diff options
Diffstat (limited to 'libavcodec/ccaption_dec.c')
| -rw-r--r-- | libavcodec/ccaption_dec.c | 824 |
1 files changed, 824 insertions, 0 deletions
diff --git a/libavcodec/ccaption_dec.c b/libavcodec/ccaption_dec.c new file mode 100644 index 0000000000..f831399ee9 --- /dev/null +++ b/libavcodec/ccaption_dec.c @@ -0,0 +1,824 @@ +/* + * 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 "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}; + +/* + * TODO list + * 1) handle font and color completely + */ +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, +}; + +static const char *charset_overrides[4][128] = +{ + [CCSET_BASIC_AMERICAN] = { + [0x27] = "\u2019", + [0x2a] = "\u00e1", + [0x5c] = "\u00e9", + [0x5e] = "\u00ed", + [0x5f] = "\u00f3", + [0x60] = "\u00fa", + [0x7b] = "\u00e7", + [0x7c] = "\u00f7", + [0x7d] = "\u00d1", + [0x7e] = "\u00f1", + [0x7f] = "\u2588" + }, + [CCSET_SPECIAL_AMERICAN] = { + [0x30] = "\u00ae", + [0x31] = "\u00b0", + [0x32] = "\u00bd", + [0x33] = "\u00bf", + [0x34] = "\u2122", + [0x35] = "\u00a2", + [0x36] = "\u00a3", + [0x37] = "\u266a", + [0x38] = "\u00e0", + [0x39] = "\u00A0", + [0x3a] = "\u00e8", + [0x3b] = "\u00e2", + [0x3c] = "\u00ea", + [0x3d] = "\u00ee", + [0x3e] = "\u00f4", + [0x3f] = "\u00fb", + }, + [CCSET_EXTENDED_SPANISH_FRENCH_MISC] = { + [0x20] = "\u00c1", + [0x21] = "\u00c9", + [0x22] = "\u00d3", + [0x23] = "\u00da", + [0x24] = "\u00dc", + [0x25] = "\u00fc", + [0x26] = "\u00b4", + [0x27] = "\u00a1", + [0x28] = "*", + [0x29] = "\u2018", + [0x2a] = "-", + [0x2b] = "\u00a9", + [0x2c] = "\u2120", + [0x2d] = "\u00b7", + [0x2e] = "\u201c", + [0x2f] = "\u201d", + [0x30] = "\u00c0", + [0x31] = "\u00c2", + [0x32] = "\u00c7", + [0x33] = "\u00c8", + [0x34] = "\u00ca", + [0x35] = "\u00cb", + [0x36] = "\u00eb", + [0x37] = "\u00ce", + [0x38] = "\u00cf", + [0x39] = "\u00ef", + [0x3a] = "\u00d4", + [0x3b] = "\u00d9", + [0x3c] = "\u00f9", + [0x3d] = "\u00db", + [0x3e] = "\u00ab", + [0x3f] = "\u00bb", + }, + [CCSET_EXTENDED_PORTUGUESE_GERMAN_DANISH] = { + [0x20] = "\u00c3", + [0x21] = "\u00e3", + [0x22] = "\u00cd", + [0x23] = "\u00cc", + [0x24] = "\u00ec", + [0x25] = "\u00d2", + [0x26] = "\u00f2", + [0x27] = "\u00d5", + [0x28] = "\u00f5", + [0x29] = "{", + [0x2a] = "}", + [0x2b] = "\\", + [0x2c] = "^", + [0x2d] = "_", + [0x2e] = "|", + [0x2f] = "~", + [0x30] = "\u00c4", + [0x31] = "\u00e4", + [0x32] = "\u00d6", + [0x33] = "\u00f6", + [0x34] = "\u00df", + [0x35] = "\u00a5", + [0x36] = "\u00a4", + [0x37] = "\u00a6", + [0x38] = "\u00c5", + [0x39] = "\u00e5", + [0x3a] = "\u00d8", + [0x3b] = "\u00f8", + [0x3c] = "\u250c", + [0x3d] = "\u2510", + [0x3e] = "\u2514", + [0x3f] = "\u2518", + }, +}; + +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][SCREEN_COLUMNS+1]; + uint8_t charsets[SCREEN_ROWS][SCREEN_COLUMNS+1]; + uint8_t colors[SCREEN_ROWS][SCREEN_COLUMNS+1]; + uint8_t fonts[SCREEN_ROWS][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; + struct Screen screen[2]; + int active_screen; + uint8_t cursor_row; + uint8_t cursor_column; + uint8_t cursor_color; + uint8_t cursor_font; + uint8_t cursor_charset; + AVBPrint buffer; + int buffer_changed; + int rollup; + enum cc_mode mode; + int64_t start_time; + /* visible screen time */ + int64_t startv_time; + int64_t end_time; + int screen_touched; + int64_t last_real_time; + char prev_cmd[2]; + /* buffer to store pkt data */ + AVBufferRef *pktbuf; + int readorder; +} CCaptionSubContext; + + +static av_cold int init_decoder(AVCodecContext *avctx) +{ + int ret; + CCaptionSubContext *ctx = avctx->priv_data; + + av_bprint_init(&ctx->buffer, 0, AV_BPRINT_SIZE_UNLIMITED); + /* taking by default roll up to 2 */ + ctx->mode = CCMODE_ROLLUP; + ctx->rollup = 2; + ret = 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); + if (ret < 0) { + return ret; + } + /* allocate pkt buffer */ + ctx->pktbuf = av_buffer_alloc(128); + if (!ctx->pktbuf) { + ret = AVERROR(ENOMEM); + } + return ret; +} + +static av_cold int close_decoder(AVCodecContext *avctx) +{ + CCaptionSubContext *ctx = avctx->priv_data; + av_bprint_finalize(&ctx->buffer, NULL); + av_buffer_unref(&ctx->pktbuf); + 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 = 0; + ctx->cursor_column = 0; + ctx->cursor_font = 0; + ctx->cursor_color = 0; + 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); +} + +/** + * @param ctx closed caption context just to print log + */ +static int 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 *charset = screen->charsets[ctx->cursor_row]; + + if (col < SCREEN_COLUMNS) { + row[col] = ch; + font[col] = ctx->cursor_font; + charset[col] = ctx->cursor_charset; + ctx->cursor_charset = CCSET_BASIC_AMERICAN; + if (ch) ctx->cursor_column++; + return 0; + } + /* We have extra space at end only for null character */ + else if (col == SCREEN_COLUMNS && ch == 0) { + row[col] = ch; + return 0; + } + else { + av_log(ctx, AV_LOG_WARNING, "Data Ignored since exceeding screen width\n"); + return AVERROR_INVALIDDATA; + } +} + +/** + * 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(uint8_t *cc_data_pair) +{ + uint8_t cc_valid = (*cc_data_pair & 4) >>2; + uint8_t cc_type = *cc_data_pair & 3; + + 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])) { + cc_data_pair[1]=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; + + /* remove parity bit */ + cc_data_pair[1] &= 0x7F; + cc_data_pair[2] &= 0x7F; + + 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->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; + struct Screen *screen = ctx->screen + ctx->active_screen; + enum cc_font prev_font = CCFONT_REGULAR; + av_bprint_clear(&ctx->buffer); + + 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 *charset = screen->charsets[i]; + const char *override; + int j = 0; + + /* skip leading space */ + while (row[j] == ' ' && charset[j] == CCSET_BASIC_AMERICAN) + j++; + + for (; j < SCREEN_COLUMNS; j++) { + const char *e_tag = "", *s_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; + } + } + prev_font = font[j]; + override = charset_overrides[(int)charset[j]][(int)row[j]]; + if (override) { + av_bprintf(&ctx->buffer, "%s%s%s", e_tag, s_tag, override); + } else { + av_bprintf(&ctx->buffer, "%s%s%c", e_tag, s_tag, row[j]); + } + } + av_bprintf(&ctx->buffer, "\\N"); + } + } + if (!av_bprint_is_complete(&ctx->buffer)) + return AVERROR(ENOMEM); + if (screen->row_used && ctx->buffer.len >= 2) { + ctx->buffer.len -= 2; + ctx->buffer.str[ctx->buffer.len] = 0; + } + ctx->buffer_changed = 1; + return 0; +} + +static int reap_screen(CCaptionSubContext *ctx, int64_t pts) +{ + ctx->start_time = ctx->startv_time; + ctx->startv_time = pts; + ctx->end_time = pts; + return capture_screen(ctx); +} + +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, ' '); + } +} + +/** + * @param pts it is required to set end time + */ +static void handle_edm(CCaptionSubContext *ctx, int64_t pts) +{ + struct Screen *screen = ctx->screen + ctx->active_screen; + + // In buffered mode, keep writing to screen until it is wiped. + // Before wiping the display, capture contents to emit subtitle. + if (!ctx->real_time) + reap_screen(ctx, pts); + + screen->row_used = 0; + + // In realtime mode, emit an empty caption so the last one doesn't + // stay on the screen. + if (ctx->real_time) + reap_screen(ctx, pts); +} + +static void handle_eoc(CCaptionSubContext *ctx, int64_t pts) +{ + // In buffered mode, we wait til the *next* EOC and + // reap what was already on the screen since the last EOC. + if (!ctx->real_time) + handle_edm(ctx,pts); + + ctx->active_screen = !ctx->active_screen; + 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) + reap_screen(ctx, pts); +} + +static void handle_delete_end_of_row(CCaptionSubContext *ctx, char hi, char lo) +{ + struct Screen *screen = get_writing_screen(ctx); + write_char(ctx, screen, 0); +} + +static void handle_char(CCaptionSubContext *ctx, char hi, char lo, int64_t pts) +{ + 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 void process_cc608(CCaptionSubContext *ctx, int64_t pts, uint8_t hi, uint8_t lo) +{ + if (hi == ctx->prev_cmd[0] && lo == ctx->prev_cmd[1]) { + /* ignore redundant command */ + return; + } + + /* 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 == 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, hi, lo); + 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, pts); + break; + case 0x2d: + /* carriage return */ + ff_dlog(ctx, "carriage return\n"); + if (!ctx->real_time) + reap_screen(ctx, pts); + 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"); + handle_eoc(ctx, pts); + 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, pts); + } else if (hi >= 0x20) { + /* Standard characters (always in pairs) */ + handle_char(ctx, hi, lo, pts); + 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, pts); + } + } else { + /* Ignoring all other non data code */ + ff_dlog(ctx, "Unknown command 0x%hhx 0x%hhx\n", hi, lo); + } +} + +static int decode(AVCodecContext *avctx, void *data, int *got_sub, AVPacket *avpkt) +{ + CCaptionSubContext *ctx = avctx->priv_data; + AVSubtitle *sub = data; + const int64_t start_time = sub->pts; + uint8_t *bptr = NULL; + int len = avpkt->size; + int ret = 0; + int i; + + if (ctx->pktbuf->size < len) { + ret = av_buffer_realloc(&ctx->pktbuf, len); + if (ret < 0) { + av_log(ctx, AV_LOG_WARNING, "Insufficient Memory of %d truncated to %d\n", len, ctx->pktbuf->size); + len = ctx->pktbuf->size; + ret = 0; + } + } + memcpy(ctx->pktbuf->data, avpkt->data, len); + bptr = ctx->pktbuf->data; + + for (i = 0; i < len; i += 3) { + uint8_t cc_type = *(bptr + i) & 3; + if (validate_cc_data_pair(bptr + i)) + continue; + /* ignoring data field 1 */ + if(cc_type == 1) + continue; + else + process_cc608(ctx, start_time, *(bptr + i + 1) & 0x7f, *(bptr + i + 2) & 0x7f); + + if (!ctx->buffer_changed) + continue; + ctx->buffer_changed = 0; + + if (*ctx->buffer.str || ctx->real_time) + { + ff_dlog(ctx, "cdp writing data (%s)\n",ctx->buffer.str); + ret = ff_ass_add_rect(sub, ctx->buffer.str, ctx->readorder++, 0, NULL, NULL); + if (ret < 0) + return ret; + sub->pts = ctx->start_time; + if (!ctx->real_time) + sub->end_display_time = av_rescale_q(ctx->end_time - ctx->start_time, + AV_TIME_BASE_Q, ms_tb); + else + sub->end_display_time = -1; + ctx->buffer_changed = 0; + ctx->last_real_time = sub->pts; + ctx->screen_touched = 0; + } + } + + if (ctx->real_time && ctx->screen_touched && + sub->pts > ctx->last_real_time + av_rescale_q(200, 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_rect(sub, ctx->buffer.str, ctx->readorder++, 0, NULL, NULL); + if (ret < 0) + return ret; + sub->end_display_time = -1; + } + + *got_sub = sub->num_rects > 0; + return ret; +} + +#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 }, + {NULL} +}; + +static const AVClass ccaption_dec_class = { + .class_name = "Closed caption Decoder", + .item_name = av_default_item_name, + .option = options, + .version = LIBAVUTIL_VERSION_INT, +}; + +AVCodec ff_ccaption_decoder = { + .name = "cc_dec", + .long_name = NULL_IF_CONFIG_SMALL("Closed Caption (EIA-608 / CEA-708) Decoder"), + .type = AVMEDIA_TYPE_SUBTITLE, + .id = AV_CODEC_ID_EIA_608, + .priv_data_size = sizeof(CCaptionSubContext), + .init = init_decoder, + .close = close_decoder, + .flush = flush_decoder, + .decode = decode, + .priv_class = &ccaption_dec_class, +}; |