X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=libavcodec%2Fccaption_dec.c;h=9ad00cb2541490428d6decde8b2527375cd3571b;hb=b9fff6e15e73dc995695db9be8db084238cca14c;hp=09ceb1b3bf1c20ce67defffd0f481165a9015e0b;hpb=47e12966b75490cfa5fb8ed65a48a9a3d84a7bce;p=ffmpeg diff --git a/libavcodec/ccaption_dec.c b/libavcodec/ccaption_dec.c index 09ceb1b3bf1..9ad00cb2541 100644 --- a/libavcodec/ccaption_dec.c +++ b/libavcodec/ccaption_dec.c @@ -32,10 +32,6 @@ static const AVRational ms_tb = {1, 1000}; -/* - * TODO list - * 1) handle font and color completely - */ enum cc_mode { CCMODE_POPON, CCMODE_PAINTON, @@ -173,6 +169,18 @@ static const char *charset_overrides[4][128] = }, }; +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 @@ -212,10 +220,11 @@ static const unsigned char pac2_attribs[32][3] = // Color, font, ident 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]; + 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. @@ -228,39 +237,37 @@ struct Screen { typedef struct CCaptionSubContext { AVClass *class; int real_time; + 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; + AVBPrint buffer[2]; + int buffer_index; int buffer_changed; int rollup; enum cc_mode mode; - int64_t start_time; - /* visible screen time */ - int64_t startv_time; - int64_t end_time; + int64_t buffer_time[2]; int screen_touched; int64_t last_real_time; - char prev_cmd[2]; - /* buffer to store pkt data */ - uint8_t *pktbuf; - int pktbuf_size; + uint8_t prev_cmd[2]; 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); + 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; ret = ff_ass_subtitle_header(avctx, "Monospace", @@ -282,9 +289,8 @@ static av_cold int init_decoder(AVCodecContext *avctx) static av_cold int close_decoder(AVCodecContext *avctx) { CCaptionSubContext *ctx = avctx->priv_data; - av_bprint_finalize(&ctx->buffer, NULL); - av_freep(&ctx->pktbuf); - ctx->pktbuf_size = 0; + av_bprint_finalize(&ctx->buffer[0], NULL); + av_bprint_finalize(&ctx->buffer[1], NULL); return 0; } @@ -301,6 +307,7 @@ static void flush_decoder(AVCodecContext *avctx) 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; @@ -308,7 +315,8 @@ static void flush_decoder(AVCodecContext *avctx) ctx->buffer_changed = 0; if (!(avctx->flags2 & AV_CODEC_FLAG2_RO_FLUSH_NOOP)) ctx->readorder = 0; - av_bprint_clear(&ctx->buffer); + av_bprint_clear(&ctx->buffer[0]); + av_bprint_clear(&ctx->buffer[1]); } /** @@ -319,11 +327,15 @@ 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++; @@ -347,11 +359,13 @@ static void write_char(CCaptionSubContext *ctx, struct Screen *screen, char ch) * 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) +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; @@ -361,7 +375,7 @@ static int validate_cc_data_pair(uint8_t *cc_data_pair) return AVERROR_INVALIDDATA; } if (!av_parity(cc_data_pair[1])) { - cc_data_pair[1]=0x7F; + *hi = 0x7F; } } @@ -374,10 +388,6 @@ static int validate_cc_data_pair(uint8_t *cc_data_pair) 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; } @@ -423,6 +433,7 @@ static void roll_up(CCaptionSubContext *ctx) 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)) @@ -437,7 +448,11 @@ 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; - av_bprint_clear(&ctx->buffer); + 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++) { @@ -457,6 +472,8 @@ static int capture_screen(CCaptionSubContext *ctx) 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; @@ -468,10 +485,10 @@ static int capture_screen(CCaptionSubContext *ctx) x = ASS_DEFAULT_PLAYRESX * (0.1 + 0.0250 * j); y = ASS_DEFAULT_PLAYRESY * (0.1 + 0.0533 * i); - av_bprintf(&ctx->buffer, "{\\an7}{\\pos(%d,%d)}", x, y); + av_bprintf(&ctx->buffer[bidx], "{\\an7}{\\pos(%d,%d)}", x, y); for (; j < SCREEN_COLUMNS; j++) { - const char *e_tag = "", *s_tag = ""; + const char *e_tag = "", *s_tag = "", *c_tag = "", *b_tag = ""; if (row[j] == 0) break; @@ -500,38 +517,99 @@ static int capture_screen(CCaptionSubContext *ctx) 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) { - av_bprintf(&ctx->buffer, "%s%s%s", e_tag, s_tag, override); + 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, "%s%s\\h", e_tag, s_tag); + av_bprintf(&ctx->buffer[bidx], "%s%s%s%s\\h", e_tag, s_tag, c_tag, b_tag); } else { - av_bprintf(&ctx->buffer, "%s%s%c", e_tag, s_tag, row[j]); + 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, "\\N"); + av_bprintf(&ctx->buffer[bidx], "\\N"); } } - if (!av_bprint_is_complete(&ctx->buffer)) + if (!av_bprint_is_complete(&ctx->buffer[bidx])) return AVERROR(ENOMEM); - if (screen->row_used && ctx->buffer.len >= 2) { - ctx->buffer.len -= 2; - ctx->buffer.str[ctx->buffer.len] = 0; + 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 int reap_screen(CCaptionSubContext *ctx, int64_t pts) +static void update_time(CCaptionSubContext *ctx, int64_t pts) { - ctx->start_time = ctx->startv_time; - ctx->startv_time = pts; - ctx->end_time = pts; - return capture_screen(ctx); + 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) @@ -576,49 +654,55 @@ static void handle_pac(CCaptionSubContext *ctx, uint8_t hi, uint8_t lo) } } -/** - * @param pts it is required to set end time - */ -static void handle_edm(CCaptionSubContext *ctx, int64_t pts) +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) - reap_screen(ctx, pts); + 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) - reap_screen(ctx, pts); + ret = capture_screen(ctx); + + return ret; } -static void handle_eoc(CCaptionSubContext *ctx, int64_t pts) +static int handle_eoc(CCaptionSubContext *ctx) { + int ret; + + ctx->active_screen = !ctx->active_screen; + // In buffered mode, we wait til the *next* EOC and - // reap what was already on the screen since the last EOC. + // capture what was already on the screen since the last EOC. if (!ctx->real_time) - handle_edm(ctx,pts); + ret = handle_edm(ctx); - 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); + ret = capture_screen(ctx); + + return ret; } -static void handle_delete_end_of_row(CCaptionSubContext *ctx, char hi, char lo) +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, int64_t pts) +static void handle_char(CCaptionSubContext *ctx, char hi, char lo) { struct Screen *screen = get_writing_screen(ctx); @@ -658,11 +742,12 @@ static void handle_char(CCaptionSubContext *ctx, char hi, char lo, int64_t pts) ff_dlog(ctx, "(%c)\n", hi); } -static void process_cc608(CCaptionSubContext *ctx, int64_t pts, uint8_t hi, uint8_t lo) +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]) { - /* ignore redundant command */ - return; + return 0; } /* set prev command */ @@ -675,6 +760,8 @@ static void process_cc608(CCaptionSubContext *ctx, int64_t pts, uint8_t hi, uint } 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: @@ -682,7 +769,7 @@ static void process_cc608(CCaptionSubContext *ctx, int64_t pts, uint8_t hi, uint ctx->mode = CCMODE_POPON; break; case 0x24: - handle_delete_end_of_row(ctx, hi, lo); + handle_delete_end_of_row(ctx); break; case 0x25: case 0x26: @@ -700,13 +787,13 @@ static void process_cc608(CCaptionSubContext *ctx, int64_t pts, uint8_t hi, uint break; case 0x2c: /* erase display memory */ - handle_edm(ctx, pts); + handle_edm(ctx); break; case 0x2d: /* carriage return */ ff_dlog(ctx, "carriage return\n"); if (!ctx->real_time) - reap_screen(ctx, pts); + ret = capture_screen(ctx); roll_up(ctx); ctx->cursor_column = 0; break; @@ -722,7 +809,7 @@ static void process_cc608(CCaptionSubContext *ctx, int64_t pts, uint8_t hi, uint case 0x2f: /* end of caption */ ff_dlog(ctx, "handle_eoc\n"); - handle_eoc(ctx, pts); + ret = handle_eoc(ctx); break; default: ff_dlog(ctx, "Unknown command 0x%hhx 0x%hhx\n", hi, lo); @@ -730,73 +817,93 @@ static void process_cc608(CCaptionSubContext *ctx, int64_t pts, uint8_t hi, uint } } else if (hi >= 0x11 && hi <= 0x13) { /* Special characters */ - handle_char(ctx, hi, lo, pts); + handle_char(ctx, hi, lo); } else if (hi >= 0x20) { /* Standard characters (always in pairs) */ - handle_char(ctx, hi, lo, pts); + 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, pts); + 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, 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; + 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; - av_fast_padded_malloc(&ctx->pktbuf, &ctx->pktbuf_size, len); - if (!ctx->pktbuf) { - av_log(ctx, AV_LOG_WARNING, "Insufficient Memory of %d truncated to %d\n", len, ctx->pktbuf_size); - return AVERROR(ENOMEM); - } - memcpy(ctx->pktbuf, avpkt->data, len); - bptr = ctx->pktbuf; + 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; - for (i = 0; i < len; i += 3) { - uint8_t cc_type = *(bptr + i) & 3; - if (validate_cc_data_pair(bptr + i)) + if (validate_cc_data_pair(bptr + i, &hi)) continue; - /* ignoring data field 1 */ - if(cc_type == 1) + + if (cc_type != ctx->data_field) continue; - else - process_cc608(ctx, start_time, *(bptr + i + 1) & 0x7f, *(bptr + i + 2) & 0x7f); + + 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->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 && 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(ctx->end_time - ctx->start_time, + sub->end_display_time = av_rescale_q(end_time - start_time, AV_TIME_BASE_Q, ms_tb); else sub->end_display_time = -1; - ctx->buffer_changed = 0; + ret = ff_ass_add_rect(sub, ctx->buffer[bidx].str, ctx->readorder++, 0, NULL, NULL); + 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_rect(sub, ctx->buffer[bidx].str, ctx->readorder++, 0, NULL, NULL); + if (ret < 0) + return ret; + 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(200, ms_tb, AV_TIME_BASE_Q)) { ctx->last_real_time = sub->pts; @@ -805,7 +912,7 @@ static int decode(AVCodecContext *avctx, void *data, int *got_sub, AVPacket *avp capture_screen(ctx); ctx->buffer_changed = 0; - ret = ff_ass_add_rect(sub, ctx->buffer.str, ctx->readorder++, 0, NULL, NULL); + ret = ff_ass_add_rect(sub, ctx->buffer[bidx].str, ctx->readorder++, 0, NULL, NULL); if (ret < 0) return ret; sub->end_display_time = -1; @@ -819,6 +926,10 @@ static int decode(AVCodecContext *avctx, void *data, int *got_sub, AVPacket *avp #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 }, + { "data_field", "select data field", OFFSET(data_field), AV_OPT_TYPE_INT, { .i64 = -1 }, -1, 1, SD, "data_field" }, + { "auto", "pick first one that appears", 0, AV_OPT_TYPE_CONST, { .i64 =-1 }, 0, 0, SD, "data_field" }, + { "first", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = 0 }, 0, 0, SD, "data_field" }, + { "second", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = 1 }, 0, 0, SD, "data_field" }, {NULL} }; @@ -829,7 +940,7 @@ static const AVClass ccaption_dec_class = { .version = LIBAVUTIL_VERSION_INT, }; -AVCodec ff_ccaption_decoder = { +const AVCodec ff_ccaption_decoder = { .name = "cc_dec", .long_name = NULL_IF_CONFIG_SMALL("Closed Caption (EIA-608 / CEA-708)"), .type = AVMEDIA_TYPE_SUBTITLE, @@ -840,4 +951,5 @@ AVCodec ff_ccaption_decoder = { .flush = flush_decoder, .decode = decode, .priv_class = &ccaption_dec_class, + .capabilities = AV_CODEC_CAP_DELAY, };