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00020
00021 #include "avcodec.h"
00022 #include "get_bits.h"
00023 #include "dsputil.h"
00024 #include "libavutil/colorspace.h"
00025
00026
00027
00028 typedef struct DVDSubContext
00029 {
00030 uint32_t palette[16];
00031 int has_palette;
00032 uint8_t colormap[4];
00033 uint8_t alpha[256];
00034 } DVDSubContext;
00035
00036 static void yuv_a_to_rgba(const uint8_t *ycbcr, const uint8_t *alpha, uint32_t *rgba, int num_values)
00037 {
00038 uint8_t *cm = ff_cropTbl + MAX_NEG_CROP;
00039 uint8_t r, g, b;
00040 int i, y, cb, cr;
00041 int r_add, g_add, b_add;
00042
00043 for (i = num_values; i > 0; i--) {
00044 y = *ycbcr++;
00045 cr = *ycbcr++;
00046 cb = *ycbcr++;
00047 YUV_TO_RGB1_CCIR(cb, cr);
00048 YUV_TO_RGB2_CCIR(r, g, b, y);
00049 *rgba++ = (*alpha++ << 24) | (r << 16) | (g << 8) | b;
00050 }
00051 }
00052
00053 static int decode_run_2bit(GetBitContext *gb, int *color)
00054 {
00055 unsigned int v, t;
00056
00057 v = 0;
00058 for (t = 1; v < t && t <= 0x40; t <<= 2)
00059 v = (v << 4) | get_bits(gb, 4);
00060 *color = v & 3;
00061 if (v < 4) {
00062 return INT_MAX;
00063 }
00064 return v >> 2;
00065 }
00066
00067 static int decode_run_8bit(GetBitContext *gb, int *color)
00068 {
00069 int len;
00070 int has_run = get_bits1(gb);
00071 if (get_bits1(gb))
00072 *color = get_bits(gb, 8);
00073 else
00074 *color = get_bits(gb, 2);
00075 if (has_run) {
00076 if (get_bits1(gb)) {
00077 len = get_bits(gb, 7);
00078 if (len == 0)
00079 len = INT_MAX;
00080 else
00081 len += 9;
00082 } else
00083 len = get_bits(gb, 3) + 2;
00084 } else
00085 len = 1;
00086 return len;
00087 }
00088
00089 static int decode_rle(uint8_t *bitmap, int linesize, int w, int h,
00090 const uint8_t *buf, int start, int buf_size, int is_8bit)
00091 {
00092 GetBitContext gb;
00093 int bit_len;
00094 int x, y, len, color;
00095 uint8_t *d;
00096
00097 bit_len = (buf_size - start) * 8;
00098 init_get_bits(&gb, buf + start, bit_len);
00099
00100 x = 0;
00101 y = 0;
00102 d = bitmap;
00103 for(;;) {
00104 if (get_bits_count(&gb) > bit_len)
00105 return -1;
00106 if (is_8bit)
00107 len = decode_run_8bit(&gb, &color);
00108 else
00109 len = decode_run_2bit(&gb, &color);
00110 len = FFMIN(len, w - x);
00111 memset(d + x, color, len);
00112 x += len;
00113 if (x >= w) {
00114 y++;
00115 if (y >= h)
00116 break;
00117 d += linesize;
00118 x = 0;
00119
00120 align_get_bits(&gb);
00121 }
00122 }
00123 return 0;
00124 }
00125
00126 static void guess_palette(uint32_t *rgba_palette,
00127 DVDSubContext* ctx,
00128 uint32_t subtitle_color)
00129 {
00130 static const uint8_t level_map[4][4] = {
00131
00132
00133 {0xff},
00134 {0x00, 0xff},
00135 {0x00, 0x80, 0xff},
00136 {0x00, 0x55, 0xaa, 0xff},
00137 };
00138 uint8_t color_used[16] = { 0 };
00139 int nb_opaque_colors, i, level, j, r, g, b;
00140 uint8_t *colormap = ctx->colormap, *alpha = ctx->alpha;
00141
00142 if(ctx->has_palette) {
00143 for(i = 0; i < 4; i++)
00144 rgba_palette[i] = (ctx->palette[colormap[i]] & 0x00ffffff)
00145 | ((alpha[i] * 17) << 24);
00146 return;
00147 }
00148
00149 for(i = 0; i < 4; i++)
00150 rgba_palette[i] = 0;
00151
00152 nb_opaque_colors = 0;
00153 for(i = 0; i < 4; i++) {
00154 if (alpha[i] != 0 && !color_used[colormap[i]]) {
00155 color_used[colormap[i]] = 1;
00156 nb_opaque_colors++;
00157 }
00158 }
00159
00160 if (nb_opaque_colors == 0)
00161 return;
00162
00163 j = 0;
00164 memset(color_used, 0, 16);
00165 for(i = 0; i < 4; i++) {
00166 if (alpha[i] != 0) {
00167 if (!color_used[colormap[i]]) {
00168 level = level_map[nb_opaque_colors][j];
00169 r = (((subtitle_color >> 16) & 0xff) * level) >> 8;
00170 g = (((subtitle_color >> 8) & 0xff) * level) >> 8;
00171 b = (((subtitle_color >> 0) & 0xff) * level) >> 8;
00172 rgba_palette[i] = b | (g << 8) | (r << 16) | ((alpha[i] * 17) << 24);
00173 color_used[colormap[i]] = (i + 1);
00174 j++;
00175 } else {
00176 rgba_palette[i] = (rgba_palette[color_used[colormap[i]] - 1] & 0x00ffffff) |
00177 ((alpha[i] * 17) << 24);
00178 }
00179 }
00180 }
00181 }
00182
00183 #define READ_OFFSET(a) (big_offsets ? AV_RB32(a) : AV_RB16(a))
00184
00185 static int decode_dvd_subtitles(DVDSubContext *ctx, AVSubtitle *sub_header,
00186 const uint8_t *buf, int buf_size)
00187 {
00188 int cmd_pos, pos, cmd, x1, y1, x2, y2, offset1, offset2, next_cmd_pos;
00189 int big_offsets, offset_size, is_8bit = 0;
00190 const uint8_t *yuv_palette = 0;
00191 uint8_t *colormap = ctx->colormap, *alpha = ctx->alpha;
00192 int date;
00193 int i;
00194 int is_menu = 0;
00195
00196 if (buf_size < 10)
00197 return -1;
00198
00199 if (AV_RB16(buf) == 0) {
00200 big_offsets = 1;
00201 offset_size = 4;
00202 cmd_pos = 6;
00203 } else {
00204 big_offsets = 0;
00205 offset_size = 2;
00206 cmd_pos = 2;
00207 }
00208
00209 cmd_pos = READ_OFFSET(buf + cmd_pos);
00210
00211 while (cmd_pos > 0 && cmd_pos < buf_size - 2 - offset_size) {
00212 date = AV_RB16(buf + cmd_pos);
00213 next_cmd_pos = READ_OFFSET(buf + cmd_pos + 2);
00214 av_dlog(NULL, "cmd_pos=0x%04x next=0x%04x date=%d\n",
00215 cmd_pos, next_cmd_pos, date);
00216 pos = cmd_pos + 2 + offset_size;
00217 offset1 = -1;
00218 offset2 = -1;
00219 x1 = y1 = x2 = y2 = 0;
00220 while (pos < buf_size) {
00221 cmd = buf[pos++];
00222 av_dlog(NULL, "cmd=%02x\n", cmd);
00223 switch(cmd) {
00224 case 0x00:
00225
00226 is_menu = 1;
00227 break;
00228 case 0x01:
00229
00230 sub_header->start_display_time = (date << 10) / 90;
00231 break;
00232 case 0x02:
00233
00234 sub_header->end_display_time = (date << 10) / 90;
00235 break;
00236 case 0x03:
00237
00238 if ((buf_size - pos) < 2)
00239 goto fail;
00240 colormap[3] = buf[pos] >> 4;
00241 colormap[2] = buf[pos] & 0x0f;
00242 colormap[1] = buf[pos + 1] >> 4;
00243 colormap[0] = buf[pos + 1] & 0x0f;
00244 pos += 2;
00245 break;
00246 case 0x04:
00247
00248 if ((buf_size - pos) < 2)
00249 goto fail;
00250 alpha[3] = buf[pos] >> 4;
00251 alpha[2] = buf[pos] & 0x0f;
00252 alpha[1] = buf[pos + 1] >> 4;
00253 alpha[0] = buf[pos + 1] & 0x0f;
00254 pos += 2;
00255 av_dlog(NULL, "alpha=%x%x%x%x\n", alpha[0],alpha[1],alpha[2],alpha[3]);
00256 break;
00257 case 0x05:
00258 case 0x85:
00259 if ((buf_size - pos) < 6)
00260 goto fail;
00261 x1 = (buf[pos] << 4) | (buf[pos + 1] >> 4);
00262 x2 = ((buf[pos + 1] & 0x0f) << 8) | buf[pos + 2];
00263 y1 = (buf[pos + 3] << 4) | (buf[pos + 4] >> 4);
00264 y2 = ((buf[pos + 4] & 0x0f) << 8) | buf[pos + 5];
00265 if (cmd & 0x80)
00266 is_8bit = 1;
00267 av_dlog(NULL, "x1=%d x2=%d y1=%d y2=%d\n", x1, x2, y1, y2);
00268 pos += 6;
00269 break;
00270 case 0x06:
00271 if ((buf_size - pos) < 4)
00272 goto fail;
00273 offset1 = AV_RB16(buf + pos);
00274 offset2 = AV_RB16(buf + pos + 2);
00275 av_dlog(NULL, "offset1=0x%04x offset2=0x%04x\n", offset1, offset2);
00276 pos += 4;
00277 break;
00278 case 0x86:
00279 if ((buf_size - pos) < 8)
00280 goto fail;
00281 offset1 = AV_RB32(buf + pos);
00282 offset2 = AV_RB32(buf + pos + 4);
00283 av_dlog(NULL, "offset1=0x%04x offset2=0x%04x\n", offset1, offset2);
00284 pos += 8;
00285 break;
00286
00287 case 0x83:
00288
00289 if ((buf_size - pos) < 768)
00290 goto fail;
00291 yuv_palette = buf + pos;
00292 pos += 768;
00293 break;
00294 case 0x84:
00295
00296 if ((buf_size - pos) < 256)
00297 goto fail;
00298 for (i = 0; i < 256; i++)
00299 alpha[i] = 0xFF - buf[pos+i];
00300 pos += 256;
00301 break;
00302
00303 case 0xff:
00304 goto the_end;
00305 default:
00306 av_dlog(NULL, "unrecognised subpicture command 0x%x\n", cmd);
00307 goto the_end;
00308 }
00309 }
00310 the_end:
00311 if (offset1 >= 0) {
00312 int w, h;
00313 uint8_t *bitmap;
00314
00315
00316 w = x2 - x1 + 1;
00317 if (w < 0)
00318 w = 0;
00319 h = y2 - y1;
00320 if (h < 0)
00321 h = 0;
00322 if (w > 0 && h > 0) {
00323 if (sub_header->rects != NULL) {
00324 for (i = 0; i < sub_header->num_rects; i++) {
00325 av_freep(&sub_header->rects[i]->pict.data[0]);
00326 av_freep(&sub_header->rects[i]->pict.data[1]);
00327 av_freep(&sub_header->rects[i]);
00328 }
00329 av_freep(&sub_header->rects);
00330 sub_header->num_rects = 0;
00331 }
00332
00333 bitmap = av_malloc(w * h);
00334 sub_header->rects = av_mallocz(sizeof(*sub_header->rects));
00335 sub_header->rects[0] = av_mallocz(sizeof(AVSubtitleRect));
00336 sub_header->num_rects = 1;
00337 sub_header->rects[0]->pict.data[0] = bitmap;
00338 decode_rle(bitmap, w * 2, w, (h + 1) / 2,
00339 buf, offset1, buf_size, is_8bit);
00340 decode_rle(bitmap + w, w * 2, w, h / 2,
00341 buf, offset2, buf_size, is_8bit);
00342 sub_header->rects[0]->pict.data[1] = av_mallocz(AVPALETTE_SIZE);
00343 if (is_8bit) {
00344 if (yuv_palette == 0)
00345 goto fail;
00346 sub_header->rects[0]->nb_colors = 256;
00347 yuv_a_to_rgba(yuv_palette, alpha, (uint32_t*)sub_header->rects[0]->pict.data[1], 256);
00348 } else {
00349 sub_header->rects[0]->nb_colors = 4;
00350 guess_palette((uint32_t*)sub_header->rects[0]->pict.data[1], ctx,
00351 0xffff00);
00352 }
00353 sub_header->rects[0]->x = x1;
00354 sub_header->rects[0]->y = y1;
00355 sub_header->rects[0]->w = w;
00356 sub_header->rects[0]->h = h;
00357 sub_header->rects[0]->type = SUBTITLE_BITMAP;
00358 sub_header->rects[0]->pict.linesize[0] = w;
00359 sub_header->rects[0]->forced = is_menu;
00360 }
00361 }
00362 if (next_cmd_pos < cmd_pos) {
00363 av_log(NULL, AV_LOG_ERROR, "Invalid command offset\n");
00364 break;
00365 }
00366 if (next_cmd_pos == cmd_pos)
00367 break;
00368 cmd_pos = next_cmd_pos;
00369 }
00370 if (sub_header->num_rects > 0)
00371 return is_menu;
00372 fail:
00373 if (sub_header->rects != NULL) {
00374 for (i = 0; i < sub_header->num_rects; i++) {
00375 av_freep(&sub_header->rects[i]->pict.data[0]);
00376 av_freep(&sub_header->rects[i]->pict.data[1]);
00377 av_freep(&sub_header->rects[i]);
00378 }
00379 av_freep(&sub_header->rects);
00380 sub_header->num_rects = 0;
00381 }
00382 return -1;
00383 }
00384
00385 static int is_transp(const uint8_t *buf, int pitch, int n,
00386 const uint8_t *transp_color)
00387 {
00388 int i;
00389 for(i = 0; i < n; i++) {
00390 if (!transp_color[*buf])
00391 return 0;
00392 buf += pitch;
00393 }
00394 return 1;
00395 }
00396
00397
00398 static int find_smallest_bounding_rectangle(AVSubtitle *s)
00399 {
00400 uint8_t transp_color[256] = { 0 };
00401 int y1, y2, x1, x2, y, w, h, i;
00402 uint8_t *bitmap;
00403
00404 if (s->num_rects == 0 || s->rects == NULL || s->rects[0]->w <= 0 || s->rects[0]->h <= 0)
00405 return 0;
00406
00407 for(i = 0; i < s->rects[0]->nb_colors; i++) {
00408 if ((((uint32_t*)s->rects[0]->pict.data[1])[i] >> 24) == 0)
00409 transp_color[i] = 1;
00410 }
00411 y1 = 0;
00412 while (y1 < s->rects[0]->h && is_transp(s->rects[0]->pict.data[0] + y1 * s->rects[0]->pict.linesize[0],
00413 1, s->rects[0]->w, transp_color))
00414 y1++;
00415 if (y1 == s->rects[0]->h) {
00416 av_freep(&s->rects[0]->pict.data[0]);
00417 s->rects[0]->w = s->rects[0]->h = 0;
00418 return 0;
00419 }
00420
00421 y2 = s->rects[0]->h - 1;
00422 while (y2 > 0 && is_transp(s->rects[0]->pict.data[0] + y2 * s->rects[0]->pict.linesize[0], 1,
00423 s->rects[0]->w, transp_color))
00424 y2--;
00425 x1 = 0;
00426 while (x1 < (s->rects[0]->w - 1) && is_transp(s->rects[0]->pict.data[0] + x1, s->rects[0]->pict.linesize[0],
00427 s->rects[0]->h, transp_color))
00428 x1++;
00429 x2 = s->rects[0]->w - 1;
00430 while (x2 > 0 && is_transp(s->rects[0]->pict.data[0] + x2, s->rects[0]->pict.linesize[0], s->rects[0]->h,
00431 transp_color))
00432 x2--;
00433 w = x2 - x1 + 1;
00434 h = y2 - y1 + 1;
00435 bitmap = av_malloc(w * h);
00436 if (!bitmap)
00437 return 1;
00438 for(y = 0; y < h; y++) {
00439 memcpy(bitmap + w * y, s->rects[0]->pict.data[0] + x1 + (y1 + y) * s->rects[0]->pict.linesize[0], w);
00440 }
00441 av_freep(&s->rects[0]->pict.data[0]);
00442 s->rects[0]->pict.data[0] = bitmap;
00443 s->rects[0]->pict.linesize[0] = w;
00444 s->rects[0]->w = w;
00445 s->rects[0]->h = h;
00446 s->rects[0]->x += x1;
00447 s->rects[0]->y += y1;
00448 return 1;
00449 }
00450
00451 #ifdef DEBUG
00452 #undef fprintf
00453 #undef perror
00454 #undef exit
00455 static void ppm_save(const char *filename, uint8_t *bitmap, int w, int h,
00456 uint32_t *rgba_palette)
00457 {
00458 int x, y, v;
00459 FILE *f;
00460
00461 f = fopen(filename, "w");
00462 if (!f) {
00463 perror(filename);
00464 exit(1);
00465 }
00466 fprintf(f, "P6\n"
00467 "%d %d\n"
00468 "%d\n",
00469 w, h, 255);
00470 for(y = 0; y < h; y++) {
00471 for(x = 0; x < w; x++) {
00472 v = rgba_palette[bitmap[y * w + x]];
00473 putc((v >> 16) & 0xff, f);
00474 putc((v >> 8) & 0xff, f);
00475 putc((v >> 0) & 0xff, f);
00476 }
00477 }
00478 fclose(f);
00479 }
00480 #endif
00481
00482 static int dvdsub_decode(AVCodecContext *avctx,
00483 void *data, int *data_size,
00484 AVPacket *avpkt)
00485 {
00486 DVDSubContext *ctx = (DVDSubContext*) avctx->priv_data;
00487 const uint8_t *buf = avpkt->data;
00488 int buf_size = avpkt->size;
00489 AVSubtitle *sub = data;
00490 int is_menu;
00491
00492 is_menu = decode_dvd_subtitles(ctx, sub, buf, buf_size);
00493
00494 if (is_menu < 0) {
00495 no_subtitle:
00496 *data_size = 0;
00497
00498 return buf_size;
00499 }
00500 if (!is_menu && find_smallest_bounding_rectangle(sub) == 0)
00501 goto no_subtitle;
00502
00503 #if defined(DEBUG)
00504 av_dlog(NULL, "start=%d ms end =%d ms\n",
00505 sub->start_display_time,
00506 sub->end_display_time);
00507 ppm_save("/tmp/a.ppm", sub->rects[0]->pict.data[0],
00508 sub->rects[0]->w, sub->rects[0]->h, sub->rects[0]->pict.data[1]);
00509 #endif
00510
00511 *data_size = 1;
00512 return buf_size;
00513 }
00514
00515 static int dvdsub_init(AVCodecContext *avctx)
00516 {
00517 DVDSubContext *ctx = (DVDSubContext*) avctx->priv_data;
00518 char *dataorig, *data;
00519
00520 if (!avctx->extradata || !avctx->extradata_size)
00521 return 1;
00522
00523 dataorig = data = av_malloc(avctx->extradata_size+1);
00524 if (!data)
00525 return AVERROR(ENOMEM);
00526 memcpy(data, avctx->extradata, avctx->extradata_size);
00527 data[avctx->extradata_size] = '\0';
00528
00529 for(;;) {
00530 int pos = strcspn(data, "\n\r");
00531 if (pos==0 && *data==0)
00532 break;
00533
00534 if (strncmp("palette:", data, 8) == 0) {
00535 int i;
00536 char *p = data+8;
00537 ctx->has_palette = 1;
00538 for(i=0;i<16;i++) {
00539 ctx->palette[i] = strtoul(p, &p, 16);
00540 while(*p == ',' || isspace(*p))
00541 p++;
00542 }
00543 }
00544
00545 data += pos;
00546 data += strspn(data, "\n\r");
00547 }
00548
00549 if (ctx->has_palette) {
00550 int i;
00551 av_log(avctx, AV_LOG_DEBUG, "palette:");
00552 for(i=0;i<16;i++)
00553 av_log(avctx, AV_LOG_DEBUG, " 0x%06x", ctx->palette[i]);
00554 av_log(avctx, AV_LOG_DEBUG, "\n");
00555 }
00556
00557 av_free(dataorig);
00558 return 1;
00559 }
00560
00561 AVCodec ff_dvdsub_decoder = {
00562 .name = "dvdsub",
00563 .type = AVMEDIA_TYPE_SUBTITLE,
00564 .id = CODEC_ID_DVD_SUBTITLE,
00565 .priv_data_size = sizeof(DVDSubContext),
00566 .init = dvdsub_init,
00567 .decode = dvdsub_decode,
00568 .long_name = NULL_IF_CONFIG_SMALL("DVD subtitles"),
00569 };
