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 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_sys = malloc( sizeof( demux_sys_t ) );
  90     if( unlikely(p_sys == NULL) )
  91         return VLC_ENOMEM;
  92
  93     p_demux->pf_demux   = Demux;
  94     p_demux->pf_control = Control;
  95     p_demux->p_sys      = p_sys;
  96
  97     /* */
  98     es_format_Init( &p_sys->fmt, VIDEO_ES, VLC_CODEC_CDG );
  99     p_sys->fmt.video.i_width  = 300-2*6;
 100     p_sys->fmt.video.i_height = 216-2*12 ;
 101     p_sys->fmt.video.i_visible_width = p_sys->fmt.video.i_width;
 102     p_sys->fmt.video.i_visible_height = p_sys->fmt.video.i_height;
 103
 104     p_sys->p_es = es_out_Add( p_demux->out, &p_sys->fmt );
 105
 106     /* There is CDG_FRAME_RATE frames per second */
 107     date_Init( &p_sys->pts, CDG_FRAME_RATE, 1 );
 108     date_Set( &p_sys->pts, 0 );
 109
 110     return VLC_SUCCESS;
 111 }
 112
 113 /*****************************************************************************
 114  * Demux: read packet and send them to decoders
 115  *****************************************************************************
 116  * Returns -1 in case of error, 0 in case of EOF, 1 otherwise
 117  *****************************************************************************/
 118 static int Demux( demux_t *p_demux )
 119 {
 120     demux_sys_t *p_sys = p_demux->p_sys;
 121     block_t     *p_block;
 122     mtime_t     i_date;
 123     mtime_t     i_delta;
 124
 125     i_delta = INT64_C(1000000) / CDG_FRAME_RATE;
 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 0;
 132     }
 133
 134     i_date = vlc_stream_Tell( p_demux->s ) / CDG_FRAME_SIZE * i_delta;
 135     if( i_date >= date_Get( &p_sys->pts ) + i_delta )
 136     {
 137         p_block->i_dts = p_block->i_pts = i_date;
 138         date_Set( &p_sys->pts, i_date );
 139     }
 140     else
 141     {
 142         p_block->i_dts = 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
 148     es_out_Send( p_demux->out, p_sys->p_es, p_block );
 149
 150     return 1;
 151 }
 152
 153 /*****************************************************************************
 154  * Close: frees unused data
 155  *****************************************************************************/
 156 static void Close ( vlc_object_t * p_this )
 157 {
 158     demux_t *p_demux = (demux_t *)p_this;
 159     demux_sys_t *p_sys = p_demux->p_sys;
 160
 161     free( p_sys );
 162 }
 163
 164 /*****************************************************************************
 165  * Control:
 166  *****************************************************************************/
 167 static int Control( demux_t *p_demux, int i_query, va_list args )
 168 {
 169     uint64_t i_old_offset = vlc_stream_Tell( p_demux->s );
 170     int i_ret = demux_vaControlHelper( p_demux->s, 0, -1,
 171                                        8*CDG_FRAME_SIZE*CDG_FRAME_RATE, CDG_FRAME_SIZE,
 172                                        i_query, args );
 173     if( !i_ret && ( i_query == DEMUX_SET_POSITION || i_query == DEMUX_SET_TIME ) )
 174     {
 175         date_Set( &p_demux->p_sys->pts,
 176                   vlc_stream_Tell( p_demux->s ) / CDG_FRAME_SIZE *
 177                     INT64_C(1000000) / CDG_FRAME_RATE );
 178         if ( i_old_offset > vlc_stream_Tell( p_demux->s ) )
 179             i_ret = vlc_stream_Seek( p_demux->s, 0 );
 180         else
 181             i_ret = vlc_stream_Seek( p_demux->s, i_old_offset );
 182     }
 183
 184     return i_ret;
 185 }
 186