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FFmpeg/libavcodec/ccaption_dec.c

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  1. /*

  2.  * Closed Caption Decoding

  3.  * Copyright (c) 2015 Anshul Maheshwari

  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. 

  22. #include "avcodec.h"

  23. #include "ass.h"

  24. #include "libavutil/opt.h"

  25. 

  26. #define SCREEN_ROWS 15

  27. #define SCREEN_COLUMNS 32

  28. 

  29. #define SET_FLAG(var, val)   ( (var) |=   ( 1 << (val)) )

  30. #define UNSET_FLAG(var, val) ( (var) &=  ~( 1 << (val)) )

  31. #define CHECK_FLAG(var, val) ( (var) &    ( 1 << (val)) )

  32. 

  33. /*

  34.  * TODO list

  35.  * 1) handle font and color completely

  36.  */

  37. enum cc_mode {

  38.     CCMODE_POPON,

  39.     CCMODE_PAINTON,

  40.     CCMODE_ROLLUP_2,

  41.     CCMODE_ROLLUP_3,

  42.     CCMODE_ROLLUP_4,

  43.     CCMODE_TEXT,

  44. };

  45. 

  46. enum cc_color_code {

  47.     CCCOL_WHITE,

  48.     CCCOL_GREEN,

  49.     CCCOL_BLUE,

  50.     CCCOL_CYAN,

  51.     CCCOL_RED,

  52.     CCCOL_YELLOW,

  53.     CCCOL_MAGENTA,

  54.     CCCOL_USERDEFINED,

  55.     CCCOL_BLACK,

  56.     CCCOL_TRANSPARENT,

  57. };

  58. 

  59. enum cc_font {

  60.     CCFONT_REGULAR,

  61.     CCFONT_ITALICS,

  62.     CCFONT_UNDERLINED,

  63.     CCFONT_UNDERLINED_ITALICS,

  64. };

  65. 

  66. static const unsigned char pac2_attribs[32][3] = // Color, font, ident

  67. {

  68.     { CCCOL_WHITE,   CCFONT_REGULAR,            0 },  // 0x40 || 0x60

  69.     { CCCOL_WHITE,   CCFONT_UNDERLINED,         0 },  // 0x41 || 0x61

  70.     { CCCOL_GREEN,   CCFONT_REGULAR,            0 },  // 0x42 || 0x62

  71.     { CCCOL_GREEN,   CCFONT_UNDERLINED,         0 },  // 0x43 || 0x63

  72.     { CCCOL_BLUE,    CCFONT_REGULAR,            0 },  // 0x44 || 0x64

  73.     { CCCOL_BLUE,    CCFONT_UNDERLINED,         0 },  // 0x45 || 0x65

  74.     { CCCOL_CYAN,    CCFONT_REGULAR,            0 },  // 0x46 || 0x66

  75.     { CCCOL_CYAN,    CCFONT_UNDERLINED,         0 },  // 0x47 || 0x67

  76.     { CCCOL_RED,     CCFONT_REGULAR,            0 },  // 0x48 || 0x68

  77.     { CCCOL_RED,     CCFONT_UNDERLINED,         0 },  // 0x49 || 0x69

  78.     { CCCOL_YELLOW,  CCFONT_REGULAR,            0 },  // 0x4a || 0x6a

  79.     { CCCOL_YELLOW,  CCFONT_UNDERLINED,         0 },  // 0x4b || 0x6b

  80.     { CCCOL_MAGENTA, CCFONT_REGULAR,            0 },  // 0x4c || 0x6c

  81.     { CCCOL_MAGENTA, CCFONT_UNDERLINED,         0 },  // 0x4d || 0x6d

  82.     { CCCOL_WHITE,   CCFONT_ITALICS,            0 },  // 0x4e || 0x6e

  83.     { CCCOL_WHITE,   CCFONT_UNDERLINED_ITALICS, 0 },  // 0x4f || 0x6f

  84.     { CCCOL_WHITE,   CCFONT_REGULAR,            0 },  // 0x50 || 0x70

  85.     { CCCOL_WHITE,   CCFONT_UNDERLINED,         0 },  // 0x51 || 0x71

  86.     { CCCOL_WHITE,   CCFONT_REGULAR,            4 },  // 0x52 || 0x72

  87.     { CCCOL_WHITE,   CCFONT_UNDERLINED,         4 },  // 0x53 || 0x73

  88.     { CCCOL_WHITE,   CCFONT_REGULAR,            8 },  // 0x54 || 0x74

  89.     { CCCOL_WHITE,   CCFONT_UNDERLINED,         8 },  // 0x55 || 0x75

  90.     { CCCOL_WHITE,   CCFONT_REGULAR,           12 },  // 0x56 || 0x76

  91.     { CCCOL_WHITE,   CCFONT_UNDERLINED,        12 },  // 0x57 || 0x77

  92.     { CCCOL_WHITE,   CCFONT_REGULAR,           16 },  // 0x58 || 0x78

  93.     { CCCOL_WHITE,   CCFONT_UNDERLINED,        16 },  // 0x59 || 0x79

  94.     { CCCOL_WHITE,   CCFONT_REGULAR,           20 },  // 0x5a || 0x7a

  95.     { CCCOL_WHITE,   CCFONT_UNDERLINED,        20 },  // 0x5b || 0x7b

  96.     { CCCOL_WHITE,   CCFONT_REGULAR,           24 },  // 0x5c || 0x7c

  97.     { CCCOL_WHITE,   CCFONT_UNDERLINED,        24 },  // 0x5d || 0x7d

  98.     { CCCOL_WHITE,   CCFONT_REGULAR,           28 },  // 0x5e || 0x7e

  99.     { CCCOL_WHITE,   CCFONT_UNDERLINED,        28 }   // 0x5f || 0x7f

  100.     /* total 32 entries */

  101. };

  102. 

  103. /* 0-255 needs 256 spaces */

  104. static const uint8_t parity_table[256] = { 0, 1, 1, 0, 1, 0, 0, 1,

  105.                                            1, 0, 0, 1, 0, 1, 1, 0,

  106.                                            1, 0, 0, 1, 0, 1, 1, 0,

  107.                                            0, 1, 1, 0, 1, 0, 0, 1,

  108.                                            1, 0, 0, 1, 0, 1, 1, 0,

  109.                                            0, 1, 1, 0, 1, 0, 0, 1,

  110.                                            0, 1, 1, 0, 1, 0, 0, 1,

  111.                                            1, 0, 0, 1, 0, 1, 1, 0,

  112.                                            1, 0, 0, 1, 0, 1, 1, 0,

  113.                                            0, 1, 1, 0, 1, 0, 0, 1,

  114.                                            0, 1, 1, 0, 1, 0, 0, 1,

  115.                                            1, 0, 0, 1, 0, 1, 1, 0,

  116.                                            0, 1, 1, 0, 1, 0, 0, 1,

  117.                                            1, 0, 0, 1, 0, 1, 1, 0,

  118.                                            1, 0, 0, 1, 0, 1, 1, 0,

  119.                                            0, 1, 1, 0, 1, 0, 0, 1,

  120.                                            1, 0, 0, 1, 0, 1, 1, 0,

  121.                                            0, 1, 1, 0, 1, 0, 0, 1,

  122.                                            0, 1, 1, 0, 1, 0, 0, 1,

  123.                                            1, 0, 0, 1, 0, 1, 1, 0,

  124.                                            0, 1, 1, 0, 1, 0, 0, 1,

  125.                                            1, 0, 0, 1, 0, 1, 1, 0,

  126.                                            1, 0, 0, 1, 0, 1, 1, 0,

  127.                                            0, 1, 1, 0, 1, 0, 0, 1,

  128.                                            0, 1, 1, 0, 1, 0, 0, 1,

  129.                                            1, 0, 0, 1, 0, 1, 1, 0,

  130.                                            1, 0, 0, 1, 0, 1, 1, 0,

  131.                                            0, 1, 1, 0, 1, 0, 0, 1,

  132.                                            1, 0, 0, 1, 0, 1, 1, 0,

  133.                                            0, 1, 1, 0, 1, 0, 0, 1,

  134.                                            0, 1, 1, 0, 1, 0, 0, 1,

  135.                                            1, 0, 0, 1, 0, 1, 1, 0 };

  136. 

  137. struct Screen {

  138.     /* +1 is used to compensate null character of string */

  139.     uint8_t characters[SCREEN_ROWS][SCREEN_COLUMNS+1];

  140.     uint8_t colors[SCREEN_ROWS][SCREEN_COLUMNS+1];

  141.     uint8_t fonts[SCREEN_ROWS][SCREEN_COLUMNS+1];

  142.     /*

  143.      * Bitmask of used rows; if a bit is not set, the

  144.      * corresponding row is not used.

  145.      * for setting row 1  use row | (1 << 0)

  146.      * for setting row 15 use row | (1 << 14)

  147.      */

  148.     int16_t  row_used;

  149. };

  150. 

  151. 

  152. typedef struct CCaptionSubContext {

  153.     AVClass *class;

  154.     struct Screen screen[2];

  155.     int active_screen;

  156.     uint8_t cursor_row;

  157.     uint8_t cursor_column;

  158.     uint8_t cursor_color;

  159.     uint8_t cursor_font;

  160.     AVBPrint buffer;

  161.     int screen_changed;

  162.     int rollup;

  163.     enum  cc_mode mode;

  164.     int64_t start_time;

  165.     /* visible screen time */

  166.     int64_t startv_time;

  167.     int64_t end_time;

  168.     char prev_cmd[2];

  169.     /* buffer to store pkt data */

  170.     AVBufferRef *pktbuf;

  171. }CCaptionSubContext;

  172. 

  173. 

  174. static av_cold int init_decoder(AVCodecContext *avctx)

  175. {

  176.     int ret;

  177.     CCaptionSubContext *ctx = avctx->priv_data;

  178. 

  179.     av_bprint_init(&ctx->buffer, 0, AV_BPRINT_SIZE_UNLIMITED);

  180.     /* taking by default roll up to 2 */

  181.     ctx->mode = CCMODE_ROLLUP_2;

  182.     ctx->rollup = 2;

  183.     ret = ff_ass_subtitle_header_default(avctx);

  184.     if(ret < 0) {

  185.         return ret;

  186.     }

  187.     /* allocate pkt buffer */

  188.     ctx->pktbuf = av_buffer_alloc(128);

  189.     if( !ctx->pktbuf) {

  190.         ret = AVERROR(ENOMEM);

  191.     }

  192.     return ret;

  193. }

  194. 

  195. static av_cold int close_decoder(AVCodecContext *avctx)

  196. {

  197.     CCaptionSubContext *ctx = avctx->priv_data;

  198.     av_bprint_finalize( &ctx->buffer, NULL);

  199.     av_buffer_unref(&ctx->pktbuf);

  200.     return 0;

  201. }

  202. 

  203. /**

  204.  * @param ctx closed caption context just to print log

  205.  */

  206. static int write_char (CCaptionSubContext *ctx, char *row,uint8_t col, char ch)

  207. {

  208.     if(col < SCREEN_COLUMNS) {

  209.         row[col] = ch;

  210.         return 0;

  211.     }

  212.     /* We have extra space at end only for null character */

  213.     else if ( col == SCREEN_COLUMNS && ch == 0) {

  214.         row[col] = ch;

  215.         return 0;

  216.     }

  217.     else {

  218.         av_log(ctx, AV_LOG_WARNING,"Data Ignored since exceeding screen width\n");

  219.         return AVERROR_INVALIDDATA;

  220.     }

  221. }

  222. 

  223. /**

  224.  * This function after validating parity bit, also remove it from data pair.

  225.  * The first byte doesn't pass parity, we replace it with a solid blank

  226.  * and process the pair.

  227.  * If the second byte doesn't pass parity, it returns INVALIDDATA

  228.  * user can ignore the whole pair and pass the other pair.

  229.  */

  230. static int validate_cc_data_pair (uint8_t *cc_data_pair)

  231. {

  232.     uint8_t cc_valid = (*cc_data_pair & 4) >>2;

  233.     uint8_t cc_type = *cc_data_pair & 3;

  234. 

  235.     if (!cc_valid)

  236.         return AVERROR_INVALIDDATA;

  237. 

  238.     // if EIA-608 data then verify parity.

  239.     if (cc_type==0 || cc_type==1) {

  240.         if (!parity_table[cc_data_pair[2]]) {

  241.             return AVERROR_INVALIDDATA;

  242.         }

  243.         if (!parity_table[cc_data_pair[1]]) {

  244.             cc_data_pair[1]=0x7F;

  245.         }

  246.     }

  247. 

  248.     //Skip non-data

  249.     if( (cc_data_pair[0] == 0xFA || cc_data_pair[0] == 0xFC || cc_data_pair[0] == 0xFD )

  250.          && (cc_data_pair[1] & 0x7F) == 0 && (cc_data_pair[2] & 0x7F) == 0)

  251.         return AVERROR_PATCHWELCOME;

  252. 

  253.     //skip 708 data

  254.     if(cc_type == 3 || cc_type == 2 )

  255.         return AVERROR_PATCHWELCOME;

  256. 

  257.     /* remove parity bit */

  258.     cc_data_pair[1] &= 0x7F;

  259.     cc_data_pair[2] &= 0x7F;

  260. 

  261. 

  262.     return 0;

  263. 

  264. }

  265. 

  266. static struct Screen *get_writing_screen(CCaptionSubContext *ctx)

  267. {

  268.     switch (ctx->mode) {

  269.     case CCMODE_POPON:

  270.         // use Inactive screen

  271.         return ctx->screen + !ctx->active_screen;

  272.     case CCMODE_PAINTON:

  273.     case CCMODE_ROLLUP_2:

  274.     case CCMODE_ROLLUP_3:

  275.     case CCMODE_ROLLUP_4:

  276.     case CCMODE_TEXT:

  277.         // use active screen

  278.         return ctx->screen + ctx->active_screen;

  279.     }

  280.     /* It was never an option */

  281.     return NULL;

  282. }

  283. 

  284. static void roll_up(CCaptionSubContext *ctx)

  285. {

  286.     struct Screen *screen;

  287.     int i, keep_lines;

  288. 

  289.     if(ctx->mode == CCMODE_TEXT)

  290.         return;

  291. 

  292.     screen = get_writing_screen(ctx);

  293. 

  294.     /* +1 signify cursor_row starts from 0

  295.      * Can't keep lines less then row cursor pos

  296.      */

  297.     keep_lines = FFMIN(ctx->cursor_row + 1, ctx->rollup);

  298. 

  299.     for( i = 0; i < ctx->cursor_row - keep_lines; i++ )

  300.         UNSET_FLAG(screen->row_used, i);

  301. 

  302. 

  303.     for( i = 0; i < keep_lines && screen->row_used; i++ ) {

  304.         const int i_row = ctx->cursor_row - keep_lines + i + 1;

  305. 

  306.         memcpy( screen->characters[i_row], screen->characters[i_row+1], SCREEN_COLUMNS );

  307.         memcpy( screen->colors[i_row], screen->colors[i_row+1], SCREEN_COLUMNS);

  308.         memcpy( screen->fonts[i_row], screen->fonts[i_row+1], SCREEN_COLUMNS);

  309.         if(CHECK_FLAG(screen->row_used, i_row + 1))

  310.             SET_FLAG(screen->row_used, i_row);

  311. 

  312.     }

  313.     UNSET_FLAG(screen->row_used, ctx->cursor_row);

  314. 

  315. }

  316. 

  317. static int reap_screen(CCaptionSubContext *ctx, int64_t pts)

  318. {

  319.     int i;

  320.     int ret = 0;

  321.     struct Screen *screen = ctx->screen + ctx->active_screen;

  322.     ctx->start_time = ctx->startv_time;

  323. 

  324.     for( i = 0; screen->row_used && i < SCREEN_ROWS; i++)

  325.     {

  326.         if(CHECK_FLAG(screen->row_used,i)) {

  327.             char *str = screen->characters[i];

  328.             /* skip space */

  329.             while (*str == ' ')

  330.                 str++;

  331. 

  332.             av_bprintf(&ctx->buffer, "%s\\N", str);

  333.             ret = av_bprint_is_complete(&ctx->buffer);

  334.             if( ret == 0) {

  335.                 ret = AVERROR(ENOMEM);

  336.                 break;

  337.             }

  338.         }

  339. 

  340.     }

  341.     if(screen->row_used && ctx->buffer.len >= 2 ) {

  342.         ctx->buffer.len -= 2;

  343.         ctx->buffer.str[ctx->buffer.len] = 0;

  344.     }

  345.     ctx->startv_time = pts;

  346.     ctx->end_time = pts;

  347.     return ret;

  348. }

  349. 

  350. static void handle_textattr( CCaptionSubContext *ctx, uint8_t hi, uint8_t lo )

  351. {

  352.     int i = lo - 0x20;

  353.     int ret;

  354.     struct Screen *screen = get_writing_screen(ctx);

  355.     char *row = screen->characters[ctx->cursor_row];

  356. 

  357.     if( i >= 32)

  358.         return;

  359. 

  360.     ctx->cursor_color =  pac2_attribs[i][0];

  361.     ctx->cursor_font = pac2_attribs[i][1];

  362. 

  363.     SET_FLAG(screen->row_used,ctx->cursor_row);

  364.     ret = write_char(ctx, row, ctx->cursor_column, ' ');

  365.     if(ret == 0)

  366.         ctx->cursor_column++;

  367. }

  368. 

  369. static void handle_pac( CCaptionSubContext *ctx, uint8_t hi, uint8_t lo )

  370. {

  371.     static const int8_t row_map[] = {

  372.         11, -1, 1, 2, 3, 4, 12, 13, 14, 15, 5, 6, 7, 8, 9, 10

  373.     };

  374.     const int index = ( (hi<<1) & 0x0e) | ( (lo>>5) & 0x01 );

  375.     struct Screen *screen = get_writing_screen(ctx);

  376.     char *row;

  377.     int indent,i,ret;

  378. 

  379.     if( row_map[index] <= 0 ) {

  380.         av_log(ctx, AV_LOG_DEBUG,"Invalid pac index encountered\n");

  381.         return;

  382.     }

  383. 

  384.     lo &= 0x1f;

  385. 

  386.     ctx->cursor_row = row_map[index] - 1;

  387.     ctx->cursor_color =  pac2_attribs[lo][0];

  388.     ctx->cursor_font = pac2_attribs[lo][1];

  389.     ctx->cursor_column = 0;

  390.     indent = pac2_attribs[lo][2];

  391.     row = screen->characters[ctx->cursor_row];

  392.     for(i = 0;i < indent; i++) {

  393.         ret = write_char(ctx, row, ctx->cursor_column, ' ');

  394.         if(  ret == 0 )

  395.             ctx->cursor_column++;

  396.     }

  397. 

  398. }

  399. 

  400. /**

  401.  * @param pts it is required to set end time

  402.  */

  403. static int handle_edm(CCaptionSubContext *ctx,int64_t pts)

  404. {

  405.     int ret = 0;

  406.     struct Screen *screen = ctx->screen + ctx->active_screen;

  407. 

  408.     reap_screen(ctx, pts);

  409.     screen->row_used = 0;

  410.     ctx->screen_changed = 1;

  411.     return ret;

  412. }

  413. 

  414. static int handle_eoc(CCaptionSubContext *ctx, int64_t pts)

  415. {

  416.     int ret;

  417.     ret = handle_edm(ctx,pts);

  418.     ctx->active_screen = !ctx->active_screen;

  419.     ctx->cursor_column = 0;

  420.     return ret;

  421. }

  422. 

  423. static void handle_delete_end_of_row( CCaptionSubContext *ctx, char hi, char lo)

  424. {

  425.     struct Screen *screen = get_writing_screen(ctx);

  426.     char *row = screen->characters[ctx->cursor_row];

  427.     write_char(ctx, row, ctx->cursor_column, 0);

  428. 

  429. }

  430. 

  431. static void handle_char(CCaptionSubContext *ctx, char hi, char lo, int64_t pts)

  432. {

  433.     struct Screen *screen = get_writing_screen(ctx);

  434.     char *row = screen->characters[ctx->cursor_row];

  435.     int ret;

  436. 

  437.     SET_FLAG(screen->row_used,ctx->cursor_row);

  438. 

  439.     ret = write_char(ctx, row, ctx->cursor_column, hi);

  440.     if( ret == 0 )

  441.         ctx->cursor_column++;

  442. 

  443.     if(lo) {

  444.         ret = write_char(ctx, row, ctx->cursor_column, lo);

  445.         if ( ret == 0 )

  446.             ctx->cursor_column++;

  447.     }

  448.     write_char(ctx, row, ctx->cursor_column, 0);

  449. 

  450.     /* reset prev command since character can repeat */

  451.     ctx->prev_cmd[0] = 0;

  452.     ctx->prev_cmd[1] = 0;

  453.     if (lo)

  454.        av_dlog(ctx, "(%c,%c)\n",hi,lo);

  455.     else

  456.        av_dlog(ctx, "(%c)\n",hi);

  457. }

  458. 

  459. static int process_cc608(CCaptionSubContext *ctx, int64_t pts, uint8_t hi, uint8_t lo)

  460. {

  461.     int ret = 0;

  462. #define COR3(var, with1, with2, with3)  ( (var) == (with1) ||  (var) == (with2) || (var) == (with3) )

  463.     if ( hi == ctx->prev_cmd[0] && lo == ctx->prev_cmd[1]) {

  464.     /* ignore redundant command */

  465.     } else if ( (hi == 0x10 && (lo >= 0x40 || lo <= 0x5f)) ||

  466.               ( (hi >= 0x11 && hi <= 0x17) && (lo >= 0x40 && lo <= 0x7f) ) ) {

  467.         handle_pac(ctx, hi, lo);

  468.     } else if ( ( hi == 0x11 && lo >= 0x20 && lo <= 0x2f ) ||

  469.                 ( hi == 0x17 && lo >= 0x2e && lo <= 0x2f) ) {

  470.         handle_textattr(ctx, hi, lo);

  471.     } else if ( COR3(hi, 0x14, 0x15, 0x1C) && lo == 0x20 ) {

  472.     /* resume caption loading */

  473.         ctx->mode = CCMODE_POPON;

  474.     } else if ( COR3(hi, 0x14, 0x15, 0x1C) && lo == 0x24 ) {

  475.         handle_delete_end_of_row(ctx, hi, lo);

  476.     } else if ( COR3(hi, 0x14, 0x15, 0x1C) && lo == 0x25 ) {

  477.         ctx->rollup = 2;

  478.         ctx->mode = CCMODE_ROLLUP_2;

  479.     } else if ( COR3(hi, 0x14, 0x15, 0x1C) && lo == 0x26 ) {

  480.         ctx->rollup = 3;

  481.         ctx->mode = CCMODE_ROLLUP_3;

  482.     } else if ( COR3(hi, 0x14, 0x15, 0x1C) && lo == 0x27 ) {

  483.         ctx->rollup = 4;

  484.         ctx->mode = CCMODE_ROLLUP_4;

  485.     } else if ( COR3(hi, 0x14, 0x15, 0x1C) && lo == 0x29 ) {

  486.     /* resume direct captioning */

  487.         ctx->mode = CCMODE_PAINTON;

  488.     } else if ( COR3(hi, 0x14, 0x15, 0x1C) && lo == 0x2B ) {

  489.     /* resume text display */

  490.         ctx->mode = CCMODE_TEXT;

  491.     } else if ( COR3(hi, 0x14, 0x15, 0x1C) && lo == 0x2C ) {

  492.     /* erase display memory */

  493.         ret = handle_edm(ctx, pts);

  494.     } else if ( COR3(hi, 0x14, 0x15, 0x1C) && lo == 0x2D ) {

  495.     /* carriage return */

  496.         av_dlog(ctx, "carriage return\n");

  497.         reap_screen(ctx, pts);

  498.         roll_up(ctx);

  499.         ctx->screen_changed = 1;

  500.         ctx->cursor_column = 0;

  501.     } else if ( COR3(hi, 0x14, 0x15, 0x1C) && lo == 0x2F ) {

  502.     /* end of caption */

  503.         av_dlog(ctx, "handle_eoc\n");

  504.         ret = handle_eoc(ctx, pts);

  505.     } else if (hi>=0x20) {

  506.     /* Standard characters (always in pairs) */

  507.         handle_char(ctx, hi, lo, pts);

  508.     } else {

  509.     /* Ignoring all other non data code */

  510.         av_dlog(ctx, "Unknown command 0x%hhx 0x%hhx\n", hi, lo);

  511.     }

  512. 

  513.     /* set prev command */

  514.      ctx->prev_cmd[0] = hi;

  515.      ctx->prev_cmd[1] = lo;

  516. 

  517. #undef COR3

  518.     return ret;

  519. 

  520. }

  521. 

  522. static int decode(AVCodecContext *avctx, void *data, int *got_sub, AVPacket *avpkt)

  523. {

  524.     CCaptionSubContext *ctx = avctx->priv_data;

  525.     AVSubtitle *sub = data;

  526.     uint8_t *bptr = NULL;

  527.     int len = avpkt->size;

  528.     int ret = 0;

  529.     int i;

  530. 

  531.     if ( ctx->pktbuf->size < len) {

  532.         ret = av_buffer_realloc(&ctx->pktbuf, len);

  533.          if(ret < 0) {

  534.             av_log(ctx, AV_LOG_WARNING, "Insufficient Memory of %d truncated to %d\n",len, ctx->pktbuf->size);

  535.             len = ctx->pktbuf->size;

  536.             ret = 0;

  537.         }

  538.     }

  539.     memcpy(ctx->pktbuf->data, avpkt->data, len);

  540.     bptr = ctx->pktbuf->data;

  541. 

  542. 

  543.     for (i  = 0; i < len; i += 3) {

  544.         uint8_t cc_type = *(bptr + i) & 3;

  545.         if (validate_cc_data_pair( bptr + i) )

  546.             continue;

  547.         /* ignoring data field 1 */

  548.         if(cc_type == 1)

  549.             continue;

  550.         else

  551.             process_cc608(ctx, avpkt->pts, *(bptr + i + 1) & 0x7f, *(bptr + i + 2) & 0x7f);

  552.         if(ctx->screen_changed && *ctx->buffer.str)

  553.         {

  554.             int start_time = av_rescale_q(ctx->start_time, avctx->time_base, (AVRational){ 1, 100 });

  555.             int end_time = av_rescale_q(ctx->end_time, avctx->time_base, (AVRational){ 1, 100 });

  556.             av_dlog(ctx, "cdp writing data (%s)\n",ctx->buffer.str);

  557.             ret = ff_ass_add_rect_bprint(sub, &ctx->buffer, start_time, end_time - start_time);

  558.             if (ret < 0)

  559.                 return ret;

  560.             sub->pts = av_rescale_q(ctx->start_time, avctx->time_base, AV_TIME_BASE_Q);

  561.             ctx->screen_changed = 0;

  562.             av_bprint_clear(&ctx->buffer);

  563.         }

  564.     }

  565. 

  566.     *got_sub = sub->num_rects > 0;

  567.     return ret;

  568. }

  569. 

  570. static const AVOption options[] = {

  571.     {NULL}

  572. };

  573. 

  574. static const AVClass ccaption_dec_class = {

  575.     .class_name = "Closed caption Decoder",

  576.     .item_name  = av_default_item_name,

  577.     .option     = options,

  578.     .version    = LIBAVUTIL_VERSION_INT,

  579. };

  580. 

  581. AVCodec ff_ccaption_decoder = {

  582.     .name           = "cc_dec",

  583.     .long_name      = NULL_IF_CONFIG_SMALL("Closed Caption (EIA-608 / CEA-708) Decoder"),

  584.     .type           = AVMEDIA_TYPE_SUBTITLE,

  585.     .id             = AV_CODEC_ID_EIA_608,

  586.     .priv_data_size = sizeof(CCaptionSubContext),

  587.     .init           = init_decoder,

  588.     .close          = close_decoder,

  589.     .decode         = decode,

  590.     .priv_class     = &ccaption_dec_class,

  591. };