},
657 static const AVClass dvdsub_class
= {
658 .class_name
= "dvdsubdec",
659 .item_name
= av_default_item_name
,
661 .version
= LIBAVUTIL_VERSION_INT
,
664 AVCodec ff_dvdsub_decoder
= {
666 .long_name
= NULL_IF_CONFIG_SMALL("DVD subtitles"),
667 .type
= AVMEDIA_TYPE_SUBTITLE
,
668 .id
= AV_CODEC_ID_DVD_SUBTITLE
,
669 .priv_data_size
= sizeof(DVDSubContext
),
671 .decode
= dvdsub_decode
,
672 .close
= dvdsub_close
,
673 .priv_class
= &dvdsub_class
,