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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 CHAR_DEBUG

  27. #define SCREEN_ROWS 15

  28. #define SCREEN_COLUMNS 32

  29. 

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

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

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

  33. 

  34. /*

  35.  * TODO list

  36.  * 1) handle font and color completely

  37.  */

  38. enum cc_mode {

  39.     CCMODE_POPON,

  40.     CCMODE_PAINTON,

  41.     CCMODE_ROLLUP_2,

  42.     CCMODE_ROLLUP_3,

  43.     CCMODE_ROLLUP_4,

  44.     CCMODE_TEXT,

  45. };

  46. 

  47. enum cc_color_code {

  48.     CCCOL_WHITE,

  49.     CCCOL_GREEN,

  50.     CCCOL_BLUE,

  51.     CCCOL_CYAN,

  52.     CCCOL_RED,

  53.     CCCOL_YELLOW,

  54.     CCCOL_MAGENTA,

  55.     CCCOL_USERDEFINED,

  56.     CCCOL_BLACK,

  57.     CCCOL_TRANSPARENT,

  58. };

  59. 

  60. enum cc_font {

  61.     CCFONT_REGULAR,

  62.     CCFONT_ITALICS,

  63.     CCFONT_UNDERLINED,

  64.     CCFONT_UNDERLINED_ITALICS,

  65. };

  66. 

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

  68. {

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

  101.     /* total 32 entries */

  102. };

  103. 

  104. /* 0-255 needs 256 spaces */

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

  135.                                            0, 1, 1, 0, 1, 0, 0, 1,

  136.                                            1, 0, 0, 1, 0, 1, 1, 0 };

  137. 

  138. struct Screen {

  139.     /* +1 is used to compensate null character of string */

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

  141.     /*

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

  143.      * corresponding row is not used.

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

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

  146.      */

  147.     int16_t  row_used;

  148. };

  149. 

  150. 

  151. typedef struct CCaptionSubContext {

  152.     AVClass *class;

  153.     int row_cnt;

  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 erase_display_memory;

  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->rollup = 2;

  182.     ret = ff_ass_subtitle_header_default(avctx);

  183.     /* allocate pkt buffer */

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

  185.     if( !ctx->pktbuf) {

  186.         ret = AVERROR(ENOMEM);

  187.     }

  188. 

  189. 

  190.     return ret;

  191. }

  192. 

  193. static av_cold int close_decoder(AVCodecContext *avctx)

  194. {

  195.     CCaptionSubContext *ctx = avctx->priv_data;

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

  197.     av_buffer_unref(&ctx->pktbuf);

  198.     return 0;

  199. }

  200. 

  201. /**

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

  203.  */

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

  205. {

  206.     if(col < SCREEN_COLUMNS) {

  207.         row[col] = ch;

  208.         return 0;

  209.     }

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

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

  212.         row[col] = ch;

  213.         return 0;

  214.     }

  215.     else {

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

  217.         return AVERROR_INVALIDDATA;

  218.     }

  219. }

  220. 

  221. /**

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

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

  224.  * and process the pair.

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

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

  227.  */

  228. static int validate_cc_data_pair (uint8_t *cc_data_pair)

  229. {

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

  231.     uint8_t cc_type = *cc_data_pair & 3;

  232. 

  233.     if (!cc_valid)

  234.         return AVERROR_INVALIDDATA;

  235. 

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

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

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

  239.             return AVERROR_INVALIDDATA;

  240.         }

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

  242.             cc_data_pair[1]=0x7F;

  243.         }

  244.     }

  245. 

  246.     //Skip non-data

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

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

  249.         return AVERROR_PATCHWELCOME;

  250. 

  251.     //skip 708 data

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

  253.         return AVERROR_PATCHWELCOME;

  254. 

  255.     /* remove parity bit */

  256.     cc_data_pair[1] &= 0x7F;

  257.     cc_data_pair[2] &= 0x7F;

  258. 

  259. 

  260.     return 0;

  261. 

  262. }

  263. 

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

  265. {

  266.     switch (ctx->mode) {

  267.     case CCMODE_POPON:

  268.         // use Inactive screen

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

  270.     case CCMODE_PAINTON:

  271.     case CCMODE_ROLLUP_2:

  272.     case CCMODE_ROLLUP_3:

  273.     case CCMODE_ROLLUP_4:

  274.     case CCMODE_TEXT:

  275.         // use active screen

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

  277.     }

  278.     /* It was never an option */

  279.     return NULL;

  280. }

  281. 

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

  283. {

  284.     int i = lo - 0x20;

  285.     int ret;

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

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

  288. 

  289.     if( i >= 32)

  290.         return;

  291. 

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

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

  294. 

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

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

  297.     if(ret == 0)

  298.         ctx->cursor_column++;

  299. }

  300. 

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

  302. {

  303.     static const int8_t row_map[] = {

  304.         11, -1, 1, 2, 3, 4, 12, 13, 14, 15, 5, 6, 7, 8, 9, 10

  305.     };

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

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

  308.     char *row;

  309.     int indent,i,ret;

  310. 

  311.     if( row_map[index] <= 0 )

  312.         return;

  313. 

  314.     lo &= 0x1f;

  315. 

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

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

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

  319.     ctx->cursor_column = 0;

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

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

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

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

  324.         if(  ret == 0 )

  325.             ctx->cursor_column++;

  326.     }

  327. 

  328. }

  329. 

  330. /**

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

  332.  */

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

  334. {

  335.     int i;

  336.     int ret = 0;

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

  338. 

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

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

  341.     {

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

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

  344.             /* skip space */

  345.             while (*str == ' ')

  346.                 str++;

  347.             av_bprint_append_data(&ctx->buffer, str, strlen(str));

  348.             av_bprint_append_data(&ctx->buffer, "\\N",2);

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

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

  351.             if( ret == 0) {

  352.                 ret = AVERROR(ENOMEM);

  353.                 break;

  354.             }

  355.         }

  356. 

  357.     }

  358.     ctx->startv_time = pts;

  359.     ctx->erase_display_memory = 1;

  360.     ctx->end_time = pts;

  361.     return ret;

  362. }

  363. 

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

  365. {

  366.     int ret;

  367.     ret = handle_edm(ctx,pts);

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

  369.     ctx->cursor_column = 0;

  370.     return ret;

  371. }

  372. 

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

  374. {

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

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

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

  378. 

  379. }

  380. 

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

  382. {

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

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

  385.     int ret;

  386. 

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

  388. 

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

  390.     if( ret == 0 )

  391.         ctx->cursor_column++;

  392. 

  393.     if(lo) {

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

  395.         if ( ret == 0 )

  396.             ctx->cursor_column++;

  397.     }

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

  399. 

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

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

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

  403. #ifdef CHAR_DEBUG

  404.     av_log(ctx, AV_LOG_DEBUG,"(%c,%c)\n",hi,lo);

  405. #endif

  406. }

  407. 

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

  409. {

  410.     int ret = 0;

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

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

  413.     /* ignore redundant command */

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

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

  416.         handle_pac(ctx, hi, lo);

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

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

  419.         handle_textattr(ctx, hi, lo);

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

  421.     /* resume caption loading */

  422.         ctx->mode = CCMODE_POPON;

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

  424.         handle_delete_end_of_row(ctx, hi, lo);

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

  426.         ctx->rollup = 2;

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

  428.         ctx->rollup = 3;

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

  430.         ctx->rollup = 4;

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

  432.     /* resume direct captioning */

  433.         ctx->mode = CCMODE_PAINTON;

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

  435.     /* resume text display */

  436.         ctx->mode = CCMODE_TEXT;

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

  438.     /* erase display memory */

  439.         ret = handle_edm(ctx, pts);

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

  441.     /* carriage return */

  442.         ctx->row_cnt++;

  443.         if(ctx->row_cnt >= ctx->rollup) {

  444.             ctx->row_cnt = 0;

  445.             ret = handle_edm(ctx, pts);

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

  447.         }

  448.         ctx->cursor_column = 0;

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

  450.     /* end of caption */

  451.         ret = handle_eoc(ctx, pts);

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

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

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

  455.     } else {

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

  457.     }

  458. 

  459.     /* set prev command */

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

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

  462. 

  463. #undef COR3

  464.     return ret;

  465. 

  466. }

  467. 

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

  469. {

  470.     CCaptionSubContext *ctx = avctx->priv_data;

  471.     AVSubtitle *sub = data;

  472.     uint8_t *bptr = NULL;

  473.     int len = avpkt->size;

  474.     int ret = 0;

  475.     int i;

  476. 

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

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

  479.          if(ret < 0) {

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

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

  482.             ret = 0;

  483.         }

  484.     }

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

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

  487. 

  488. 

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

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

  491.         if (validate_cc_data_pair( bptr + i) )

  492.             continue;

  493.         /* ignoring data field 1 */

  494.         if(cc_type == 1)

  495.             continue;

  496.         else

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

  498.         if(ctx->erase_display_memory && *ctx->buffer.str)

  499.         {

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

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

  502. #ifdef CHAR_DEBUG

  503.             av_log(ctx, AV_LOG_DEBUG,"cdp writing data (%s)\n",ctx->buffer.str);

  504. #endif

  505.             ret = ff_ass_add_rect(sub, ctx->buffer.str, start_time, end_time - start_time , 0);

  506.             if (ret < 0)

  507.                 return ret;

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

  509.             ctx->erase_display_memory = 0;

  510.             av_bprint_clear(&ctx->buffer);

  511.         }

  512.     }

  513. 

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

  515.     return ret;

  516. }

  517. 

  518. static const AVOption options[] = {

  519.     {NULL}

  520. };

  521. 

  522. static const AVClass ccaption_dec_class = {

  523.     .class_name = "Closed caption Decoder",

  524.     .item_name  = av_default_item_name,

  525.     .option     = options,

  526.     .version    = LIBAVUTIL_VERSION_INT,

  527. };

  528. 

  529. AVCodec ff_ccaption_decoder = {

  530.     .name           = "cc_dec",

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

  532.     .type           = AVMEDIA_TYPE_SUBTITLE,

  533.     .id             = AV_CODEC_ID_EIA_608,

  534.     .priv_data_size = sizeof(CCaptionSubContext),

  535.     .init           = init_decoder,

  536.     .close          = close_decoder,

  537.     .decode         = decode,

  538.     .priv_class     = &ccaption_dec_class,

  539. };