/*****************************************************************************
 * mkv.cpp : matroska demuxer
 *****************************************************************************
 * Copyright (C) 2003-2005, 2008, 2010 VLC authors and VideoLAN
 * $Id: 63984094d4e004a2acf30bb96f93aa39118aad85 $
 *
 * Authors: Laurent Aimar <fenrir@via.ecp.fr>
 *          Steve Lhomme <steve.lhomme@free.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.
 *****************************************************************************/

#include "mkv.hpp"
#include "util.hpp"

#include "matroska_segment.hpp"
#include "demux.hpp"

#include "chapters.hpp"
#include "Ebml_parser.hpp"

#include "stream_io_callback.hpp"

#include <vlc_fs.h>
#include <vlc_url.h>

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

vlc_module_begin ()
    set_shortname( "Matroska" )
    set_description( N_("Matroska stream demuxer" ) )
    set_capability( "demux", 50 )
    set_callbacks( Open, Close )
    set_category( CAT_INPUT )
    set_subcategory( SUBCAT_INPUT_DEMUX )

    add_bool( "mkv-use-ordered-chapters", true,
            N_("Respect ordered chapters"),
            N_("Play chapters in the order specified in the segment."), false );

    add_bool( "mkv-use-chapter-codec", true,
            N_("Chapter codecs"),
            N_("Use chapter codecs found in the segment."), true );

    add_bool( "mkv-preload-local-dir", true,
            N_("Preload MKV files in the same directory"),
            N_("Preload matroska files in the same directory to find linked segments (not good for broken files)."), false );

    add_bool( "mkv-seek-percent", false,
            N_("Seek based on percent not time"),
            N_("Seek based on percent not time."), true );

    add_bool( "mkv-use-dummy", false,
            N_("Dummy Elements"),
            N_("Read and discard unknown EBML elements (not good for broken files)."), true );

    add_shortcut( "mka", "mkv" )
vlc_module_end ()

class demux_sys_t;

static int  Demux  ( demux_t * );
static int  Control( demux_t *, int, va_list );
static void Seek   ( demux_t *, mtime_t i_date, double f_percent, virtual_chapter_c *p_chapter );

/*****************************************************************************
 * Open: initializes matroska demux structures
 *****************************************************************************/
static int Open( vlc_object_t * p_this )
{
    demux_t            *p_demux = (demux_t*)p_this;
    demux_sys_t        *p_sys;
    matroska_stream_c  *p_stream;
    matroska_segment_c *p_segment;
    const uint8_t      *p_peek;
    std::string         s_path, s_filename;
    vlc_stream_io_callback *p_io_callback;
    EbmlStream         *p_io_stream;
    bool                b_need_preload = false;

    /* peek the begining */
    if( stream_Peek( p_demux->s, &p_peek, 4 ) < 4 ) return VLC_EGENERIC;

    /* is a valid file */
    if( p_peek[0] != 0x1a || p_peek[1] != 0x45 ||
        p_peek[2] != 0xdf || p_peek[3] != 0xa3 ) return VLC_EGENERIC;

    /* Set the demux function */
    p_demux->pf_demux   = Demux;
    p_demux->pf_control = Control;
    p_demux->p_sys      = p_sys = new demux_sys_t( *p_demux );

    p_io_callback = new vlc_stream_io_callback( p_demux->s, false );
    p_io_stream = new EbmlStream( *p_io_callback );

    if( p_io_stream == NULL )
    {
        msg_Err( p_demux, "failed to create EbmlStream" );
        delete p_io_callback;
        delete p_sys;
        return VLC_EGENERIC;
    }

    p_stream = p_sys->AnalyseAllSegmentsFound( p_demux, p_io_stream, true );
    if( p_stream == NULL )
    {
        msg_Err( p_demux, "cannot find KaxSegment or missing mandatory KaxInfo" );
        goto error;
    }
    p_sys->streams.push_back( p_stream );

    p_stream->p_io_callback = p_io_callback;
    p_stream->p_estream = p_io_stream;

    for (size_t i=0; i<p_stream->segments.size(); i++)
    {
        p_stream->segments[i]->Preload();
        b_need_preload |= p_stream->segments[i]->b_ref_external_segments;
    }

    p_segment = p_stream->segments[0];
    if( p_segment->cluster == NULL )
    {
        msg_Err( p_demux, "cannot find any cluster, damaged file ?" );
        goto error;
    }

    if (b_need_preload && var_InheritBool( p_demux, "mkv-preload-local-dir" ))
    {
        msg_Dbg( p_demux, "Preloading local dir" );
        /* get the files from the same dir from the same family (based on p_demux->psz_path) */
        if ( p_demux->psz_file && !strcmp( p_demux->psz_access, "file" ) )
        {
            // assume it's a regular file
            // get the directory path
            s_path = p_demux->psz_file;
            if (s_path.at(s_path.length() - 1) == DIR_SEP_CHAR)
            {
                s_path = s_path.substr(0,s_path.length()-1);
            }
            else
            {
                if (s_path.find_last_of(DIR_SEP_CHAR) > 0)
                {
                    s_path = s_path.substr(0,s_path.find_last_of(DIR_SEP_CHAR));
                }
            }

            DIR *p_src_dir = vlc_opendir(s_path.c_str());

            if (p_src_dir != NULL)
            {
                char *psz_file;
                while ((psz_file = vlc_readdir(p_src_dir)) != NULL)
                {
                    if (strlen(psz_file) > 4)
                    {
                        s_filename = s_path + DIR_SEP_CHAR + psz_file;

#if defined(_WIN32) || defined(__OS2__)
                        if (!strcasecmp(s_filename.c_str(), p_demux->psz_file))
#else
                        if (!s_filename.compare(p_demux->psz_file))
#endif
                        {
                            free (psz_file);
                            continue; // don't reuse the original opened file
                        }

                        if (!s_filename.compare(s_filename.length() - 3, 3, "mkv") ||
                            !s_filename.compare(s_filename.length() - 3, 3, "mka"))
                        {
                            // test whether this file belongs to our family
                            const uint8_t *p_peek;
                            bool          file_ok = false;
#warning Memory leak!
                            std::string   s_url = vlc_path2uri( s_filename.c_str(), "file" );
                            stream_t      *p_file_stream = stream_UrlNew(
                                                            p_demux,
                                                            s_url.c_str() );
                            /* peek the begining */
                            if( p_file_stream &&
                                stream_Peek( p_file_stream, &p_peek, 4 ) >= 4
                                && p_peek[0] == 0x1a && p_peek[1] == 0x45 &&
                                p_peek[2] == 0xdf && p_peek[3] == 0xa3 ) file_ok = true;

                            if ( file_ok )
                            {
                                vlc_stream_io_callback *p_file_io = new vlc_stream_io_callback( p_file_stream, true );
                                EbmlStream *p_estream = new EbmlStream(*p_file_io);

                                p_stream = p_sys->AnalyseAllSegmentsFound( p_demux, p_estream );

                                if ( p_stream == NULL )
                                {
                                    msg_Dbg( p_demux, "the file '%s' will not be used", s_filename.c_str() );
                                    delete p_estream;
                                    delete p_file_io;
                                }
                                else
                                {
                                    p_stream->p_io_callback = p_file_io;
                                    p_stream->p_estream = p_estream;
                                    p_sys->streams.push_back( p_stream );
                                }
                            }
                            else
                            {
                                if( p_file_stream ) {
                                    stream_Delete( p_file_stream );
                                }
                                msg_Dbg( p_demux, "the file '%s' cannot be opened", s_filename.c_str() );
                            }
                        }
                    }
                    free (psz_file);
                }
                closedir( p_src_dir );
            }
        }

        p_sys->PreloadFamily( *p_segment );
    }
    else if (b_need_preload)
        msg_Warn( p_demux, "This file references other files, you may want to enable the preload of local directory");

    if ( !p_sys->PreloadLinked() ||
         !p_sys->PreparePlayback( NULL ) )
    {
        msg_Err( p_demux, "cannot use the segment" );
        goto error;
    }

    p_sys->FreeUnused();

    p_sys->InitUi();

    return VLC_SUCCESS;

error:
    delete p_sys;
    return VLC_EGENERIC;
}

/*****************************************************************************
 * 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;
    virtual_segment_c *p_vsegment = p_sys->p_current_segment;
    if( p_vsegment )
    {
        matroska_segment_c *p_segment = p_vsegment->CurrentSegment();
        if( p_segment )
            p_segment->UnSelect();
    }

    delete p_sys;
}

/*****************************************************************************
 * Control:
 *****************************************************************************/
static int Control( demux_t *p_demux, int i_query, va_list args )
{
    demux_sys_t        *p_sys = p_demux->p_sys;
    int64_t     *pi64, i64;
    double      *pf, f;
    int         i_skp;
    size_t      i_idx;

    vlc_meta_t *p_meta;
    input_attachment_t ***ppp_attach;
    int *pi_int;

    switch( i_query )
    {
        case DEMUX_GET_ATTACHMENTS:
            ppp_attach = (input_attachment_t***)va_arg( args, input_attachment_t*** );
            pi_int = (int*)va_arg( args, int * );

            if( p_sys->stored_attachments.size() <= 0 )
                return VLC_EGENERIC;

            *pi_int = p_sys->stored_attachments.size();
            *ppp_attach = (input_attachment_t**)malloc( sizeof(input_attachment_t*) *
                                                        p_sys->stored_attachments.size() );
            if( !(*ppp_attach) )
                return VLC_ENOMEM;
            for( size_t i = 0; i < p_sys->stored_attachments.size(); i++ )
            {
                attachment_c *a = p_sys->stored_attachments[i];
                (*ppp_attach)[i] = vlc_input_attachment_New( a->fileName(), a->mimeType(), NULL,
                                                             a->p_data, a->size() );
            }
            return VLC_SUCCESS;

        case DEMUX_GET_META:
            p_meta = (vlc_meta_t*)va_arg( args, vlc_meta_t* );
            vlc_meta_Merge( p_meta, p_sys->meta );
            return VLC_SUCCESS;

        case DEMUX_GET_LENGTH:
            pi64 = (int64_t*)va_arg( args, int64_t * );
            if( p_sys->f_duration > 0.0 )
            {
                *pi64 = (int64_t)(p_sys->f_duration * 1000);
                return VLC_SUCCESS;
            }
            return VLC_EGENERIC;

        case DEMUX_GET_POSITION:
            pf = (double*)va_arg( args, double * );
            if ( p_sys->f_duration > 0.0 )
                *pf = (double)(p_sys->i_pts >= p_sys->i_start_pts ? p_sys->i_pts : p_sys->i_start_pts ) / (1000.0 * p_sys->f_duration);
            return VLC_SUCCESS;

        case DEMUX_SET_POSITION:
            if( p_sys->f_duration > 0.0 )
            {
                f = (double)va_arg( args, double );
                Seek( p_demux, -1, f, NULL );
                return VLC_SUCCESS;
            }
            return VLC_EGENERIC;

        case DEMUX_GET_TIME:
            pi64 = (int64_t*)va_arg( args, int64_t * );
            *pi64 = p_sys->i_pts;
            return VLC_SUCCESS;

        case DEMUX_GET_TITLE_INFO:
            if( p_sys->titles.size() > 1 || ( p_sys->titles.size() == 1 && p_sys->titles[0]->i_seekpoint > 0 ) )
            {
                input_title_t ***ppp_title = (input_title_t***)va_arg( args, input_title_t*** );
                int *pi_int    = (int*)va_arg( args, int* );

                *pi_int = p_sys->titles.size();
                *ppp_title = (input_title_t**)malloc( sizeof( input_title_t* ) * p_sys->titles.size() );

                for( size_t i = 0; i < p_sys->titles.size(); i++ )
                    (*ppp_title)[i] = vlc_input_title_Duplicate( p_sys->titles[i] );
                return VLC_SUCCESS;
            }
            return VLC_EGENERIC;

        case DEMUX_SET_TITLE:
            /* handle editions as titles */
            i_idx = (int)va_arg( args, int );
            if(i_idx <  p_sys->titles.size() && p_sys->titles[i_idx]->i_seekpoint)
            {
                p_sys->p_current_segment->i_current_edition = i_idx;
                p_sys->i_current_title = i_idx;
                p_sys->p_current_segment->p_current_chapter = p_sys->p_current_segment->editions[p_sys->p_current_segment->i_current_edition]->getChapterbyTimecode(0);

                Seek( p_demux, (int64_t)p_sys->titles[i_idx]->seekpoint[0]->i_time_offset, -1, NULL);
                p_demux->info.i_update |= INPUT_UPDATE_SEEKPOINT;
                p_demux->info.i_seekpoint = 0;
                p_sys->f_duration = (float) p_sys->titles[i_idx]->i_length / 1000.f;
                return VLC_SUCCESS;
            }
            return VLC_EGENERIC;

        case DEMUX_SET_SEEKPOINT:
            i_skp = (int)va_arg( args, int );

            // TODO change the way it works with the << & >> buttons on the UI (+1/-1 instead of a number)
            if( p_sys->titles.size() && i_skp < p_sys->titles[p_sys->i_current_title]->i_seekpoint)
            {
                Seek( p_demux, (int64_t)p_sys->titles[p_sys->i_current_title]->seekpoint[i_skp]->i_time_offset, -1, NULL);
                p_demux->info.i_update |= INPUT_UPDATE_SEEKPOINT;
                p_demux->info.i_seekpoint = i_skp;
                return VLC_SUCCESS;
            }
            return VLC_EGENERIC;

        case DEMUX_GET_FPS:
            pf = (double *)va_arg( args, double * );
            *pf = 0.0;
            if( p_sys->p_current_segment && p_sys->p_current_segment->CurrentSegment() )
            {
                const matroska_segment_c *p_segment = p_sys->p_current_segment->CurrentSegment();
                for( size_t i = 0; i < p_segment->tracks.size(); i++ )
                {
                    mkv_track_t *tk = p_segment->tracks[i];
                    if( tk->fmt.i_cat == VIDEO_ES && tk->fmt.video.i_frame_rate_base > 0 )
                    {
                        *pf = (double)tk->fmt.video.i_frame_rate / tk->fmt.video.i_frame_rate_base;
                        break;
                    }
                }
            }
            return VLC_SUCCESS;

        case DEMUX_SET_TIME:
            i64 = (int64_t) va_arg( args, int64_t );
            msg_Dbg(p_demux,"SET_TIME to %"PRId64, i64 );
            Seek( p_demux, i64, -1, NULL );
            return VLC_SUCCESS;
        default:
            return VLC_EGENERIC;
    }
}

/* Seek */
static void Seek( demux_t *p_demux, mtime_t i_date, double f_percent, virtual_chapter_c *p_chapter )
{
    demux_sys_t        *p_sys = p_demux->p_sys;
    virtual_segment_c  *p_vsegment = p_sys->p_current_segment;
    matroska_segment_c *p_segment = p_vsegment->CurrentSegment();
    mtime_t            i_time_offset = 0;
    int64_t            i_global_position = -1;

    int         i_index;

    msg_Dbg( p_demux, "seek request to %"PRId64" (%f%%)", i_date, f_percent );
    if( i_date < 0 && f_percent < 0 )
    {
        msg_Warn( p_demux, "cannot seek nowhere!" );
        return;
    }
    if( f_percent > 1.0 )
    {
        msg_Warn( p_demux, "cannot seek so far!" );
        return;
    }
    if( p_sys->f_duration < 0 )
    {
        msg_Warn( p_demux, "cannot seek without duration!");
        return;
    }

    /* seek without index or without date */
    if( f_percent >= 0 && (var_InheritBool( p_demux, "mkv-seek-percent" ) || !p_segment->b_cues || i_date < 0 ))
    {
        i_date = int64_t( f_percent * p_sys->f_duration * 1000.0 );
        if( !p_segment->b_cues )
        {
            int64_t i_pos = int64_t( f_percent * stream_Size( p_demux->s ) );

            msg_Dbg( p_demux, "lengthy way of seeking for pos:%"PRId64, i_pos );
            for( i_index = 0; i_index < p_segment->i_index; i_index++ )
            {
                if( p_segment->p_indexes[i_index].i_position >= i_pos &&
                    p_segment->p_indexes[i_index].i_time > 0 )
                    break;
            }
            if( i_index == p_segment->i_index )
                i_index--;

            if( p_segment->p_indexes[i_index].i_position < i_pos )
            {
                msg_Dbg( p_demux, "no cues, seek request to global pos: %"PRId64, i_pos );
                i_global_position = i_pos;
            }
        }
    }
    p_vsegment->Seek( *p_demux, i_date, i_time_offset, p_chapter, i_global_position );
}

/* Needed by matroska_segment::Seek() and Seek */
void BlockDecode( demux_t *p_demux, KaxBlock *block, KaxSimpleBlock *simpleblock,
                         mtime_t i_pts, mtime_t i_duration, bool f_mandatory )
{
    demux_sys_t        *p_sys = p_demux->p_sys;
    matroska_segment_c *p_segment = p_sys->p_current_segment->CurrentSegment();

    if( !p_segment ) return;

    size_t          i_track;
    if( p_segment->BlockFindTrackIndex( &i_track, block, simpleblock ) )
    {
        msg_Err( p_demux, "invalid track number" );
        return;
    }

    mkv_track_t *tk = p_segment->tracks[i_track];

    if( tk->fmt.i_cat != NAV_ES && tk->p_es == NULL )
    {
        msg_Err( p_demux, "unknown track number" );
        return;
    }
    if( i_pts + i_duration < p_sys->i_start_pts && tk->fmt.i_cat == AUDIO_ES )
    {
        return; /* discard audio packets that shouldn't be rendered */
    }

    if ( tk->fmt.i_cat != NAV_ES )
    {
        bool b;
        es_out_Control( p_demux->out, ES_OUT_GET_ES_STATE, tk->p_es, &b );

        if( !b )
        {
            tk->b_inited = false;
            if( tk->fmt.i_cat == VIDEO_ES || tk->fmt.i_cat == AUDIO_ES )
                tk->i_last_dts = i_pts;
            return;
        }
    }


    /* First send init data */
    if( !tk->b_inited && tk->i_data_init > 0 )
    {
        block_t *p_init;

        msg_Dbg( p_demux, "sending header (%d bytes)", tk->i_data_init );
        p_init = MemToBlock( tk->p_data_init, tk->i_data_init, 0 );
        if( p_init ) es_out_Send( p_demux->out, tk->p_es, p_init );
    }
    tk->b_inited = true;


    size_t frame_size = 0;
    size_t block_size = 0;

    if( simpleblock != NULL )
        block_size = simpleblock->GetSize();
    else
        block_size = block->GetSize();
 
    for( unsigned int i = 0;
         ( block != NULL && i < block->NumberFrames()) || ( simpleblock != NULL && i < simpleblock->NumberFrames() );
         i++ )
    {
        block_t *p_block;
        DataBuffer *data;
        if( simpleblock != NULL )
        {
            data = &simpleblock->GetBuffer(i);
            // condition when the DTS is correct (keyframe or B frame == NOT P frame)
            f_mandatory = simpleblock->IsDiscardable() || simpleblock->IsKeyframe();
        }
        else
        {
            data = &block->GetBuffer(i);
            // condition when the DTS is correct (keyframe or B frame == NOT P frame)
        }
        frame_size += data->Size();
        if( !data->Buffer() || data->Size() > SIZE_MAX || frame_size > block_size  )
        {
            msg_Warn( p_demux, "Cannot read frame (too long or no frame)" );
            break;
        }

        if( tk->i_compression_type == MATROSKA_COMPRESSION_HEADER &&
            tk->p_compression_data != NULL &&
            tk->i_encoding_scope & MATROSKA_ENCODING_SCOPE_ALL_FRAMES )
            p_block = MemToBlock( data->Buffer(), data->Size(), tk->p_compression_data->GetSize() );
        else if( unlikely( tk->fmt.i_codec == VLC_CODEC_WAVPACK ) )
            p_block = packetize_wavpack(tk, data->Buffer(), data->Size());
        else
            p_block = MemToBlock( data->Buffer(), data->Size(), 0 );

        if( p_block == NULL )
        {
            break;
        }

#if defined(HAVE_ZLIB_H)
        if( tk->i_compression_type == MATROSKA_COMPRESSION_ZLIB &&
            tk->i_encoding_scope & MATROSKA_ENCODING_SCOPE_ALL_FRAMES )
        {
            p_block = block_zlib_decompress( VLC_OBJECT(p_demux), p_block );
            if( p_block == NULL )
                break;
        }
        else
#endif
        if( tk->i_compression_type == MATROSKA_COMPRESSION_HEADER &&
            tk->i_encoding_scope & MATROSKA_ENCODING_SCOPE_ALL_FRAMES )
        {
            memcpy( p_block->p_buffer, tk->p_compression_data->GetBuffer(), tk->p_compression_data->GetSize() );
        }

        if( tk->fmt.i_codec == VLC_CODEC_COOK ||
            tk->fmt.i_codec == VLC_CODEC_ATRAC3 )
        {
            handle_real_audio(p_demux, tk, p_block, i_pts);
            block_Release(p_block);
            i_pts = ( tk->i_default_duration )?
                i_pts + ( mtime_t )( tk->i_default_duration / 1000 ):
                VLC_TS_INVALID;
            continue;
        }

        if ( tk->fmt.i_cat == NAV_ES )
        {
            // TODO handle the start/stop times of this packet
            p_sys->p_ev->SetPci( (const pci_t *)&p_block->p_buffer[1]);
            block_Release( p_block );
            return;
        }
        // correct timestamping when B frames are used
        if( tk->fmt.i_cat != VIDEO_ES )
        {
            p_block->i_dts = p_block->i_pts = i_pts;
        }
        else
        {
            if( tk->b_dts_only )
            {
                p_block->i_pts = VLC_TS_INVALID;
                p_block->i_dts = i_pts;
            }
            else if( tk->b_pts_only )
            {
                p_block->i_pts = i_pts;
                p_block->i_dts = i_pts;
            }
            else
            {
                p_block->i_pts = i_pts;
                if ( f_mandatory )
                    p_block->i_dts = p_block->i_pts;
                else
                    p_block->i_dts = min( i_pts, tk->i_last_dts + ( mtime_t )( tk->i_default_duration / 1000 ) );
            }
        }
        if( tk->fmt.i_cat == VIDEO_ES || tk->fmt.i_cat == AUDIO_ES )
            tk->i_last_dts = p_block->i_dts;

#if 0
msg_Dbg( p_demux, "block i_dts: %"PRId64" / i_pts: %"PRId64, p_block->i_dts, p_block->i_pts);
#endif
        if( strcmp( tk->psz_codec, "S_VOBSUB" ) )
        {
            p_block->i_length = i_duration * tk-> f_timecodescale * (double) p_segment->i_timescale / 1000.0;
        }

        /* FIXME remove when VLC_TS_INVALID work is done */
        if( i == 0 || p_block->i_dts > VLC_TS_INVALID )
            p_block->i_dts += VLC_TS_0;
        if( !tk->b_dts_only && ( i == 0 || p_block->i_pts > VLC_TS_INVALID ) )
            p_block->i_pts += VLC_TS_0;

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

        /* use time stamp only for first block */
        i_pts = ( tk->i_default_duration )?
                 i_pts + ( mtime_t )( tk->i_default_duration / 1000 ):
                 VLC_TS_INVALID;
    }
}

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

    vlc_mutex_lock( &p_sys->lock_demuxer );

    virtual_segment_c  *p_vsegment = p_sys->p_current_segment;
    matroska_segment_c *p_segment = p_vsegment->CurrentSegment();
    if ( p_segment == NULL )
    {
        vlc_mutex_unlock( &p_sys->lock_demuxer );
        return 0;
    }
    int                i_block_count = 0;
    int                i_return = 0;

    for( ;; )
    {
        if( p_sys->i_pts >= p_sys->i_start_pts  )
            if ( p_vsegment->UpdateCurrentToChapter( *p_demux ) )
            {
                i_return = 1;
                break;
            }

        if ( p_vsegment->CurrentEdition() &&
             p_vsegment->CurrentEdition()->b_ordered &&
             p_vsegment->CurrentChapter() == NULL )
            /* nothing left to read in this ordered edition */
            break;

        KaxBlock *block;
        KaxSimpleBlock *simpleblock;
        int64_t i_block_duration = 0;
        bool b_key_picture;
        bool b_discardable_picture;
        if( p_segment->BlockGet( block, simpleblock, &b_key_picture, &b_discardable_picture, &i_block_duration ) )
        {
            if ( p_vsegment->CurrentEdition() && p_vsegment->CurrentEdition()->b_ordered )
            {
                const virtual_chapter_c *p_chap = p_vsegment->CurrentChapter();
                // check if there are more chapters to read
                if ( p_chap != NULL )
                {
                    /* TODO handle successive chapters with the same user_start_time/user_end_time
                    */
                    p_sys->i_pts = p_chap->i_virtual_stop_time;
                    p_sys->i_pts++; // trick to avoid staying on segments with no duration and no content

                    i_return = 1;
                }

                break;
            }
            else
            {
                msg_Warn( p_demux, "cannot get block EOF?" );
                break;
            }
        }

        if( simpleblock != NULL )
            p_sys->i_pts = p_sys->i_chapter_time + ( (mtime_t)simpleblock->GlobalTimecode() / INT64_C(1000) );
        else
            p_sys->i_pts = p_sys->i_chapter_time + ( (mtime_t)block->GlobalTimecode() / INT64_C(1000) );

        mtime_t i_pcr = VLC_TS_INVALID;
        for( size_t i = 0; i < p_segment->tracks.size(); i++)
            if( p_segment->tracks[i]->i_last_dts > VLC_TS_INVALID &&
                ( p_segment->tracks[i]->i_last_dts < i_pcr || i_pcr == VLC_TS_INVALID ))
                i_pcr = p_segment->tracks[i]->i_last_dts;

        if( i_pcr > p_sys->i_pcr + 300000 )
        {
            es_out_Control( p_demux->out, ES_OUT_SET_PCR, VLC_TS_0 + p_sys->i_pcr );
            p_sys->i_pcr = i_pcr;
        }

        if( p_sys->i_pts >= p_sys->i_start_pts  )
        {
            if ( p_vsegment->UpdateCurrentToChapter( *p_demux ) )
            {
                i_return = 1;
                delete block;
                break;
            }
        }

        if ( p_vsegment->CurrentEdition() &&
             p_vsegment->CurrentEdition()->b_ordered &&
             p_vsegment->CurrentChapter() == NULL )
        {
            /* nothing left to read in this ordered edition */
            delete block;
            break;
        }

        BlockDecode( p_demux, block, simpleblock, p_sys->i_pts, i_block_duration, b_key_picture || b_discardable_picture );

        delete block;
        i_block_count++;

        // TODO optimize when there is need to leave or when seeking has been called
        if( i_block_count > 5 )
        {
            i_return = 1;
            break;
        }
    }

    vlc_mutex_unlock( &p_sys->lock_demuxer );

    return i_return;
}

