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-rw-r--r--libavcodec/ccaption_dec.c592
1 files changed, 592 insertions, 0 deletions
diff --git a/libavcodec/ccaption_dec.c b/libavcodec/ccaption_dec.c
new file mode 100644
index 0000000000..9f67caa028
--- /dev/null
+++ b/libavcodec/ccaption_dec.c
@@ -0,0 +1,592 @@
+/*
+ * 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/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)) )
+
+/*
+ * TODO list
+ * 1) handle font and color completely
+ */
+enum cc_mode {
+ CCMODE_POPON,
+ CCMODE_PAINTON,
+ CCMODE_ROLLUP_2,
+ CCMODE_ROLLUP_3,
+ CCMODE_ROLLUP_4,
+ 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,
+};
+
+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 */
+};
+
+/* 0-255 needs 256 spaces */
+static const uint8_t parity_table[256] = { 0, 1, 1, 0, 1, 0, 0, 1,
+ 1, 0, 0, 1, 0, 1, 1, 0,
+ 1, 0, 0, 1, 0, 1, 1, 0,
+ 0, 1, 1, 0, 1, 0, 0, 1,
+ 1, 0, 0, 1, 0, 1, 1, 0,
+ 0, 1, 1, 0, 1, 0, 0, 1,
+ 0, 1, 1, 0, 1, 0, 0, 1,
+ 1, 0, 0, 1, 0, 1, 1, 0,
+ 1, 0, 0, 1, 0, 1, 1, 0,
+ 0, 1, 1, 0, 1, 0, 0, 1,
+ 0, 1, 1, 0, 1, 0, 0, 1,
+ 1, 0, 0, 1, 0, 1, 1, 0,
+ 0, 1, 1, 0, 1, 0, 0, 1,
+ 1, 0, 0, 1, 0, 1, 1, 0,
+ 1, 0, 0, 1, 0, 1, 1, 0,
+ 0, 1, 1, 0, 1, 0, 0, 1,
+ 1, 0, 0, 1, 0, 1, 1, 0,
+ 0, 1, 1, 0, 1, 0, 0, 1,
+ 0, 1, 1, 0, 1, 0, 0, 1,
+ 1, 0, 0, 1, 0, 1, 1, 0,
+ 0, 1, 1, 0, 1, 0, 0, 1,
+ 1, 0, 0, 1, 0, 1, 1, 0,
+ 1, 0, 0, 1, 0, 1, 1, 0,
+ 0, 1, 1, 0, 1, 0, 0, 1,
+ 0, 1, 1, 0, 1, 0, 0, 1,
+ 1, 0, 0, 1, 0, 1, 1, 0,
+ 1, 0, 0, 1, 0, 1, 1, 0,
+ 0, 1, 1, 0, 1, 0, 0, 1,
+ 1, 0, 0, 1, 0, 1, 1, 0,
+ 0, 1, 1, 0, 1, 0, 0, 1,
+ 0, 1, 1, 0, 1, 0, 0, 1,
+ 1, 0, 0, 1, 0, 1, 1, 0 };
+
+struct Screen {
+ /* +1 is used to compensate null character of string */
+ uint8_t characters[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;
+ struct Screen screen[2];
+ int active_screen;
+ uint8_t cursor_row;
+ uint8_t cursor_column;
+ uint8_t cursor_color;
+ uint8_t cursor_font;
+ AVBPrint buffer;
+ int screen_changed;
+ int rollup;
+ enum cc_mode mode;
+ int64_t start_time;
+ /* visible screen time */
+ int64_t startv_time;
+ int64_t end_time;
+ char prev_cmd[2];
+ /* buffer to store pkt data */
+ AVBufferRef *pktbuf;
+}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_2;
+ ctx->rollup = 2;
+ ret = ff_ass_subtitle_header_default(avctx);
+ 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;
+}
+
+/**
+ * @param ctx closed caption context just to print log
+ */
+static int write_char (CCaptionSubContext *ctx, char *row,uint8_t col, char ch)
+{
+ if(col < SCREEN_COLUMNS) {
+ row[col] = ch;
+ 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 (!parity_table[cc_data_pair[2]]) {
+ return AVERROR_INVALIDDATA;
+ }
+ if (!parity_table[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_2:
+ case CCMODE_ROLLUP_3:
+ case CCMODE_ROLLUP_4:
+ 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 < ctx->cursor_row - keep_lines; i++ )
+ 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);
+ 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 reap_screen(CCaptionSubContext *ctx, int64_t pts)
+{
+ int i;
+ int ret = 0;
+ struct Screen *screen = ctx->screen + ctx->active_screen;
+ ctx->start_time = ctx->startv_time;
+
+ for( i = 0; screen->row_used && i < SCREEN_ROWS; i++)
+ {
+ if(CHECK_FLAG(screen->row_used,i)) {
+ char *str = screen->characters[i];
+ /* skip space */
+ while (*str == ' ')
+ str++;
+
+ av_bprintf(&ctx->buffer, "%s\\N", str);
+ ret = av_bprint_is_complete(&ctx->buffer);
+ if( ret == 0) {
+ ret = AVERROR(ENOMEM);
+ break;
+ }
+ }
+
+ }
+ if(screen->row_used && ctx->buffer.len >= 2 ) {
+ ctx->buffer.len -= 2;
+ ctx->buffer.str[ctx->buffer.len] = 0;
+ }
+ ctx->startv_time = pts;
+ ctx->end_time = pts;
+ return ret;
+}
+
+static void handle_textattr( CCaptionSubContext *ctx, uint8_t hi, uint8_t lo )
+{
+ int i = lo - 0x20;
+ int ret;
+ struct Screen *screen = get_writing_screen(ctx);
+ char *row = screen->characters[ctx->cursor_row];
+
+ 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);
+ ret = write_char(ctx, row, ctx->cursor_column, ' ');
+ if(ret == 0)
+ ctx->cursor_column++;
+}
+
+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);
+ char *row;
+ int indent,i,ret;
+
+ 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_column = 0;
+ indent = pac2_attribs[lo][2];
+ row = screen->characters[ctx->cursor_row];
+ for(i = 0;i < indent; i++) {
+ ret = write_char(ctx, row, ctx->cursor_column, ' ');
+ if( ret == 0 )
+ ctx->cursor_column++;
+ }
+
+}
+
+/**
+ * @param pts it is required to set end time
+ */
+static int handle_edm(CCaptionSubContext *ctx,int64_t pts)
+{
+ int ret = 0;
+ struct Screen *screen = ctx->screen + ctx->active_screen;
+
+ reap_screen(ctx, pts);
+ screen->row_used = 0;
+ ctx->screen_changed = 1;
+ return ret;
+}
+
+static int handle_eoc(CCaptionSubContext *ctx, int64_t pts)
+{
+ int ret;
+ ret = handle_edm(ctx,pts);
+ ctx->active_screen = !ctx->active_screen;
+ ctx->cursor_column = 0;
+ return ret;
+}
+
+static void handle_delete_end_of_row( CCaptionSubContext *ctx, char hi, char lo)
+{
+ struct Screen *screen = get_writing_screen(ctx);
+ char *row = screen->characters[ctx->cursor_row];
+ write_char(ctx, row, ctx->cursor_column, 0);
+
+}
+
+static void handle_char(CCaptionSubContext *ctx, char hi, char lo, int64_t pts)
+{
+ struct Screen *screen = get_writing_screen(ctx);
+ char *row = screen->characters[ctx->cursor_row];
+ int ret;
+
+ SET_FLAG(screen->row_used,ctx->cursor_row);
+
+ ret = write_char(ctx, row, ctx->cursor_column, hi);
+ if( ret == 0 )
+ ctx->cursor_column++;
+
+ if(lo) {
+ ret = write_char(ctx, row, ctx->cursor_column, lo);
+ if ( ret == 0 )
+ ctx->cursor_column++;
+ }
+ write_char(ctx, row, ctx->cursor_column, 0);
+
+ /* reset prev command since character can repeat */
+ ctx->prev_cmd[0] = 0;
+ ctx->prev_cmd[1] = 0;
+ if (lo)
+ ff_dlog(ctx, "(%c,%c)\n",hi,lo);
+ else
+ ff_dlog(ctx, "(%c)\n",hi);
+}
+
+static int process_cc608(CCaptionSubContext *ctx, int64_t pts, uint8_t hi, uint8_t lo)
+{
+ int ret = 0;
+#define COR3(var, with1, with2, with3) ( (var) == (with1) || (var) == (with2) || (var) == (with3) )
+ if ( hi == ctx->prev_cmd[0] && lo == ctx->prev_cmd[1]) {
+ /* ignore redundant command */
+ } else 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 ( COR3(hi, 0x14, 0x15, 0x1C) && lo == 0x20 ) {
+ /* resume caption loading */
+ ctx->mode = CCMODE_POPON;
+ } else if ( COR3(hi, 0x14, 0x15, 0x1C) && lo == 0x24 ) {
+ handle_delete_end_of_row(ctx, hi, lo);
+ } else if ( COR3(hi, 0x14, 0x15, 0x1C) && lo == 0x25 ) {
+ ctx->rollup = 2;
+ ctx->mode = CCMODE_ROLLUP_2;
+ } else if ( COR3(hi, 0x14, 0x15, 0x1C) && lo == 0x26 ) {
+ ctx->rollup = 3;
+ ctx->mode = CCMODE_ROLLUP_3;
+ } else if ( COR3(hi, 0x14, 0x15, 0x1C) && lo == 0x27 ) {
+ ctx->rollup = 4;
+ ctx->mode = CCMODE_ROLLUP_4;
+ } else if ( COR3(hi, 0x14, 0x15, 0x1C) && lo == 0x29 ) {
+ /* resume direct captioning */
+ ctx->mode = CCMODE_PAINTON;
+ } else if ( COR3(hi, 0x14, 0x15, 0x1C) && lo == 0x2B ) {
+ /* resume text display */
+ ctx->mode = CCMODE_TEXT;
+ } else if ( COR3(hi, 0x14, 0x15, 0x1C) && lo == 0x2C ) {
+ /* erase display memory */
+ ret = handle_edm(ctx, pts);
+ } else if ( COR3(hi, 0x14, 0x15, 0x1C) && lo == 0x2D ) {
+ /* carriage return */
+ ff_dlog(ctx, "carriage return\n");
+ reap_screen(ctx, pts);
+ roll_up(ctx);
+ ctx->screen_changed = 1;
+ ctx->cursor_column = 0;
+ } else if ( COR3(hi, 0x14, 0x15, 0x1C) && lo == 0x2F ) {
+ /* end of caption */
+ ff_dlog(ctx, "handle_eoc\n");
+ ret = handle_eoc(ctx, pts);
+ } else if (hi>=0x20) {
+ /* Standard characters (always in pairs) */
+ handle_char(ctx, hi, lo, pts);
+ } else {
+ /* Ignoring all other non data code */
+ ff_dlog(ctx, "Unknown command 0x%hhx 0x%hhx\n", hi, lo);
+ }
+
+ /* set prev command */
+ ctx->prev_cmd[0] = hi;
+ ctx->prev_cmd[1] = lo;
+
+#undef COR3
+ return ret;
+
+}
+
+static int decode(AVCodecContext *avctx, void *data, int *got_sub, AVPacket *avpkt)
+{
+ CCaptionSubContext *ctx = avctx->priv_data;
+ AVSubtitle *sub = data;
+ 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, avpkt->pts, *(bptr + i + 1) & 0x7f, *(bptr + i + 2) & 0x7f);
+ if(ctx->screen_changed && *ctx->buffer.str)
+ {
+ int start_time = av_rescale_q(ctx->start_time, avctx->time_base, (AVRational){ 1, 100 });
+ int end_time = av_rescale_q(ctx->end_time, avctx->time_base, (AVRational){ 1, 100 });
+ ff_dlog(ctx, "cdp writing data (%s)\n",ctx->buffer.str);
+ ret = ff_ass_add_rect_bprint(sub, &ctx->buffer, start_time, end_time - start_time);
+ if (ret < 0)
+ return ret;
+ sub->pts = av_rescale_q(ctx->start_time, avctx->time_base, AV_TIME_BASE_Q);
+ ctx->screen_changed = 0;
+ av_bprint_clear(&ctx->buffer);
+ }
+ }
+
+ *got_sub = sub->num_rects > 0;
+ return ret;
+}
+
+static const AVOption options[] = {
+ {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,
+ .decode = decode,
+ .priv_class = &ccaption_dec_class,
+};