/* * libzvbi - Unified text buffer format * * Copyright (C) 2000, 2001 Michael H. Schimek * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. * * This program 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 General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ /* $Id: format.h,v 1.8 2005/02/17 10:21:16 mschimek Exp $ */ #ifndef FORMAT_H #define FORMAT_H #include "event.h" /* vbi_nuid */ #ifndef VBI_DECODER #define VBI_DECODER typedef struct vbi_decoder vbi_decoder; #endif /* Public */ #include /** * @addtogroup Page Formatted text page * @ingroup HiDec */ /** * @ingroup Page * @brief Index into the vbi_page->color_map. * * The enumerated color names * refer to the Teletext and Closed Caption base palette of eight * colors. Note however the color_map really has 40 entries for * Teletext Level 2.5+, 32 of which are redefinable, the remaining * eight are private colors of libzvbi e. g. for * navigational information. So these symbols may not necessarily * correspond to the respective color. */ /* Code depends on order, don't change. */ typedef enum { VBI_BLACK, VBI_RED, VBI_GREEN, VBI_YELLOW, VBI_BLUE, VBI_MAGENTA, VBI_CYAN, VBI_WHITE } vbi_color; /** * @ingroup Page * @brief Colormap entry: 0xAABBGGRR. libzvbi sets the alpha channel * always to 0xFF. */ typedef uint32_t vbi_rgba; /* Private */ #define VBI_RGBA(r, g, b) \ ((((r) & 0xFF) << 0) | (((g) & 0xFF) << 8) \ | (((b) & 0xFF) << 16) | (0xFF << 24)) #define VBI_R(rgba) (((rgba) >> 0) & 0xFF) #define VBI_G(rgba) (((rgba) >> 8) & 0xFF) #define VBI_B(rgba) (((rgba) >> 16) & 0xFF) #define VBI_A(rgba) (((rgba) >> 24) & 0xFF) /* Public */ /** * @ingroup Page * @brief Defines the opacity of a vbi_char and vbi_page border. * * Teletext Level 2.5 defines a special transparent color which * permits unusual characters with transparent foreground, opaque * background. For simplicity this type of opacity has been omitted. Also * renderers shall rely on the opacity attribute and not attempt to * interpret the color value as transparency indicator. */ typedef enum { /** * This page is supposed to be overlayed onto * video, with video displayed in place of this character (or the page * border). In other words the character is a space (vbi_char->unicode = * U+0020) and the glyph background is transparent. If desired the * renderer may also fall back to VBI_SEMI_TRANSPARENT or VBI_OPAQUE * mode. For this case vbi_char->background names the color to use as * the semi-transparent or opaque background. * * VBI_TRANSPARENT_SPACE is the opacity of subtitle pages (both border and * characters, while the 'boxed' words are marked as VBI_SEMI_TRANSPARENT), * but can also occur on a mainly VBI_OPAQUE page to create a 'window' * effect. */ VBI_TRANSPARENT_SPACE, /** * Display video instead of the background color. * Here the character is not a space and shall be displayed * in vbi_char->foreground color. Only in the background of the character * video shall look through. Again the renderer may fall back to * VBI_SEMI_TRANSPARENT or VBI_OPAQUE. */ VBI_TRANSPARENT_FULL, /** * Alpha blend video into background color, the * character background becomes translucent. This is the opacity used * for 'boxed' text on an otherwise VBI_TRANSPARENT_SPACE page, typically * a subtitle or Teletext newsflash page. The renderer may fall back * to VBI_OPAQUE. */ VBI_SEMI_TRANSPARENT, /** * Display foreground and background color. Showing * foreground or background transparent instead is not recommended because * the editor may have swapped foreground and background color, then * replaced a glyph by its inverse image, so one cannot really know if * the character foreground or background will appear transparent. */ VBI_OPAQUE } vbi_opacity; /** * @ingroup Page * @brief Defines the size of a vbi_char in a vbi_page. * Double width or height characters expand into the next * column right and/or next row below. * * Scanning two rows left to right, you will find
* 
 * VBI_NORMAL_SIZE | VBI_DOUBLE_WIDTH VBI_OVER_TOP | VBI_DOUBLE_HEIGHT  | VBI_DOUBLE_SIZE  VBI_OVER_TOP
 *       x         |         x             x       | VBI_DOUBLE_HEIGHT2 | VBI_DOUBLE_SIZE2 VBI_OVER_BOTTOM
 *
* * A VBI_DOUBLE_HEIGHT2, VBI_DOUBLE_SIZE2, VBI_OVER_TOP, VBI_OVER_BOTTOM * vbi_char has the same character unicode and attributes as the top/left anchor. * Partial characters (like a single VBI_DOUBLE_HEIGHT2) will not appear, so * VBI_DOUBLE_HEIGHT2, VBI_DOUBLE_SIZE2, VBI_OVER_TOP, VBI_OVER_BOTTOM * can be safely ignored when scanning the page. */ /* Code depends on order, don't change. */ typedef enum { VBI_NORMAL_SIZE, VBI_DOUBLE_WIDTH, VBI_DOUBLE_HEIGHT, VBI_DOUBLE_SIZE, VBI_OVER_TOP, VBI_OVER_BOTTOM, VBI_DOUBLE_HEIGHT2, VBI_DOUBLE_SIZE2 } vbi_size; /** * @ingroup Page * @brief Attributed character. */ typedef struct vbi_char { unsigned underline : 1; /**< Display character underlined. */ unsigned bold : 1; /**< Display character bold. */ unsigned italic : 1; /**< Display character slanted right. */ /** * Display character or space (U+0020), one second cycle time. */ unsigned flash : 1; /** * Replace character by space (U+0020) if not revealed. * This is used for example to hide text on question & answer pages. */ unsigned conceal : 1; /** * No function yet, default is fixed spacing. */ unsigned proportional : 1; /** * This character is part of a hyperlink. Call vbi_resolve_link() * to get more information. */ unsigned link : 1; /** * Reserved for VPT link flag. */ unsigned reserved : 1; /** * Character size, see vbi_size. */ unsigned size : 8; /** * Character opacity, see vbi_opacity. Both @a foreground * and @a background color are valid independent of @a opacity. */ unsigned opacity : 8; /** * Character foreground color, a vbi_color index * into the vbi_page->color_map. */ unsigned foreground : 8; /** * Character background color, a vbi_color index * into the vbi_page->color_map. */ unsigned background : 8; /** * DRCS color look-up table offset, see vbi_page for details. */ unsigned drcs_clut_offs : 8; /** * Character code according to ISO 10646 UCS-2 (not UTF-16). * * All Closed Caption characters can be represented in Unicode, * but unfortunately not all Teletext characters. * * ETS 300 706 * Table 36 Latin National Subset Turkish, character * 0x23 "Turkish currency symbol" is not representable in Unicode, * thus translated to private code U+E800. I was unable to identify * all Arabic glyphs in Table 44 and 45 Arabic G0 and G2, so for now * these are mapped to private code U+E620 ... U+E67F and U+E720 ... * U+E77F respectively. Table 47 G1 Block Mosaic is not representable * in Unicode, translated to private code U+EE00 ... U+EE7F. That is, * the contiguous form has bit 5 (0x20) set, the separate form cleared. * Table 48 G3 "Smooth Mosaics and Line Drawing Set" is not * representable in Unicode, translated to private code * U+EF20 ... U+EF7F. * * Teletext Level 2.5+ DRCS are represented by private code * U+F000 ... U+F7FF. The 6 lsb select character 0x00 ... 0x3F * from a DRCS plane, the 5 msb select DRCS plane 0 ... 31, see * vbi_page for details. * * @bug * Some Teletext character sets contain complementary * Latin characters. For example the Greek capital letters Alpha * and Beta are re-used as Latin capital letter A and B, while a * separate code exists for Latin capital letter C. libzvbi will * not analyse the page contents, so Greek A and B are always * translated to Greek Alpha and Beta, C to Latin C, even if they * appear in a pure Latin character word. */ unsigned unicode : 16; } vbi_char; struct vbi_font_descr; /** * @ingroup Page * @brief Formatted Teletext or Closed Caption page. * * Clients can fetch pages * from the respective cache using vbi_fetch_vt_page() or * vbi_fetch_cc_page() for evaluation, display or output. Since * the page may reference other objects in cache which are locked * by the fetch functions, vbi_unref_page() must be called when done. * Note this structure is large, some 10 KB. */ typedef struct vbi_page { /** * Points back to the source context. */ vbi_decoder * vbi; /** * Identifies the network broadcasting this page. */ vbi_nuid nuid; /** * Page number, see vbi_pgno. */ /* FIXME this shouldn't be int */ int pgno; /** * Subpage number, see vbi_subno. */ /* FIXME this shouldn't be int */ int subno; /** * Number of character rows in the page. */ int rows; /** * Number of character columns in the page. */ int columns; /** * The page contents, these are @a rows x @a columns without * padding between the rows. See vbi_char for details. */ vbi_char text[1056]; /** * To speed up rendering these variables mark the rows * which actually changed since the page has been last fetched * from cache. @a y0 ... @a y1 are the first to last row changed, * inclusive, in range 0 ... @a rows - 1. @a roll indicates the * page has been vertically scrolled this number of rows, * negative numbers up (towards lower row numbers), positive * numbers down. For example -1 means row @a y0 + 1 ... @a y1 * moved to @a y0 ... @a y1 - 1, erasing row @a y1 to all spaces. * * Practically this is only used in Closed Caption roll-up * mode, otherwise all rows are always marked dirty. Clients * are free to ignore this information. */ struct { /* int x0, x1; */ int y0, y1; int roll; } dirty; /** * When a TV displays Teletext or Closed Caption * pages, only a section in the center of the screen is * actually covered by characters. The remaining space is * referred to here as 'border', which can have a color different * from the typical black. (In the Teletext specs this is referred * to as the screen color, hence the field name.) This is a * vbi_color index into the @a color_map. */ vbi_color screen_color; /** * The 'border' can also have a distinguished * opacity. Typically this will be VBI_OPAQUE, but pages intended * for overlay onto video (Teletext subtitles, newsflash, Caption * pages) will have a @a screen_opacity of VBI_TRANSPARENT_SPACE. * See vbi_opacity for details. */ vbi_opacity screen_opacity; /** * This is the color palette indexed by vbi_color in * vbi_char and elsewhere, colors defined as vbi_rgba. Note this * palette may not correspond to the vbi_color enumeration since * Teletext allows editors to redefine the entire palette. * Closed Caption and Teletext Level 1.0/1.5 pages use * entries 0 ... 7. Teletext Level 2.5/3.5 pages use entries * 0 ... 31. Navigation related text (TOP, FLOF) added by libzvbi * uses entries 32 ... 39 which are not subject to redefinition. */ vbi_rgba color_map[40]; /** * DRCS (dynamically redefinable characters) can have * two, four or sixteen different colors. Without further details, * the effective color of each pixel is given by * @code * vbi_page->color_map[drcs_clut[drcs pixel color + vbi_char->drcs_clut_offs]], * @endcode * whereby drcs_clut[0] shall be replaced by vbi_char->foreground, * drcs_clut[1] by vbi_char->background. (Renderers are supposed to convert the * drcs_clut into a private color map of the desired pixel format.) * * Practically vbi_char->drcs_clut_offs encodes the DRCS color depth * and selects between the vbi_char colors and one of two 4- or * 16-entry Color Look-Up Tables. Also the different resolution of DRCS and * the bitplane color coding is hidden to speed up rendering. */ uint8_t * drcs_clut; /* 64 entries */ /** * Pointer to DRCS data. Per definition the maximum number of DRCS * usable at the same time, i. e. on one page, is limited to 96. However the * number of DRCS defined in a Teletext data stream can be much larger. The * 32 pointers here correspond to the 32 DRCS character planes mentioned * in the vbi_char description. Each of them points to an array of character * definitions, a DRCS font. One character occupies 60 bytes or 12 x 10 pixels, * stored left to right and top to bottom. The color of each pixel (index * into @a drcs_clut) is coded in four bits stored in little endian order, * first pixel 0x0F, second pixel 0xF0 and so on. For example the first, * top/leftmost pixel can be found at * @code * vbi_page->drcs[(unicode >> 6) & 0x1F][(unicode & 0x3F) * 60] * @endcode * * Do not access DRCS data unless referenced by a vbi_char in @a text, a * segfault may result. Do not access DRCS data after calling * vbi_unref_page(), it may not be cached anymore. */ uint8_t * drcs[32]; struct { int pgno, subno; } nav_link[6]; char nav_index[64]; struct vbi_font_descr * font[2]; unsigned int double_height_lower; /* legacy */ vbi_opacity page_opacity[2]; vbi_opacity boxed_opacity[2]; } vbi_page; /* Private */ #endif /* FORMAT_H */