subsdec.c

VLC Player Source Code

/*****************************************************************************
 * subsdec.c : text subtitles decoder
 *****************************************************************************
 * Copyright (C) 2000-2006 the VideoLAN team
 * $Id: 37ae32f73f26102e4f7c724fd773d7f1d24c7447 $
 *
 * Authors: Gildas Bazin <[e-mail]>
 *          Samuel Hocevar <[e-mail]>
 *          Derk-Jan Hartman <hartman at videolan dot org>
 *          Bernie Purcell <[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., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
 *****************************************************************************/

/*****************************************************************************
 * Preamble
 *****************************************************************************/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif

#include "subsdec.h"
#include <vlc_plugin.h>

/*****************************************************************************
 * Local prototypes
 *****************************************************************************/
static int  OpenDecoder   ( vlc_object_t * );
static void CloseDecoder  ( vlc_object_t * );

static subpicture_t   *DecodeBlock   ( decoder_t *, block_t ** );
static subpicture_t   *ParseText     ( decoder_t *, block_t * );
static char           *StripTags      ( char * );
static char           *CreateHtmlSubtitle ( char * );


/*****************************************************************************
 * Module descriptor.
 *****************************************************************************/
static const char *const ppsz_encodings[] = {
    DEFAULT_NAME, "ASCII", "UTF-8", "",
    "ISO-8859-1", "CP1252", "MacRoman", "MacIceland","ISO-8859-15", "",
    "ISO-8859-2", "CP1250", "MacCentralEurope", "MacCroatian", "MacRomania", "",
    "ISO-8859-5", "CP1251", "MacCyrillic", "MacUkraine", "KOI8-R", "KOI8-U", "KOI8-RU", "",
    "ISO-8859-6", "CP1256", "MacArabic", "",
    "ISO-8859-7", "CP1253", "MacGreek", "",
    "ISO-8859-8", "CP1255", "MacHebrew", "",
    "ISO-8859-9", "CP1254", "MacTurkish", "",
    "ISO-8859-13", "CP1257", "",
    "ISO-2022-JP", "ISO-2022-JP-1", "ISO-2022-JP-2", "EUC-JP", "SHIFT_JIS", "",
    "ISO-2022-CN", "ISO-2022-CN-EXT", "EUC-CN", "EUC-TW", "BIG5", "BIG5-HKSCS", "",
    "ISO-2022-KR", "EUC-KR", "",
    "MacThai", "KOI8-T", "",
    "ISO-8859-3", "ISO-8859-4", "ISO-8859-10", "ISO-8859-14", "ISO-8859-16", "",
    "CP850", "CP862", "CP866", "CP874", "CP932", "CP949", "CP950", "CP1133", "CP1258", "",
    "Macintosh", "",
    "UTF-7", "UTF-16", "UTF-16BE", "UTF-16LE", "UTF-32", "UTF-32BE", "UTF-32LE",
    "C99", "JAVA", "UCS-2", "UCS-2BE", "UCS-2LE", "UCS-4", "UCS-4BE", "UCS-4LE", "",
    "HZ", "GBK", "GB18030", "JOHAB", "ARMSCII-8",
    "Georgian-Academy", "Georgian-PS", "TIS-620", "MuleLao-1", "VISCII", "TCVN",
    "HPROMAN8", "NEXTSTEP" };
/*
SSA supports charset selection.
The following known charsets are used:

0 = Ansi - Western European
1 = default
2 = symbol
3 = invalid
77 = Mac
128 = Japanese (Shift JIS)
129 = Hangul
130 = Johab
134 = GB2312 Simplified Chinese
136 = Big5 Traditional Chinese
161 = Greek
162 = Turkish
163 = Vietnamese
177 = Hebrew
178 = Arabic
186 = Baltic
204 = Russian (Cyrillic)
222 = Thai
238 = Eastern European
254 = PC 437
*/

static const int  pi_justification[] = { 0, 1, 2 };
static const char *const ppsz_justification_text[] = {
    N_("Center"),N_("Left"),N_("Right")};

#define ENCODING_TEXT N_("Subtitles text encoding")
#define ENCODING_LONGTEXT N_("Set the encoding used in text subtitles")
#define ALIGN_TEXT N_("Subtitles justification")
#define ALIGN_LONGTEXT N_("Set the justification of subtitles")
#define AUTODETECT_UTF8_TEXT N_("UTF-8 subtitles autodetection")
#define AUTODETECT_UTF8_LONGTEXT N_("This enables automatic detection of " \
            "UTF-8 encoding within subtitles files.")
#define FORMAT_TEXT N_("Formatted Subtitles")
#define FORMAT_LONGTEXT N_("Some subtitle formats allow for text formatting. " \
 "VLC partly implements this, but you can choose to disable all formatting.")


vlc_module_begin();
    set_shortname( N_("Subtitles"));
    set_description( N_("Text subtitles decoder") );
    set_capability( "decoder", 50 );
    set_callbacks( OpenDecoder, CloseDecoder );
    set_category( CAT_INPUT );
    set_subcategory( SUBCAT_INPUT_SCODEC );

    add_integer( "subsdec-align", 0, NULL, ALIGN_TEXT, ALIGN_LONGTEXT,
                 false );
        change_integer_list( pi_justification, ppsz_justification_text, NULL );
    add_string( "subsdec-encoding", DEFAULT_NAME, NULL,
                ENCODING_TEXT, ENCODING_LONGTEXT, false );
        change_string_list( ppsz_encodings, 0, 0 );
    add_bool( "subsdec-autodetect-utf8", true, NULL,
              AUTODETECT_UTF8_TEXT, AUTODETECT_UTF8_LONGTEXT, false );
    add_bool( "subsdec-formatted", true, NULL, FORMAT_TEXT, FORMAT_LONGTEXT,
                 false );
vlc_module_end();

/*****************************************************************************
 * OpenDecoder: probe the decoder and return score
 *****************************************************************************
 * Tries to launch a decoder and return score so that the interface is able
 * to chose.
 *****************************************************************************/
static int OpenDecoder( vlc_object_t *p_this )
{
    decoder_t     *p_dec = (decoder_t*)p_this;
    decoder_sys_t *p_sys;
    vlc_value_t    val;

    switch( p_dec->fmt_in.i_codec )
    {
        case VLC_FOURCC('s','u','b','t'):
        case VLC_FOURCC('s','s','a',' '):
        case VLC_FOURCC('t','1','4','0'):
            break;
        default:
            return VLC_EGENERIC;
    }

    p_dec->pf_decode_sub = DecodeBlock;

    /* Allocate the memory needed to store the decoder's structure */
    p_dec->p_sys = p_sys = malloc( sizeof( *p_sys ) );
    if( p_sys == NULL )
        return VLC_ENOMEM;

    /* init of p_sys */
    memset( p_sys, 0, sizeof( *p_sys ) );
    p_sys->i_align = 0;
    p_sys->iconv_handle = (vlc_iconv_t)-1;
    p_sys->b_autodetect_utf8 = false;
    p_sys->b_ass = false;
    p_sys->i_original_height = -1;
    p_sys->i_original_width = -1;
    TAB_INIT( p_sys->i_ssa_styles, p_sys->pp_ssa_styles );
    TAB_INIT( p_sys->i_images, p_sys->pp_images );

    char *psz_charset = NULL;

    /* First try demux-specified encoding */
    if( p_dec->fmt_in.i_codec == VLC_FOURCC('t','1','4','0') )
        psz_charset = strdup( "UTF-8" ); /* IUT T.140 is always using UTF-8 */
    else
    if( p_dec->fmt_in.subs.psz_encoding && *p_dec->fmt_in.subs.psz_encoding )
    {
        psz_charset = strdup (p_dec->fmt_in.subs.psz_encoding);
        msg_Dbg (p_dec, "trying demuxer-specified character encoding: %s",
                 p_dec->fmt_in.subs.psz_encoding ?: "not specified");
    }

    /* Second, try configured encoding */
    if (psz_charset == NULL)
    {
        psz_charset = var_CreateGetNonEmptyString (p_dec, "subsdec-encoding");
        if ((psz_charset != NULL) && !strcasecmp (psz_charset, DEFAULT_NAME))
        {
            free (psz_charset);
            psz_charset = NULL;
        }

        msg_Dbg (p_dec, "trying configured character encoding: %s",
                 psz_charset ?: "not specified");
    }

    /* Third, try "local" encoding with optional UTF-8 autodetection */
    if (psz_charset == NULL)
    {
        psz_charset = strdup (GetFallbackEncoding ());
        msg_Dbg (p_dec, "trying default character encoding: %s",
                 psz_charset ?: "not specified");

        if (var_CreateGetBool (p_dec, "subsdec-autodetect-utf8"))
        {
            msg_Dbg (p_dec, "using automatic UTF-8 detection");
            p_sys->b_autodetect_utf8 = true;
        }
    }

    /* Forth, don't do character decoding, i.e. assume UTF-8 */
    if (psz_charset == NULL)
    {
        psz_charset = strdup ("UTF-8");
        msg_Dbg (p_dec, "using UTF-8 character encoding" );
    }

    if ((psz_charset != NULL)
     && strcasecmp (psz_charset, "UTF-8")
     && strcasecmp (psz_charset, "utf8"))
    {
        p_sys->iconv_handle = vlc_iconv_open ("UTF-8", psz_charset);
        if (p_sys->iconv_handle == (vlc_iconv_t)(-1))
            msg_Err (p_dec, "cannot convert from %s: %m", psz_charset);
    }
    free (psz_charset);

    var_Create( p_dec, "subsdec-align", VLC_VAR_INTEGER | VLC_VAR_DOINHERIT );
    var_Get( p_dec, "subsdec-align", &val );
    p_sys->i_align = val.i_int;

    if( p_dec->fmt_in.i_codec == VLC_FOURCC('s','s','a',' ')
     && var_CreateGetBool( p_dec, "subsdec-formatted" ) )
    {
        if( p_dec->fmt_in.i_extra > 0 )
            ParseSSAHeader( p_dec );
    }

    return VLC_SUCCESS;
}

/****************************************************************************
 * DecodeBlock: the whole thing
 ****************************************************************************
 * This function must be fed with complete subtitles units.
 ****************************************************************************/
static subpicture_t *DecodeBlock( decoder_t *p_dec, block_t **pp_block )
{
    subpicture_t *p_spu;
    block_t *p_block;

    if( !pp_block || *pp_block == NULL )
        return NULL;

    p_block = *pp_block;
    if( p_block->i_rate != 0 )
        p_block->i_length = p_block->i_length * p_block->i_rate / INPUT_RATE_DEFAULT;

    p_spu = ParseText( p_dec, p_block );

    block_Release( p_block );
    *pp_block = NULL;

    return p_spu;
}

/*****************************************************************************
 * CloseDecoder: clean up the decoder
 *****************************************************************************/
static void CloseDecoder( vlc_object_t *p_this )
{
    decoder_t *p_dec = (decoder_t *)p_this;
    decoder_sys_t *p_sys = p_dec->p_sys;

    if( p_sys->iconv_handle != (vlc_iconv_t)-1 )
        vlc_iconv_close( p_sys->iconv_handle );

    if( p_sys->pp_ssa_styles )
    {
        int i;
        for( i = 0; i < p_sys->i_ssa_styles; i++ )
        {
            if( !p_sys->pp_ssa_styles[i] )
                continue;

            free( p_sys->pp_ssa_styles[i]->psz_stylename );
            free( p_sys->pp_ssa_styles[i]->font_style.psz_fontname );
            free( p_sys->pp_ssa_styles[i] );
        }
        TAB_CLEAN( p_sys->i_ssa_styles, p_sys->pp_ssa_styles );
    }
    if( p_sys->pp_images )
    {
        int i;
        for( i = 0; i < p_sys->i_images; i++ )
        {
            if( !p_sys->pp_images[i] )
                continue;

            if( p_sys->pp_images[i]->p_pic )
                picture_Release( p_sys->pp_images[i]->p_pic );
            free( p_sys->pp_images[i]->psz_filename );

            free( p_sys->pp_images[i] );
        }
        TAB_CLEAN( p_sys->i_images, p_sys->pp_images );
    }

    free( p_sys );
}

/*****************************************************************************
 * ParseText: parse an text subtitle packet and send it to the video output
 *****************************************************************************/
static subpicture_t *ParseText( decoder_t *p_dec, block_t *p_block )
{
    decoder_sys_t *p_sys = p_dec->p_sys;
    subpicture_t *p_spu = NULL;
    char *psz_subtitle = NULL;
    video_format_t fmt;

    /* We cannot display a subpicture with no date */
    if( p_block->i_pts == 0 )
    {
        msg_Warn( p_dec, "subtitle without a date" );
        return NULL;
    }

    /* Check validity of packet data */
    /* An "empty" line containing only \0 can be used to force
       and ephemer picture from the screen */
    if( p_block->i_buffer < 1 )
    {
        msg_Warn( p_dec, "no subtitle data" );
        return NULL;
    }

    /* Should be resiliant against bad subtitles */
    psz_subtitle = strndup( (const char *)p_block->p_buffer,
                            p_block->i_buffer );
    if( psz_subtitle == NULL )
        return NULL;

    if( p_sys->iconv_handle == (vlc_iconv_t)-1 )
    {
        if (EnsureUTF8( psz_subtitle ) == NULL)
        {
            msg_Err( p_dec, "failed to convert subtitle encoding.\n"
                     "Try manually setting a character-encoding "
                     "before you open the file." );
        }
    }
    else
    {

        if( p_sys->b_autodetect_utf8 )
        {
            if( IsUTF8( psz_subtitle ) == NULL )
            {
                msg_Dbg( p_dec, "invalid UTF-8 sequence: "
                         "disabling UTF-8 subtitles autodetection" );
                p_sys->b_autodetect_utf8 = false;
            }
        }

        if( !p_sys->b_autodetect_utf8 )
        {
            size_t inbytes_left = strlen( psz_subtitle );
            size_t outbytes_left = 6 * inbytes_left;
            char *psz_new_subtitle = malloc( outbytes_left + 1 );
            char *psz_convert_buffer_out = psz_new_subtitle;
            const char *psz_convert_buffer_in = psz_subtitle;

            size_t ret = vlc_iconv( p_sys->iconv_handle,
                                    &psz_convert_buffer_in, &inbytes_left,
                                    &psz_convert_buffer_out, &outbytes_left );

            *psz_convert_buffer_out++ = '\0';
            free( psz_subtitle );

            if( ( ret == (size_t)(-1) ) || inbytes_left )
            {
                free( psz_new_subtitle );
                msg_Err( p_dec, "failed to convert subtitle encoding.\n"
                        "Try manually setting a character-encoding "
                                "before you open the file." );
                return NULL;
            }

            psz_subtitle = realloc( psz_new_subtitle,
                                    psz_convert_buffer_out - psz_new_subtitle );
        }
    }

    /* Create the subpicture unit */
    p_spu = p_dec->pf_spu_buffer_new( p_dec );
    if( !p_spu )
    {
        msg_Warn( p_dec, "can't get spu buffer" );
        free( psz_subtitle );
        return NULL;
    }

    p_spu->b_pausable = true;