/* * Closed Caption Decoding * Copyright (c) 2015 Anshul Maheshwari * * This file is part of FFmpeg. * * FFmpeg is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * FFmpeg is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ #include "avcodec.h" #include "ass.h" #include "codec_internal.h" #include "libavutil/opt.h" #define SCREEN_ROWS 15 #define SCREEN_COLUMNS 32 #define SET_FLAG(var, val) ( (var) |= ( 1 << (val)) ) #define UNSET_FLAG(var, val) ( (var) &= ~( 1 << (val)) ) #define CHECK_FLAG(var, val) ( (var) & ( 1 << (val)) ) static const AVRational ms_tb = {1, 1000}; enum cc_mode { CCMODE_POPON, CCMODE_PAINTON, CCMODE_ROLLUP, CCMODE_TEXT, }; enum cc_color_code { CCCOL_WHITE, CCCOL_GREEN, CCCOL_BLUE, CCCOL_CYAN, CCCOL_RED, CCCOL_YELLOW, CCCOL_MAGENTA, CCCOL_USERDEFINED, CCCOL_BLACK, CCCOL_TRANSPARENT, }; enum cc_font { CCFONT_REGULAR, CCFONT_ITALICS, CCFONT_UNDERLINED, CCFONT_UNDERLINED_ITALICS, }; enum cc_charset { CCSET_BASIC_AMERICAN, CCSET_SPECIAL_AMERICAN, CCSET_EXTENDED_SPANISH_FRENCH_MISC, CCSET_EXTENDED_PORTUGUESE_GERMAN_DANISH, }; #define CHARSET_OVERRIDE_LIST(START_SET, ENTRY, END_SET) \ START_SET(CCSET_BASIC_AMERICAN) \ ENTRY(0x27, "\u2019") \ ENTRY(0x2a, "\u00e1") \ ENTRY(0x5c, "\u00e9") \ ENTRY(0x5e, "\u00ed") \ ENTRY(0x5f, "\u00f3") \ ENTRY(0x60, "\u00fa") \ ENTRY(0x7b, "\u00e7") \ ENTRY(0x7c, "\u00f7") \ ENTRY(0x7d, "\u00d1") \ ENTRY(0x7e, "\u00f1") \ ENTRY(0x7f, "\u2588") \ END_SET \ START_SET(CCSET_SPECIAL_AMERICAN) \ ENTRY(0x30, "\u00ae") \ ENTRY(0x31, "\u00b0") \ ENTRY(0x32, "\u00bd") \ ENTRY(0x33, "\u00bf") \ ENTRY(0x34, "\u2122") \ ENTRY(0x35, "\u00a2") \ ENTRY(0x36, "\u00a3") \ ENTRY(0x37, "\u266a") \ ENTRY(0x38, "\u00e0") \ ENTRY(0x39, "\u00A0") \ ENTRY(0x3a, "\u00e8") \ ENTRY(0x3b, "\u00e2") \ ENTRY(0x3c, "\u00ea") \ ENTRY(0x3d, "\u00ee") \ ENTRY(0x3e, "\u00f4") \ ENTRY(0x3f, "\u00fb") \ END_SET \ START_SET(CCSET_EXTENDED_SPANISH_FRENCH_MISC) \ ENTRY(0x20, "\u00c1") \ ENTRY(0x21, "\u00c9") \ ENTRY(0x22, "\u00d3") \ ENTRY(0x23, "\u00da") \ ENTRY(0x24, "\u00dc") \ ENTRY(0x25, "\u00fc") \ ENTRY(0x26, "\u00b4") \ ENTRY(0x27, "\u00a1") \ ENTRY(0x28, "*") \ ENTRY(0x29, "\u2018") \ ENTRY(0x2a, "-") \ ENTRY(0x2b, "\u00a9") \ ENTRY(0x2c, "\u2120") \ ENTRY(0x2d, "\u00b7") \ ENTRY(0x2e, "\u201c") \ ENTRY(0x2f, "\u201d") \ ENTRY(0x30, "\u00c0") \ ENTRY(0x31, "\u00c2") \ ENTRY(0x32, "\u00c7") \ ENTRY(0x33, "\u00c8") \ ENTRY(0x34, "\u00ca") \ ENTRY(0x35, "\u00cb") \ ENTRY(0x36, "\u00eb") \ ENTRY(0x37, "\u00ce") \ ENTRY(0x38, "\u00cf") \ ENTRY(0x39, "\u00ef") \ ENTRY(0x3a, "\u00d4") \ ENTRY(0x3b, "\u00d9") \ ENTRY(0x3c, "\u00f9") \ ENTRY(0x3d, "\u00db") \ ENTRY(0x3e, "\u00ab") \ ENTRY(0x3f, "\u00bb") \ END_SET \ START_SET(CCSET_EXTENDED_PORTUGUESE_GERMAN_DANISH) \ ENTRY(0x20, "\u00c3") \ ENTRY(0x21, "\u00e3") \ ENTRY(0x22, "\u00cd") \ ENTRY(0x23, "\u00cc") \ ENTRY(0x24, "\u00ec") \ ENTRY(0x25, "\u00d2") \ ENTRY(0x26, "\u00f2") \ ENTRY(0x27, "\u00d5") \ ENTRY(0x28, "\u00f5") \ ENTRY(0x29, "{") \ ENTRY(0x2a, "}") \ ENTRY(0x2b, "\\") \ ENTRY(0x2c, "^") \ ENTRY(0x2d, "_") \ ENTRY(0x2e, "|") \ ENTRY(0x2f, "~") \ ENTRY(0x30, "\u00c4") \ ENTRY(0x31, "\u00e4") \ ENTRY(0x32, "\u00d6") \ ENTRY(0x33, "\u00f6") \ ENTRY(0x34, "\u00df") \ ENTRY(0x35, "\u00a5") \ ENTRY(0x36, "\u00a4") \ ENTRY(0x37, "\u00a6") \ ENTRY(0x38, "\u00c5") \ ENTRY(0x39, "\u00e5") \ ENTRY(0x3a, "\u00d8") \ ENTRY(0x3b, "\u00f8") \ ENTRY(0x3c, "\u250c") \ ENTRY(0x3d, "\u2510") \ ENTRY(0x3e, "\u2514") \ ENTRY(0x3f, "\u2518") \ END_SET \ static const char charset_overrides[4][128][sizeof("\u266a")] = { #define START_SET(IDX) \ [IDX] = { #define ENTRY(idx, string) \ [idx] = string, #define END_SET \ }, CHARSET_OVERRIDE_LIST(START_SET, ENTRY, END_SET) }; #define EMPTY_START(IDX) #define EMPTY_END #define ASSERT_ENTRY(IDX, str) \ _Static_assert(sizeof(str) <= sizeof(charset_overrides[0][0]), \ "'" str "' string takes too much space"); CHARSET_OVERRIDE_LIST(EMPTY_START, ASSERT_ENTRY, EMPTY_END) static const unsigned char bg_attribs[8] = // Color { CCCOL_WHITE, CCCOL_GREEN, CCCOL_BLUE, CCCOL_CYAN, CCCOL_RED, CCCOL_YELLOW, CCCOL_MAGENTA, CCCOL_BLACK, }; static const unsigned char pac2_attribs[32][3] = // Color, font, ident { { CCCOL_WHITE, CCFONT_REGULAR, 0 }, // 0x40 || 0x60 { CCCOL_WHITE, CCFONT_UNDERLINED, 0 }, // 0x41 || 0x61 { CCCOL_GREEN, CCFONT_REGULAR, 0 }, // 0x42 || 0x62 { CCCOL_GREEN, CCFONT_UNDERLINED, 0 }, // 0x43 || 0x63 { CCCOL_BLUE, CCFONT_REGULAR, 0 }, // 0x44 || 0x64 { CCCOL_BLUE, CCFONT_UNDERLINED, 0 }, // 0x45 || 0x65 { CCCOL_CYAN, CCFONT_REGULAR, 0 }, // 0x46 || 0x66 { CCCOL_CYAN, CCFONT_UNDERLINED, 0 }, // 0x47 || 0x67 { CCCOL_RED, CCFONT_REGULAR, 0 }, // 0x48 || 0x68 { CCCOL_RED, CCFONT_UNDERLINED, 0 }, // 0x49 || 0x69 { CCCOL_YELLOW, CCFONT_REGULAR, 0 }, // 0x4a || 0x6a { CCCOL_YELLOW, CCFONT_UNDERLINED, 0 }, // 0x4b || 0x6b { CCCOL_MAGENTA, CCFONT_REGULAR, 0 }, // 0x4c || 0x6c { CCCOL_MAGENTA, CCFONT_UNDERLINED, 0 }, // 0x4d || 0x6d { CCCOL_WHITE, CCFONT_ITALICS, 0 }, // 0x4e || 0x6e { CCCOL_WHITE, CCFONT_UNDERLINED_ITALICS, 0 }, // 0x4f || 0x6f { CCCOL_WHITE, CCFONT_REGULAR, 0 }, // 0x50 || 0x70 { CCCOL_WHITE, CCFONT_UNDERLINED, 0 }, // 0x51 || 0x71 { CCCOL_WHITE, CCFONT_REGULAR, 4 }, // 0x52 || 0x72 { CCCOL_WHITE, CCFONT_UNDERLINED, 4 }, // 0x53 || 0x73 { CCCOL_WHITE, CCFONT_REGULAR, 8 }, // 0x54 || 0x74 { CCCOL_WHITE, CCFONT_UNDERLINED, 8 }, // 0x55 || 0x75 { CCCOL_WHITE, CCFONT_REGULAR, 12 }, // 0x56 || 0x76 { CCCOL_WHITE, CCFONT_UNDERLINED, 12 }, // 0x57 || 0x77 { CCCOL_WHITE, CCFONT_REGULAR, 16 }, // 0x58 || 0x78 { CCCOL_WHITE, CCFONT_UNDERLINED, 16 }, // 0x59 || 0x79 { CCCOL_WHITE, CCFONT_REGULAR, 20 }, // 0x5a || 0x7a { CCCOL_WHITE, CCFONT_UNDERLINED, 20 }, // 0x5b || 0x7b { CCCOL_WHITE, CCFONT_REGULAR, 24 }, // 0x5c || 0x7c { CCCOL_WHITE, CCFONT_UNDERLINED, 24 }, // 0x5d || 0x7d { CCCOL_WHITE, CCFONT_REGULAR, 28 }, // 0x5e || 0x7e { CCCOL_WHITE, CCFONT_UNDERLINED, 28 } // 0x5f || 0x7f /* total 32 entries */ }; struct Screen { /* +1 is used to compensate null character of string */ uint8_t characters[SCREEN_ROWS+1][SCREEN_COLUMNS+1]; uint8_t charsets[SCREEN_ROWS+1][SCREEN_COLUMNS+1]; uint8_t colors[SCREEN_ROWS+1][SCREEN_COLUMNS+1]; uint8_t bgs[SCREEN_ROWS+1][SCREEN_COLUMNS+1]; uint8_t fonts[SCREEN_ROWS+1][SCREEN_COLUMNS+1]; /* * Bitmask of used rows; if a bit is not set, the * corresponding row is not used. * for setting row 1 use row | (1 << 0) * for setting row 15 use row | (1 << 14) */ int16_t row_used; }; typedef struct CCaptionSubContext { AVClass *class; int real_time; int real_time_latency_msec; int data_field; struct Screen screen[2]; int active_screen; uint8_t cursor_row; uint8_t cursor_column; uint8_t cursor_color; uint8_t bg_color; uint8_t cursor_font; uint8_t cursor_charset; AVBPrint buffer[2]; int buffer_index; int buffer_changed; int rollup; enum cc_mode mode; int64_t buffer_time[2]; int screen_touched; int64_t last_real_time; uint8_t prev_cmd[2]; int readorder; } CCaptionSubContext; static av_cold int init_decoder(AVCodecContext *avctx) { CCaptionSubContext *ctx = avctx->priv_data; av_bprint_init(&ctx->buffer[0], 0, AV_BPRINT_SIZE_UNLIMITED); av_bprint_init(&ctx->buffer[1], 0, AV_BPRINT_SIZE_UNLIMITED); /* taking by default roll up to 2 */ ctx->mode = CCMODE_ROLLUP; ctx->bg_color = CCCOL_BLACK; ctx->rollup = 2; ctx->cursor_row = 10; return ff_ass_subtitle_header(avctx, "Monospace", ASS_DEFAULT_FONT_SIZE, ASS_DEFAULT_COLOR, ASS_DEFAULT_BACK_COLOR, ASS_DEFAULT_BOLD, ASS_DEFAULT_ITALIC, ASS_DEFAULT_UNDERLINE, 3, ASS_DEFAULT_ALIGNMENT); } static av_cold int close_decoder(AVCodecContext *avctx) { CCaptionSubContext *ctx = avctx->priv_data; av_bprint_finalize(&ctx->buffer[0], NULL); av_bprint_finalize(&ctx->buffer[1], NULL); return 0; } static void flush_decoder(AVCodecContext *avctx) { CCaptionSubContext *ctx = avctx->priv_data; ctx->screen[0].row_used = 0; ctx->screen[1].row_used = 0; ctx->prev_cmd[0] = 0; ctx->prev_cmd[1] = 0; ctx->mode = CCMODE_ROLLUP; ctx->rollup = 2; ctx->cursor_row = 10; ctx->cursor_column = 0; ctx->cursor_font = 0; ctx->cursor_color = 0; ctx->bg_color = CCCOL_BLACK; ctx->cursor_charset = 0; ctx->active_screen = 0; ctx->last_real_time = 0; ctx->screen_touched = 0; ctx->buffer_changed = 0; if (!(avctx->flags2 & AV_CODEC_FLAG2_RO_FLUSH_NOOP)) ctx->readorder = 0; av_bprint_clear(&ctx->buffer[0]); av_bprint_clear(&ctx->buffer[1]); } /** * @param ctx closed caption context just to print log */ static void write_char(CCaptionSubContext *ctx, struct Screen *screen, char ch) { uint8_t col = ctx->cursor_column; char *row = screen->characters[ctx->cursor_row]; char *font = screen->fonts[ctx->cursor_row]; char *color = screen->colors[ctx->cursor_row]; char *bg = screen->bgs[ctx->cursor_row]; char *charset = screen->charsets[ctx->cursor_row]; if (col < SCREEN_COLUMNS) { row[col] = ch; font[col] = ctx->cursor_font; color[col] = ctx->cursor_color; bg[col] = ctx->bg_color; charset[col] = ctx->cursor_charset; ctx->cursor_charset = CCSET_BASIC_AMERICAN; if (ch) ctx->cursor_column++; return; } /* We have extra space at end only for null character */ else if (col == SCREEN_COLUMNS && ch == 0) { row[col] = ch; return; } else { av_log(ctx, AV_LOG_WARNING, "Data ignored due to columns exceeding screen width\n"); return; } } /** * This function after validating parity bit, also remove it from data pair. * The first byte doesn't pass parity, we replace it with a solid blank * and process the pair. * If the second byte doesn't pass parity, it returns INVALIDDATA * user can ignore the whole pair and pass the other pair. */ static int validate_cc_data_pair(const uint8_t *cc_data_pair, uint8_t *hi) { uint8_t cc_valid = (*cc_data_pair & 4) >>2; uint8_t cc_type = *cc_data_pair & 3; *hi = cc_data_pair[1]; if (!cc_valid) return AVERROR_INVALIDDATA; // if EIA-608 data then verify parity. if (cc_type==0 || cc_type==1) { if (!av_parity(cc_data_pair[2])) { return AVERROR_INVALIDDATA; } if (!av_parity(cc_data_pair[1])) { *hi = 0x7F; } } //Skip non-data if ((cc_data_pair[0] == 0xFA || cc_data_pair[0] == 0xFC || cc_data_pair[0] == 0xFD) && (cc_data_pair[1] & 0x7F) == 0 && (cc_data_pair[2] & 0x7F) == 0) return AVERROR_PATCHWELCOME; //skip 708 data if (cc_type == 3 || cc_type == 2) return AVERROR_PATCHWELCOME; return 0; } static struct Screen *get_writing_screen(CCaptionSubContext *ctx) { switch (ctx->mode) { case CCMODE_POPON: // use Inactive screen return ctx->screen + !ctx->active_screen; case CCMODE_PAINTON: case CCMODE_ROLLUP: case CCMODE_TEXT: // use active screen return ctx->screen + ctx->active_screen; } /* It was never an option */ return NULL; } static void roll_up(CCaptionSubContext *ctx) { struct Screen *screen; int i, keep_lines; if (ctx->mode == CCMODE_TEXT) return; screen = get_writing_screen(ctx); /* +1 signify cursor_row starts from 0 * Can't keep lines less then row cursor pos */ keep_lines = FFMIN(ctx->cursor_row + 1, ctx->rollup); for (i = 0; i < SCREEN_ROWS; i++) { if (i > ctx->cursor_row - keep_lines && i <= ctx->cursor_row) continue; UNSET_FLAG(screen->row_used, i); } for (i = 0; i < keep_lines && screen->row_used; i++) { const int i_row = ctx->cursor_row - keep_lines + i + 1; memcpy(screen->characters[i_row], screen->characters[i_row+1], SCREEN_COLUMNS); memcpy(screen->colors[i_row], screen->colors[i_row+1], SCREEN_COLUMNS); memcpy(screen->bgs[i_row], screen->bgs[i_row+1], SCREEN_COLUMNS); memcpy(screen->fonts[i_row], screen->fonts[i_row+1], SCREEN_COLUMNS); memcpy(screen->charsets[i_row], screen->charsets[i_row+1], SCREEN_COLUMNS); if (CHECK_FLAG(screen->row_used, i_row + 1)) SET_FLAG(screen->row_used, i_row); } UNSET_FLAG(screen->row_used, ctx->cursor_row); } static int capture_screen(CCaptionSubContext *ctx) { int i, j, tab = 0; struct Screen *screen = ctx->screen + ctx->active_screen; enum cc_font prev_font = CCFONT_REGULAR; enum cc_color_code prev_color = CCCOL_WHITE; enum cc_color_code prev_bg_color = CCCOL_BLACK; const int bidx = ctx->buffer_index; av_bprint_clear(&ctx->buffer[bidx]); for (i = 0; screen->row_used && i < SCREEN_ROWS; i++) { if (CHECK_FLAG(screen->row_used, i)) { const char *row = screen->characters[i]; const char *charset = screen->charsets[i]; j = 0; while (row[j] == ' ' && charset[j] == CCSET_BASIC_AMERICAN) j++; if (!tab || j < tab) tab = j; } } for (i = 0; screen->row_used && i < SCREEN_ROWS; i++) { if (CHECK_FLAG(screen->row_used, i)) { const char *row = screen->characters[i]; const char *font = screen->fonts[i]; const char *bg = screen->bgs[i]; const char *color = screen->colors[i]; const char *charset = screen->charsets[i]; const char *override; int x, y, seen_char = 0; j = 0; /* skip leading space */ while (row[j] == ' ' && charset[j] == CCSET_BASIC_AMERICAN && j < tab) j++; x = ASS_DEFAULT_PLAYRESX * (0.1 + 0.0250 * j); y = ASS_DEFAULT_PLAYRESY * (0.1 + 0.0533 * i); av_bprintf(&ctx->buffer[bidx], "{\\an7}{\\pos(%d,%d)}", x, y); for (; j < SCREEN_COLUMNS; j++) { const char *e_tag = "", *s_tag = "", *c_tag = "", *b_tag = ""; if (row[j] == 0) break; if (prev_font != font[j]) { switch (prev_font) { case CCFONT_ITALICS: e_tag = "{\\i0}"; break; case CCFONT_UNDERLINED: e_tag = "{\\u0}"; break; case CCFONT_UNDERLINED_ITALICS: e_tag = "{\\u0}{\\i0}"; break; } switch (font[j]) { case CCFONT_ITALICS: s_tag = "{\\i1}"; break; case CCFONT_UNDERLINED: s_tag = "{\\u1}"; break; case CCFONT_UNDERLINED_ITALICS: s_tag = "{\\u1}{\\i1}"; break; } } if (prev_color != color[j]) { switch (color[j]) { case CCCOL_WHITE: c_tag = "{\\c&HFFFFFF&}"; break; case CCCOL_GREEN: c_tag = "{\\c&H00FF00&}"; break; case CCCOL_BLUE: c_tag = "{\\c&HFF0000&}"; break; case CCCOL_CYAN: c_tag = "{\\c&HFFFF00&}"; break; case CCCOL_RED: c_tag = "{\\c&H0000FF&}"; break; case CCCOL_YELLOW: c_tag = "{\\c&H00FFFF&}"; break; case CCCOL_MAGENTA: c_tag = "{\\c&HFF00FF&}"; break; } } if (prev_bg_color != bg[j]) { switch (bg[j]) { case CCCOL_WHITE: b_tag = "{\\3c&HFFFFFF&}"; break; case CCCOL_GREEN: b_tag = "{\\3c&H00FF00&}"; break; case CCCOL_BLUE: b_tag = "{\\3c&HFF0000&}"; break; case CCCOL_CYAN: b_tag = "{\\3c&HFFFF00&}"; break; case CCCOL_RED: b_tag = "{\\3c&H0000FF&}"; break; case CCCOL_YELLOW: b_tag = "{\\3c&H00FFFF&}"; break; case CCCOL_MAGENTA: b_tag = "{\\3c&HFF00FF&}"; break; case CCCOL_BLACK: b_tag = "{\\3c&H000000&}"; break; } } prev_font = font[j]; prev_color = color[j]; prev_bg_color = bg[j]; override = charset_overrides[(int)charset[j]][(int)row[j]]; if (override[0]) { av_bprintf(&ctx->buffer[bidx], "%s%s%s%s%s", e_tag, s_tag, c_tag, b_tag, override); seen_char = 1; } else if (row[j] == ' ' && !seen_char) { av_bprintf(&ctx->buffer[bidx], "%s%s%s%s\\h", e_tag, s_tag, c_tag, b_tag); } else { av_bprintf(&ctx->buffer[bidx], "%s%s%s%s%c", e_tag, s_tag, c_tag, b_tag, row[j]); seen_char = 1; } } av_bprintf(&ctx->buffer[bidx], "\\N"); } } if (!av_bprint_is_complete(&ctx->buffer[bidx])) return AVERROR(ENOMEM); if (screen->row_used && ctx->buffer[bidx].len >= 2) { ctx->buffer[bidx].len -= 2; ctx->buffer[bidx].str[ctx->buffer[bidx].len] = 0; } ctx->buffer_changed = 1; return 0; } static void update_time(CCaptionSubContext *ctx, int64_t pts) { ctx->buffer_time[0] = ctx->buffer_time[1]; ctx->buffer_time[1] = pts; } static void handle_bgattr(CCaptionSubContext *ctx, uint8_t hi, uint8_t lo) { const int i = (lo & 0xf) >> 1; ctx->bg_color = bg_attribs[i]; } static void handle_textattr(CCaptionSubContext *ctx, uint8_t hi, uint8_t lo) { int i = lo - 0x20; struct Screen *screen = get_writing_screen(ctx); if (i >= 32) return; ctx->cursor_color = pac2_attribs[i][0]; ctx->cursor_font = pac2_attribs[i][1]; SET_FLAG(screen->row_used, ctx->cursor_row); write_char(ctx, screen, ' '); } static void handle_pac(CCaptionSubContext *ctx, uint8_t hi, uint8_t lo) { static const int8_t row_map[] = { 11, -1, 1, 2, 3, 4, 12, 13, 14, 15, 5, 6, 7, 8, 9, 10 }; const int index = ( (hi<<1) & 0x0e) | ( (lo>>5) & 0x01 ); struct Screen *screen = get_writing_screen(ctx); int indent, i; if (row_map[index] <= 0) { av_log(ctx, AV_LOG_DEBUG, "Invalid pac index encountered\n"); return; } lo &= 0x1f; ctx->cursor_row = row_map[index] - 1; ctx->cursor_color = pac2_attribs[lo][0]; ctx->cursor_font = pac2_attribs[lo][1]; ctx->cursor_charset = CCSET_BASIC_AMERICAN; ctx->cursor_column = 0; indent = pac2_attribs[lo][2]; for (i = 0; i < indent; i++) { write_char(ctx, screen, ' '); } } static int handle_edm(CCaptionSubContext *ctx) { struct Screen *screen = ctx->screen + ctx->active_screen; int ret; // In buffered mode, keep writing to screen until it is wiped. // Before wiping the display, capture contents to emit subtitle. if (!ctx->real_time) ret = capture_screen(ctx); screen->row_used = 0; ctx->bg_color = CCCOL_BLACK; // In realtime mode, emit an empty caption so the last one doesn't // stay on the screen. if (ctx->real_time) ret = capture_screen(ctx); return ret; } static int handle_eoc(CCaptionSubContext *ctx) { int ret; ctx->active_screen = !ctx->active_screen; // In buffered mode, we wait til the *next* EOC and // capture what was already on the screen since the last EOC. if (!ctx->real_time) ret = handle_edm(ctx); ctx->cursor_column = 0; // In realtime mode, we display the buffered contents (after // flipping the buffer to active above) as soon as EOC arrives. if (ctx->real_time) ret = capture_screen(ctx); return ret; } static void handle_delete_end_of_row(CCaptionSubContext *ctx) { struct Screen *screen = get_writing_screen(ctx); write_char(ctx, screen, 0); } static void handle_char(CCaptionSubContext *ctx, char hi, char lo) { struct Screen *screen = get_writing_screen(ctx); SET_FLAG(screen->row_used, ctx->cursor_row); switch (hi) { case 0x11: ctx->cursor_charset = CCSET_SPECIAL_AMERICAN; break; case 0x12: if (ctx->cursor_column > 0) ctx->cursor_column -= 1; ctx->cursor_charset = CCSET_EXTENDED_SPANISH_FRENCH_MISC; break; case 0x13: if (ctx->cursor_column > 0) ctx->cursor_column -= 1; ctx->cursor_charset = CCSET_EXTENDED_PORTUGUESE_GERMAN_DANISH; break; default: ctx->cursor_charset = CCSET_BASIC_AMERICAN; write_char(ctx, screen, hi); break; } if (lo) { write_char(ctx, screen, lo); } write_char(ctx, screen, 0); if (ctx->mode != CCMODE_POPON) ctx->screen_touched = 1; if (lo) ff_dlog(ctx, "(%c,%c)\n", hi, lo); else ff_dlog(ctx, "(%c)\n", hi); } static int process_cc608(CCaptionSubContext *ctx, uint8_t hi, uint8_t lo) { int ret = 0; if (hi == ctx->prev_cmd[0] && lo == ctx->prev_cmd[1]) { return 0; } /* set prev command */ ctx->prev_cmd[0] = hi; ctx->prev_cmd[1] = lo; if ( (hi == 0x10 && (lo >= 0x40 && lo <= 0x5f)) || ( (hi >= 0x11 && hi <= 0x17) && (lo >= 0x40 && lo <= 0x7f) ) ) { handle_pac(ctx, hi, lo); } else if ( ( hi == 0x11 && lo >= 0x20 && lo <= 0x2f ) || ( hi == 0x17 && lo >= 0x2e && lo <= 0x2f) ) { handle_textattr(ctx, hi, lo); } else if ((hi == 0x10 && lo >= 0x20 && lo <= 0x2f)) { handle_bgattr(ctx, hi, lo); } else if (hi == 0x14 || hi == 0x15 || hi == 0x1c) { switch (lo) { case 0x20: /* resume caption loading */ ctx->mode = CCMODE_POPON; break; case 0x24: handle_delete_end_of_row(ctx); break; case 0x25: case 0x26: case 0x27: ctx->rollup = lo - 0x23; ctx->mode = CCMODE_ROLLUP; break; case 0x29: /* resume direct captioning */ ctx->mode = CCMODE_PAINTON; break; case 0x2b: /* resume text display */ ctx->mode = CCMODE_TEXT; break; case 0x2c: /* erase display memory */ handle_edm(ctx); break; case 0x2d: /* carriage return */ ff_dlog(ctx, "carriage return\n"); if (!ctx->real_time) ret = capture_screen(ctx); roll_up(ctx); ctx->cursor_column = 0; break; case 0x2e: /* erase buffered (non displayed) memory */ // Only in realtime mode. In buffered mode, we re-use the inactive screen // for our own buffering. if (ctx->real_time) { struct Screen *screen = ctx->screen + !ctx->active_screen; screen->row_used = 0; } break; case 0x2f: /* end of caption */ ff_dlog(ctx, "handle_eoc\n"); ret = handle_eoc(ctx); break; default: ff_dlog(ctx, "Unknown command 0x%hhx 0x%hhx\n", hi, lo); break; } } else if (hi >= 0x11 && hi <= 0x13) { /* Special characters */ handle_char(ctx, hi, lo); } else if (hi >= 0x20) { /* Standard characters (always in pairs) */ handle_char(ctx, hi, lo); ctx->prev_cmd[0] = ctx->prev_cmd[1] = 0; } else if (hi == 0x17 && lo >= 0x21 && lo <= 0x23) { int i; /* Tab offsets (spacing) */ for (i = 0; i < lo - 0x20; i++) { handle_char(ctx, ' ', 0); } } else { /* Ignoring all other non data code */ ff_dlog(ctx, "Unknown command 0x%hhx 0x%hhx\n", hi, lo); } return ret; } static int decode(AVCodecContext *avctx, AVSubtitle *sub, int *got_sub, const AVPacket *avpkt) { CCaptionSubContext *ctx = avctx->priv_data; int64_t in_time = sub->pts; int64_t start_time; int64_t end_time; int bidx = ctx->buffer_index; const uint8_t *bptr = avpkt->data; int len = avpkt->size; int ret = 0; int i; unsigned nb_rect_allocated = 0; for (i = 0; i < len; i += 3) { uint8_t hi, cc_type = bptr[i] & 1; if (ctx->data_field < 0) ctx->data_field = cc_type; if (validate_cc_data_pair(bptr + i, &hi)) continue; if (cc_type != ctx->data_field) continue; ret = process_cc608(ctx, hi & 0x7f, bptr[i + 2] & 0x7f); if (ret < 0) return ret; if (!ctx->buffer_changed) continue; ctx->buffer_changed = 0; if (!ctx->real_time && ctx->mode == CCMODE_POPON) ctx->buffer_index = bidx = !ctx->buffer_index; update_time(ctx, in_time); if (ctx->buffer[bidx].str[0] || ctx->real_time) { ff_dlog(ctx, "cdp writing data (%s)\n", ctx->buffer[bidx].str); start_time = ctx->buffer_time[0]; sub->pts = start_time; end_time = ctx->buffer_time[1]; if (!ctx->real_time) sub->end_display_time = av_rescale_q(end_time - start_time, AV_TIME_BASE_Q, ms_tb); else sub->end_display_time = -1; ret = ff_ass_add_rect2(sub, ctx->buffer[bidx].str, ctx->readorder++, 0, NULL, NULL, &nb_rect_allocated); if (ret < 0) return ret; ctx->last_real_time = sub->pts; ctx->screen_touched = 0; } } if (!bptr && !ctx->real_time && ctx->buffer[!ctx->buffer_index].str[0]) { bidx = !ctx->buffer_index; ret = ff_ass_add_rect2(sub, ctx->buffer[bidx].str, ctx->readorder++, 0, NULL, NULL, &nb_rect_allocated); if (ret < 0) return ret; av_bprint_clear(&ctx->buffer[bidx]); sub->pts = ctx->buffer_time[1]; sub->end_display_time = av_rescale_q(ctx->buffer_time[1] - ctx->buffer_time[0], AV_TIME_BASE_Q, ms_tb); if (sub->end_display_time == 0) sub->end_display_time = ctx->buffer[bidx].len * 20; } if (ctx->real_time && ctx->screen_touched && sub->pts >= ctx->last_real_time + av_rescale_q(ctx->real_time_latency_msec, ms_tb, AV_TIME_BASE_Q)) { ctx->last_real_time = sub->pts; ctx->screen_touched = 0; capture_screen(ctx); ctx->buffer_changed = 0; ret = ff_ass_add_rect2(sub, ctx->buffer[bidx].str, ctx->readorder++, 0, NULL, NULL, &nb_rect_allocated); if (ret < 0) return ret; sub->end_display_time = -1; } *got_sub = sub->num_rects > 0; return avpkt->size; } #define OFFSET(x) offsetof(CCaptionSubContext, x) #define SD AV_OPT_FLAG_SUBTITLE_PARAM | AV_OPT_FLAG_DECODING_PARAM static const AVOption options[] = { { "real_time", "emit subtitle events as they are decoded for real-time display", OFFSET(real_time), AV_OPT_TYPE_BOOL, { .i64 = 0 }, 0, 1, SD }, { "real_time_latency_msec", "minimum elapsed time between emitting real-time subtitle events", OFFSET(real_time_latency_msec), AV_OPT_TYPE_INT, { .i64 = 200 }, 0, 500, SD }, { "data_field", "select data field", OFFSET(data_field), AV_OPT_TYPE_INT, { .i64 = -1 }, -1, 1, SD, .unit = "data_field" }, { "auto", "pick first one that appears", 0, AV_OPT_TYPE_CONST, { .i64 =-1 }, 0, 0, SD, .unit = "data_field" }, { "first", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = 0 }, 0, 0, SD, .unit = "data_field" }, { "second", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = 1 }, 0, 0, SD, .unit = "data_field" }, {NULL} }; static const AVClass ccaption_dec_class = { .class_name = "Closed Captions Decoder", .item_name = av_default_item_name, .option = options, .version = LIBAVUTIL_VERSION_INT, }; const FFCodec ff_ccaption_decoder = { .p.name = "cc_dec", CODEC_LONG_NAME("Closed Captions (EIA-608 / CEA-708)"), .p.type = AVMEDIA_TYPE_SUBTITLE, .p.id = AV_CODEC_ID_EIA_608, .p.priv_class = &ccaption_dec_class, .p.capabilities = AV_CODEC_CAP_DELAY, .priv_data_size = sizeof(CCaptionSubContext), .init = init_decoder, .close = close_decoder, .flush = flush_decoder, FF_CODEC_DECODE_SUB_CB(decode), };