freetype.c

/*****************************************************************************
 * freetype.c : Put text on the video, using freetype2
 *****************************************************************************
 * Copyright (C) 2002 - 2012 VLC authors and VideoLAN
 * $Id$
 *
 * Authors: Sigmund Augdal Helberg <dnumgis@videolan.org>
 *          Gildas Bazin <gbazin@videolan.org>
 *          Bernie Purcell <bitmap@videolan.org>
 *          Jean-Baptiste Kempf <jb@videolan.org>
 *          Felix Paul Kühne <fkuehne@videolan.org>
 *
 * This program 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.
 *
 * 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 Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program; if not, write to the Free Software Foundation, Inc.,
 * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
 *****************************************************************************/

/*****************************************************************************
 * Preamble
 *****************************************************************************/

#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include <math.h>

#include <vlc_common.h>
#include <vlc_plugin.h>
#include <vlc_stream.h>                        /* stream_MemoryNew */
#include <vlc_input.h>                         /* vlc_input_attachment_* */
#include <vlc_xml.h>                           /* xml_reader */
#include <vlc_dialog.h>                        /* FcCache dialog */
#include <vlc_filter.h>                                      /* filter_sys_t */
#include <vlc_text_style.h>                                   /* text_style_t*/

/* Freetype */
#include <ft2build.h>
#include FT_FREETYPE_H
#include FT_GLYPH_H
#include FT_STROKER_H
#include FT_SYNTHESIS_H

#define FT_FLOOR(X)     ((X & -64) >> 6)
#define FT_CEIL(X)      (((X + 63) & -64) >> 6)
#ifndef FT_MulFix
 #define FT_MulFix(v, s) (((v)*(s))>>16)
#endif

/* apple stuff */
#ifdef __APPLE__
#include <TargetConditionals.h>
#if !TARGET_OS_IPHONE
#include <Carbon/Carbon.h>
#endif
#include <sys/param.h>                         /* for MAXPATHLEN */
#undef HAVE_FONTCONFIG
#define HAVE_STYLES
#endif

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

/* Win32 GDI */
#ifdef _WIN32
# define HAVE_STYLES
# undef HAVE_FONTCONFIG
#endif

/* FontConfig */
#ifdef HAVE_FONTCONFIG
# define HAVE_STYLES
#endif

#include <assert.h>

#include "text_renderer.h"
#include "platform_fonts.h"

/*****************************************************************************
 * Module descriptor
 *****************************************************************************/
static int  Create ( vlc_object_t * );
static void Destroy( vlc_object_t * );

#define FONT_TEXT N_("Font")
#define MONOSPACE_FONT_TEXT N_("Monospace Font")

#define FAMILY_LONGTEXT N_("Font family for the font you want to use")
#define FONT_LONGTEXT N_("Font file for the font you want to use")

#define FONTSIZE_TEXT N_("Font size in pixels")
#define FONTSIZE_LONGTEXT N_("This is the default size of the fonts " \
    "that will be rendered on the video. " \
    "If set to something different than 0 this option will override the " \
    "relative font size." )
#define OPACITY_TEXT N_("Text opacity")
#define OPACITY_LONGTEXT N_("The opacity (inverse of transparency) of the " \
    "text that will be rendered on the video. 0 = transparent, " \
    "255 = totally opaque. " )
#define COLOR_TEXT N_("Text default color")
#define COLOR_LONGTEXT N_("The color of the text that will be rendered on "\
    "the video. This must be an hexadecimal (like HTML colors). The first two "\
    "chars are for red, then green, then blue. #000000 = black, #FF0000 = red,"\
    " #00FF00 = green, #FFFF00 = yellow (red + green), #FFFFFF = white" )
#define FONTSIZER_TEXT N_("Relative font size")
#define FONTSIZER_LONGTEXT N_("This is the relative default size of the " \
    "fonts that will be rendered on the video. If absolute font size is set, "\
    "relative size will be overridden." )
#define BOLD_TEXT N_("Force bold")

#define BG_OPACITY_TEXT N_("Background opacity")
#define BG_COLOR_TEXT N_("Background color")

#define OUTLINE_OPACITY_TEXT N_("Outline opacity")
#define OUTLINE_COLOR_TEXT N_("Outline color")
#define OUTLINE_THICKNESS_TEXT N_("Outline thickness")

#define SHADOW_OPACITY_TEXT N_("Shadow opacity")
#define SHADOW_COLOR_TEXT N_("Shadow color")
#define SHADOW_ANGLE_TEXT N_("Shadow angle")
#define SHADOW_DISTANCE_TEXT N_("Shadow distance")


static const int pi_sizes[] = { 20, 18, 16, 12, 6 };
static const char *const ppsz_sizes_text[] = {
    N_("Smaller"), N_("Small"), N_("Normal"), N_("Large"), N_("Larger") };
#define YUVP_TEXT N_("Use YUVP renderer")
#define YUVP_LONGTEXT N_("This renders the font using \"paletized YUV\". " \
  "This option is only needed if you want to encode into DVB subtitles" )

static const int pi_color_values[] = {
  0x00000000, 0x00808080, 0x00C0C0C0, 0x00FFFFFF, 0x00800000,
  0x00FF0000, 0x00FF00FF, 0x00FFFF00, 0x00808000, 0x00008000, 0x00008080,
  0x0000FF00, 0x00800080, 0x00000080, 0x000000FF, 0x0000FFFF };

static const char *const 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") };

static const int pi_outline_thickness[] = {
    0, 2, 4, 6,
};
static const char *const ppsz_outline_thickness[] = {
    N_("None"), N_("Thin"), N_("Normal"), N_("Thick"),
};

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

#ifdef HAVE_STYLES
    add_font( "freetype-font", DEFAULT_FAMILY, FONT_TEXT, FAMILY_LONGTEXT, false )
    add_font( "freetype-monofont", DEFAULT_MONOSPACE_FAMILY, MONOSPACE_FONT_TEXT, FAMILY_LONGTEXT, false )
#else
    add_loadfile( "freetype-font", DEFAULT_FONT_FILE, FONT_TEXT, FONT_LONGTEXT, false )
    add_loadfile( "freetype-monofont", DEFAULT_MONOSPACE_FONT_FILE, MONOSPACE_FONT_TEXT, FONT_LONGTEXT, false )
#endif

    add_integer( "freetype-fontsize", 0, FONTSIZE_TEXT,
                 FONTSIZE_LONGTEXT, true )
        change_integer_range( 0, 4096)
        change_safe()

    add_integer( "freetype-rel-fontsize", 16, FONTSIZER_TEXT,
                 FONTSIZER_LONGTEXT, false )
        change_integer_list( pi_sizes, ppsz_sizes_text )
        change_safe()

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

    /* hook to the color values list, with default 0x00ffffff = white */
    add_rgb( "freetype-color", 0x00FFFFFF, COLOR_TEXT,
                 COLOR_LONGTEXT, false )
        change_integer_list( pi_color_values, ppsz_color_descriptions )
        change_safe()

    add_bool( "freetype-bold", false, BOLD_TEXT, NULL, false )
        change_safe()

    add_integer_with_range( "freetype-background-opacity", 0, 0, 255,
                            BG_OPACITY_TEXT, NULL, false )
        change_safe()
    add_rgb( "freetype-background-color", 0x00000000, BG_COLOR_TEXT,
             NULL, false )
        change_integer_list( pi_color_values, ppsz_color_descriptions )
        change_safe()

    add_integer_with_range( "freetype-outline-opacity", 255, 0, 255,
                            OUTLINE_OPACITY_TEXT, NULL, false )
        change_safe()
    add_rgb( "freetype-outline-color", 0x00000000, OUTLINE_COLOR_TEXT,
             NULL, false )
        change_integer_list( pi_color_values, ppsz_color_descriptions )
        change_safe()
    add_integer_with_range( "freetype-outline-thickness", 4, 0, 50, OUTLINE_THICKNESS_TEXT,
             NULL, false )
        change_integer_list( pi_outline_thickness, ppsz_outline_thickness )
        change_safe()

    add_integer_with_range( "freetype-shadow-opacity", 128, 0, 255,
                            SHADOW_OPACITY_TEXT, NULL, false )
        change_safe()
    add_rgb( "freetype-shadow-color", 0x00000000, SHADOW_COLOR_TEXT,
             NULL, false )
        change_integer_list( pi_color_values, ppsz_color_descriptions )
        change_safe()
    add_float_with_range( "freetype-shadow-angle", -45, -360, 360,
                          SHADOW_ANGLE_TEXT, NULL, false )
        change_safe()
    add_float_with_range( "freetype-shadow-distance", 0.06, 0.0, 1.0,
                          SHADOW_DISTANCE_TEXT, NULL, false )
        change_safe()

    add_obsolete_integer( "freetype-effect" );

    add_bool( "freetype-yuvp", false, YUVP_TEXT,
              YUVP_LONGTEXT, true )
    set_capability( "text renderer", 100 )
    add_shortcut( "text" )
    set_callbacks( Create, Destroy )
vlc_module_end ()


/*****************************************************************************
 * Local prototypes
 *****************************************************************************/

typedef struct
{
    FT_BitmapGlyph p_glyph;
    FT_BitmapGlyph p_outline;
    FT_BitmapGlyph p_shadow;
    uint32_t       i_color;             /* ARGB color */
    int            i_line_offset;       /* underline/strikethrough offset */
    int            i_line_thickness;    /* underline/strikethrough thickness */
} line_character_t;

typedef struct line_desc_t line_desc_t;
struct line_desc_t
{
    line_desc_t      *p_next;

    int              i_width;
    int              i_height;
    int              i_base_line;
    int              i_character_count;
    line_character_t *p_character;
};

/*****************************************************************************
 * 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 */
    FT_Stroker     p_stroker;   /* handle to path stroker object */

    xml_reader_t  *p_xml;       /* vlc xml parser */

    text_style_t   style;       /* Current Style */

    /* More styles... */
    float          f_shadow_vector_x;
    float          f_shadow_vector_y;
    int            i_default_font_size;

    /* Attachments */
    input_attachment_t **pp_font_attachments;
    int                  i_font_attachments;

    char * (*pf_select) (filter_t *, const char* family,
                               bool bold, bool italic, int size,
                               int *index);

};

/* */
static void YUVFromRGB( uint32_t i_argb,
                    uint8_t *pi_y, uint8_t *pi_u, uint8_t *pi_v )
{
    int i_red   = ( i_argb & 0x00ff0000 ) >> 16;
    int i_green = ( i_argb & 0x0000ff00 ) >>  8;
    int i_blue  = ( i_argb & 0x000000ff );

    *pi_y = (uint8_t)__MIN(abs( 2104 * i_red  + 4130 * i_green +
                      802 * i_blue + 4096 + 131072 ) >> 13, 235);
    *pi_u = (uint8_t)__MIN(abs( -1214 * i_red  + -2384 * i_green +
                     3598 * i_blue + 4096 + 1048576) >> 13, 240);
    *pi_v = (uint8_t)__MIN(abs( 3598 * i_red + -3013 * i_green +
                      -585 * i_blue + 4096 + 1048576) >> 13, 240);
}
static void RGBFromRGB( uint32_t i_argb,
                        uint8_t *pi_r, uint8_t *pi_g, uint8_t *pi_b )
{
    *pi_r = ( i_argb & 0x00ff0000 ) >> 16;
    *pi_g = ( i_argb & 0x0000ff00 ) >>  8;
    *pi_b = ( i_argb & 0x000000ff );
}

/*****************************************************************************
 * Make any TTF/OTF fonts present in the attachments of the media file
 * and store them for later use by the FreeType Engine
 *****************************************************************************/
static int LoadFontsFromAttachments( filter_t *p_filter )
{
    filter_sys_t         *p_sys = p_filter->p_sys;
    input_attachment_t  **pp_attachments;
    int                   i_attachments_cnt;

    if( filter_GetInputAttachments( p_filter, &pp_attachments, &i_attachments_cnt ) )
        return VLC_EGENERIC;

    p_sys->i_font_attachments = 0;
    p_sys->pp_font_attachments = malloc( i_attachments_cnt * sizeof(*p_sys->pp_font_attachments));
    if( !p_sys->pp_font_attachments )
        return VLC_ENOMEM;

    for( int k = 0; k < i_attachments_cnt; k++ )
    {
        input_attachment_t *p_attach = pp_attachments[k];

        if( ( !strcmp( p_attach->psz_mime, "application/x-truetype-font" ) || // TTF
              !strcmp( p_attach->psz_mime, "application/x-font-otf" ) ) &&    // OTF
            p_attach->i_data > 0 && p_attach->p_data )
        {
            p_sys->pp_font_attachments[ p_sys->i_font_attachments++ ] = p_attach;
        }
        else
        {
            vlc_input_attachment_Delete( p_attach );
        }
    }
    free( pp_attachments );

    return VLC_SUCCESS;
}

static int GetFontSize( filter_t *p_filter )
{
    filter_sys_t *p_sys = p_filter->p_sys;
    int           i_size = 0;

    if( p_sys->i_default_font_size )
    {
        i_size = p_sys->i_default_font_size;
    }
    else
    {
        int i_ratio = var_InheritInteger( p_filter, "freetype-rel-fontsize" );
        if( i_ratio > 0 )
        {
            i_size = (int)p_filter->fmt_out.video.i_height / i_ratio;
        }
    }
    if( i_size <= 0 )
    {
        msg_Warn( p_filter, "invalid fontsize, using 12" );
        i_size = 12;
    }
    return i_size;
}

static int SetFontSize( filter_t *p_filter, int i_size )
{
    filter_sys_t *p_sys = p_filter->p_sys;

    if( !i_size )
    {
        i_size = GetFontSize( p_filter );

        msg_Dbg( p_filter, "using fontsize: %i", i_size );
    }

    p_sys->style.i_font_size = i_size;

    if( FT_Set_Pixel_Sizes( p_sys->p_face, 0, i_size ) )
    {
        msg_Err( p_filter, "couldn't set font size to %d", i_size );
        return VLC_EGENERIC;
    }

    return VLC_SUCCESS;
}

/*****************************************************************************
 * RenderYUVP: place string in picture
 *****************************************************************************
 * This function merges the previously rendered freetype glyphs into a picture
 *****************************************************************************/
static int RenderYUVP( filter_t *p_filter, subpicture_region_t *p_region,
                       line_desc_t *p_line,
                       FT_BBox *p_bbox )
{
    VLC_UNUSED(p_filter);
    static const uint8_t pi_gamma[16] =
        {0x00, 0x52, 0x84, 0x96, 0xb8, 0xca, 0xdc, 0xee, 0xff,
          0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff};

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

    /* Create a new subpicture region */
    video_format_Init( &fmt, VLC_CODEC_YUVP );
    fmt.i_width          =
    fmt.i_visible_width  = p_bbox->xMax - p_bbox->xMin + 4;
    fmt.i_height         =
    fmt.i_visible_height = p_bbox->yMax - p_bbox->yMin + 4;

    assert( !p_region->p_picture );
    p_region->p_picture = picture_NewFromFormat( &fmt );
    if( !p_region->p_picture )
        return VLC_EGENERIC;
    fmt.p_palette = p_region->fmt.p_palette ? p_region->fmt.p_palette : malloc(sizeof(*fmt.p_palette));
    p_region->fmt = fmt;

    /* Calculate text color components
     * Only use the first color */
    int i_alpha = (p_line->p_character[0].i_color >> 24) & 0xff;
    YUVFromRGB( p_line->p_character[0].i_color, &i_y, &i_u, &i_v );

    /* Build palette */
    fmt.p_palette->i_entries = 16;
    for( i = 0; i < 8; i++ )
    {
        fmt.p_palette->palette[i][0] = 0;
        fmt.p_palette->palette[i][1] = 0x80;
        fmt.p_palette->palette[i][2] = 0x80;
        fmt.p_palette->palette[i][3] = pi_gamma[i];
        fmt.p_palette->palette[i][3] =
            (int)fmt.p_palette->palette[i][3] * i_alpha / 255;
    }
    for( i = 8; 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] * i_alpha / 255;
    }

    p_dst = p_region->p_picture->Y_PIXELS;
    i_pitch = p_region->p_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_align_left = 0;
        if( p_line->i_width < (int)fmt.i_visible_width )
        {
            if( (p_region->i_align & 0x3) == SUBPICTURE_ALIGN_RIGHT )
                i_align_left = ( fmt.i_visible_width - p_line->i_width );
            else if( (p_region->i_align & 0x3) != SUBPICTURE_ALIGN_LEFT )
                i_align_left = ( fmt.i_visible_width - p_line->i_width ) / 2;
        }
        int i_align_top = 0;

        for( i = 0; i < p_line->i_character_count; i++ )
        {
            const line_character_t *ch = &p_line->p_character[i];
            FT_BitmapGlyph p_glyph = ch->p_glyph;

            int i_glyph_y = i_align_top  - p_glyph->top  + p_bbox->yMax + p_line->i_base_line;
            int i_glyph_x = i_align_left + p_glyph->left - p_bbox->xMin;

            for( y = 0; y < p_glyph->bitmap.rows; y++ )
            {
                for( x = 0; x < p_glyph->bitmap.width; x++ )
                {
                    if( p_glyph->bitmap.buffer[y * p_glyph->bitmap.width + x] )
                        p_dst[(i_glyph_y + y) * i_pitch + (i_glyph_x + x)] =
                            (p_glyph->bitmap.buffer[y * p_glyph->bitmap.width + x] + 8)/16;
                }
            }
        }
    }

    /* Outlining (find something better than nearest neighbour filtering ?) */
    if( 1 )
    {
        uint8_t *p_dst = p_region->p_picture->Y_PIXELS;
        uint8_t *p_top = p_dst; /* Use 1st line as a cache */
        uint8_t left, current;

        for( y = 1; y < (int)fmt.i_height - 1; y++ )
        {
            if( y > 1 ) memcpy( p_top, p_dst, fmt.i_width );
            p_dst += p_region->p_picture->Y_PITCH;
            left = 0;

            for( x = 1; x < (int)fmt.i_width - 1; x++ )
            {
                current = p_dst[x];
                p_dst[x] = ( 8 * (int)p_dst[x] + left + p_dst[x+1] + p_top[x -1]+ p_top[x] + p_top[x+1] +
                             p_dst[x -1 + p_region->p_picture->Y_PITCH ] + p_dst[x + p_region->p_picture->Y_PITCH] + p_dst[x + 1 + p_region->p_picture->Y_PITCH]) / 16;
                left = current;
            }
        }
        memset( p_top, 0, fmt.i_width );
    }

    return VLC_SUCCESS;
}

/*****************************************************************************
 * RenderYUVA: place string in picture
 *****************************************************************************
 * This function merges the previously rendered freetype glyphs into a picture
 *****************************************************************************/
static void FillYUVAPicture( picture_t *p_picture,
                             int i_a, int i_y, int i_u, int i_v )
{
    memset( p_picture->p[0].p_pixels, i_y,
            p_picture->p[0].i_pitch * p_picture->p[0].i_lines );
    memset( p_picture->p[1].p_pixels, i_u,
            p_picture->p[1].i_pitch * p_picture->p[1].i_lines );
    memset( p_picture->p[2].p_pixels, i_v,
            p_picture->p[2].i_pitch * p_picture->p[2].i_lines );
    memset( p_picture->p[3].p_pixels, i_a,
            p_picture->p[3].i_pitch * p_picture->p[3].i_lines );
}

static inline void BlendYUVAPixel( picture_t *p_picture,
                                   int i_picture_x, int i_picture_y,
                                   int i_a, int i_y, int i_u, int i_v,
                                   int i_alpha )
{
    int i_an = i_a * i_alpha / 255;

    uint8_t *p_y = &p_picture->p[0].p_pixels[i_picture_y * p_picture->p[0].i_pitch + i_picture_x];
    uint8_t *p_u = &p_picture->p[1].p_pixels[i_picture_y * p_picture->p[1].i_pitch + i_picture_x];
    uint8_t *p_v = &p_picture->p[2].p_pixels[i_picture_y * p_picture->p[2].i_pitch + i_picture_x];
    uint8_t *p_a = &p_picture->p[3].p_pixels[i_picture_y * p_picture->p[3].i_pitch + i_picture_x];

    int i_ao = *p_a;
    if( i_ao == 0 )
    {
        *p_y = i_y;
        *p_u = i_u;
        *p_v = i_v;
        *p_a = i_an;
    }
    else
    {
        *p_a = 255 - (255 - *p_a) * (255 - i_an) / 255;
        if( *p_a != 0 )
        {
            *p_y = ( *p_y * i_ao * (255 - i_an) / 255 + i_y * i_an ) / *p_a;
            *p_u = ( *p_u * i_ao * (255 - i_an) / 255 + i_u * i_an ) / *p_a;
            *p_v = ( *p_v * i_ao * (255 - i_an) / 255 + i_v * i_an ) / *p_a;
        }
    }
}

static void FillRGBAPicture( picture_t *p_picture,
                             int i_a, int i_r, int i_g, int i_b )
{
    for( int dy = 0; dy < p_picture->p[0].i_visible_lines; dy++ )
    {
        for( int dx = 0; dx < p_picture->p[0].i_visible_pitch; dx += 4 )
        {
            uint8_t *p_rgba = &p_picture->p->p_pixels[dy * p_picture->p->i_pitch + dx];
            p_rgba[0] = i_r;
            p_rgba[1] = i_g;
            p_rgba[2] = i_b;
            p_rgba[3] = i_a;
        }
    }
}

static inline void BlendRGBAPixel( picture_t *p_picture,
                                   int i_picture_x, int i_picture_y,
                                   int i_a, int i_r, int i_g, int i_b,
                                   int i_alpha )
{
    int i_an = i_a * i_alpha / 255;

    uint8_t *p_rgba = &p_picture->p->p_pixels[i_picture_y * p_picture->p->i_pitch + 4 * i_picture_x];

    int i_ao = p_rgba[3];
    if( i_ao == 0 )
    {
        p_rgba[0] = i_r;
        p_rgba[1] = i_g;
        p_rgba[2] = i_b;
        p_rgba[3] = i_an;
    }
    else
    {
        p_rgba[3] = 255 - (255 - p_rgba[3]) * (255 - i_an) / 255;
        if( p_rgba[3] != 0 )
        {
            p_rgba[0] = ( p_rgba[0] * i_ao * (255 - i_an) / 255 + i_r * i_an ) / p_rgba[3];
            p_rgba[1] = ( p_rgba[1] * i_ao * (255 - i_an) / 255 + i_g * i_an ) / p_rgba[3];
            p_rgba[2] = ( p_rgba[2] * i_ao * (255 - i_an) / 255 + i_b * i_an ) / p_rgba[3];
        }
    }
}

static void FillARGBPicture(picture_t *pic, int a, int r, int g, int b)
{
    if (a == 0)
        r = g = b = 0;
    if (a == r && a == b && a == g)
    {   /* fast path */
        memset(pic->p->p_pixels, a, pic->p->i_visible_lines * pic->p->i_pitch);
        return;
    }

    uint_fast32_t pixel = VLC_FOURCC(a, r, g, b);
    uint8_t *line = pic->p->p_pixels;

    for (unsigned lines = pic->p->i_visible_lines; lines > 0; lines--)
    {
        uint32_t *pixels = (uint32_t *)line;
        for (unsigned cols = pic->p->i_visible_pitch; cols > 0; cols -= 4)
            *(pixels++) = pixel;
        line += pic->p->i_pitch;
    }
}

static inline void BlendARGBPixel(picture_t *pic, int pic_x, int pic_y,
                                  int a, int r, int g, int b, int alpha)
{
    uint8_t *rgba = &pic->p->p_pixels[pic_y * pic->p->i_pitch + 4 * pic_x];
    int an = a * alpha / 255;
    int ao = rgba[3];

    if (ao == 0)
    {
        rgba[0] = an;
        rgba[1] = r;
        rgba[2] = g;
        rgba[3] = b;
    }
    else
    {
        rgba[0] = 255 - (255 - rgba[0]) * (255 - an) / 255;
        if (rgba[0] != 0)
        {
            rgba[1] = (rgba[1] * ao * (255 - an) / 255 + r * an ) / rgba[0];
            rgba[2] = (rgba[2] * ao * (255 - an) / 255 + g * an ) / rgba[0];
            rgba[3] = (rgba[3] * ao * (255 - an) / 255 + b * an ) / rgba[0];
        }
    }
}

static inline void BlendAXYZGlyph( picture_t *p_picture,
                                   int i_picture_x, int i_picture_y,
                                   int i_a, int i_x, int i_y, int i_z,
                                   FT_BitmapGlyph p_glyph,
                                   void (*BlendPixel)(picture_t *, int, int, int, int, int, int, int) )

{
    for( int dy = 0; dy < p_glyph->bitmap.rows; dy++ )
    {
        for( int dx = 0; dx < p_glyph->bitmap.width; dx++ )
            BlendPixel( p_picture, i_picture_x + dx, i_picture_y + dy,
                        i_a, i_x, i_y, i_z,
                        p_glyph->bitmap.buffer[dy * p_glyph->bitmap.width + dx] );
    }
}

static inline void BlendAXYZLine( picture_t *p_picture,
                                  int i_picture_x, int i_picture_y,
                                  int i_a, int i_x, int i_y, int i_z,
                                  const line_character_t *p_current,
                                  const line_character_t *p_next,
                                  void (*BlendPixel)(picture_t *, int, int, int, int, int, int, int) )
{
    int i_line_width = p_current->p_glyph->bitmap.width;
    if( p_next )
        i_line_width = p_next->p_glyph->left - p_current->p_glyph->left;

    for( int dx = 0; dx < i_line_width; dx++ )
    {
        for( int dy = 0; dy < p_current->i_line_thickness; dy++ )
            BlendPixel( p_picture,
                        i_picture_x + dx,
                        i_picture_y + p_current->i_line_offset + dy,
                        i_a, i_x, i_y, i_z, 0xff );
    }
}

static inline void RenderBackground( subpicture_region_t *p_region,
                                     line_desc_t *p_line_head,
                                     FT_BBox *p_bbox,
                                     int i_margin,
                                     picture_t *p_picture,
                                     int i_text_width,
                                     void (*ExtractComponents)( uint32_t, uint8_t *, uint8_t *, uint8_t * ),
                                     void (*BlendPixel)(picture_t *, int, int, int, int, int, int, int) )
{
    for( line_desc_t *p_line = p_line_head; p_line != NULL; p_line = p_line->p_next )
    {
        int i_align_left = i_margin;
        int i_align_top = i_margin;
        int line_start = 0;
        int line_end = 0;
        unsigned line_top = 0;
        int line_bottom = 0;
        int max_height = 0;

        if( p_line->i_width < i_text_width )
        {
            /* Left offset to take into account alignment */
            if( (p_region->i_align & 0x3) == SUBPICTURE_ALIGN_RIGHT )
                i_align_left += ( i_text_width - p_line->i_width );
            else if( (p_region->i_align & 0x10) == SUBPICTURE_ALIGN_LEAVETEXT)
                i_align_left = i_margin; /* Keep it the way it is */
            else if( (p_region->i_align & 0x3) != SUBPICTURE_ALIGN_LEFT )
                i_align_left += ( i_text_width - p_line->i_width ) / 2;
        }

        /* Find the tallest character in the line */
        for( int i = 0; i < p_line->i_character_count; i++ ) {
            const line_character_t *ch = &p_line->p_character[i];
            FT_BitmapGlyph p_glyph = ch->p_outline ? ch->p_outline : ch->p_glyph;
            if (p_glyph->top > max_height)
                max_height = p_glyph->top;
        }

        /* Compute the background for the line (identify leading/trailing space) */
        for( int i = 0; i < p_line->i_character_count; i++ ) {
            const line_character_t *ch = &p_line->p_character[i];
            FT_BitmapGlyph p_glyph = ch->p_outline ? ch->p_outline : ch->p_glyph;
            if (p_glyph && p_glyph->bitmap.rows > 0) {
                // Found a non-whitespace character
                line_start = i_align_left + p_glyph->left - p_bbox->xMin;
                break;
            }
        }

        /* Fudge factor to make sure caption background edges are left aligned
           despite variable font width */
        if (line_start < 12)
            line_start = 0;

        /* Find right boundary for bounding box for background */
        for( int i = p_line->i_character_count; i > 0; i-- ) {
            const line_character_t *ch = &p_line->p_character[i - 1];
            FT_BitmapGlyph p_glyph = ch->p_shadow ? ch->p_shadow : ch->p_glyph;
            if (p_glyph && p_glyph->bitmap.rows > 0) {
                // Found a non-whitespace character
                line_end = i_align_left + p_glyph->left - p_bbox->xMin + p_glyph->bitmap.width;
                break;
            }
        }

        /* Setup color for the background */
        uint8_t i_x, i_y, i_z;
        ExtractComponents( 0x000000, &i_x, &i_y, &i_z );

        /* Compute the upper boundary for the background */
        if ((i_align_top + p_line->i_base_line - max_height) < 0)
            line_top = i_align_top + p_line->i_base_line;
        else
            line_top = i_align_top + p_line->i_base_line - max_height;

        /* Compute lower boundary for the background */
        line_bottom =  __MIN(line_top + p_line->i_height, p_region->fmt.i_visible_height);

        /* Render the actual background */
        for( int dy = line_top; dy < line_bottom; dy++ )
        {
            for( int dx = line_start; dx < line_end; dx++ )
                BlendPixel( p_picture, dx, dy, 0xff, i_x, i_y, i_z, 0xff );
        }
    }
}

static inline int RenderAXYZ( filter_t *p_filter,
                              subpicture_region_t *p_region,
                              line_desc_t *p_line_head,
                              FT_BBox *p_bbox,
                              int i_margin,
                              vlc_fourcc_t i_chroma,
                              void (*ExtractComponents)( uint32_t, uint8_t *, uint8_t *, uint8_t * ),
                              void (*FillPicture)( picture_t *p_picture, int, int, int, int ),
                              void (*BlendPixel)(picture_t *, int, int, int, int, int, int, int) )
{
    filter_sys_t *p_sys = p_filter->p_sys;

    /* Create a new subpicture region */
    const int i_text_width  = p_bbox->xMax - p_bbox->xMin;
    const int i_text_height = p_bbox->yMax - p_bbox->yMin;
    video_format_t fmt;
    video_format_Init( &fmt, i_chroma );
    fmt.i_width          =
    fmt.i_visible_width  = i_text_width  + 2 * i_margin;
    fmt.i_height         =
    fmt.i_visible_height = i_text_height + 2 * i_margin;

    picture_t *p_picture = p_region->p_picture = picture_NewFromFormat( &fmt );
    if( !p_region->p_picture )
        return VLC_EGENERIC;
    p_region->fmt = fmt;

    /* Initialize the picture background */
    uint8_t i_a = var_InheritInteger( p_filter, "freetype-background-opacity" );
    i_a = VLC_CLIP( i_a, 0, 255 );
    uint8_t i_x, i_y, i_z;

    if (p_region->b_renderbg) {
        /* Render the background just under the text */
        FillPicture( p_picture, 0x00, 0x00, 0x00, 0x00 );
        RenderBackground(p_region, p_line_head, p_bbox, i_margin, p_picture, i_text_width,
                         ExtractComponents, BlendPixel);
    } else {
        /* Render background under entire subpicture block */
        int i_background_color = var_InheritInteger( p_filter, "freetype-background-color" );
        i_background_color = VLC_CLIP( i_background_color, 0, 0xFFFFFF );
        ExtractComponents( i_background_color, &i_x, &i_y, &i_z );
        FillPicture( p_picture, i_a, i_x, i_y, i_z );
    }

    /* Render shadow then outline and then normal glyphs */
    for( int g = 0; g < 3; g++ )
    {
        /* Render all lines */
        for( line_desc_t *p_line = p_line_head; p_line != NULL; p_line = p_line->p_next )
        {
            int i_align_left = i_margin;
            if( p_line->i_width < i_text_width )
            {
                /* Left offset to take into account alignment */
                if( (p_region->i_align & 0x3) == SUBPICTURE_ALIGN_RIGHT )
                    i_align_left += ( i_text_width - p_line->i_width );
                else if( (p_region->i_align & 0x10) == SUBPICTURE_ALIGN_LEAVETEXT)
                    i_align_left = i_margin; /* Keep it the way it is */
                else if( (p_region->i_align & 0x3) != SUBPICTURE_ALIGN_LEFT )
                    i_align_left += ( i_text_width - p_line->i_width ) / 2;
            }
            int i_align_top = i_margin;

            /* Render all glyphs and underline/strikethrough */
            for( int i = 0; i < p_line->i_character_count; i++ )
            {
                const line_character_t *ch = &p_line->p_character[i];
                FT_BitmapGlyph p_glyph = g == 0 ? ch->p_shadow : g == 1 ? ch->p_outline : ch->p_glyph;
                if( !p_glyph )
                    continue;

                i_a = (ch->i_color >> 24) & 0xff;
                uint32_t i_color;
                switch (g) {
                case 0:
                    i_a     = i_a * p_sys->style.i_shadow_alpha / 255;
                    i_color = p_sys->style.i_shadow_color;
                    break;
                case 1:
                    i_a     = i_a * p_sys->style.i_outline_alpha / 255;
                    i_color = p_sys->style.i_outline_color;
                    break;
                default:
                    i_color = ch->i_color;
                    break;
                }
                ExtractComponents( i_color, &i_x, &i_y, &i_z );

                int i_glyph_y = i_align_top  - p_glyph->top  + p_bbox->yMax + p_line->i_base_line;
                int i_glyph_x = i_align_left + p_glyph->left - p_bbox->xMin;

                BlendAXYZGlyph( p_picture,
                                i_glyph_x, i_glyph_y,
                                i_a, i_x, i_y, i_z,
                                p_glyph,
                                BlendPixel );

                /* underline/strikethrough are only rendered for the normal glyph */
                if( g == 2 && ch->i_line_thickness > 0 )
                    BlendAXYZLine( p_picture,
                                   i_glyph_x, i_glyph_y + p_glyph->top,
                                   i_a, i_x, i_y, i_z,
                                   &ch[0],
                                   i + 1 < p_line->i_character_count ? &ch[1] : NULL,
                                   BlendPixel );
            }
        }
    }

    return VLC_SUCCESS;
}



static void FreeLine( line_desc_t *p_line )
{
    for( int i = 0; i < p_line->i_character_count; i++ )
    {
        line_character_t *ch = &p_line->p_character[i];
        FT_Done_Glyph( (FT_Glyph)ch->p_glyph );
        if( ch->p_outline )
            FT_Done_Glyph( (FT_Glyph)ch->p_outline );
        if( ch->p_shadow )
            FT_Done_Glyph( (FT_Glyph)ch->p_shadow );
    }

    free( p_line->p_character );
    free( p_line );
}

static void FreeLines( line_desc_t *p_lines )
{
    for( line_desc_t *p_line = p_lines; p_line != NULL; )
    {
        line_desc_t *p_next = p_line->p_next;
        FreeLine( p_line );
        p_line = p_next;
    }
}

static line_desc_t *NewLine( int i_count )
{
    line_desc_t *p_line = malloc( sizeof(*p_line) );

    if( !p_line )
        return NULL;

    p_line->p_next = NULL;
    p_line->i_width = 0;
    p_line->i_base_line = 0;