zvbi.c

VLC Player Source Code

/*****************************************************************************
 * zvbi.c : VBI and Teletext PES demux and decoder using libzvbi
 *****************************************************************************
 * Copyright (C) 2007, M2X
 * $Id: 468072c2411075bcf6ba2ff22952657da9edf65a $
 *
 * Authors: Derk-Jan Hartman <djhartman at m2x dot nl>
 *          Jean-Paul Saman <jpsaman at m2x dot nl>
 *
 * 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.
 *****************************************************************************/
/*****************************************************************************
 *
 * information on teletext format can be found here :
 * http://pdc.ro.nu/teletext.html
 *
 *****************************************************************************/

/* This module implements:
 * ETSI EN 301 775: VBI data in PES
 * ETSI EN 300 472: EBU Teletext data in PES
 * ETSI EN 300 706: Enhanced Teletext (libzvbi)
 * ETSI EN 300 231: Video Programme System [VPS] (libzvbi)
 * ETSI EN 300 294: 625-line Wide Screen Signaling [WSS] (libzvbi)
 * EIA-608 Revision A: Closed Captioning [CC] (libzvbi)
 */

#ifdef HAVE_CONFIG_H
# include "config.h"
#endif

#include <vlc_common.h>
#include <vlc_plugin.h>
#include <assert.h>
#include <libzvbi.h>

#include "vlc_vout.h"
#include "vlc_codec.h"

/*****************************************************************************
 * Module descriptor.
 *****************************************************************************/
static int  Open ( vlc_object_t * );
static void Close( vlc_object_t * );

#define PAGE_TEXT N_("Teletext page")
#define PAGE_LONGTEXT N_("Open the indicated Teletext page." \
        "Default page is index 100")

#define OPAQUE_TEXT N_("Text is always opaque")
#define OPAQUE_LONGTEXT N_("Setting vbi-opaque to false " \
        "makes the boxed text transparent." )

#define POS_TEXT N_("Teletext alignment")
#define POS_LONGTEXT N_( \
  "You can enforce the teletext position on the video " \
  "(0=center, 1=left, 2=right, 4=top, 8=bottom, you can " \
  "also use combinations of these values, eg. 6 = top-right).")

#define TELX_TEXT N_("Teletext text subtitles")
#define TELX_LONGTEXT N_( "Output teletext subtitles as text " \
  "instead of as RGBA" )

static const int pi_pos_values[] = { 0, 1, 2, 4, 8, 5, 6, 9, 10 };
static const char *const ppsz_pos_descriptions[] =
{ N_("Center"), N_("Left"), N_("Right"), N_("Top"), N_("Bottom"),
  N_("Top-Left"), N_("Top-Right"), N_("Bottom-Left"), N_("Bottom-Right") };

vlc_module_begin();
    set_description( N_("VBI and Teletext decoder") );
    set_shortname( N_("VBI & Teletext") );
    set_capability( "decoder", 51 );
    set_category( CAT_INPUT );
    set_subcategory( SUBCAT_INPUT_SCODEC );
    set_callbacks( Open, Close );

    add_integer( "vbi-page", 100, NULL,
                 PAGE_TEXT, PAGE_LONGTEXT, false );
    add_bool( "vbi-opaque", true, NULL,
                 OPAQUE_TEXT, OPAQUE_LONGTEXT, false );
    add_integer( "vbi-position", 4, NULL, POS_TEXT, POS_LONGTEXT, false );
        change_integer_list( pi_pos_values, ppsz_pos_descriptions, NULL );
    add_bool( "vbi-text", false, NULL,
              TELX_TEXT, TELX_LONGTEXT, false );
vlc_module_end();

/****************************************************************************
 * Local structures
 ****************************************************************************/

// #define ZVBI_DEBUG

//Guessing table for missing "default region triplet"
static const int pi_default_triplet[] = {
 0, 0,           // slo cze
 8,              // pol
 24,24,24,24,    //ssc scr slv rum
 32,32,32,32,32, //est lit rus bul ukr
 48,48,          //gre ell
 64,             //ara
 88,             //heb
 16 };           //default
static const char *const ppsz_default_triplet[] = {
 "slo", "cze",
 "pol",
 "ssc", "scr", "slv", "rum",
 "est", "lit", "rus", "bul", "ukr",
 "gre", "ell",
 "ara",
 "heb",
 NULL
};

typedef enum {
    DATA_UNIT_EBU_TELETEXT_NON_SUBTITLE     = 0x02,
    DATA_UNIT_EBU_TELETEXT_SUBTITLE         = 0x03,
    DATA_UNIT_EBU_TELETEXT_INVERTED         = 0x0C,

    DATA_UNIT_ZVBI_WSS_CPR1204              = 0xB4,
    DATA_UNIT_ZVBI_CLOSED_CAPTION_525       = 0xB5,
    DATA_UNIT_ZVBI_MONOCHROME_SAMPLES_525   = 0xB6,

    DATA_UNIT_VPS                           = 0xC3,
    DATA_UNIT_WSS                           = 0xC4,
    DATA_UNIT_CLOSED_CAPTION                = 0xC5,
    DATA_UNIT_MONOCHROME_SAMPLES            = 0xC6,

    DATA_UNIT_STUFFING                      = 0xFF,
} data_unit_id;

struct decoder_sys_t
{
    vbi_decoder *     p_vbi_dec;
    vbi_dvb_demux *   p_dvb_demux;
    unsigned int      i_last_page;
    bool              b_update;
    bool              b_text;   /* Subtitles as text */

    vlc_mutex_t       lock; /* Lock to protect the following variables */
    /* Positioning of Teletext images */
    int               i_align;
    /* */
    unsigned int      i_wanted_page;
    /* */
    bool              b_opaque;
};

static subpicture_t *Decode( decoder_t *, block_t ** );

static subpicture_t *Subpicture( decoder_t *p_dec, video_format_t *p_fmt,
                                 bool b_text,
                                 int i_columns, int i_rows,
                                 int i_align, mtime_t i_pts );

static void EventHandler( vbi_event *ev, void *user_data );
static int OpaquePage( picture_t *p_src, const vbi_page p_page,
                       const video_format_t fmt, bool b_opaque );

/* Properties callbacks */
static int RequestPage( vlc_object_t *p_this, char const *psz_cmd,
                        vlc_value_t oldval, vlc_value_t newval, void *p_data );
static int Opaque( vlc_object_t *p_this, char const *psz_cmd,
                   vlc_value_t oldval, vlc_value_t newval, void *p_data );
static int Position( vlc_object_t *p_this, char const *psz_cmd,
                     vlc_value_t oldval, vlc_value_t newval, void *p_data );

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

    if( p_dec->fmt_in.i_codec != VLC_FOURCC('t','e','l','x') )
        return VLC_EGENERIC;

    p_dec->pf_decode_sub = Decode;
    p_sys = p_dec->p_sys = malloc( sizeof(decoder_sys_t) );
    if( p_sys == NULL )
        return VLC_ENOMEM;
    memset( p_sys, 0, sizeof(decoder_sys_t) );

    p_sys->b_update = false;
    p_sys->p_vbi_dec = vbi_decoder_new();
    p_sys->p_dvb_demux = vbi_dvb_pes_demux_new( NULL, NULL );
    vlc_mutex_init( &p_sys->lock );

    if( (p_sys->p_vbi_dec == NULL) || (p_sys->p_dvb_demux == NULL) )
    {
        msg_Err( p_dec, "VBI decoder/demux could not be created." );
        Close( p_this );
        return VLC_ENOMEM;
    }

    /* Some broadcasters in countries with level 1 and level 1.5 still not send a G0 to do 
     * matches against table 32 of ETSI 300 706. We try to do some best effort guessing
     * This is not perfect, but might handle some cases where we know the vbi language 
     * is known. It would be better if people started sending G0 */
    for( int i = 0; ppsz_default_triplet[i] != NULL; i++ )
    {
        if( p_dec->fmt_in.psz_language && !strcasecmp( p_dec->fmt_in.psz_language, ppsz_default_triplet[i] ) )
        {
            vbi_teletext_set_default_region( p_sys->p_vbi_dec, pi_default_triplet[i]);
            msg_Dbg( p_dec, "overwriting default zvbi region: %d", pi_default_triplet[i] );
        }
    }

    vbi_event_handler_register( p_sys->p_vbi_dec, VBI_EVENT_TTX_PAGE |
                                VBI_EVENT_CAPTION | VBI_EVENT_NETWORK |
                                VBI_EVENT_ASPECT | VBI_EVENT_PROG_INFO,
                                EventHandler, p_dec );

    /* Create the var on vlc_global. */
    p_sys->i_wanted_page = var_CreateGetInteger( p_dec, "vbi-page" );
    var_AddCallback( p_dec, "vbi-page",
                     RequestPage, p_sys );

    /* Check if the Teletext track has a known "initial page". */
    if( p_sys->i_wanted_page == 100 && p_dec->fmt_in.subs.dvb.i_id != -1 )
    {
        int i_wanted_magazine = p_dec->fmt_in.subs.dvb.i_id >> 16;
        if( i_wanted_magazine == 0 )
            i_wanted_magazine = 8;
        p_sys->i_wanted_page = vbi_bcd2dec(p_dec->fmt_in.subs.dvb.i_id & 0xff);
        p_sys->i_wanted_page += 100*i_wanted_magazine;
    }

    p_sys->b_opaque = var_CreateGetBool( p_dec, "vbi-opaque" );
    var_AddCallback( p_dec, "vbi-opaque", Opaque, p_sys );

    p_sys->i_align = var_CreateGetInteger( p_dec, "vbi-position" );
    var_AddCallback( p_dec, "vbi-position", Position, p_sys );

    p_sys->b_text = var_CreateGetBool( p_dec, "vbi-text" );
//    var_AddCallback( p_dec, "vbi-text", Text, p_sys );

    es_format_Init( &p_dec->fmt_out, SPU_ES, VLC_FOURCC( 's','p','u',' ' ) );
    if( p_sys->b_text )
        p_dec->fmt_out.video.i_chroma = VLC_FOURCC('T','E','X','T');
    else
        p_dec->fmt_out.video.i_chroma = VLC_FOURCC('R','G','B','A');
    return VLC_SUCCESS;
}

/*****************************************************************************
 * Close:
 *****************************************************************************/
static void Close( vlc_object_t *p_this )
{
    decoder_t     *p_dec = (decoder_t*) p_this;
    decoder_sys_t *p_sys = p_dec->p_sys;

    var_DelCallback( p_dec, "vbi-position", Position, p_sys );
    var_DelCallback( p_dec, "vbi-opaque", Opaque, p_sys );
    var_DelCallback( p_dec, "vbi-page", RequestPage, p_sys );

    vlc_mutex_destroy( &p_sys->lock );

    if( p_sys->p_vbi_dec )
        vbi_decoder_delete( p_sys->p_vbi_dec );
    if( p_sys->p_dvb_demux )
        vbi_dvb_demux_delete( p_sys->p_dvb_demux );
    free( p_sys );
}

#define MAX_SLICES 32

#ifdef WORDS_BIGENDIAN
# define ZVBI_PIXFMT_RGBA32 VBI_PIXFMT_RGBA32_BE
#else
# define ZVBI_PIXFMT_RGBA32 VBI_PIXFMT_RGBA32_LE
#endif


/*****************************************************************************
 * Decode:
 *****************************************************************************/
static subpicture_t *Decode( decoder_t *p_dec, block_t **pp_block )
{
    decoder_sys_t   *p_sys = p_dec->p_sys;
    block_t         *p_block;
    subpicture_t    *p_spu = NULL;
    video_format_t  fmt;
    bool            b_cached = false;
    vbi_page        p_page;
    const uint8_t   *p_pos;
    unsigned int    i_left;