modules/demux/cdg.c

   1 /*****************************************************************************
   2  * cdg.c : cdg file demux module for vlc
   3  *****************************************************************************
   4  * Copyright (C) 2007 Laurent Aimar
   5  * $Id$
   6  *
   7  * Authors: Laurent Aimar <fenrir # via.ecp.fr>
   8  *
   9  * This program is free software; you can redistribute it and/or modify it
  10  * under the terms of the GNU Lesser General Public License as published by
  11  * the Free Software Foundation; either version 2.1 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  17  * GNU Lesser General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU Lesser General Public License
  20  * along with this program; if not, write to the Free Software Foundation,
  21  * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  22  *****************************************************************************/
  23
  24 /*****************************************************************************
  25  * Preamble
  26  *****************************************************************************/
  27
  28 #ifdef HAVE_CONFIG_H
  29 # include "config.h"
  30 #endif
  31
  32 #include <vlc_common.h>
  33 #include <vlc_plugin.h>
  34 #include <vlc_demux.h>
  35
  36 /*****************************************************************************
  37  * Module descriptor
  38  *****************************************************************************/
  39 static int  Open ( vlc_object_t * );
  40
  41 vlc_module_begin ()
  42     set_description( N_("CDG demuxer") )
  43     set_category( CAT_INPUT )
  44     set_subcategory( SUBCAT_INPUT_DEMUX )
  45     set_capability( "demux", 3 )
  46     set_callbacks( Open, NULL )
  47     add_shortcut( "cdg", "subtitle" )
  48 vlc_module_end ()
  49
  50 /*****************************************************************************
  51  * Local prototypes
  52  *****************************************************************************/
  53 static int Demux  ( demux_t * );
  54 static int Control( demux_t *, int i_query, va_list args );
  55
  56 typedef struct
  57 {
  58     es_format_t     fmt;
  59     es_out_id_t     *p_es;
  60
  61     date_t          pts;
  62 } demux_sys_t;
  63
  64 #define CDG_FRAME_SIZE (96)
  65 #define CDG_FRAME_RATE (75)
  66 #define CDG_FRAME_DELTA (CLOCK_FREQ / CDG_FRAME_RATE)
  67
  68 /*****************************************************************************
  69  * Open: check file and initializes structures
  70  *****************************************************************************/
  71 static int Open( vlc_object_t * p_this )
  72 {
  73     demux_t     *p_demux = (demux_t*)p_this;
  74
  75     /* Identify cdg file by extension, as there is no simple way to
  76      * detect it */
  77     if( !demux_IsPathExtension( p_demux, ".cdg" ) && !demux_IsForced( p_demux, "cdg" ) )
  78         return VLC_EGENERIC;
  79
  80     /* CDG file size has to be multiple of CDG_FRAME_SIZE (it works even
  81      * if size is unknown ie 0) */
  82 //    if( (stream_Size( p_demux->s ) % CDG_FRAME_SIZE) != 0 )
  83 //    {
  84 //        msg_Err( p_demux, "Reject CDG file based on its size" );
  85 //        return VLC_EGENERIC;
  86 //    }
  87
  88     demux_sys_t *p_sys = vlc_obj_malloc( p_this, sizeof (*p_sys) );
  89     if( unlikely(p_sys == NULL) )
  90         return VLC_ENOMEM;
  91
  92     es_format_Init( &p_sys->fmt, VIDEO_ES, VLC_CODEC_CDG );
  93     p_sys->fmt.video.i_width  = 300-2*6;
  94     p_sys->fmt.video.i_height = 216-2*12 ;
  95     p_sys->fmt.video.i_visible_width = p_sys->fmt.video.i_width;
  96     p_sys->fmt.video.i_visible_height = p_sys->fmt.video.i_height;
  97
  98     p_sys->p_es = es_out_Add( p_demux->out, &p_sys->fmt );
  99     if( unlikely(p_sys->p_es == NULL) )
 100         return VLC_ENOMEM;
 101
 102     /* There is CDG_FRAME_RATE frames per second */
 103     date_Init( &p_sys->pts, CDG_FRAME_RATE, 1 );
 104     date_Set( &p_sys->pts, VLC_TICK_0 );
 105
 106     p_demux->pf_demux   = Demux;
 107     p_demux->pf_control = Control;
 108     p_demux->p_sys      = p_sys;
 109     return VLC_SUCCESS;
 110 }
 111
 112 static vlc_tick_t PosToDate( demux_t *p_demux )
 113 {
 114     return vlc_stream_Tell( p_demux->s ) / CDG_FRAME_SIZE * CDG_FRAME_DELTA;
 115 }
 116
 117 /*****************************************************************************
 118  * Demux: read packet and send them to decoders
 119  *****************************************************************************
 120  * Returns -1 in case of error, 0 in case of EOF, 1 otherwise
 121  *****************************************************************************/
 122 static int Demux( demux_t *p_demux )
 123 {
 124     demux_sys_t *p_sys = p_demux->p_sys;
 125     block_t     *p_block;
 126     vlc_tick_t  i_date;
 127
 128     p_block = vlc_stream_Block( p_demux->s, CDG_FRAME_SIZE );
 129     if( p_block == NULL )
 130     {
 131         msg_Dbg( p_demux, "cannot read data, eof" );
 132         return VLC_DEMUXER_EOF;
 133     }
 134
 135     i_date = PosToDate( p_demux );
 136     if( i_date >= date_Get( &p_sys->pts ) + CDG_FRAME_DELTA )
 137     {
 138         p_block->i_dts = p_block->i_pts = VLC_TICK_0 + i_date;
 139         date_Set( &p_sys->pts, VLC_TICK_0 + i_date );
 140     }
 141     else
 142     {
 143         p_block->i_dts = VLC_TICK_0 + i_date;
 144         p_block->i_pts = date_Get( &p_sys->pts );
 145     }
 146
 147     es_out_SetPCR( p_demux->out, p_block->i_pts );
 148     es_out_Send( p_demux->out, p_sys->p_es, p_block );
 149     return VLC_DEMUXER_SUCCESS;
 150 }
 151
 152 /*****************************************************************************
 153  * Control:
 154  *****************************************************************************/
 155 static int Control( demux_t *p_demux, int i_query, va_list args )
 156 {
 157     demux_sys_t *p_sys = p_demux->p_sys;
 158     uint64_t i_old_offset = vlc_stream_Tell( p_demux->s );
 159     int i_ret = demux_vaControlHelper( p_demux->s, 0, -1,
 160                                        8*CDG_FRAME_SIZE*CDG_FRAME_RATE, CDG_FRAME_SIZE,
 161                                        i_query, args );
 162     if( !i_ret && ( i_query == DEMUX_SET_POSITION || i_query == DEMUX_SET_TIME ) )
 163     {
 164         date_Set( &p_sys->pts, PosToDate( p_demux ) );
 165         if ( i_old_offset > vlc_stream_Tell( p_demux->s ) )
 166             i_ret = vlc_stream_Seek( p_demux->s, 0 );
 167         else
 168             i_ret = vlc_stream_Seek( p_demux->s, i_old_offset );
 169     }
 170
 171     return i_ret;
 172 }
 173