/*****************************************************************************

 * substx3g.c : MP4 tx3g subtitles decoder

 *****************************************************************************

 * Copyright (C) 2014 VLC authors and VideoLAN

 *

 * 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.

 *****************************************************************************/

#ifdef HAVE_CONFIG_H

# include "config.h"

#endif

#include <vlc_common.h>

#include <vlc_plugin.h>

#include <vlc_codec.h>

#include <vlc_sout.h>

#include <vlc_charset.h>

#include "substext.h"

#include "../demux/mp4/minibox.h"

/*****************************************************************************

 * Module descriptor.

 *****************************************************************************/

static int OpenDecoder ( vlc_object_t * );

static void CloseDecoder ( vlc_object_t * );

static int Decode( decoder_t *, block_t * );

#ifdef ENABLE_SOUT

static int OpenEncoder ( vlc_object_t * );

static block_t * Encode( encoder_t *, subpicture_t * );

#endif

vlc_module_begin ()

    set_description( N_("tx3g subtitles decoder") )

    set_shortname( N_("tx3g subtitles") )

    set_capability( "spu decoder", 100 )

    set_subcategory( SUBCAT_INPUT_SCODEC )

    set_callbacks( OpenDecoder, CloseDecoder )

#ifdef ENABLE_SOUT

    add_submodule ()

        set_description( N_("tx3g subtitles encoder") )

        set_shortname( N_("tx3g subtitles encoder") )

        set_capability( "spu encoder", 101 )

        set_callback( OpenEncoder )

#endif

vlc_module_end ()

/****************************************************************************

 * Local structs

 ****************************************************************************/

/*****************************************************************************

 * Local:

 *****************************************************************************/

#define FONT_FACE_BOLD      0x1

#define FONT_FACE_ITALIC    0x2

#define FONT_FACE_UNDERLINE 0x4

static int ConvertToVLCFlags( int i_atomflags )

{

    int i_vlcstyles_flags = 0;

    if ( i_atomflags & FONT_FACE_BOLD )

        i_vlcstyles_flags |= STYLE_BOLD;

    if ( i_atomflags & FONT_FACE_ITALIC )

        i_vlcstyles_flags |= STYLE_ITALIC;

    if ( i_atomflags & FONT_FACE_UNDERLINE )

        i_vlcstyles_flags |= STYLE_UNDERLINE;

    return i_vlcstyles_flags;

}

static size_t str8len( const char *psz_string )

{

    const char *psz_tmp = psz_string;

    size_t i=0;

    while ( *psz_tmp )

    {

        if ( (*psz_tmp & 0xC0) != 0x80 ) i++;

        psz_tmp++;

    }

    return i;

}

static char * str8indup( const char *psz_string, size_t i_skip, size_t n )

{

    for( size_t i = 0; i< i_skip && *psz_string; i++ )

    {

        while( *(++psz_string) && (*psz_string & 0xC0) == 0x80 )

        {};

    }

    if ( ! *psz_string )

        return NULL;

    const char *psz_tmp = psz_string;

    for( size_t i = 0; i < n && *psz_tmp; i++ )

    {

        while( *(++psz_tmp) && (*psz_tmp & 0xC0) == 0x80 )

        {};

    }

    return strndup( psz_string, psz_tmp - psz_string );

}

typedef struct tx3g_segment_t tx3g_segment_t;

struct tx3g_segment_t

{

    text_segment_t *s;

    size_t i_size;

    tx3g_segment_t *p_next3g;

};

static tx3g_segment_t * tx3g_segment_New( const char *psz_string )

{

    tx3g_segment_t *p_seg = malloc( sizeof(tx3g_segment_t) );

    if( p_seg )

    {

        p_seg->i_size = 0;

        p_seg->p_next3g = NULL;

        p_seg->s = text_segment_New( psz_string );

        if( !p_seg->s )

        {

            free( p_seg );

            p_seg = NULL;

        }

    }

    return p_seg;

}

static void SegmentDoSplit( tx3g_segment_t *p_segment, uint16_t i_start, uint16_t i_end,

                            tx3g_segment_t **pp_segment_left,

                            tx3g_segment_t **pp_segment_middle,

                            tx3g_segment_t **pp_segment_right )

{

    tx3g_segment_t *p_segment_left = NULL, *p_segment_right = NULL, *p_segment_middle = NULL;

    if ( (p_segment->i_size - i_start < 1) || (p_segment->i_size - i_end < 1) )

        goto error;

    if ( i_start > 0 )

    {

        char* psz_text = str8indup( p_segment->s->psz_text, 0, i_start );

        p_segment_left = tx3g_segment_New( psz_text );

        free( psz_text );

        if ( !p_segment_left ) goto error;

        p_segment_left->s->style = text_style_Duplicate( p_segment->s->style );

        p_segment_left->i_size = str8len( p_segment_left->s->psz_text );

    }

    char* psz_midtext = str8indup( p_segment->s->psz_text, i_start, i_end - i_start + 1 );

    p_segment_middle = tx3g_segment_New( psz_midtext );

    free( psz_midtext );

    if ( !p_segment_middle ) goto error;

    p_segment_middle->s->style = text_style_Duplicate( p_segment->s->style );

    p_segment_middle->i_size = str8len( p_segment_middle->s->psz_text );

    if ( i_end < (p_segment->i_size - 1) )

    {

        char* psz_text = str8indup( p_segment->s->psz_text, i_end + 1, p_segment->i_size - i_end - 1 );

        p_segment_right = tx3g_segment_New( psz_text );

        free( psz_text );

        if ( !p_segment_right ) goto error;

        p_segment_right->s->style = text_style_Duplicate( p_segment->s->style );

        p_segment_right->i_size = str8len( p_segment_right->s->psz_text );

    }

    if ( p_segment_left ) p_segment_left->p_next3g = p_segment_middle;

    if ( p_segment_right ) p_segment_middle->p_next3g = p_segment_right;

    *pp_segment_left = p_segment_left;

    *pp_segment_middle = p_segment_middle;

    *pp_segment_right = p_segment_right;

    return;

error:

    if( p_segment_middle )

    {

        text_segment_Delete( p_segment_middle->s );

        free( p_segment_middle );

    }

    if( p_segment_left )

    {

        text_segment_Delete( p_segment_left->s );

        free( p_segment_left );

    }

    *pp_segment_left = *pp_segment_middle = *pp_segment_right = NULL;

}

static bool SegmentSplit( tx3g_segment_t *p_prev, tx3g_segment_t **pp_segment,

                          const uint16_t i_start, const uint16_t i_end,

                          const text_style_t *p_styles )

{

    tx3g_segment_t *p_segment_left = NULL, *p_segment_middle = NULL, *p_segment_right = NULL;

    if ( (*pp_segment)->i_size == 0 ) return false;

    if ( i_start > i_end ) return false;

    if ( (size_t)(i_end - i_start) > (*pp_segment)->i_size - 1 ) return false;

    if ( i_end > (*pp_segment)->i_size - 1 ) return false;

    SegmentDoSplit( *pp_segment, i_start, i_end, &p_segment_left, &p_segment_middle, &p_segment_right );

    if ( !p_segment_middle )

    {

        /* Failed */

        text_segment_Delete( p_segment_left->s );

        free( p_segment_left );

        text_segment_Delete( p_segment_right->s );

        free( p_segment_right );

        return false;

    }

    tx3g_segment_t *p_next3g = (*pp_segment)->p_next3g;

    text_segment_Delete( (*pp_segment)->s );

    free( *pp_segment );

    *pp_segment = ( p_segment_left ) ? p_segment_left : p_segment_middle ;

    if ( p_prev ) p_prev->p_next3g = *pp_segment;

    if ( p_segment_right )

        p_segment_right->p_next3g = p_next3g;

    else

        p_segment_middle->p_next3g = p_next3g;

    if( p_segment_middle->s->style )

        text_style_Merge( p_segment_middle->s->style, p_styles, true );

    else

        p_segment_middle->s->style = text_style_Duplicate( p_styles );

    return true;

}

/* Creates a new segment using the given style and split existing ones according

   to the start & end offsets */

static void ApplySegmentStyle( tx3g_segment_t **pp_segment, const uint16_t i_absstart,

                               const uint16_t i_absend, const text_style_t *p_styles )

{

    /* find the matching segment */

    uint16_t i_curstart = 0;

    tx3g_segment_t *p_prev = NULL;

    tx3g_segment_t *p_cur = *pp_segment;

    while ( p_cur )

    {

        uint16_t i_curend = i_curstart + p_cur->i_size - 1;

        if ( (i_absstart >= i_curstart) && (i_absend <= i_curend) )

        {

            /* segment found */

            if ( !SegmentSplit( p_prev, &p_cur, i_absstart - i_curstart,

                                i_absend - i_curstart, p_styles ) )

                return;

            if ( !p_prev ) *pp_segment = p_cur;

            break;

        }

        else

        {

            i_curstart += p_cur->i_size;

            p_prev = p_cur;

            p_cur = p_cur->p_next3g;

        }

    }

}

/* Do relative size conversion using default style size (from stsd),

   as the line should always be 5%. Apply to each segment specific text size */

static void FontSizeConvert( const text_style_t *p_reference, text_style_t *p_style )

{

    if( unlikely(!p_style) )

    {

        return;

    }

    else if( unlikely(!p_reference) || p_reference->i_font_size == 0 )

    {

        p_style->i_font_size = 0;

        p_style->f_font_relsize = 5.0;

    }

    else

    {

        p_style->f_font_relsize = 5.0 * (float) p_style->i_font_size / p_reference->i_font_size;

        p_style->i_font_size = 0;

    }

}

/*****************************************************************************

 * Decode:

 *****************************************************************************/

static int Decode( decoder_t *p_dec, block_t *p_block )

{

    subpicture_t  *p_spu = NULL;

    if( p_block == NULL ) /* No Drain */

        return VLCDEC_SUCCESS;

    if( ( p_block->i_flags & (BLOCK_FLAG_CORRUPTED) ) ||

          p_block->i_buffer < 2U )

    {

        block_Release( p_block );

        return VLCDEC_SUCCESS;

    }

    /* Read our raw string and create the styled segment for HTML */

    uint16_t i_psz_bytelength = GetWBE( p_block->p_buffer );

    if( p_block->i_buffer < i_psz_bytelength + 2U )

    {

        block_Release( p_block );

        return VLCDEC_SUCCESS;

    }

    const uint8_t *p_pszstart = p_block->p_buffer + 2U;

    char *psz_subtitle;

    if ( i_psz_bytelength > 2 &&

         ( !memcmp( p_pszstart, "\xFE\xFF", 2 ) || !memcmp( p_pszstart, "\xFF\xFE", 2 ) )

       )

        psz_subtitle = FromCharset( "UTF-16", p_pszstart, i_psz_bytelength );

    else

        psz_subtitle = strndup( (const char*) p_pszstart, i_psz_bytelength );

    if ( !psz_subtitle )

    {

        block_Release( p_block );

        return VLCDEC_SUCCESS;

    }

    for( uint16_t i=0; i < i_psz_bytelength; i++ )

     if ( psz_subtitle[i] == '\r' ) psz_subtitle[i] = '\n';

    tx3g_segment_t *p_segment3g = tx3g_segment_New( psz_subtitle );

    p_segment3g->i_size = str8len( psz_subtitle );

    free( psz_subtitle );

    if ( !p_segment3g->s->psz_text )

    {

        text_segment_Delete( p_segment3g->s );

        free( p_segment3g );

        block_Release( p_block );

        return VLCDEC_SUCCESS;

    }

    /* Create the subpicture unit */

    p_spu = decoder_NewSubpictureText( p_dec );

    if( !p_spu )

    {

        text_segment_Delete( p_segment3g->s );

        free( p_segment3g );

        block_Release( p_block );

        return VLCDEC_SUCCESS;

    }

    subtext_updater_sys_t *p_spu_sys = p_spu->updater.sys;

    const text_style_t *p_root_style = (text_style_t *) p_dec->p_sys;

    mp4_box_iterator_t it;

    mp4_box_iterator_Init( &it, p_block->p_buffer + 2U + i_psz_bytelength,

                           p_block->i_buffer - (2U + i_psz_bytelength) );

    /* Parse our styles */

    if( p_dec->fmt_in->i_codec != VLC_CODEC_QTXT )

    while( mp4_box_iterator_Next( &it ) )

    {

        switch( it.i_type )

        {

        case VLC_FOURCC('s','t','y','l'):

        {

            if( it.i_payload < 14 )

                break;

            uint16_t i_nbrecords = GetWBE(it.p_payload);

            uint16_t i_cur_record = 0;

            it.p_payload += 2; it.i_payload -= 2;

            while( i_cur_record++ < i_nbrecords && it.i_payload >= 12 )

            {

                uint16_t i_start = __MIN( GetWBE(it.p_payload), i_psz_bytelength - 1 );

                uint16_t i_end =  GetWBE(it.p_payload + 2); /* index is past last char */

                if( i_start < i_end )

                {

                    i_end = VLC_CLIP( i_end - 1, i_start, i_psz_bytelength - 1 );

                    text_style_t *p_style = text_style_Create( STYLE_NO_DEFAULTS );

                    if( p_style )

                    {

                        if( (p_style->i_style_flags = ConvertToVLCFlags( it.p_payload[6] )) )

                            p_style->i_features |= STYLE_HAS_FLAGS;

                        p_style->i_font_size = it.p_payload[7];

                        p_style->i_font_color = GetDWBE(&it.p_payload[8]) >> 8;// RGBA -> RGB

                        p_style->i_font_alpha = GetDWBE(&it.p_payload[8]) & 0xFF;

                        p_style->i_features |= STYLE_HAS_FONT_COLOR | STYLE_HAS_FONT_ALPHA;

                        ApplySegmentStyle( &p_segment3g, i_start, i_end, p_style );

                        text_style_Delete( p_style );

                    }

                }

                it.p_payload += 12; it.i_payload -= 12;

            }

        }   break;

        default:

            break;

        }

    }

    p_spu->i_start    = p_block->i_pts;

    p_spu->i_stop     = p_block->i_pts + p_block->i_length;

    p_spu->b_ephemer  = (p_block->i_length == 0);

    p_spu_sys->region.b_absolute = false; p_spu_sys->region.b_in_window = false;

    p_spu_sys->region.align = SUBPICTURE_ALIGN_BOTTOM;

    text_style_Merge( p_spu_sys->p_default_style, p_root_style, true );

    FontSizeConvert( p_root_style, p_spu_sys->p_default_style );

    /* Unwrap */

    text_segment_t *p_text_segments = p_segment3g->s;

    text_segment_t *p_cur = p_text_segments;

    while( p_segment3g )

    {

        FontSizeConvert( p_root_style, p_segment3g->s->style );

        tx3g_segment_t * p_old = p_segment3g;

        p_segment3g = p_segment3g->p_next3g;

        free( p_old );

        if( p_segment3g )

            p_cur->p_next = p_segment3g->s;

        p_cur = p_cur->p_next;

    }

    p_spu_sys->region.p_segments = p_text_segments;

    block_Release( p_block );

    decoder_QueueSub( p_dec, p_spu );

    return VLCDEC_SUCCESS;

}

/*****************************************************************************

 * Extradata Parsing

 *****************************************************************************/

static void ParseExtradataTx3g( decoder_t *p_dec )

{

    text_style_t *p_style = (text_style_t *) p_dec->p_sys;

    const uint8_t *p_extra = p_dec->fmt_in->p_extra;

    if( p_dec->fmt_in->i_extra < 32 )

        return;

    /* DF @0 */

    /* Just @4 */

    /* BGColor @6 */

    p_style->i_background_color = GetDWBE(&p_extra[6]) >> 8;

    p_style->i_background_alpha = p_extra[9];

    p_style->i_features |= STYLE_HAS_BACKGROUND_COLOR|STYLE_HAS_BACKGROUND_ALPHA;

    /* BoxRecord @10 */

    /* StyleRecord @18 */

    p_style->i_style_flags = ConvertToVLCFlags( p_extra[24] );

    if( p_style->i_style_flags )

        p_style->i_features |= STYLE_HAS_FLAGS;

    p_style->i_font_size = p_extra[25];

    p_style->i_font_color = GetDWBE(&p_extra[26]) >> 8;// RGBA -> RGB

    p_style->i_font_alpha = p_extra[29];

    p_style->i_features |= STYLE_HAS_FONT_COLOR | STYLE_HAS_FONT_ALPHA;

    /* FontTableBox @30 */

}

static void ParseExtradataTextMedia( decoder_t *p_dec )

{

    text_style_t *p_style = (text_style_t *) p_dec->p_sys;

    const uint8_t *p_extra = p_dec->fmt_in->p_extra;

    if( p_dec->fmt_in->i_extra < 44 )

        return;

    /* DF @0 */

    uint32_t i_flags = GetDWBE(p_extra);

    if(i_flags & 0x1000) /* drop shadow */

    {

        p_style->i_style_flags |= STYLE_SHADOW;

        p_style->i_features    |= STYLE_HAS_SHADOW_COLOR|STYLE_HAS_FLAGS|STYLE_HAS_SHADOW_ALPHA;

        p_style->i_shadow_color = 0xC0C0C0;

        p_style->i_shadow_alpha = STYLE_ALPHA_OPAQUE;

    }

    if(i_flags & 0x4000) /* key text*/

    {

        /*Controls background color. If this flag is set to 1, the text media handler does not display the

          background color, so that the text overlay background tracks.*/

        p_style->i_style_flags &= ~STYLE_BACKGROUND;

    }

    /* Just @4 */

    /* BGColor @8, read top of 16 bits */

    p_style->i_background_color = (p_extra[8]  << 16) |

                                  (p_extra[10] <<  8) |

                                   p_extra[12];

    p_style->i_features |= STYLE_HAS_BACKGROUND_COLOR | STYLE_HAS_BACKGROUND_ALPHA;

    p_style->i_background_alpha = STYLE_ALPHA_OPAQUE;

    /* BoxRecord @14 */

    /* Reserved 64 @22 */

    /* Font # @30 */

    /* Font Face @32 */

    p_style->i_style_flags |= ConvertToVLCFlags( GetWBE(&p_extra[32]) );

    if( p_style->i_style_flags )

        p_style->i_features |= STYLE_HAS_FLAGS;

    /* Reserved 8 @34 */

    /* Reserved 16 @35 */

    /* FGColor @37 */

    p_style->i_font_color = (p_extra[37] << 16) |

                            (p_extra[39] <<  8) |

                             p_extra[41];

    p_style->i_features |= STYLE_HAS_FONT_COLOR;

    /* FontName Pascal (8 + string) @43 */

}

/*****************************************************************************

 * Decoder entry/exit points

 *****************************************************************************/

static void CloseDecoder( vlc_object_t *p_this )

{

    decoder_t     *p_dec = (decoder_t *) p_this;

    text_style_Delete( (text_style_t *) p_dec->p_sys );

}

static int OpenDecoder( vlc_object_t *p_this )

{

    decoder_t     *p_dec = (decoder_t *) p_this;

    if( p_dec->fmt_in->i_codec != VLC_CODEC_TX3G &&

        p_dec->fmt_in->i_codec != VLC_CODEC_QTXT )

        return VLC_EGENERIC;

    p_dec->pf_decode = Decode;

    p_dec->p_sys = text_style_Create( STYLE_NO_DEFAULTS );

    if( !p_dec->p_sys )

        return VLC_ENOMEM;

    text_style_t *p_default_style = p_dec->p_sys;

    p_default_style->i_style_flags |= STYLE_BACKGROUND;

    p_default_style->i_features |= STYLE_HAS_FLAGS;

    if( p_dec->fmt_in->i_codec == VLC_CODEC_TX3G )

        ParseExtradataTx3g( p_dec );

    else

        ParseExtradataTextMedia( p_dec );

    p_dec->fmt_out.i_codec = VLC_CODEC_TEXT;

    return VLC_SUCCESS;

}

/*****************************************************************************

 * Encoder entry/exit

 *****************************************************************************/

#ifdef ENABLE_SOUT

static void FillExtradataTx3g(void **pp_extra, size_t *pi_extra)

{

    size_t i_extra = 32 + 37;

    uint8_t *p_extra = calloc( 1, i_extra );

    if (p_extra == NULL)

        return;

    {

        p_extra[4] = 0x01;/* 1  center, horizontal */

        p_extra[5] = 0xFF;/* -1 bottom, vertical */

        SetDWBE( &p_extra[6],  0x000000FFU ); /* bgcolor */

        p_extra[25] = STYLE_DEFAULT_FONT_SIZE;

        SetDWBE( &p_extra[26], 0xFFFFFFFFU ); /* fgcolor */

        /* FontTableBox */

        SetDWBE(&p_extra[32], 8 + 2 + 6 + 11 + 10);

        memcpy(&p_extra[36], "ftab", 4);

        SetWBE(&p_extra[40], 3); /* entry count */

        /* Font Record 0 */

        p_extra[41] = 5;

        memcpy(&p_extra[42], "Serif", 5);

        /* Font Record 1 */

        p_extra[47] = 10;

        memcpy(&p_extra[48], "Sans-serif", 10);

        /* Font Record 2 */

        p_extra[58] = 9;

        memcpy(&p_extra[59], "Monospace", 9);

        *pp_extra = p_extra;

        *pi_extra = i_extra;

    }

}

static int OpenEncoder( vlc_object_t *p_this )

{

    encoder_t *p_enc = (encoder_t *)p_this;

    if( p_enc->fmt_out.i_codec != VLC_CODEC_TX3G )

        return VLC_EGENERIC;

    p_enc->fmt_in.i_codec = VLC_CODEC_TEXT;

    if( !p_enc->fmt_out.i_extra )

        FillExtradataTx3g( &p_enc->fmt_out.p_extra, &p_enc->fmt_out.i_extra );

    static const struct vlc_encoder_operations ops =

    {

        .encode_sub = Encode,

    };

    p_enc->ops = &ops;

    return VLC_SUCCESS;

}

static int ConvertFromVLCFlags( const text_style_t *p_style )

{

    int i_atomflags = 0;

    if( p_style->i_features & STYLE_HAS_FLAGS )

    {

        if ( p_style->i_style_flags & STYLE_BOLD )

            i_atomflags |= FONT_FACE_BOLD;

        if ( p_style->i_style_flags & STYLE_ITALIC )

            i_atomflags |= FONT_FACE_ITALIC;

        if ( p_style->i_style_flags & STYLE_UNDERLINE )

            i_atomflags |= FONT_FACE_UNDERLINE;

    }

    return i_atomflags;

}

static uint32_t ConvertFromVLCColor( const text_style_t *p_style )

{

    uint32_t rgba;

    if( p_style->i_features & STYLE_HAS_FONT_COLOR )

        rgba = p_style->i_font_color << 8;

    else

        rgba = 0xFFFFFF00U;

    if( p_style->i_features & STYLE_HAS_FONT_ALPHA )

        rgba |= p_style->i_font_alpha;

    else

        rgba |= 0xFF;

    return rgba;

}

static bool NeedStyling( const text_segment_t *p_segment )

{

    const text_style_t *p_style = p_segment->style;

    if( !p_style )

        return false;

    if( p_style->i_features & STYLE_HAS_FLAGS )

    {

        if( p_style->i_style_flags & (STYLE_BOLD|STYLE_ITALIC|STYLE_UNDERLINE) )

            return true;

    }

    if( p_style->i_features & (STYLE_HAS_FONT_COLOR|STYLE_HAS_FONT_ALPHA) )

        return true;

    return false;

}

static block_t *GetStylBlock( const text_segment_t *p_segment, size_t i_styles )

{

    size_t i_start = 0;

    block_t *p_styl = block_Alloc( 10 + 12 * i_styles );

    if( p_styl )

    {

        SetDWBE( p_styl->p_buffer, p_styl->i_buffer );

        memcpy( &p_styl->p_buffer[4], "styl", 4 );

        SetWBE( &p_styl->p_buffer[8], i_styles );

        p_styl->i_buffer = 10;

        for( ; p_segment; p_segment = p_segment->p_next )

        {

            size_t i_len = str8len( p_segment->psz_text );

            if( NeedStyling( p_segment ) )

            {

                uint8_t *p = &p_styl->p_buffer[p_styl->i_buffer];

                SetWBE( &p[0], i_start );

                SetWBE( &p[2], i_start + i_len );

                SetWBE( &p[4], 0 );

                p[6] = ConvertFromVLCFlags( p_segment->style );

                p[7] = STYLE_DEFAULT_FONT_SIZE;

                SetDWBE(&p[8], ConvertFromVLCColor( p_segment->style ) );

                p_styl->i_buffer += 12;

            }

            i_start += i_len;

        }

    }

    return p_styl;

}

static block_t * Encode( encoder_t *p_enc, subpicture_t *p_spu )

{

    VLC_UNUSED(p_enc);

    subpicture_region_t *p_region =

        vlc_spu_regions_first_or_null(&p_spu->regions);

    const text_segment_t *p_segments = p_region ? p_region->p_text : NULL;

    size_t i_len = 0;

    size_t i_styles = 0;

    for(const text_segment_t  *p_segment = p_segments;

                               p_segment; p_segment = p_segment->p_next )

    {

        if( p_segment->style )

            i_styles++;

        i_len += strlen( p_segment->psz_text );

    }

    block_t *p_block = block_Alloc( i_len + 2 );

    if( !p_block )

        return NULL;

    SetWBE(p_block->p_buffer, i_len);

    p_block->i_buffer = 2;

    for(const text_segment_t  *p_segment = p_segments;

                               p_segment; p_segment = p_segment->p_next )

    {

        size_t i_seglen = strlen(p_segment->psz_text);

        memcpy(&p_block->p_buffer[p_block->i_buffer],

                p_segment->psz_text, i_seglen);

        p_block->i_buffer += i_seglen;

    }

    p_block->i_dts = p_block->i_pts = p_spu->i_start;

    p_block->i_length = p_spu->i_stop - p_spu->i_start;

    if( i_styles > 0 )

        p_block->p_next = GetStylBlock( p_segments, i_styles );

    return block_ChainGather( p_block );

}

#endif