falkTX
/
FFmpeg
mirror of https://github.com/falkTX/FFmpeg.git
1
0
Fork 0
Code Issues 0 Releases 338 Wiki Activity
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
20381 Commits
32 Branches
353MB
Tree: d5652f38fb
Branches Tags
${ item.name }
Create branch ${ searchTerm }
from 'd5652f38fb'
${ noResults }
FFmpeg/libavcodec/dvdsubdec.c

505 lines
15KB
Raw Blame History 

  1. /*

  2.  * DVD subtitle decoding for ffmpeg

  3.  * Copyright (c) 2005 Fabrice Bellard

  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. #include "avcodec.h"

  22. #include "get_bits.h"

  23. #include "colorspace.h"

  24. #include "dsputil.h"

  25. 

  26. //#define DEBUG

  27. 

  28. static void yuv_a_to_rgba(const uint8_t *ycbcr, const uint8_t *alpha, uint32_t *rgba, int num_values)

  29. {

  30.     uint8_t *cm = ff_cropTbl + MAX_NEG_CROP;

  31.     uint8_t r, g, b;

  32.     int i, y, cb, cr;

  33.     int r_add, g_add, b_add;

  34. 

  35.     for (i = num_values; i > 0; i--) {

  36.         y = *ycbcr++;

  37.         cb = *ycbcr++;

  38.         cr = *ycbcr++;

  39.         YUV_TO_RGB1_CCIR(cb, cr);

  40.         YUV_TO_RGB2_CCIR(r, g, b, y);

  41.         *rgba++ = (*alpha++ << 24) | (r << 16) | (g << 8) | b;

  42.     }

  43. }

  44. 

  45. static int decode_run_2bit(GetBitContext *gb, int *color)

  46. {

  47.     unsigned int v, t;

  48. 

  49.     v = 0;

  50.     for (t = 1; v < t && t <= 0x40; t <<= 2)

  51.         v = (v << 4) | get_bits(gb, 4);

  52.     *color = v & 3;

  53.     if (v < 4) { /* Code for fill rest of line */

  54.         return INT_MAX;

  55.     }

  56.     return v >> 2;

  57. }

  58. 

  59. static int decode_run_8bit(GetBitContext *gb, int *color)

  60. {

  61.     int len;

  62.     int has_run = get_bits1(gb);

  63.     if (get_bits1(gb))

  64.         *color = get_bits(gb, 8);

  65.     else

  66.         *color = get_bits(gb, 2);

  67.     if (has_run) {

  68.         if (get_bits1(gb)) {

  69.             len = get_bits(gb, 7);

  70.             if (len == 0)

  71.                 len = INT_MAX;

  72.             else

  73.                 len += 9;

  74.         } else

  75.             len = get_bits(gb, 3) + 2;

  76.     } else

  77.         len = 1;

  78.     return len;

  79. }

  80. 

  81. static int decode_rle(uint8_t *bitmap, int linesize, int w, int h,

  82.                       const uint8_t *buf, int start, int buf_size, int is_8bit)

  83. {

  84.     GetBitContext gb;

  85.     int bit_len;

  86.     int x, y, len, color;

  87.     uint8_t *d;

  88. 

  89.     bit_len = (buf_size - start) * 8;

  90.     init_get_bits(&gb, buf + start, bit_len);

  91. 

  92.     x = 0;

  93.     y = 0;

  94.     d = bitmap;

  95.     for(;;) {

  96.         if (get_bits_count(&gb) > bit_len)

  97.             return -1;

  98.         if (is_8bit)

  99.             len = decode_run_8bit(&gb, &color);

  100.         else

  101.             len = decode_run_2bit(&gb, &color);

  102.         len = FFMIN(len, w - x);

  103.         memset(d + x, color, len);

  104.         x += len;

  105.         if (x >= w) {

  106.             y++;

  107.             if (y >= h)

  108.                 break;

  109.             d += linesize;

  110.             x = 0;

  111.             /* byte align */

  112.             align_get_bits(&gb);

  113.         }

  114.     }

  115.     return 0;

  116. }

  117. 

  118. static void guess_palette(uint32_t *rgba_palette,

  119.                           uint8_t *colormap,

  120.                           uint8_t *alpha,

  121.                           uint32_t subtitle_color)

  122. {

  123.     uint8_t color_used[16];

  124.     int nb_opaque_colors, i, level, j, r, g, b;

  125. 

  126.     for(i = 0; i < 4; i++)

  127.         rgba_palette[i] = 0;

  128. 

  129.     memset(color_used, 0, 16);

  130.     nb_opaque_colors = 0;

  131.     for(i = 0; i < 4; i++) {

  132.         if (alpha[i] != 0 && !color_used[colormap[i]]) {

  133.             color_used[colormap[i]] = 1;

  134.             nb_opaque_colors++;

  135.         }

  136.     }

  137. 

  138.     if (nb_opaque_colors == 0)

  139.         return;

  140. 

  141.     j = nb_opaque_colors;

  142.     memset(color_used, 0, 16);

  143.     for(i = 0; i < 4; i++) {

  144.         if (alpha[i] != 0) {

  145.             if (!color_used[colormap[i]])  {

  146.                 level = (0xff * j) / nb_opaque_colors;

  147.                 r = (((subtitle_color >> 16) & 0xff) * level) >> 8;

  148.                 g = (((subtitle_color >> 8) & 0xff) * level) >> 8;

  149.                 b = (((subtitle_color >> 0) & 0xff) * level) >> 8;

  150.                 rgba_palette[i] = b | (g << 8) | (r << 16) | ((alpha[i] * 17) << 24);

  151.                 color_used[colormap[i]] = (i + 1);

  152.                 j--;

  153.             } else {

  154.                 rgba_palette[i] = (rgba_palette[color_used[colormap[i]] - 1] & 0x00ffffff) |

  155.                                     ((alpha[i] * 17) << 24);

  156.             }

  157.         }

  158.     }

  159. }

  160. 

  161. #define READ_OFFSET(a) (big_offsets ? AV_RB32(a) : AV_RB16(a))

  162. 

  163. static int decode_dvd_subtitles(AVSubtitle *sub_header,

  164.                                 const uint8_t *buf, int buf_size)

  165. {

  166.     int cmd_pos, pos, cmd, x1, y1, x2, y2, offset1, offset2, next_cmd_pos;

  167.     int big_offsets, offset_size, is_8bit = 0;

  168.     const uint8_t *yuv_palette = 0;

  169.     uint8_t colormap[4], alpha[256];

  170.     int date;

  171.     int i;

  172.     int is_menu = 0;

  173. 

  174.     if (buf_size < 10)

  175.         return -1;

  176.     sub_header->rects = NULL;

  177.     sub_header->num_rects = 0;

  178.     sub_header->format = 0;

  179.     sub_header->start_display_time = 0;

  180.     sub_header->end_display_time = 0;

  181. 

  182.     if (AV_RB16(buf) == 0) {   /* HD subpicture with 4-byte offsets */

  183.         big_offsets = 1;

  184.         offset_size = 4;

  185.         cmd_pos = 6;

  186.     } else {

  187.         big_offsets = 0;

  188.         offset_size = 2;

  189.         cmd_pos = 2;

  190.     }

  191. 

  192.     cmd_pos = READ_OFFSET(buf + cmd_pos);

  193. 

  194.     while ((cmd_pos + 2 + offset_size) < buf_size) {

  195.         date = AV_RB16(buf + cmd_pos);

  196.         next_cmd_pos = READ_OFFSET(buf + cmd_pos + 2);

  197.         dprintf(NULL, "cmd_pos=0x%04x next=0x%04x date=%d\n",

  198.                 cmd_pos, next_cmd_pos, date);

  199.         pos = cmd_pos + 2 + offset_size;

  200.         offset1 = -1;

  201.         offset2 = -1;

  202.         x1 = y1 = x2 = y2 = 0;

  203.         while (pos < buf_size) {

  204.             cmd = buf[pos++];

  205.             dprintf(NULL, "cmd=%02x\n", cmd);

  206.             switch(cmd) {

  207.             case 0x00:

  208.                 /* menu subpicture */

  209.                 is_menu = 1;

  210.                 break;

  211.             case 0x01:

  212.                 /* set start date */

  213.                 sub_header->start_display_time = (date << 10) / 90;

  214.                 break;

  215.             case 0x02:

  216.                 /* set end date */

  217.                 sub_header->end_display_time = (date << 10) / 90;

  218.                 break;

  219.             case 0x03:

  220.                 /* set colormap */

  221.                 if ((buf_size - pos) < 2)

  222.                     goto fail;

  223.                 colormap[3] = buf[pos] >> 4;

  224.                 colormap[2] = buf[pos] & 0x0f;

  225.                 colormap[1] = buf[pos + 1] >> 4;

  226.                 colormap[0] = buf[pos + 1] & 0x0f;

  227.                 pos += 2;

  228.                 break;

  229.             case 0x04:

  230.                 /* set alpha */

  231.                 if ((buf_size - pos) < 2)

  232.                     goto fail;

  233.                 alpha[3] = buf[pos] >> 4;

  234.                 alpha[2] = buf[pos] & 0x0f;

  235.                 alpha[1] = buf[pos + 1] >> 4;

  236.                 alpha[0] = buf[pos + 1] & 0x0f;

  237.                 pos += 2;

  238.             dprintf(NULL, "alpha=%x%x%x%x\n", alpha[0],alpha[1],alpha[2],alpha[3]);

  239.                 break;

  240.             case 0x05:

  241.             case 0x85:

  242.                 if ((buf_size - pos) < 6)

  243.                     goto fail;

  244.                 x1 = (buf[pos] << 4) | (buf[pos + 1] >> 4);

  245.                 x2 = ((buf[pos + 1] & 0x0f) << 8) | buf[pos + 2];

  246.                 y1 = (buf[pos + 3] << 4) | (buf[pos + 4] >> 4);

  247.                 y2 = ((buf[pos + 4] & 0x0f) << 8) | buf[pos + 5];

  248.                 if (cmd & 0x80)

  249.                     is_8bit = 1;

  250.                 dprintf(NULL, "x1=%d x2=%d y1=%d y2=%d\n", x1, x2, y1, y2);

  251.                 pos += 6;

  252.                 break;

  253.             case 0x06:

  254.                 if ((buf_size - pos) < 4)

  255.                     goto fail;

  256.                 offset1 = AV_RB16(buf + pos);

  257.                 offset2 = AV_RB16(buf + pos + 2);

  258.                 dprintf(NULL, "offset1=0x%04x offset2=0x%04x\n", offset1, offset2);

  259.                 pos += 4;

  260.                 break;

  261.             case 0x86:

  262.                 if ((buf_size - pos) < 8)

  263.                     goto fail;

  264.                 offset1 = AV_RB32(buf + pos);

  265.                 offset2 = AV_RB32(buf + pos + 4);

  266.                 dprintf(NULL, "offset1=0x%04x offset2=0x%04x\n", offset1, offset2);

  267.                 pos += 8;

  268.                 break;

  269. 

  270.             case 0x83:

  271.                 /* HD set palette */

  272.                 if ((buf_size - pos) < 768)

  273.                     goto fail;

  274.                 yuv_palette = buf + pos;

  275.                 pos += 768;

  276.                 break;

  277.             case 0x84:

  278.                 /* HD set contrast (alpha) */

  279.                 if ((buf_size - pos) < 256)

  280.                     goto fail;

  281.                 for (i = 0; i < 256; i++)

  282.                     alpha[i] = 0xFF - buf[pos+i];

  283.                 pos += 256;

  284.                 break;

  285. 

  286.             case 0xff:

  287.                 goto the_end;

  288.             default:

  289.                 dprintf(NULL, "unrecognised subpicture command 0x%x\n", cmd);

  290.                 goto the_end;

  291.             }

  292.         }

  293.     the_end:

  294.         if (offset1 >= 0) {

  295.             int w, h;

  296.             uint8_t *bitmap;

  297. 

  298.             /* decode the bitmap */

  299.             w = x2 - x1 + 1;

  300.             if (w < 0)

  301.                 w = 0;

  302.             h = y2 - y1;

  303.             if (h < 0)

  304.                 h = 0;

  305.             if (w > 0 && h > 0) {

  306.                 if (sub_header->rects != NULL) {

  307.                     for (i = 0; i < sub_header->num_rects; i++) {

  308.                         av_freep(&sub_header->rects[i]->pict.data[0]);

  309.                         av_freep(&sub_header->rects[i]->pict.data[1]);

  310.                         av_freep(&sub_header->rects[i]);

  311.                     }

  312.                     av_freep(&sub_header->rects);

  313.                     sub_header->num_rects = 0;

  314.                 }

  315. 

  316.                 bitmap = av_malloc(w * h);

  317.                 sub_header->rects = av_mallocz(sizeof(*sub_header->rects));

  318.                 sub_header->rects[0] = av_mallocz(sizeof(AVSubtitleRect));

  319.                 sub_header->num_rects = 1;

  320.                 sub_header->rects[0]->pict.data[0] = bitmap;

  321.                 decode_rle(bitmap, w * 2, w, (h + 1) / 2,

  322.                            buf, offset1, buf_size, is_8bit);

  323.                 decode_rle(bitmap + w, w * 2, w, h / 2,

  324.                            buf, offset2, buf_size, is_8bit);

  325.                 if (is_8bit) {

  326.                     if (yuv_palette == 0)

  327.                         goto fail;

  328.                     sub_header->rects[0]->pict.data[1] = av_malloc(256 * 4);

  329.                     sub_header->rects[0]->nb_colors = 256;

  330.                     yuv_a_to_rgba(yuv_palette, alpha, (uint32_t*)sub_header->rects[0]->pict.data[1], 256);

  331.                 } else {

  332.                     sub_header->rects[0]->pict.data[1] = av_malloc(4 * 4);

  333.                     sub_header->rects[0]->nb_colors = 4;

  334.                     guess_palette((uint32_t*)sub_header->rects[0]->pict.data[1],

  335.                                   colormap, alpha, 0xffff00);

  336.                 }

  337.                 sub_header->rects[0]->x = x1;

  338.                 sub_header->rects[0]->y = y1;

  339.                 sub_header->rects[0]->w = w;

  340.                 sub_header->rects[0]->h = h;

  341.                 sub_header->rects[0]->type = SUBTITLE_BITMAP;

  342.                 sub_header->rects[0]->pict.linesize[0] = w;

  343.             }

  344.         }

  345.         if (next_cmd_pos == cmd_pos)

  346.             break;

  347.         cmd_pos = next_cmd_pos;

  348.     }

  349.     if (sub_header->num_rects > 0)

  350.         return is_menu;

  351.  fail:

  352.     if (sub_header->rects != NULL) {

  353.         for (i = 0; i < sub_header->num_rects; i++) {

  354.             av_freep(&sub_header->rects[i]->pict.data[0]);

  355.             av_freep(&sub_header->rects[i]->pict.data[1]);

  356.             av_freep(&sub_header->rects[i]);

  357.         }

  358.         av_freep(&sub_header->rects);

  359.         sub_header->num_rects = 0;

  360.     }

  361.     return -1;

  362. }

  363. 

  364. static int is_transp(const uint8_t *buf, int pitch, int n,

  365.                      const uint8_t *transp_color)

  366. {

  367.     int i;

  368.     for(i = 0; i < n; i++) {

  369.         if (!transp_color[*buf])

  370.             return 0;

  371.         buf += pitch;

  372.     }

  373.     return 1;

  374. }

  375. 

  376. /* return 0 if empty rectangle, 1 if non empty */

  377. static int find_smallest_bounding_rectangle(AVSubtitle *s)

  378. {

  379.     uint8_t transp_color[256];

  380.     int y1, y2, x1, x2, y, w, h, i;

  381.     uint8_t *bitmap;

  382. 

  383.     if (s->num_rects == 0 || s->rects == NULL || s->rects[0]->w <= 0 || s->rects[0]->h <= 0)

  384.         return 0;

  385. 

  386.     memset(transp_color, 0, 256);

  387.     for(i = 0; i < s->rects[0]->nb_colors; i++) {

  388.         if ((((uint32_t*)s->rects[0]->pict.data[1])[i] >> 24) == 0)

  389.             transp_color[i] = 1;

  390.     }

  391.     y1 = 0;

  392.     while (y1 < s->rects[0]->h && is_transp(s->rects[0]->pict.data[0] + y1 * s->rects[0]->pict.linesize[0],

  393.                                   1, s->rects[0]->w, transp_color))

  394.         y1++;

  395.     if (y1 == s->rects[0]->h) {

  396.         av_freep(&s->rects[0]->pict.data[0]);

  397.         s->rects[0]->w = s->rects[0]->h = 0;

  398.         return 0;

  399.     }

  400. 

  401.     y2 = s->rects[0]->h - 1;

  402.     while (y2 > 0 && is_transp(s->rects[0]->pict.data[0] + y2 * s->rects[0]->pict.linesize[0], 1,

  403.                                s->rects[0]->w, transp_color))

  404.         y2--;

  405.     x1 = 0;

  406.     while (x1 < (s->rects[0]->w - 1) && is_transp(s->rects[0]->pict.data[0] + x1, s->rects[0]->pict.linesize[0],

  407.                                         s->rects[0]->h, transp_color))

  408.         x1++;

  409.     x2 = s->rects[0]->w - 1;

  410.     while (x2 > 0 && is_transp(s->rects[0]->pict.data[0] + x2, s->rects[0]->pict.linesize[0], s->rects[0]->h,

  411.                                   transp_color))

  412.         x2--;

  413.     w = x2 - x1 + 1;

  414.     h = y2 - y1 + 1;

  415.     bitmap = av_malloc(w * h);

  416.     if (!bitmap)

  417.         return 1;

  418.     for(y = 0; y < h; y++) {

  419.         memcpy(bitmap + w * y, s->rects[0]->pict.data[0] + x1 + (y1 + y) * s->rects[0]->pict.linesize[0], w);

  420.     }

  421.     av_freep(&s->rects[0]->pict.data[0]);

  422.     s->rects[0]->pict.data[0] = bitmap;

  423.     s->rects[0]->pict.linesize[0] = w;

  424.     s->rects[0]->w = w;

  425.     s->rects[0]->h = h;

  426.     s->rects[0]->x += x1;

  427.     s->rects[0]->y += y1;

  428.     return 1;

  429. }

  430. 

  431. #ifdef DEBUG

  432. #undef fprintf

  433. #undef perror

  434. #undef exit

  435. static void ppm_save(const char *filename, uint8_t *bitmap, int w, int h,

  436.                      uint32_t *rgba_palette)

  437. {

  438.     int x, y, v;

  439.     FILE *f;

  440. 

  441.     f = fopen(filename, "w");

  442.     if (!f) {

  443.         perror(filename);

  444.         exit(1);

  445.     }

  446.     fprintf(f, "P6\n"

  447.             "%d %d\n"

  448.             "%d\n",

  449.             w, h, 255);

  450.     for(y = 0; y < h; y++) {

  451.         for(x = 0; x < w; x++) {

  452.             v = rgba_palette[bitmap[y * w + x]];

  453.             putc((v >> 16) & 0xff, f);

  454.             putc((v >> 8) & 0xff, f);

  455.             putc((v >> 0) & 0xff, f);

  456.         }

  457.     }

  458.     fclose(f);

  459. }

  460. #endif

  461. 

  462. static int dvdsub_decode(AVCodecContext *avctx,

  463.                          void *data, int *data_size,

  464.                          AVPacket *avpkt)

  465. {

  466.     const uint8_t *buf = avpkt->data;

  467.     int buf_size = avpkt->size;

  468.     AVSubtitle *sub = (void *)data;

  469.     int is_menu;

  470. 

  471.     is_menu = decode_dvd_subtitles(sub, buf, buf_size);

  472. 

  473.     if (is_menu < 0) {

  474.     no_subtitle:

  475.         *data_size = 0;

  476. 

  477.         return buf_size;

  478.     }

  479.     if (!is_menu && find_smallest_bounding_rectangle(sub) == 0)

  480.         goto no_subtitle;

  481. 

  482. #if defined(DEBUG)

  483.     dprintf(NULL, "start=%d ms end =%d ms\n",

  484.             sub->start_display_time,

  485.             sub->end_display_time);

  486.     ppm_save("/tmp/a.ppm", sub->rects[0]->pict.data[0],

  487.              sub->rects[0]->w, sub->rects[0]->h, sub->rects[0]->pict.data[1]);

  488. #endif

  489. 

  490.     *data_size = 1;

  491.     return buf_size;

  492. }

  493. 

  494. AVCodec dvdsub_decoder = {

  495.     "dvdsub",

  496.     CODEC_TYPE_SUBTITLE,

  497.     CODEC_ID_DVD_SUBTITLE,

  498.     0,

  499.     NULL,

  500.     NULL,

  501.     NULL,

  502.     dvdsub_decode,

  503.     .long_name = NULL_IF_CONFIG_SMALL("DVD subtitles"),

  504. };