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
48 static void yuv_a_to_rgba(const uint8_t *ycbcr, const uint8_t *alpha, uint32_t *rgba, int num_values)
50 const uint8_t *cm = ff_crop_tab + MAX_NEG_CROP;
53 int r_add, g_add, b_add;
55 for (i = num_values; i > 0; i--) {
59 YUV_TO_RGB1_CCIR(cb, cr);
60 YUV_TO_RGB2_CCIR(r, g, b, y);
61 *rgba++ = (*alpha++ << 24) | (r << 16) | (g << 8) | b;
65 static int decode_run_2bit(GetBitContext *gb, int *color)
70 for (t = 1; v < t && t <= 0x40; t <<= 2)
71 v = (v << 4) | get_bits(gb, 4);
73 if (v < 4) { /* Code for fill rest of line */
79 static int decode_run_8bit(GetBitContext *gb, int *color)
82 int has_run = get_bits1(gb);
84 *color = get_bits(gb, 8);
86 *color = get_bits(gb, 2);
89 len = get_bits(gb, 7);
95 len = get_bits(gb, 3) + 2;
101 static int decode_rle(uint8_t *bitmap, int linesize, int w, int h,
102 const uint8_t *buf, int start, int buf_size, int is_8bit)
106 int x, y, len, color;
109 bit_len = (buf_size - start) * 8;
110 init_get_bits(&gb, buf + start, bit_len);
116 if (get_bits_count(&gb) > bit_len)
119 len = decode_run_8bit(&gb, &color);
121 len = decode_run_2bit(&gb, &color);
122 len = FFMIN(len, w - x);
123 memset(d + x, color, len);
138 static void guess_palette(DVDSubContext* ctx,
139 uint32_t *rgba_palette,
140 uint32_t subtitle_color)
142 static const uint8_t level_map[4][4] = {
143 // this configuration (full range, lowest to highest) in tests
144 // seemed most common, so assume this
148 {0x00, 0x55, 0xaa, 0xff},
150 uint8_t color_used[16] = { 0 };
151 int nb_opaque_colors, i, level, j, r, g, b;
152 uint8_t *colormap = ctx->colormap, *alpha = ctx->alpha;
154 if(ctx->has_palette) {
155 for(i = 0; i < 4; i++)
156 rgba_palette[i] = (ctx->palette[colormap[i]] & 0x00ffffff)
157 | ((alpha[i] * 17U) << 24);
161 for(i = 0; i < 4; i++)
164 nb_opaque_colors = 0;
165 for(i = 0; i < 4; i++) {
166 if (alpha[i] != 0 && !color_used[colormap[i]]) {
167 color_used[colormap[i]] = 1;
172 if (nb_opaque_colors == 0)
176 memset(color_used, 0, 16);
177 for(i = 0; i < 4; i++) {
179 if (!color_used[colormap[i]]) {
180 level = level_map[nb_opaque_colors][j];
181 r = (((subtitle_color >> 16) & 0xff) * level) >> 8;
182 g = (((subtitle_color >> 8) & 0xff) * level) >> 8;
183 b = (((subtitle_color >> 0) & 0xff) * level) >> 8;
184 rgba_palette[i] = b | (g << 8) | (r << 16) | ((alpha[i] * 17) << 24);
185 color_used[colormap[i]] = (i + 1);
188 rgba_palette[i] = (rgba_palette[color_used[colormap[i]] - 1] & 0x00ffffff) |
189 ((alpha[i] * 17) << 24);
195 static void reset_rects(AVSubtitle *sub_header)
199 if (sub_header->rects) {
200 for (i = 0; i < sub_header->num_rects; i++) {
201 av_freep(&sub_header->rects[i]->pict.data[0]);
202 av_freep(&sub_header->rects[i]->pict.data[1]);
203 av_freep(&sub_header->rects[i]);
205 av_freep(&sub_header->rects);
206 sub_header->num_rects = 0;
210 #define READ_OFFSET(a) (big_offsets ? AV_RB32(a) : AV_RB16(a))
212 static int decode_dvd_subtitles(DVDSubContext *ctx, AVSubtitle *sub_header,
213 const uint8_t *buf, int buf_size)
215 int cmd_pos, pos, cmd, x1, y1, x2, y2, offset1, offset2, next_cmd_pos;
216 int big_offsets, offset_size, is_8bit = 0;
217 const uint8_t *yuv_palette = NULL;
218 uint8_t *colormap = ctx->colormap, *alpha = ctx->alpha;
226 if (AV_RB16(buf) == 0) { /* HD subpicture with 4-byte offsets */
236 cmd_pos = READ_OFFSET(buf + cmd_pos);
238 if (cmd_pos < 0 || cmd_pos > buf_size - 2 - offset_size)
239 return AVERROR(EAGAIN);
241 while (cmd_pos > 0 && cmd_pos < buf_size - 2 - offset_size) {
242 date = AV_RB16(buf + cmd_pos);
243 next_cmd_pos = READ_OFFSET(buf + cmd_pos + 2);
244 av_dlog(NULL, "cmd_pos=0x%04x next=0x%04x date=%d\n",
245 cmd_pos, next_cmd_pos, date);
246 pos = cmd_pos + 2 + offset_size;
249 x1 = y1 = x2 = y2 = 0;
250 while (pos < buf_size) {
252 av_dlog(NULL, "cmd=%02x\n", cmd);
255 /* menu subpicture */
260 sub_header->start_display_time = (date << 10) / 90;
264 sub_header->end_display_time = (date << 10) / 90;
268 if ((buf_size - pos) < 2)
270 colormap[3] = buf[pos] >> 4;
271 colormap[2] = buf[pos] & 0x0f;
272 colormap[1] = buf[pos + 1] >> 4;
273 colormap[0] = buf[pos + 1] & 0x0f;
278 if ((buf_size - pos) < 2)
280 alpha[3] = buf[pos] >> 4;
281 alpha[2] = buf[pos] & 0x0f;
282 alpha[1] = buf[pos + 1] >> 4;
283 alpha[0] = buf[pos + 1] & 0x0f;
285 av_dlog(NULL, "alpha=%x%x%x%x\n", alpha[0],alpha[1],alpha[2],alpha[3]);
289 if ((buf_size - pos) < 6)
291 x1 = (buf[pos] << 4) | (buf[pos + 1] >> 4);
292 x2 = ((buf[pos + 1] & 0x0f) << 8) | buf[pos + 2];
293 y1 = (buf[pos + 3] << 4) | (buf[pos + 4] >> 4);
294 y2 = ((buf[pos + 4] & 0x0f) << 8) | buf[pos + 5];
297 av_dlog(NULL, "x1=%d x2=%d y1=%d y2=%d\n", x1, x2, y1, y2);
301 if ((buf_size - pos) < 4)
303 offset1 = AV_RB16(buf + pos);
304 offset2 = AV_RB16(buf + pos + 2);
305 av_dlog(NULL, "offset1=0x%04x offset2=0x%04x\n", offset1, offset2);
309 if ((buf_size - pos) < 8)
311 offset1 = AV_RB32(buf + pos);
312 offset2 = AV_RB32(buf + pos + 4);
313 av_dlog(NULL, "offset1=0x%04x offset2=0x%04x\n", offset1, offset2);
319 if ((buf_size - pos) < 768)
321 yuv_palette = buf + pos;
325 /* HD set contrast (alpha) */
326 if ((buf_size - pos) < 256)
328 for (i = 0; i < 256; i++)
329 alpha[i] = 0xFF - buf[pos+i];
336 av_dlog(NULL, "unrecognised subpicture command 0x%x\n", cmd);
345 /* decode the bitmap */
352 if (w > 0 && h > 0) {
353 reset_rects(sub_header);
355 bitmap = av_malloc(w * h);
356 sub_header->rects = av_mallocz(sizeof(*sub_header->rects));
357 sub_header->rects[0] = av_mallocz(sizeof(AVSubtitleRect));
358 sub_header->num_rects = 1;
359 sub_header->rects[0]->pict.data[0] = bitmap;
360 decode_rle(bitmap, w * 2, w, (h + 1) / 2,
361 buf, offset1, buf_size, is_8bit);
362 decode_rle(bitmap + w, w * 2, w, h / 2,
363 buf, offset2, buf_size, is_8bit);
364 sub_header->rects[0]->pict.data[1] = av_mallocz(AVPALETTE_SIZE);
368 sub_header->rects[0]->nb_colors = 256;
369 yuv_a_to_rgba(yuv_palette, alpha, (uint32_t*)sub_header->rects[0]->pict.data[1], 256);
371 sub_header->rects[0]->nb_colors = 4;
372 guess_palette(ctx, (uint32_t*)sub_header->rects[0]->pict.data[1],
375 sub_header->rects[0]->x = x1;
376 sub_header->rects[0]->y = y1;
377 sub_header->rects[0]->w = w;
378 sub_header->rects[0]->h = h;
379 sub_header->rects[0]->type = SUBTITLE_BITMAP;
380 sub_header->rects[0]->pict.linesize[0] = w;
381 sub_header->rects[0]->flags = is_menu ? AV_SUBTITLE_FLAG_FORCED : 0;
384 if (next_cmd_pos < cmd_pos) {
385 av_log(NULL, AV_LOG_ERROR, "Invalid command offset\n");
388 if (next_cmd_pos == cmd_pos)
390 cmd_pos = next_cmd_pos;
392 if (sub_header->num_rects > 0)
395 reset_rects(sub_header);
399 static int is_transp(const uint8_t *buf, int pitch, int n,
400 const uint8_t *transp_color)
403 for(i = 0; i < n; i++) {
404 if (!transp_color[*buf])
411 /* return 0 if empty rectangle, 1 if non empty */
412 static int find_smallest_bounding_rectangle(AVSubtitle *s)
414 uint8_t transp_color[256] = { 0 };
415 int y1, y2, x1, x2, y, w, h, i;
418 if (s->num_rects == 0 || !s->rects || s->rects[0]->w <= 0 || s->rects[0]->h <= 0)
421 for(i = 0; i < s->rects[0]->nb_colors; i++) {
422 if ((((uint32_t*)s->rects[0]->pict.data[1])[i] >> 24) == 0)
426 while (y1 < s->rects[0]->h && is_transp(s->rects[0]->pict.data[0] + y1 * s->rects[0]->pict.linesize[0],
427 1, s->rects[0]->w, transp_color))
429 if (y1 == s->rects[0]->h) {
430 av_freep(&s->rects[0]->pict.data[0]);
431 s->rects[0]->w = s->rects[0]->h = 0;
435 y2 = s->rects[0]->h - 1;
436 while (y2 > 0 && is_transp(s->rects[0]->pict.data[0] + y2 * s->rects[0]->pict.linesize[0], 1,
437 s->rects[0]->w, transp_color))
440 while (x1 < (s->rects[0]->w - 1) && is_transp(s->rects[0]->pict.data[0] + x1, s->rects[0]->pict.linesize[0],
441 s->rects[0]->h, transp_color))
443 x2 = s->rects[0]->w - 1;
444 while (x2 > 0 && is_transp(s->rects[0]->pict.data[0] + x2, s->rects[0]->pict.linesize[0], s->rects[0]->h,
449 bitmap = av_malloc(w * h);
452 for(y = 0; y < h; y++) {
453 memcpy(bitmap + w * y, s->rects[0]->pict.data[0] + x1 + (y1 + y) * s->rects[0]->pict.linesize[0], w);
455 av_freep(&s->rects[0]->pict.data[0]);
456 s->rects[0]->pict.data[0] = bitmap;
457 s->rects[0]->pict.linesize[0] = w;
460 s->rects[0]->x += x1;
461 s->rects[0]->y += y1;
466 #define ALPHA_MIX(A,BACK,FORE) (((255-(A)) * (BACK) + (A) * (FORE)) / 255)
467 static void ppm_save(const char *filename, uint8_t *bitmap, int w, int h,
468 uint32_t *rgba_palette)
472 int back[3] = {0, 255, 0}; /* green background */
475 f = fopen(filename, "w");
484 for(y = 0; y < h; y++) {
485 for(x = 0; x < w; x++) {
486 v = rgba_palette[bitmap[y * w + x]];
488 putc(ALPHA_MIX(alpha, back[0], (v >> 16) & 0xff), f);
489 putc(ALPHA_MIX(alpha, back[1], (v >> 8) & 0xff), f);
490 putc(ALPHA_MIX(alpha, back[2], (v >> 0) & 0xff), f);
497 static int append_to_cached_buf(AVCodecContext *avctx,
498 const uint8_t *buf, int buf_size)
500 DVDSubContext *ctx = avctx->priv_data;
502 if (ctx->buf_size > 0xffff - buf_size) {
503 av_log(avctx, AV_LOG_WARNING, "Attempt to reconstruct "
504 "too large SPU packets aborted.\n");
506 return AVERROR_INVALIDDATA;
508 ctx->buf = av_realloc(ctx->buf, ctx->buf_size + buf_size);
510 return AVERROR(ENOMEM);
511 memcpy(ctx->buf + ctx->buf_size, buf, buf_size);
512 ctx->buf_size += buf_size;
516 static int dvdsub_decode(AVCodecContext *avctx,
517 void *data, int *data_size,
520 DVDSubContext *ctx = avctx->priv_data;
521 const uint8_t *buf = avpkt->data;
522 int buf_size = avpkt->size;
523 AVSubtitle *sub = data;
527 int ret = append_to_cached_buf(avctx, buf, buf_size);
533 buf_size = ctx->buf_size;
536 is_menu = decode_dvd_subtitles(ctx, sub, buf, buf_size);
537 if (is_menu == AVERROR(EAGAIN)) {
539 return append_to_cached_buf(avctx, buf, buf_size);
549 if (!is_menu && find_smallest_bounding_rectangle(sub) == 0)
552 if (ctx->forced_subs_only && !(sub->rects[0]->flags & AV_SUBTITLE_FLAG_FORCED))
559 snprintf(ppm_name, sizeof(ppm_name), "/tmp/%05d.ppm", ctx->sub_id++);
560 av_dlog(NULL, "start=%d ms end =%d ms\n",
561 sub->start_display_time,
562 sub->end_display_time);
563 ppm_save(ppm_name, sub->rects[0]->pict.data[0],
564 sub->rects[0]->w, sub->rects[0]->h, (uint32_t*) sub->rects[0]->pict.data[1]);
574 static void parse_palette(DVDSubContext *ctx, char *p)
578 ctx->has_palette = 1;
580 ctx->palette[i] = strtoul(p, &p, 16);
581 while(*p == ',' || av_isspace(*p))
586 static int dvdsub_parse_extradata(AVCodecContext *avctx)
588 DVDSubContext *ctx = (DVDSubContext*) avctx->priv_data;
589 char *dataorig, *data;
591 if (!avctx->extradata || !avctx->extradata_size)
594 dataorig = data = av_malloc(avctx->extradata_size+1);
596 return AVERROR(ENOMEM);
597 memcpy(data, avctx->extradata, avctx->extradata_size);
598 data[avctx->extradata_size] = '\0';
601 int pos = strcspn(data, "\n\r");
602 if (pos==0 && *data==0)
605 if (strncmp("palette:", data, 8) == 0) {
606 parse_palette(ctx, data + 8);
607 } else if (strncmp("size:", data, 5) == 0) {
609 if (sscanf(data + 5, "%dx%d", &w, &h) == 2) {
610 int ret = ff_set_dimensions(avctx, w, h);
619 data += strspn(data, "\n\r");
626 static av_cold int dvdsub_init(AVCodecContext *avctx)
628 DVDSubContext *ctx = avctx->priv_data;
631 if ((ret = dvdsub_parse_extradata(avctx)) < 0)
634 if (ctx->palette_str)
635 parse_palette(ctx, ctx->palette_str);
636 if (ctx->has_palette) {
638 av_log(avctx, AV_LOG_DEBUG, "palette:");
640 av_log(avctx, AV_LOG_DEBUG, " 0x%06x", ctx->palette[i]);
641 av_log(avctx, AV_LOG_DEBUG, "\n");
647 static av_cold int dvdsub_close(AVCodecContext *avctx)
649 DVDSubContext *ctx = avctx->priv_data;
655 #define OFFSET(field) offsetof(DVDSubContext, field)
656 #define SD AV_OPT_FLAG_SUBTITLE_PARAM | AV_OPT_FLAG_DECODING_PARAM
657 static const AVOption options[] = {
658 { "palette", "set the global palette", OFFSET(palette_str), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, SD },
659 { "forced_subs_only", "Only show forced subtitles", OFFSET(forced_subs_only), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, SD},
662 static const AVClass dvdsub_class = {
663 .class_name = "dvdsubdec",
664 .item_name = av_default_item_name,
666 .version = LIBAVUTIL_VERSION_INT,
669 AVCodec ff_dvdsub_decoder = {
671 .long_name = NULL_IF_CONFIG_SMALL("DVD subtitles"),
672 .type = AVMEDIA_TYPE_SUBTITLE,
673 .id = AV_CODEC_ID_DVD_SUBTITLE,
674 .priv_data_size = sizeof(DVDSubContext),
676 .decode = dvdsub_decode,
677 .close = dvdsub_close,
678 .priv_class = &dvdsub_class,