dvbsub.c

uclinux 下的vlc播放器源代码

/*****************************************************************************
 * dvbsub.c : DVB subtitles decoder
 *            DVB subtitles encoder (developed for Anevia, www.anevia.com)
 *****************************************************************************
 * Copyright (C) 2003 ANEVIA
 * Copyright (C) 2003-2005 the VideoLAN team
 * $Id: dvbsub.c 19610 2007-04-01 01:37:01Z hartman $
 *
 * Authors: Gildas Bazin <[e-mail]>
 *          Damien LUCAS <[e-mail]>
 *          Laurent Aimar <[e-mail]>
 *          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.
 *****************************************************************************/
/*****************************************************************************
 * Preamble
 *
 * FIXME:
 * DVB subtitles coded as strings of characters are not handled correctly.
 * The character codes in the string should actually be indexes refering to a
 * character table identified in the subtitle descriptor.
 *****************************************************************************/
#include <vlc/vlc.h>
#include <vlc/vout.h>
#include <vlc/decoder.h>
#include <vlc/sout.h>

#include "vlc_bits.h"

/* #define DEBUG_DVBSUB 1 */

#define POSX_TEXT N_("Decoding X coordinate")
#define POSX_LONGTEXT N_("X coordinate of the rendered subtitle")

#define POSY_TEXT N_("Decoding Y coordinate")
#define POSY_LONGTEXT N_("Y coordinate of the rendered subtitle") 

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

#define ENC_POSX_TEXT N_("Encoding X coordinate")
#define ENC_POSX_LONGTEXT N_("X coordinate of the encoded subtitle" )
#define ENC_POSY_TEXT N_("Encoding Y coordinate")
#define ENC_POSY_LONGTEXT N_("Y coordinate of the encoded subtitle" )

static int pi_pos_values[] = { 0, 1, 2, 4, 8, 5, 6, 9, 10 };
static char *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") };

/*****************************************************************************
 * Module descriptor.
 *****************************************************************************/
static int  Open ( vlc_object_t * );
static void Close( vlc_object_t * );
static subpicture_t *Decode( decoder_t *, block_t ** );

static int OpenEncoder  ( vlc_object_t * );
static void CloseEncoder( vlc_object_t * );
static block_t *Encode  ( encoder_t *, subpicture_t * );

vlc_module_begin();
#   define DVBSUB_CFG_PREFIX "dvbsub-"
    set_description( _("DVB subtitles decoder") );
    set_capability( "decoder", 50 );
    set_category( CAT_INPUT );
    set_subcategory( SUBCAT_INPUT_SCODEC );
    set_callbacks( Open, Close );

    add_integer( DVBSUB_CFG_PREFIX "position", 8, NULL, POS_TEXT, POS_LONGTEXT, VLC_TRUE );
        change_integer_list( pi_pos_values, ppsz_pos_descriptions, 0 );
    add_integer( DVBSUB_CFG_PREFIX "x", -1, NULL, POSX_TEXT, POSX_LONGTEXT, VLC_FALSE );
    add_integer( DVBSUB_CFG_PREFIX "y", -1, NULL, POSY_TEXT, POSY_LONGTEXT, VLC_FALSE );

#   define ENC_CFG_PREFIX "sout-dvbsub-"
    add_submodule();
    set_description( _("DVB subtitles encoder") );
    set_capability( "encoder", 100 );
    set_callbacks( OpenEncoder, CloseEncoder );

    add_integer( ENC_CFG_PREFIX "x", -1, NULL, ENC_POSX_TEXT, ENC_POSX_LONGTEXT, VLC_FALSE );
    add_integer( ENC_CFG_PREFIX "y", -1, NULL, ENC_POSY_TEXT, ENC_POSY_LONGTEXT, VLC_FALSE );
    add_suppressed_integer( ENC_CFG_PREFIX "timeout" ); /* Suppressed since 0.8.5 */
vlc_module_end();

static const char *ppsz_enc_options[] = { "x", "y", NULL };

/****************************************************************************
 * Local structures
 ****************************************************************************
 * Those structures refer closely to the ETSI 300 743 Object model
 ****************************************************************************/

/* The object definition gives the position of the object in a region */
typedef struct dvbsub_objectdef_s
{
    int i_id;
    int i_type;
    int i_x;
    int i_y;
    int i_fg_pc;
    int i_bg_pc;
    char *psz_text; /* for string of characters objects */

} dvbsub_objectdef_t;

/* The entry in the palette CLUT */
typedef struct
{
    uint8_t                 Y;
    uint8_t                 Cr;
    uint8_t                 Cb;
    uint8_t                 T;

} dvbsub_color_t;

/* */
typedef struct dvbsub_clut_s
{
    uint8_t                 i_id;
    uint8_t                 i_version;
    dvbsub_color_t          c_2b[4];
    dvbsub_color_t          c_4b[16];
    dvbsub_color_t          c_8b[256];

    struct dvbsub_clut_s    *p_next;

} dvbsub_clut_t;

/* The Region is an aera on the image
 * with a list of the object definitions associated and a CLUT */
typedef struct dvbsub_region_s
{
    int i_id;
    int i_version;
    int i_x;
    int i_y;
    int i_width;
    int i_height;
    int i_level_comp;
    int i_depth;
    int i_clut;

    uint8_t *p_pixbuf;

    int                    i_object_defs;
    dvbsub_objectdef_t     *p_object_defs;

    struct dvbsub_region_s *p_next;

} dvbsub_region_t;

/* The object definition gives the position of the object in a region */
typedef struct dvbsub_regiondef_s
{
    int i_id;
    int i_x;
    int i_y;

} dvbsub_regiondef_t;

/* The page defines the list of regions */
typedef struct
{
    int i_id;
    int i_timeout; /* in seconds */
    int i_state;
    int i_version;

    int                i_region_defs;
    dvbsub_regiondef_t *p_region_defs;

} dvbsub_page_t;

struct decoder_sys_t
{
    bs_t            bs;

    /* Decoder internal data */
    int             i_id;
    int             i_ancillary_id;
    mtime_t         i_pts;

    vlc_bool_t      b_absolute;
    int             i_spu_position;
    int             i_spu_x;
    int             i_spu_y;

    vlc_bool_t      b_page;
    dvbsub_page_t   *p_page;
    dvbsub_region_t *p_regions;
    dvbsub_clut_t   *p_cluts;
    dvbsub_clut_t   default_clut;
};


/* List of different SEGMENT TYPES */
/* According to EN 300-743, table 2 */
#define DVBSUB_ST_PAGE_COMPOSITION      0x10
#define DVBSUB_ST_REGION_COMPOSITION    0x11
#define DVBSUB_ST_CLUT_DEFINITION       0x12
#define DVBSUB_ST_OBJECT_DATA           0x13
#define DVBSUB_ST_ENDOFDISPLAY          0x80
#define DVBSUB_ST_STUFFING              0xff
/* List of different OBJECT TYPES */
/* According to EN 300-743, table 6 */
#define DVBSUB_OT_BASIC_BITMAP          0x00
#define DVBSUB_OT_BASIC_CHAR            0x01
#define DVBSUB_OT_COMPOSITE_STRING      0x02
/* Pixel DATA TYPES */
/* According to EN 300-743, table 9 */ 
#define DVBSUB_DT_2BP_CODE_STRING       0x10
#define DVBSUB_DT_4BP_CODE_STRING       0x11
#define DVBSUB_DT_8BP_CODE_STRING       0x12
#define DVBSUB_DT_24_TABLE_DATA         0x20
#define DVBSUB_DT_28_TABLE_DATA         0x21
#define DVBSUB_DT_48_TABLE_DATA         0x22
#define DVBSUB_DT_END_LINE              0xf0
/* List of different Page Composition Segment state */
/* According to EN 300-743, 7.2.1 table 3 */
#define DVBSUB_PCS_STATE_ACQUISITION    0x01
#define DVBSUB_PCS_STATE_CHANGE         0x02

/*****************************************************************************
 * Local prototypes
 *****************************************************************************/
static void decode_segment( decoder_t *, bs_t * );
static void decode_page_composition( decoder_t *, bs_t * );
static void decode_region_composition( decoder_t *, bs_t * );
static void decode_object( decoder_t *, bs_t * );
static void decode_clut( decoder_t *, bs_t * );
static void free_all( decoder_t * );

static void default_clut_init( decoder_t * );

static subpicture_t *render( decoder_t * );

/*****************************************************************************
 * 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;
    vlc_value_t    val;
    int i_posx, i_posy;

    if( p_dec->fmt_in.i_codec != VLC_FOURCC('d','v','b','s') )
    {
        return VLC_EGENERIC;
    }

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

    p_sys->i_pts          = (mtime_t) 0;    
    p_sys->i_id           = p_dec->fmt_in.subs.dvb.i_id & 0xFFFF;
    p_sys->i_ancillary_id = p_dec->fmt_in.subs.dvb.i_id >> 16;

    p_sys->p_regions      = NULL;
    p_sys->p_cluts        = NULL;
    p_sys->p_page         = NULL;

    var_Create( p_this, DVBSUB_CFG_PREFIX "position",
                VLC_VAR_INTEGER | VLC_VAR_DOINHERIT );
    var_Get( p_this, DVBSUB_CFG_PREFIX "position", &val );
    p_sys->i_spu_position = val.i_int;
    var_Create( p_this, DVBSUB_CFG_PREFIX "x",
                VLC_VAR_INTEGER | VLC_VAR_DOINHERIT );
    var_Get( p_this, DVBSUB_CFG_PREFIX "x", &val );
    i_posx = val.i_int;
    var_Create( p_this, DVBSUB_CFG_PREFIX "y",
                VLC_VAR_INTEGER | VLC_VAR_DOINHERIT );
    var_Get( p_this, DVBSUB_CFG_PREFIX "y", &val );
    i_posy = val.i_int;

    /* Check if subpicture position was overridden */
    p_sys->b_absolute = VLC_TRUE;
    p_sys->i_spu_x = p_sys->i_spu_y = 0;

    if( i_posx >= 0 && i_posy >= 0 )
    {
        p_sys->b_absolute = VLC_FALSE;
        p_sys->i_spu_x = i_posx;
        p_sys->i_spu_y = i_posy;
    }

    es_format_Init( &p_dec->fmt_out, SPU_ES, VLC_FOURCC( 'd','v','b','s' ) );

    default_clut_init( p_dec );

    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_Destroy( p_this, DVBSUB_CFG_PREFIX "x" );
    var_Destroy( p_this, DVBSUB_CFG_PREFIX "y" );
    var_Destroy( p_this, DVBSUB_CFG_PREFIX "position" );    

    free_all( p_dec );
    free( p_sys );
}

/*****************************************************************************
 * 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;

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

    p_sys->i_pts = p_block->i_pts;
    if( p_sys->i_pts <= 0 )
    {
#ifdef DEBUG_DVBSUB
        /* Some DVB channels send stuffing segments in non-dated packets so
         * don't complain too loudly. */
        msg_Warn( p_dec, "non dated subtitle" );
#endif
        block_Release( p_block );
        return NULL;
    }

    bs_init( &p_sys->bs, p_block->p_buffer, p_block->i_buffer );

    if( bs_read( &p_sys->bs, 8 ) != 0x20 ) /* Data identifier */
    {
        msg_Dbg( p_dec, "invalid data identifier" );
        block_Release( p_block );
        return NULL;
    }

    if( bs_read( &p_sys->bs, 8 ) ) /* Subtitle stream id */
    {
        msg_Dbg( p_dec, "invalid subtitle stream id" );
        block_Release( p_block );
        return NULL;
    }

#ifdef DEBUG_DVBSUB
    msg_Dbg( p_dec, "subtitle packet received: "I64Fd, p_sys->i_pts );
#endif

    p_sys->b_page = VLC_FALSE;
    while( bs_show( &p_sys->bs, 8 ) == 0x0f ) /* Sync byte */
    {
        decode_segment( p_dec, &p_sys->bs );
    }

    if( bs_read( &p_sys->bs, 8 ) != 0xff ) /* End marker */
    {
        msg_Warn( p_dec, "end marker not found (corrupted subtitle ?)" );
        block_Release( p_block );
        return NULL;
    }

    /* Check if the page is to be displayed */
    if( p_sys->p_page && p_sys->b_page ) p_spu = render( p_dec );

    block_Release( p_block );

    return p_spu;
}

/* following functions are local */

/*****************************************************************************
 * default_clut_init: default clut as defined in EN 300-743 section 10
 *****************************************************************************/
static void default_clut_init( decoder_t *p_dec )
{
    decoder_sys_t *p_sys = p_dec->p_sys;
    uint8_t i;

#define RGB_TO_Y(r, g, b) ((int16_t) 77 * r + 150 * g + 29 * b) / 256;
#define RGB_TO_U(r, g, b) ((int16_t) -44 * r - 87 * g + 131 * b) / 256;
#define RGB_TO_V(r, g, b) ((int16_t) 131 * r - 110 * g - 21 * b) / 256;

    /* 4 entries CLUT */
    for( i = 0; i < 4; i++ )