From b577153231ee050b04e29f3bb2ea72eca2431c60 Mon Sep 17 00:00:00 2001 From: Marton Balint Date: Sun, 29 Apr 2018 03:08:12 +0200 Subject: [PATCH] avcodec/libzvbi-teletextdec: add formatted ass output Inspired by the VideoLAN text decoder and its port to FFmpeg made by Aman Gupta. Signed-off-by: Marton Balint --- doc/decoders.texi | 18 ++- libavcodec/libzvbi-teletextdec.c | 263 ++++++++++++++++++++++++++++++- libavcodec/version.h | 2 +- 3 files changed, 269 insertions(+), 14 deletions(-) diff --git a/doc/decoders.texi b/doc/decoders.texi index 31e96fbc8d..25187e30f1 100644 --- a/doc/decoders.texi +++ b/doc/decoders.texi @@ -261,12 +261,18 @@ Default value is *. @item txt_chop_top Discards the top teletext line. Default value is 1. @item txt_format -Specifies the format of the decoded subtitles. The teletext decoder is capable -of decoding the teletext pages to bitmaps or to simple text, you should use -"bitmap" for teletext pages, because certain graphics and colors cannot be -expressed in simple text. You might use "text" for teletext based subtitles if -your application can handle simple text based subtitles. Default value is -bitmap. +Specifies the format of the decoded subtitles. +@table @option +@item bitmap +The default format, you should use this for teletext pages, because certain +graphics and colors cannot be expressed in simple text or even ASS. +@item text +Simple text based output without formatting. +@item ass +Formatted ASS output, subtitle pages and teletext pages are returned in +different styles, subtitle pages are stripped down to text, but an effort is +made to keep the text alignment and the formatting. +@end table @item txt_left X offset of generated bitmaps, default is 0. @item txt_top diff --git a/libavcodec/libzvbi-teletextdec.c b/libavcodec/libzvbi-teletextdec.c index 809547545b..3515f33924 100644 --- a/libavcodec/libzvbi-teletextdec.c +++ b/libavcodec/libzvbi-teletextdec.c @@ -26,6 +26,7 @@ #include "libavutil/internal.h" #include "libavutil/intreadwrite.h" #include "libavutil/log.h" +#include "libavutil/common.h" #include @@ -56,7 +57,7 @@ typedef struct TeletextContext char *pgno; int x_offset; int y_offset; - int format_id; /* 0 = bitmap, 1 = text/ass */ + int format_id; /* 0 = bitmap, 1 = text/ass, 2 = ass */ int chop_top; int sub_duration; /* in msec */ int transparent_bg; @@ -76,8 +77,55 @@ typedef struct TeletextContext uint8_t subtitle_map[2048]; int last_pgno; int last_p5; + int last_ass_alignment; } TeletextContext; +static int my_ass_subtitle_header(AVCodecContext *avctx) +{ + int ret = ff_ass_subtitle_header_default(avctx); + char *new_header; + uint8_t *event_pos; + + if (ret < 0) + return ret; + + event_pos = strstr(avctx->subtitle_header, "\r\n[Events]\r\n"); + if (!event_pos) + return AVERROR_BUG; + + new_header = av_asprintf("%.*s%s%s", + (int)(event_pos - avctx->subtitle_header), avctx->subtitle_header, + "Style: " + "Teletext," /* Name */ + "Monospace,11," /* Font{name,size} */ + "&Hffffff,&Hffffff,&H0,&H0," /* {Primary,Secondary,Outline,Back}Colour */ + "0,0,0,0," /* Bold, Italic, Underline, StrikeOut */ + "160,100," /* Scale{X,Y} */ + "0,0," /* Spacing, Angle */ + "3,0.1,0," /* BorderStyle, Outline, Shadow */ + "5,1,1,1," /* Alignment, Margin[LRV] */ + "0\r\n" /* Encoding */ + "Style: " + "Subtitle," /* Name */ + "Monospace,16," /* Font{name,size} */ + "&Hffffff,&Hffffff,&H0,&H0," /* {Primary,Secondary,Outline,Back}Colour */ + "0,0,0,0," /* Bold, Italic, Underline, StrikeOut */ + "100,100," /* Scale{X,Y} */ + "0,0," /* Spacing, Angle */ + "1,1,1," /* BorderStyle, Outline, Shadow */ + "8,48,48,20," /* Alignment, Margin[LRV] */ + "0\r\n" /* Encoding */ + , event_pos); + + if (!new_header) + return AVERROR(ENOMEM); + + av_free(avctx->subtitle_header); + avctx->subtitle_header = new_header; + avctx->subtitle_header_size = strlen(new_header); + return 0; +} + static int chop_spaces_utf8(const unsigned char* t, int len) { t += len; @@ -181,6 +229,184 @@ static int gen_sub_text(TeletextContext *ctx, AVSubtitleRect *sub_rect, vbi_page return 0; } +static void bprint_color(const char *type, AVBPrint *buf, vbi_page *page, unsigned ci) +{ + int r = VBI_R(page->color_map[ci]); + int g = VBI_G(page->color_map[ci]); + int b = VBI_B(page->color_map[ci]); + av_bprintf(buf, "{\\%s&H%02X%02X%02X&}", type, b, g, r); +} + +#define IS_TXT_SPACE(ch) ((ch).unicode < 0x0020 || (ch).unicode >= 0xe000 || (ch).unicode == 0x00a0 ||\ + (ch).size > VBI_DOUBLE_SIZE || (ch).opacity == VBI_TRANSPARENT_SPACE) + +static void get_trim_info(vbi_page *page, vbi_char *row, int *leading, int *trailing, int *olen) +{ + int i, len = 0; + int char_seen = 0; + + *leading = 0; + + for (i = 0; i < page->columns; i++) { + uint16_t out = IS_TXT_SPACE(row[i]) ? 32 : row[i].unicode; + + if (out == 32 && !char_seen) + (*leading)++; + else if (out != 32) + char_seen = 1, len = i - (*leading) + 1; + } + + *olen = len; + *trailing = len > 0 ? page->columns - *leading - len : page->columns; +} + +static void decode_string(vbi_page *page, vbi_char *row, AVBPrint *buf, + int start, int end, vbi_color *cur_color, vbi_color *cur_back_color) +{ + int i; + + for (i = start; i < end; i++) { + uint16_t out = IS_TXT_SPACE(row[i]) ? 32 : row[i].unicode; + + if (*cur_color != row[i].foreground) { + bprint_color("c", buf, page, row[i].foreground); + *cur_color = row[i].foreground; + } + if (*cur_back_color != row[i].background) { + bprint_color("3c", buf, page, row[i].background); + *cur_back_color = row[i].background; + } + + if (out == 32) { + av_bprintf(buf, "\\h"); + } else if (out == '\\' || out == '{' || out == '}') { + av_bprintf(buf, "\\%c", (char)out); + } else { + char tmp; + /* convert to utf-8 */ + PUT_UTF8(out, tmp, av_bprint_chars(buf, tmp, 1);); + } + } +} + +/* Draw a page as ass formatted text */ +static int gen_sub_ass(TeletextContext *ctx, AVSubtitleRect *sub_rect, vbi_page *page, int chop_top) +{ + int i; + int leading, trailing, len; + int last_trailing = -1, last_leading = -1; + int min_trailing = page->columns, min_leading = page->columns; + int alignment = 2; + int vertical_align = -1; + int can_align_left = 1, can_align_right = 1, can_align_center = 1; + int is_subtitle_page = ctx->subtitle_map[page->pgno & 0x7ff]; + int empty_lines = 0; + vbi_color cur_color = VBI_WHITE; + vbi_color cur_back_color = VBI_BLACK; + AVBPrint buf; + + av_bprint_init(&buf, 0, AV_BPRINT_SIZE_UNLIMITED); + + for (i = chop_top; i < page->rows; i++) { + vbi_char *row = page->text + i * page->columns; + + get_trim_info(page, row, &leading, &trailing, &len); + + if (len) { + if (last_leading != -1 && last_leading != leading || leading > 5) + can_align_left = 0; + if (last_trailing != -1 && last_trailing != trailing || trailing > 2) + can_align_right = 0; + if (last_trailing != -1 && (FFABS((trailing - leading) - (last_trailing - last_leading)) > 1) || trailing - leading > 4) + can_align_center = 0; + last_leading = leading; + last_trailing = trailing; + min_leading = FFMIN(leading, min_leading); + min_trailing = FFMIN(trailing, min_trailing); + } + } + + if (!can_align_right && can_align_left && !can_align_center) { + ctx->last_ass_alignment = alignment = 1; + } else if (!can_align_right && !can_align_left && can_align_center) { + ctx->last_ass_alignment = alignment = 2; + } else if (can_align_right && !can_align_left && !can_align_center) { + ctx->last_ass_alignment = alignment = 3; + } else { + if (ctx->last_ass_alignment == 1 && can_align_left || + ctx->last_ass_alignment == 2 && can_align_center || + ctx->last_ass_alignment == 3 && can_align_right) + alignment = ctx->last_ass_alignment; + } + + for (i = chop_top; i < page->rows; i++) { + int j; + vbi_char *row = page->text + i * page->columns; + int is_transparent_line; + + for (j = 0; j < page->columns; j++) + if (row[j].opacity != VBI_TRANSPARENT_SPACE) + break; + is_transparent_line = (j == page->columns); + + len = is_transparent_line ? 0 : page->columns; + leading = trailing = is_transparent_line ? page->columns : 0; + + if (is_subtitle_page) { + if (!is_transparent_line) + get_trim_info(page, row, &leading, &trailing, &len); + + if (vertical_align == -1 && len) { + vertical_align = (2 - (av_clip(i + 1, 0, 23) / 8)); + av_bprintf(&buf, "{\\an%d}", alignment + vertical_align * 3); + if (vertical_align != 2) + empty_lines = 0; + } + + if (len && empty_lines > 1) + for (empty_lines /= 2; empty_lines > 0; empty_lines--) + av_bprintf(&buf, " \\N"); + + if (alignment == 1 || alignment == 2 && !can_align_center) + leading = min_leading; + if (alignment == 3 || alignment == 2 && !can_align_center) + trailing = min_trailing; + } + + if (len || !is_subtitle_page) { + decode_string(page, row, &buf, leading, page->columns - trailing, &cur_color, &cur_back_color); + av_bprintf(&buf, " \\N"); + empty_lines = 0; + } else { + empty_lines++; + } + } + + if (vertical_align == 0) + for (empty_lines = (empty_lines - 1) / 2; empty_lines > 0; empty_lines--) + av_bprintf(&buf, " \\N"); + + if (!av_bprint_is_complete(&buf)) { + av_bprint_finalize(&buf, NULL); + return AVERROR(ENOMEM); + } + + if (buf.len) { + sub_rect->type = SUBTITLE_ASS; + sub_rect->ass = ff_ass_get_dialog(ctx->readorder++, 0, is_subtitle_page ? "Subtitle" : "Teletext", NULL, buf.str); + + if (!sub_rect->ass) { + av_bprint_finalize(&buf, NULL); + return AVERROR(ENOMEM); + } + av_log(ctx, AV_LOG_DEBUG, "subtext:%s:txetbus\n", sub_rect->ass); + } else { + sub_rect->type = SUBTITLE_NONE; + } + av_bprint_finalize(&buf, NULL); + return 0; +} + static void fix_transparency(TeletextContext *ctx, AVSubtitleRect *sub_rect, vbi_page *page, int chop_top, int resx, int resy) { @@ -318,9 +544,20 @@ static void handler(vbi_event *ev, void *user_data) cur_page->pgno = ev->ev.ttx_page.pgno; cur_page->subno = ev->ev.ttx_page.subno; if (cur_page->sub_rect) { - res = (ctx->format_id == 0) ? - gen_sub_bitmap(ctx, cur_page->sub_rect, &page, chop_top) : - gen_sub_text (ctx, cur_page->sub_rect, &page, chop_top); + switch (ctx->format_id) { + case 0: + res = gen_sub_bitmap(ctx, cur_page->sub_rect, &page, chop_top); + break; + case 1: + res = gen_sub_text(ctx, cur_page->sub_rect, &page, chop_top); + break; + case 2: + res = gen_sub_ass(ctx, cur_page->sub_rect, &page, chop_top); + break; + default: + res = AVERROR_BUG; + break; + } if (res < 0) { av_freep(&cur_page->sub_rect); ctx->handler_ret = res; @@ -448,7 +685,7 @@ static int teletext_decode_frame(AVCodecContext *avctx, void *data, int *data_si // is there a subtitle to pass? if (ctx->nb_pages) { int i; - sub->format = ctx->format_id; + sub->format = !!ctx->format_id; sub->start_display_time = 0; sub->end_display_time = ctx->sub_duration; sub->num_rects = 0; @@ -508,12 +745,22 @@ static int teletext_init_decoder(AVCodecContext *avctx) ctx->vbi = NULL; ctx->pts = AV_NOPTS_VALUE; ctx->last_pgno = -1; + ctx->last_ass_alignment = 2; if (ctx->opacity == -1) ctx->opacity = ctx->transparent_bg ? 0 : 255; av_log(avctx, AV_LOG_VERBOSE, "page filter: %s\n", ctx->pgno); - return (ctx->format_id == 1) ? ff_ass_subtitle_header_default(avctx) : 0; + + switch (ctx->format_id) { + case 0: + return 0; + case 1: + return ff_ass_subtitle_header_default(avctx); + case 2: + return my_ass_subtitle_header(avctx); + } + return AVERROR_BUG; } static int teletext_close_decoder(AVCodecContext *avctx) @@ -529,6 +776,7 @@ static int teletext_close_decoder(AVCodecContext *avctx) ctx->vbi = NULL; ctx->pts = AV_NOPTS_VALUE; ctx->last_pgno = -1; + ctx->last_ass_alignment = 2; memset(ctx->subtitle_map, 0, sizeof(ctx->subtitle_map)); if (!(avctx->flags2 & AV_CODEC_FLAG2_RO_FLUSH_NOOP)) ctx->readorder = 0; @@ -545,9 +793,10 @@ static void teletext_flush(AVCodecContext *avctx) static const AVOption options[] = { {"txt_page", "page numbers to decode, subtitle for subtitles, * for all", OFFSET(pgno), AV_OPT_TYPE_STRING, {.str = "*"}, 0, 0, SD}, {"txt_chop_top", "discards the top teletext line", OFFSET(chop_top), AV_OPT_TYPE_INT, {.i64 = 1}, 0, 1, SD}, - {"txt_format", "format of the subtitles (bitmap or text)", OFFSET(format_id), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, SD, "txt_format"}, + {"txt_format", "format of the subtitles (bitmap or text or ass)", OFFSET(format_id), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 2, SD, "txt_format"}, {"bitmap", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = 0}, 0, 0, SD, "txt_format"}, {"text", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = 1}, 0, 0, SD, "txt_format"}, + {"ass", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = 2}, 0, 0, SD, "txt_format"}, {"txt_left", "x offset of generated bitmaps", OFFSET(x_offset), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 65535, SD}, {"txt_top", "y offset of generated bitmaps", OFFSET(y_offset), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 65535, SD}, {"txt_chop_spaces", "chops leading and trailing spaces from text", OFFSET(chop_spaces), AV_OPT_TYPE_INT, {.i64 = 1}, 0, 1, SD}, diff --git a/libavcodec/version.h b/libavcodec/version.h index fa3fd01025..7a9484b9a1 100644 --- a/libavcodec/version.h +++ b/libavcodec/version.h @@ -29,7 +29,7 @@ #define LIBAVCODEC_VERSION_MAJOR 58 #define LIBAVCODEC_VERSION_MINOR 31 -#define LIBAVCODEC_VERSION_MICRO 101 +#define LIBAVCODEC_VERSION_MICRO 102 #define LIBAVCODEC_VERSION_INT AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \ LIBAVCODEC_VERSION_MINOR, \