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

 * mpgv.c : MPEG-I/II Video demuxer

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

 * Copyright (C) 2001-2004 VLC authors and VideoLAN

 *

 * 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>

#include <vlc_codec.h>

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

 * Module descriptor

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

static int  Open ( vlc_object_t * );

static void Close( vlc_object_t * );

vlc_module_begin ()

    set_subcategory( SUBCAT_INPUT_DEMUX )

    set_description( N_("MPEG-I/II video demuxer" ) )

    set_capability( "demux", 7 )

    set_callbacks( Open, Close )

    add_shortcut( "mpgv" )

vlc_module_end ()

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

 * Local prototypes

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

typedef struct

{

    bool  b_start;

    es_out_id_t *p_es;

    decoder_t *p_packetizer;

} demux_sys_t;

static int Demux( demux_t * );

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

#define MPGV_PACKET_SIZE 4096

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

 * Close: frees unused data

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

static void Close( vlc_object_t * p_this )

{

    demux_t     *p_demux = (demux_t*)p_this;

    demux_sys_t *p_sys = p_demux->p_sys;

    demux_PacketizerDestroy( p_sys->p_packetizer );

    free( p_sys );

}

static int CheckMPEGStartCode( const uint8_t *p_peek )

{

    switch( p_peek[3] )

    {

        case 0x00:

            if( (p_peek[5] & 0x38) == 0x00 )

                return VLC_EGENERIC;

            break;

        case 0xB0:

        case 0xB1:

        case 0xB6:

            return VLC_EGENERIC;

        default:

            if( p_peek[3] > 0xB9 )

                return VLC_EGENERIC;

            break;

    }

    return VLC_SUCCESS;

}

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

 * Open: initializes demux structures

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

static int Open( vlc_object_t * p_this )

{

    demux_t     *p_demux = (demux_t*)p_this;

    demux_sys_t *p_sys;

    bool   b_forced = false;

    const uint8_t *p_peek;

    es_format_t  fmt;

    if( vlc_stream_Peek( p_demux->s, &p_peek, 8 ) < 8 )

        return VLC_EGENERIC;

    if( p_demux->obj.force )

        b_forced = true;

    if( p_peek[0] != 0x00 || p_peek[1] != 0x00 || p_peek[2] != 0x01 )

    {

        if( !b_forced ) return VLC_EGENERIC;

        msg_Err( p_demux, "this doesn't look like an MPEG ES stream, continuing" );

    }

    if( CheckMPEGStartCode( p_peek ) != VLC_SUCCESS )

    {

        if( !b_forced ) return VLC_EGENERIC;

        msg_Err( p_demux, "this seems to be a system stream (PS plug-in ?), but continuing" );

    }

    p_demux->pf_demux  = Demux;

    p_demux->pf_control= Control;

    p_demux->p_sys     = p_sys = malloc( sizeof( demux_sys_t ) );

    p_sys->b_start     = true;

    p_sys->p_es        = NULL;

    /* Load the mpegvideo packetizer */

    es_format_Init( &fmt, VIDEO_ES, VLC_CODEC_MPGV );

    p_sys->p_packetizer = demux_PacketizerNew( VLC_OBJECT(p_demux), &fmt, "mpeg video" );

    if( !p_sys->p_packetizer )

    {

        free( p_sys );

        return VLC_EGENERIC;

    }

    /* create the output */

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

    if( p_sys->p_es == NULL )

    {

        Close( p_this );

        return VLC_EGENERIC;

    }

    return VLC_SUCCESS;

}

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

 * Demux: reads and demuxes data packets

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

 * 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_in, *p_block_out;

    bool b_eof = false;

    if( ( p_block_in = vlc_stream_Block( p_demux->s, MPGV_PACKET_SIZE ) ) == NULL )

    {

        b_eof = true;

    }

    if( p_block_in )

    {

        p_block_in->i_pts =

        p_block_in->i_dts = ( p_sys->b_start ) ? VLC_TICK_0 : VLC_TICK_INVALID;

    }

    while( (p_block_out = p_sys->p_packetizer->pf_packetize( p_sys->p_packetizer,

                                                             p_block_in ? &p_block_in : NULL )) )

    {

        p_sys->b_start = false;

        while( p_block_out )

        {

            block_t *p_next = p_block_out->p_next;

            es_out_SetPCR( p_demux->out, p_block_out->i_dts );

            p_block_out->p_next = NULL;

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

            p_block_out = p_next;

        }

    }

    return (b_eof) ? VLC_DEMUXER_EOF : 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; */

    /* FIXME calculate the bitrate */

    if( i_query == DEMUX_SET_TIME )

        return VLC_EGENERIC;

    else

        return demux_vaControlHelper( p_demux->s,

                                       0, -1,

                                       0, 1, i_query, args );

}