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

 * spudec.c : SPU decoder thread

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

 * Copyright (C) 2000-2001, 2006 VLC authors and VideoLAN

 *

 * Authors: Sam Hocevar <sam@zoy.org>

 *          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_codec.h>

#include "spudec.h"

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

 * Module descriptor.

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

static int  DecoderOpen   ( vlc_object_t * );

static int  PacketizerOpen( vlc_object_t * );

static void Close         ( vlc_object_t * );

#define DVDSUBTRANS_DISABLE_TEXT N_("Disable DVD subtitle transparency")

#define DVDSUBTRANS_DISABLE_LONGTEXT N_("Removes all transparency effects " \

                                        "used in DVD subtitles.")

vlc_module_begin ()

    set_description( N_("DVD subtitles decoder") )

    set_shortname( N_("DVD subtitles") )

    set_capability( "spu decoder", 75 )

    set_subcategory( SUBCAT_INPUT_SCODEC )

    set_callbacks( DecoderOpen, Close )

    add_bool( "dvdsub-transparency", false,

              DVDSUBTRANS_DISABLE_TEXT, DVDSUBTRANS_DISABLE_LONGTEXT )

    add_submodule ()

    set_description( N_("DVD subtitles packetizer") )

    set_capability( "spu packetizer", 50 )

    set_callbacks( PacketizerOpen, Close )

vlc_module_end ()

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

 * Local prototypes

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

static block_t *      Reassemble( decoder_t *, block_t * );

static int            Decode    ( decoder_t *, block_t * );

static block_t *      Packetize ( decoder_t *, block_t ** );

static int OpenCommon( vlc_object_t *p_this, bool b_packetizer )

{

    decoder_t     *p_dec = (decoder_t*)p_this;

    decoder_sys_t *p_sys;

    if( p_dec->fmt_in->i_codec != VLC_CODEC_SPU )

        return VLC_EGENERIC;

    p_dec->p_sys = p_sys = malloc( sizeof( decoder_sys_t ) );

    if( !p_sys )

        return VLC_ENOMEM;

    p_sys->b_packetizer = b_packetizer;

    p_sys->b_disabletrans = var_InheritBool( p_dec, "dvdsub-transparency" );

    p_sys->i_spu_size = 0;

    p_sys->buffer     = NULL;

    p_sys->buffer_size = 0;

    p_sys->i_spu      = 0;

    p_sys->p_block    = NULL;

    if( b_packetizer )

    {

        p_dec->pf_packetize  = Packetize;

        es_format_Copy( &p_dec->fmt_out, p_dec->fmt_in );

        p_dec->fmt_out.i_codec = VLC_CODEC_SPU;

    }

    else

    {

        p_dec->fmt_out.i_codec = VLC_CODEC_SPU;

        p_dec->pf_decode    = Decode;

    }

    return VLC_SUCCESS;

}

static int DecoderOpen( vlc_object_t *p_this )

{

    return OpenCommon( p_this, false );

}

static int PacketizerOpen( vlc_object_t *p_this )

{

    return OpenCommon( p_this, true );

}

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

 * 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;

    if( p_sys->p_block )

    {

        block_ChainRelease( p_sys->p_block );

    }

    free( p_sys->buffer );

    free( p_sys );

}

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

 * Decode:

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

static int Decode( decoder_t *p_dec, block_t *p_block )

{

    decoder_sys_t *p_sys = p_dec->p_sys;

    block_t       *p_spu_block;

    if( p_block == NULL ) /* No Drain */

        return VLCDEC_SUCCESS;

    p_spu_block = Reassemble( p_dec, p_block );

    if( ! p_spu_block )

    {

        return VLCDEC_SUCCESS;

    }

    size_t block_size;

    vlc_frame_ChainProperties( p_spu_block, NULL, &block_size, NULL );

    if ( p_sys->buffer_size < block_size )

    {

        void *bigger = realloc( p_sys->buffer, block_size );

        if ( unlikely(bigger == NULL) )

        {

            return VLCDEC_ECRITICAL;

        }

        p_sys->buffer = bigger;

        p_sys->buffer_size = block_size;

    }

    p_sys->i_spu = block_ChainExtract( p_spu_block, p_sys->buffer, block_size );

    p_sys->i_pts = p_spu_block->i_pts;

    block_ChainRelease( p_spu_block );

    /* Parse and decode */

    ParsePacket( p_dec, decoder_QueueSub );

    /* reinit context */

    p_sys->i_spu_size = 0;

    p_sys->i_rle_size = 0;

    p_sys->i_spu      = 0;

    p_sys->p_block    = NULL;

    return VLCDEC_SUCCESS;

}

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

 * Packetize:

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

static block_t *Packetize( decoder_t *p_dec, block_t **pp_block )

{

    decoder_sys_t *p_sys = p_dec->p_sys;

    if( pp_block == NULL ) /* No Drain */

        return NULL;

    block_t *p_block = *pp_block; *pp_block = NULL;

    if( p_block == NULL )

        return NULL;

    block_t *p_spu = Reassemble( p_dec, p_block );

    if( ! p_spu )

    {

        return NULL;

    }

    p_spu->i_dts = p_spu->i_pts;

    p_spu->i_length = VLC_TICK_INVALID;

    /* reinit context */

    p_sys->i_spu_size = 0;

    p_sys->i_rle_size = 0;

    p_sys->i_spu      = 0;

    p_sys->p_block    = NULL;

    return block_ChainGather( p_spu );

}

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

 * Reassemble:

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

static block_t *Reassemble( decoder_t *p_dec, block_t *p_block )

{

    decoder_sys_t *p_sys = p_dec->p_sys;

    if( p_block->i_flags & BLOCK_FLAG_CORRUPTED )

    {

        block_Release( p_block );

        return NULL;

    }

    if( p_sys->i_spu_size <= 0 &&

        ( p_block->i_pts == VLC_TICK_INVALID || p_block->i_buffer < 4 ) )

    {

        msg_Dbg( p_dec, "invalid starting packet (size < 4 or pts <=0)" );

        msg_Dbg( p_dec, "spu size: %d, i_pts: %"PRId64" i_buffer: %zu",

                 p_sys->i_spu_size, p_block->i_pts, p_block->i_buffer );

        block_Release( p_block );

        return NULL;

    }

    block_ChainAppend( &p_sys->p_block, p_block );

    p_sys->i_spu += p_block->i_buffer;

    if( p_sys->i_spu_size <= 0 )

    {

        p_sys->i_spu_size = ( p_block->p_buffer[0] << 8 )|

            p_block->p_buffer[1];

        p_sys->i_rle_size = ( ( p_block->p_buffer[2] << 8 )|

            p_block->p_buffer[3] ) - 4;

        /* msg_Dbg( p_dec, "i_spu_size=%d i_rle=%d",

                    p_sys->i_spu_size, p_sys->i_rle_size ); */

        if( p_sys->i_spu_size <= 0 || p_sys->i_rle_size >= p_sys->i_spu_size )

        {

            p_sys->i_spu_size = 0;

            p_sys->i_rle_size = 0;

            p_sys->i_spu      = 0;

            p_sys->p_block    = NULL;

            block_Release( p_block );

            return NULL;

        }

    }

    if( p_sys->i_spu >= p_sys->i_spu_size )

    {

        /* We have a complete sub */

        if( p_sys->i_spu > p_sys->i_spu_size )

            msg_Dbg( p_dec, "SPU packets size=%d should be %d",

                     p_sys->i_spu, p_sys->i_spu_size );

        return p_sys->p_block;

    }

    return NULL;

}