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
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 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 General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, 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 static void Close( vlc_object_t * );
  41
  42 vlc_module_begin ()
  43     set_description( N_("CDG demuxer") )
  44     set_category( CAT_INPUT )
  45     set_subcategory( SUBCAT_INPUT_DEMUX )
  46     set_capability( "demux", 3 )
  47     set_callbacks( Open, Close )
  48     add_shortcut( "cdg", "subtitle" )
  49 vlc_module_end ()
  50
  51 /*****************************************************************************
  52  * Local prototypes
  53  *****************************************************************************/
  54 static int Demux  ( demux_t * );
  55 static int Control( demux_t *, int i_query, va_list args );
  56
  57 struct demux_sys_t
  58 {
  59     es_format_t     fmt;
  60     es_out_id_t     *p_es;
  61
  62     date_t          pts;
  63 };
  64
  65 #define CDG_FRAME_SIZE (96)
  66 #define CDG_FRAME_RATE (75)
  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     demux_sys_t *p_sys;
  75
  76     /* Identify cdg file by extension, as there is no simple way to
  77      * detect it */
  78     if( !demux_IsPathExtension( p_demux, ".cdg" ) && !demux_IsForced( p_demux, "cdg" ) )
  79         return VLC_EGENERIC;
  80
  81     /* CDG file size has to be multiple of CDG_FRAME_SIZE (it works even
  82      * if size is unknown ie 0) */
  83 //    if( (stream_Size( p_demux->s ) % CDG_FRAME_SIZE) != 0 )
  84 //    {
  85 //        msg_Err( p_demux, "Reject CDG file based on its size" );
  86 //        return VLC_EGENERIC;
  87 //    }
  88
  89     p_demux->pf_demux   = Demux;
  90     p_demux->pf_control = Control;
  91     p_demux->p_sys      = p_sys = malloc( sizeof( demux_sys_t ) );
  92
  93     /* */
  94     es_format_Init( &p_sys->fmt, VIDEO_ES, VLC_CODEC_CDG );
  95     p_sys->fmt.video.i_width  = 300-2*6;
  96     p_sys->fmt.video.i_height = 216-2*12 ;
  97
  98     p_sys->p_es = es_out_Add( p_demux->out, &p_sys->fmt );
  99
 100     /* There is CDG_FRAME_RATE frames per second */
 101     date_Init( &p_sys->pts, CDG_FRAME_RATE, 1 );
 102     date_Set( &p_sys->pts, 0 );
 103
 104     return VLC_SUCCESS;
 105 }
 106
 107 /*****************************************************************************
 108  * Demux: read packet and send them to decoders
 109  *****************************************************************************
 110  * Returns -1 in case of error, 0 in case of EOF, 1 otherwise
 111  *****************************************************************************/
 112 static int Demux( demux_t *p_demux )
 113 {
 114     demux_sys_t *p_sys = p_demux->p_sys;
 115     block_t     *p_block;
 116
 117     p_block = stream_Block( p_demux->s, CDG_FRAME_SIZE );
 118     if( p_block == NULL )
 119     {
 120         msg_Dbg( p_demux, "cannot read data, eof" );
 121         return 0;
 122     }
 123
 124     p_block->i_dts =
 125     p_block->i_pts = VLC_TS_0 + date_Get( &p_sys->pts );
 126
 127     es_out_Control( p_demux->out, ES_OUT_SET_PCR, p_block->i_pts );
 128
 129     es_out_Send( p_demux->out, p_sys->p_es, p_block );
 130
 131     date_Increment( &p_sys->pts, 1 );
 132
 133     return 1;
 134 }
 135
 136 /*****************************************************************************
 137  * Close: frees unused data
 138  *****************************************************************************/
 139 static void Close ( vlc_object_t * p_this )
 140 {
 141     demux_t *p_demux = (demux_t *)p_this;
 142     demux_sys_t *p_sys = p_demux->p_sys;
 143
 144     free( p_sys );
 145 }
 146
 147 /*****************************************************************************
 148  * Control:
 149  *****************************************************************************/
 150 static int Control( demux_t *p_demux, int i_query, va_list args )
 151 {
 152     int i_ret = demux_vaControlHelper( p_demux->s, 0, -1,
 153                                        8*CDG_FRAME_SIZE*CDG_FRAME_RATE, CDG_FRAME_SIZE,
 154                                        i_query, args );
 155     if( !i_ret && ( i_query == DEMUX_SET_POSITION || i_query == DEMUX_SET_TIME ) )
 156         date_Set( &p_demux->p_sys->pts,
 157                   stream_Tell( p_demux->s ) / CDG_FRAME_SIZE *
 158                     INT64_C(1000000) / CDG_FRAME_RATE );
 159
 160     return i_ret;
 161 }
 162