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

 * cdg.c : cdg file demux module for vlc

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

 * Copyright (C) 2007 Laurent Aimar

 *

 * 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 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., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.

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

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

 * Preamble

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

#ifdef HAVE_CONFIG_H

# include "config.h"

#endif

#include <vlc_common.h>

#include <vlc_plugin.h>

#include <vlc_demux.h>

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

 * Module descriptor

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

static int  Open ( vlc_object_t * );

vlc_module_begin ()

    set_description( N_("CDG demuxer") )

    set_subcategory( SUBCAT_INPUT_DEMUX )

    set_capability( "demux", 6 )

    set_callback( Open )

    add_shortcut( "cdg", "subtitle" )

vlc_module_end ()

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

 * Local prototypes

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

static int Demux  ( demux_t * );

static int Control( demux_t *, int i_query, va_list args );

typedef struct

{

    es_format_t     fmt;

    es_out_id_t     *p_es;

    date_t          pts;

} demux_sys_t;

#define CDG_FRAME_SIZE (96)

#define CDG_FRAME_RATE (75)

#define CDG_FRAME_DELTA (CLOCK_FREQ / CDG_FRAME_RATE)

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

 * Open: check file and initializes structures

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

static int Open( vlc_object_t * p_this )

{

    demux_t     *p_demux = (demux_t*)p_this;

    /* Identify cdg file by extension, as there is no simple way to

     * detect it */

    if( !demux_IsPathExtension( p_demux, ".cdg" ) && !demux_IsForced( p_demux, "cdg" ) )

        return VLC_EGENERIC;

    /* CDG file size has to be multiple of CDG_FRAME_SIZE (it works even

     * if size is unknown ie 0) */

//    if( (stream_Size( p_demux->s ) % CDG_FRAME_SIZE) != 0 )

//    {

//        msg_Err( p_demux, "Reject CDG file based on its size" );

//        return VLC_EGENERIC;

//    }

    demux_sys_t *p_sys = vlc_obj_malloc( p_this, sizeof (*p_sys) );

    if( unlikely(p_sys == NULL) )

        return VLC_ENOMEM;

    es_format_Init( &p_sys->fmt, VIDEO_ES, VLC_CODEC_CDG );

    p_sys->fmt.video.i_width  = 300-2*6;

    p_sys->fmt.video.i_height = 216-2*12 ;

    p_sys->fmt.video.i_visible_width = p_sys->fmt.video.i_width;

    p_sys->fmt.video.i_visible_height = p_sys->fmt.video.i_height;

    p_sys->fmt.i_id = 0;

    p_sys->p_es = es_out_Add( p_demux->out, &p_sys->fmt );

    if( unlikely(p_sys->p_es == NULL) )

        return VLC_ENOMEM;

    /* There is CDG_FRAME_RATE frames per second */

    date_Init( &p_sys->pts, CDG_FRAME_RATE, 1 );

    date_Set( &p_sys->pts, VLC_TICK_0 );

    p_demux->pf_demux   = Demux;

    p_demux->pf_control = Control;

    p_demux->p_sys      = p_sys;

    return VLC_SUCCESS;

}

static vlc_tick_t PosToDate( demux_t *p_demux )

{

    return vlc_stream_Tell( p_demux->s ) / CDG_FRAME_SIZE * CDG_FRAME_DELTA;

}

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

 * Demux: read packet and send them to decoders

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

 * Returns -1 in case of error, 0 in case of EOF, 1 otherwise

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

static int Demux( demux_t *p_demux )

{

    demux_sys_t *p_sys = p_demux->p_sys;

    block_t     *p_block;

    vlc_tick_t  i_date;

    p_block = vlc_stream_Block( p_demux->s, CDG_FRAME_SIZE );

    if( p_block == NULL )

    {

        msg_Dbg( p_demux, "cannot read data, eof" );

        return VLC_DEMUXER_EOF;

    }

    i_date = PosToDate( p_demux );

    if( i_date >= date_Get( &p_sys->pts ) + CDG_FRAME_DELTA )

    {

        p_block->i_dts = p_block->i_pts = VLC_TICK_0 + i_date;

        date_Set( &p_sys->pts, VLC_TICK_0 + i_date );

    }

    else

    {

        p_block->i_dts = VLC_TICK_0 + i_date;

        p_block->i_pts = date_Get( &p_sys->pts );

    }

    es_out_SetPCR( p_demux->out, p_block->i_pts );

    es_out_Send( p_demux->out, p_sys->p_es, p_block );

    return VLC_DEMUXER_SUCCESS;

}

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

 * Control:

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

static int Control( demux_t *p_demux, int i_query, va_list args )

{

    demux_sys_t *p_sys = p_demux->p_sys;

    uint64_t i_old_offset = vlc_stream_Tell( p_demux->s );

    int i_ret = demux_vaControlHelper( p_demux->s, 0, -1,

                                       8*CDG_FRAME_SIZE*CDG_FRAME_RATE, CDG_FRAME_SIZE,

                                       i_query, args );

    if( !i_ret && ( i_query == DEMUX_SET_POSITION || i_query == DEMUX_SET_TIME ) )

    {

        date_Set( &p_sys->pts, PosToDate( p_demux ) );

        if ( i_old_offset > vlc_stream_Tell( p_demux->s ) )

            i_ret = vlc_stream_Seek( p_demux->s, 0 );

        else

            i_ret = vlc_stream_Seek( p_demux->s, i_old_offset );

    }

    return i_ret;

}