cc.c

VLC Player Source Code

/*****************************************************************************
 * cc608.c : CC 608/708 subtitles decoder
 *****************************************************************************
 * Copyright (C) 2007 Laurent Aimar
 * $Id: f753ff026f0dbcbe9abee9935e44cb59f9a38dd0 $
 *
 * Authors: Laurent Aimar < fenrir # via.ecp.fr>
 *
 * 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
 *****************************************************************************/
/* The EIA 608 decoder part has been initialy based on ccextractor (GPL)
 * and rewritten */

/* TODO:
 *  On discontinuity reset the decoder state
 *  Check parity
 *  708 decoding
 */

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

#include <vlc_common.h>
#include <vlc_plugin.h>
#include <vlc_vout.h>
#include <vlc_codec.h>
#include <vlc_input.h>

#include <vlc_osd.h>
#include <vlc_filter.h>
#include <vlc_image.h>
#include <vlc_charset.h>
#include <vlc_stream.h>
#include <vlc_xml.h>
#include <errno.h>
#include <string.h>

#include <assert.h>

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

vlc_module_begin();
    set_shortname( N_("CC 608/708"));
    set_description( N_("Closed Captions decoder") );
    set_capability( "decoder", 50 );
    set_callbacks( Open, Close );
vlc_module_end();

/*****************************************************************************
 * Local prototypes
 *****************************************************************************/
typedef enum
{
    EIA608_MODE_POPUP = 0,
    EIA608_MODE_ROLLUP_2 = 1,
    EIA608_MODE_ROLLUP_3 = 2,
    EIA608_MODE_ROLLUP_4 = 3,
    EIA608_MODE_PAINTON = 4,
    EIA608_MODE_TEXT = 5
} eia608_mode_t;

typedef enum
{
    EIA608_COLOR_WHITE = 0,
    EIA608_COLOR_GREEN = 1,
    EIA608_COLOR_BLUE = 2,
    EIA608_COLOR_CYAN = 3,
    EIA608_COLOR_RED = 4,
    EIA608_COLOR_YELLOW = 5,
    EIA608_COLOR_MAGENTA = 6,
    EIA608_COLOR_USERDEFINED = 7
} eia608_color_t;

typedef enum
{
    EIA608_FONT_REGULAR    = 0x00,
    EIA608_FONT_ITALICS    = 0x01,
    EIA608_FONT_UNDERLINE  = 0x02,
    EIA608_FONT_UNDERLINE_ITALICS = EIA608_FONT_UNDERLINE | EIA608_FONT_ITALICS
} eia608_font_t;

#define EIA608_SCREEN_ROWS 15
#define EIA608_SCREEN_COLUMNS 32

struct eia608_screen // A CC buffer
{
    uint8_t characters[EIA608_SCREEN_ROWS][EIA608_SCREEN_COLUMNS+1];
    eia608_color_t colors[EIA608_SCREEN_ROWS][EIA608_SCREEN_COLUMNS+1];
    eia608_font_t fonts[EIA608_SCREEN_ROWS][EIA608_SCREEN_COLUMNS+1]; // Extra char at the end for a 0
    int row_used[EIA608_SCREEN_ROWS]; // Any data in row?
};
typedef struct eia608_screen eia608_screen;

typedef struct
{
    /* Current channel (used to reject packet without channel information) */
    int i_channel;

    /* */
    int           i_screen; /* Displayed screen */
    eia608_screen screen[2];

    struct
    {
        int i_row;
        int i_column;
    } cursor;

    /* */
    eia608_mode_t mode;
    eia608_color_t color;
    eia608_font_t font;
    int i_row_rollup;

    /* Last command pair (used to reject duplicated command) */
    struct
    {
        uint8_t d1;
        uint8_t d2;
    } last;
} eia608_t;

static void         Eia608Init( eia608_t * );
static bool   Eia608Parse( eia608_t *h, int i_channel_selected, const uint8_t data[2] );
static char        *Eia608Text( eia608_t *h, bool b_html );
static void         Eia608Exit( eia608_t * );

/* It will be enough up to 63 B frames, which is far too high for
 * broadcast environment */
#define CC_MAX_REORDER_SIZE (64)
struct decoder_sys_t
{
    int i;

    int     i_block;
    block_t *pp_block[CC_MAX_REORDER_SIZE];

    int i_field;
    int i_channel;

    eia608_t eia608;
};

static subpicture_t *Decode( decoder_t *, block_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;
    int i_field;
    int i_channel;

    switch( p_dec->fmt_in.i_codec )
    {
        case VLC_FOURCC('c','c','1',' '):
            i_field = 0; i_channel = 1;
            break;
        case VLC_FOURCC('c','c','2',' '):
            i_field = 0; i_channel = 2;
            break;
        case VLC_FOURCC('c','c','3',' '):
            i_field = 1; i_channel = 1;
            break;
        case VLC_FOURCC('c','c','4',' '):
            i_field = 1; i_channel = 2;
            break;

        default:
            return VLC_EGENERIC;
    }

    p_dec->pf_decode_sub = Decode;

    /* 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_block = 0;

    p_sys->i_field = i_field;
    p_sys->i_channel = i_channel;

    Eia608Init( &p_sys->eia608 );

    return VLC_SUCCESS;
}

/****************************************************************************
 * Decode: the whole thing
 ****************************************************************************
 *
 ****************************************************************************/
static void     Push( decoder_t *, block_t * );
static block_t *Pop( decoder_t * );
static subpicture_t *Convert( decoder_t *, block_t * );

static subpicture_t *Decode( decoder_t *p_dec, block_t **pp_block )
{
    if( pp_block && *pp_block )
    {
        Push( p_dec, *pp_block );
        *pp_block = NULL;
    }

    for( ;; )
    {
        block_t *p_block = Pop( p_dec );
        if( !p_block )
            break;

        subpicture_t *p_spu = Convert( p_dec, p_block );
        if( p_spu )
            return p_spu;
    }
    return NULL;
}

/*****************************************************************************
 * CloseDecoder: clean up the decoder
 *****************************************************************************/
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;
    int i;

    for( i = 0; i < p_sys->i_block; i++ )
        block_Release( p_sys->pp_block[i] );
    Eia608Exit( &p_sys->eia608 );
    free( p_sys );
}

/*****************************************************************************
 *
 *****************************************************************************/
static void Push( decoder_t *p_dec, block_t *p_block )
{
    decoder_sys_t *p_sys = p_dec->p_sys;

    if( p_sys->i_block >= CC_MAX_REORDER_SIZE )
    {
        msg_Warn( p_dec, "Trashing a CC entry" );
        memmove( &p_sys->pp_block[0], &p_sys->pp_block[1], sizeof(*p_sys->pp_block) * (CC_MAX_REORDER_SIZE-1) );
        p_sys->i_block--;
    }
    p_sys->pp_block[p_sys->i_block++] = p_block;
}
static block_t *Pop( decoder_t *p_dec )
{
    decoder_sys_t *p_sys = p_dec->p_sys;
    block_t *p_block;
    int i_index;
    int i;
    /* XXX Cc captions data are OUT OF ORDER (because we receive them in the bitstream
     * order (ie ordered by video picture dts) instead of the display order.
     *  We will simulate a simple IPB buffer scheme
     * and reorder with pts.
     * XXX it won't work with H264 which use non out of order B picture or MMCO
     */

    /* Wait for a P and output all *previous* picture by pts order (for
     * hierarchical B frames) */
    if( p_sys->i_block <= 1 ||
        ( p_sys->pp_block[p_sys->i_block-1]->i_flags & BLOCK_FLAG_TYPE_B ) )
        return NULL;

    p_block = p_sys->pp_block[i_index = 0];
    if( p_block->i_pts > 0 )
    {
        for( i = 1; i < p_sys->i_block-1; i++ )
        {
            if( p_sys->pp_block[i]->i_pts > 0 && p_block->i_pts > 0 &&
                p_sys->pp_block[i]->i_pts < p_block->i_pts )
                p_block = p_sys->pp_block[i_index = i];
        }
    }
    assert( i_index+1 < p_sys->i_block );
    memmove( &p_sys->pp_block[i_index], &p_sys->pp_block[i_index+1], sizeof(*p_sys->pp_block) * ( p_sys->i_block - i_index - 1 ) );
    p_sys->i_block--;

    return p_block;
}

static subpicture_t *Subtitle( decoder_t *p_dec, char *psz_subtitle, char *psz_html, mtime_t i_pts )
{
    //decoder_sys_t *p_sys = p_dec->p_sys;
    subpicture_t *p_spu = NULL;
    video_format_t fmt;

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

    EnsureUTF8( psz_subtitle );
    if( psz_html )
        EnsureUTF8( psz_html );

    /* 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 );
        free( psz_html );
        return NULL;
    }

    p_spu->b_pausable = true;

    /* Create a new subpicture region */
    memset( &fmt, 0, sizeof(video_format_t) );
    fmt.i_chroma = VLC_FOURCC('T','E','X','T');
    fmt.i_aspect = 0;
    fmt.i_width = fmt.i_height = 0;
    fmt.i_x_offset = fmt.i_y_offset = 0;
    p_spu->p_region = p_spu->pf_create_region( VLC_OBJECT(p_dec), &fmt );
    if( !p_spu->p_region )
    {
        msg_Err( p_dec, "cannot allocate SPU region" );
        free( psz_subtitle );
        free( psz_html );
        p_dec->pf_spu_buffer_del( p_dec, p_spu );
        return NULL;
    }

    /* Decode and format the subpicture unit */
    /* Normal text subs, easy markup */
    p_spu->p_region->i_align = SUBPICTURE_ALIGN_BOTTOM;// | SUBPICTURE_ALIGN_LEFT;// | p_sys->i_align;
    p_spu->i_x = 0; //p_sys->i_align ? 20 : 0;
    p_spu->i_y = 10;

    p_spu->p_region->psz_text = psz_subtitle;
    p_spu->p_region->psz_html = psz_html;

    p_spu->i_start = i_pts;
    p_spu->i_stop = i_pts + 10000000;   /* 10s max */
    p_spu->b_ephemer = true;
    p_spu->b_absolute = false;

    return p_spu;
}

static subpicture_t *Convert( decoder_t *p_dec, block_t *p_block )
{
    decoder_sys_t *p_sys = p_dec->p_sys;
    const int64_t i_pts = p_block->i_pts;