freetype.c

video linux conference

/*****************************************************************************
 * freetype.c : Put text on the video, using freetype2
 *****************************************************************************
 * Copyright (C) 2002 - 2005 VideoLAN
 * $Id: freetype.c 11387 2005-06-10 15:32:08Z hartman $
 *
 * Authors: Sigmund Augdal <[e-mail]>
 *          Gildas Bazin <[e-mail]>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * 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., 59 Temple Place - Suite 330, Boston, MA  02111, USA.
 *****************************************************************************/

/*****************************************************************************
 * Preamble
 *****************************************************************************/
#include <stdlib.h>                                      /* malloc(), free() */
#include <string.h>

#ifdef HAVE_LINUX_LIMITS_H
#   include <linux/limits.h>
#endif

#include <vlc/vlc.h>
#include <vlc/vout.h>
#include "osd.h"
#include "vlc_block.h"
#include "vlc_filter.h"

#include <math.h>

#ifdef HAVE_ERRNO_H
#   include <errno.h>
#endif

#include <ft2build.h>
#include FT_FREETYPE_H
#include FT_GLYPH_H

#ifdef SYS_DARWIN
#define DEFAULT_FONT "/System/Library/Fonts/LucidaGrande.dfont"
#elif defined( SYS_BEOS )
#define DEFAULT_FONT "/boot/beos/etc/fonts/ttfonts/Swiss721.ttf"
#elif defined( WIN32 )
#define DEFAULT_FONT "" /* Default font found at run-time */
#else
#define DEFAULT_FONT "/usr/share/fonts/truetype/freefont/FreeSerifBold.ttf"
#endif

#if defined(HAVE_FRIBIDI)
#include <fribidi/fribidi.h>
#endif

typedef struct line_desc_t line_desc_t;

/*****************************************************************************
 * Local prototypes
 *****************************************************************************/
static int  Create ( vlc_object_t * );
static void Destroy( vlc_object_t * );

/* The RenderText call maps to pf_render_string, defined in vlc_filter.h */
static int RenderText( filter_t *, subpicture_region_t *,
                       subpicture_region_t * );
static line_desc_t *NewLine( byte_t * );

static int SetFontSize( filter_t *, int );

/*****************************************************************************
 * Module descriptor
 *****************************************************************************/
#define FONT_TEXT N_("Font")
#define FONT_LONGTEXT N_("Font filename")
#define FONTSIZE_TEXT N_("Font size in pixels")
#define FONTSIZE_LONGTEXT N_("The size of the fonts used by the osd module. " \
    "If set to something different than 0 this option will override the " \
    "relative font size " )
#define OPACITY_TEXT N_("Opacity, 0..255")
#define OPACITY_LONGTEXT N_("The opacity (inverse of transparency) of " \
    "overlay text. 0 = transparent, 255 = totally opaque. " )
#define COLOR_TEXT N_("Text Default Color")
#define COLOR_LONGTEXT N_("The color of overlay text. 1 byte for each color, "\
    "hexadecimal. #000000 = all colors off, 0xFF0000 = just Red, " \
    "0xFFFFFF = all color on [White]" )
#define FONTSIZER_TEXT N_("Font size")
#define FONTSIZER_LONGTEXT N_("The size of the fonts used by the osd module" )

static int   pi_sizes[] = { 20, 18, 16, 12, 6 };
static char *ppsz_sizes_text[] = { N_("Smaller"), N_("Small"), N_("Normal"),
                                   N_("Large"), N_("Larger") };
static int pi_color_values[] = {
  0x00000000, 0x00808080, 0x00C0C0C0, 0x00FFFFFF, 0x00800000,
  0x00FF0000, 0x00FF00FF, 0x00FFFF00, 0x00808000, 0x00008000, 0x00008080, 
  0x0000FF00, 0x00800080, 0x00000080, 0x000000FF, 0x0000FFFF }; 

static char *ppsz_color_descriptions[] = {
  N_("Black"), N_("Gray"), N_("Silver"), N_("White"), N_("Maroon"),
  N_("Red"), N_("Fuchsia"), N_("Yellow"), N_("Olive"), N_("Green"), N_("Teal"),
  N_("Lime"), N_("Purple"), N_("Navy"), N_("Blue"), N_("Aqua") };

vlc_module_begin();
    set_shortname( _("Text renderer"));
    set_description( _("Freetype2 font renderer") );
    set_category( CAT_VIDEO );
    set_subcategory( SUBCAT_VIDEO_SUBPIC );

    add_file( "freetype-font", DEFAULT_FONT, NULL, FONT_TEXT, FONT_LONGTEXT,
              VLC_FALSE );

    add_integer( "freetype-fontsize", 0, NULL, FONTSIZE_TEXT,
                 FONTSIZE_LONGTEXT, VLC_TRUE );

    /* opacity valid on 0..255, with default 255 = fully opaque */
    add_integer_with_range( "freetype-opacity", 255, 0, 255, NULL,
        OPACITY_TEXT, OPACITY_LONGTEXT, VLC_TRUE );

    /* hook to the color values list, with default 0x00ffffff = white */
    add_integer( "freetype-color", 0x00FFFFFF, NULL, COLOR_TEXT,
                 COLOR_LONGTEXT, VLC_FALSE );
        change_integer_list( pi_color_values, ppsz_color_descriptions, 0 );

    add_integer( "freetype-rel-fontsize", 16, NULL, FONTSIZER_TEXT,
                 FONTSIZER_LONGTEXT, VLC_FALSE );
        change_integer_list( pi_sizes, ppsz_sizes_text, 0 );

    set_capability( "text renderer", 100 );
    add_shortcut( "text" );
    set_callbacks( Create, Destroy );
vlc_module_end();

struct line_desc_t
{
    /** NULL-terminated list of glyphs making the string */
    FT_BitmapGlyph *pp_glyphs;
    /** list of relative positions for the glyphs */
    FT_Vector      *p_glyph_pos;

    int             i_height;
    int             i_width;
    int             i_red, i_green, i_blue;
    int             i_alpha;

    line_desc_t    *p_next;
};

static int Render( filter_t *, subpicture_region_t *, line_desc_t *, int, int);
static void FreeLines( line_desc_t * );
static void FreeLine( line_desc_t * );

/*****************************************************************************
 * filter_sys_t: freetype local data
 *****************************************************************************
 * This structure is part of the video output thread descriptor.
 * It describes the freetype specific properties of an output thread.
 *****************************************************************************/
struct filter_sys_t
{
    FT_Library     p_library;   /* handle to library     */
    FT_Face        p_face;      /* handle to face object */
    vlc_bool_t     i_use_kerning;
    uint8_t        i_font_opacity;
    int            i_font_color;
    int            i_font_size;

    int            i_default_font_size;
    int            i_display_height;
};

/*****************************************************************************
 * Create: allocates osd-text video thread output method
 *****************************************************************************
 * This function allocates and initializes a Clone vout method.
 *****************************************************************************/
static int Create( vlc_object_t *p_this )
{
    filter_t *p_filter = (filter_t *)p_this;
    filter_sys_t *p_sys;
    char *psz_fontfile = NULL;
    int i_error;
    vlc_value_t val;

    /* Allocate structure */
    p_filter->p_sys = p_sys = malloc( sizeof( filter_sys_t ) );
    if( !p_sys )
    {
        msg_Err( p_filter, "out of memory" );
        return VLC_ENOMEM;
    }
    p_sys->p_face = 0;
    p_sys->p_library = 0;
    p_sys->i_font_size = 0;
    p_sys->i_display_height = 0;

    var_Create( p_filter, "freetype-font",
                VLC_VAR_STRING | VLC_VAR_DOINHERIT );
    var_Create( p_filter, "freetype-fontsize",
                VLC_VAR_INTEGER | VLC_VAR_DOINHERIT );
    var_Create( p_filter, "freetype-rel-fontsize",
                VLC_VAR_INTEGER | VLC_VAR_DOINHERIT );
    var_Create( p_filter, "freetype-opacity",
                VLC_VAR_INTEGER | VLC_VAR_DOINHERIT );
    var_Get( p_filter, "freetype-opacity", &val );
    p_sys->i_font_opacity = __MAX( __MIN( val.i_int, 255 ), 0 );
    var_Create( p_filter, "freetype-color",
                VLC_VAR_INTEGER | VLC_VAR_DOINHERIT );
    var_Get( p_filter, "freetype-color", &val );
    p_sys->i_font_color = __MAX( __MIN( val.i_int, 0xFFFFFF ), 0 );

    /* Look what method was requested */
    var_Get( p_filter, "freetype-font", &val );
    psz_fontfile = val.psz_string;
    if( !psz_fontfile || !*psz_fontfile )
    {
        if( psz_fontfile ) free( psz_fontfile );
        psz_fontfile = (char *)malloc( PATH_MAX + 1 );
#ifdef WIN32
        GetWindowsDirectory( psz_fontfile, PATH_MAX + 1 );
        strcat( psz_fontfile, "\\fonts\\arial.ttf" );
#elif SYS_DARWIN
        strcpy( psz_fontfile, DEFAULT_FONT );
#else
        msg_Err( p_filter, "user didn't specify a font" );
        goto error;
#endif
    }

    i_error = FT_Init_FreeType( &p_sys->p_library );
    if( i_error )
    {
        msg_Err( p_filter, "couldn't initialize freetype" );
        goto error;
    }

    i_error = FT_New_Face( p_sys->p_library, psz_fontfile ? psz_fontfile : "",
                           0, &p_sys->p_face );
    if( i_error == FT_Err_Unknown_File_Format )
    {
        msg_Err( p_filter, "file %s have unknown format", psz_fontfile );
        goto error;
    }
    else if( i_error )
    {
        msg_Err( p_filter, "failed to load font file %s", psz_fontfile );
        goto error;
    }

    i_error = FT_Select_Charmap( p_sys->p_face, ft_encoding_unicode );
    if( i_error )
    {
        msg_Err( p_filter, "Font has no unicode translation table" );
        goto error;
    }

    p_sys->i_use_kerning = FT_HAS_KERNING( p_sys->p_face );

    var_Get( p_filter, "freetype-fontsize", &val );
    p_sys->i_default_font_size = val.i_int;
    if( SetFontSize( p_filter, 0 ) != VLC_SUCCESS ) goto error;

    if( psz_fontfile ) free( psz_fontfile );
    p_filter->pf_render_text = RenderText;
    return VLC_SUCCESS;

 error:
    if( p_sys->p_face ) FT_Done_Face( p_sys->p_face );
    if( p_sys->p_library ) FT_Done_FreeType( p_sys->p_library );
    if( psz_fontfile ) free( psz_fontfile );
    free( p_sys );
    return VLC_EGENERIC;
}

/*****************************************************************************
 * Destroy: destroy Clone video thread output method
 *****************************************************************************
 * Clean up all data and library connections
 *****************************************************************************/
static void Destroy( vlc_object_t *p_this )
{
    filter_t *p_filter = (filter_t *)p_this;
    filter_sys_t *p_sys = p_filter->p_sys;

    FT_Done_Face( p_sys->p_face );
    FT_Done_FreeType( p_sys->p_library );
    free( p_sys );
}

/*****************************************************************************
 * Render: place string in picture
 *****************************************************************************
 * This function merges the previously rendered freetype glyphs into a picture
 *****************************************************************************/
static int Render( filter_t *p_filter, subpicture_region_t *p_region,
                   line_desc_t *p_line, int i_width, int i_height )
{
    static uint8_t pi_gamma[16] =
        {0x00, 0x41, 0x52, 0x63, 0x84, 0x85, 0x96, 0xa7, 0xb8, 0xc9,
         0xca, 0xdb, 0xdc, 0xed, 0xee, 0xff};

    uint8_t *p_dst;
    video_format_t fmt;
    int i, x, y, i_pitch;
    uint8_t i_y; /* YUV values, derived from incoming RGB */
    int8_t i_u, i_v;
    subpicture_region_t *p_region_tmp;

    /* Create a new subpicture region */
    memset( &fmt, 0, sizeof(video_format_t) );
    fmt.i_chroma = VLC_FOURCC('Y','U','V','P');
    fmt.i_aspect = 0;
    fmt.i_width = fmt.i_visible_width = i_width + 4;
    fmt.i_height = fmt.i_visible_height = i_height + 4;
    fmt.i_x_offset = fmt.i_y_offset = 0;
    p_region_tmp = spu_CreateRegion( p_filter, &fmt );
    if( !p_region_tmp )
    {
        msg_Err( p_filter, "cannot allocate SPU region" );
        return VLC_EGENERIC;
    }

    p_region->fmt = p_region_tmp->fmt;
    p_region->picture = p_region_tmp->picture;
    free( p_region_tmp );

    /* Calculate text color components */
    i_y = (uint8_t)(( 66 * p_line->i_red  + 129 * p_line->i_green +
                      25 * p_line->i_blue + 128) >> 8) +  16;
    i_u = (int8_t)(( -38 * p_line->i_red  -  74 * p_line->i_green +
                     112 * p_line->i_blue + 128) >> 8) + 128;
    i_v = (int8_t)(( 112 * p_line->i_red  -  94 * p_line->i_green -
                      18 * p_line->i_blue + 128) >> 8) + 128;

    /* Build palette */
    fmt.p_palette->i_entries = 16;
    for( i = 0; i < fmt.p_palette->i_entries; i++ )
    {
        fmt.p_palette->palette[i][0] = i * 16 * i_y / 256;
        fmt.p_palette->palette[i][1] = i_u;
        fmt.p_palette->palette[i][2] = i_v;
        fmt.p_palette->palette[i][3] = pi_gamma[i];
        fmt.p_palette->palette[i][3] =
            (int)fmt.p_palette->palette[i][3] * (255 - p_line->i_alpha) / 255;
    }

    p_dst = p_region->picture.Y_PIXELS;
    i_pitch = p_region->picture.Y_PITCH;

    /* Initialize the region pixels */
    memset( p_dst, 0, i_pitch * p_region->fmt.i_height );

    for( ; p_line != NULL; p_line = p_line->p_next )
    {
        int i_glyph_tmax = 0;
        int i_bitmap_offset, i_offset, i_align_offset = 0;
        for( i = 0; p_line->pp_glyphs[i] != NULL; i++ )
        {
            FT_BitmapGlyph p_glyph = p_line->pp_glyphs[ i ];
            i_glyph_tmax = __MAX( i_glyph_tmax, p_glyph->top );
        }

        if( p_line->i_width < i_width )
        {
            if( p_region->i_text_align == SUBPICTURE_ALIGN_RIGHT )
            {
                i_align_offset = i_width - p_line->i_width;
            }
            else if( p_region->i_text_align != SUBPICTURE_ALIGN_LEFT )
            {
                i_align_offset = ( i_width - p_line->i_width ) / 2;
            }
        }

        for( i = 0; p_line->pp_glyphs[i] != NULL; i++ )
        {
            FT_BitmapGlyph p_glyph = p_line->pp_glyphs[ i ];

            i_offset = ( p_line->p_glyph_pos[ i ].y +
                i_glyph_tmax - p_glyph->top + 2 ) *
                i_pitch + p_line->p_glyph_pos[ i ].x + p_glyph->left + 2 +
                i_align_offset;