modules/demux/cdg.c

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