modules/demux/mpeg/mpgv.c

   1 /*****************************************************************************
   2  * mpgv.c : MPEG-I/II Video demuxer
   3  *****************************************************************************
   4  * Copyright (C) 2001-2004 VLC authors and VideoLAN
   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 #include <vlc_codec.h>
  36
  37 /*****************************************************************************
  38  * Module descriptor
  39  *****************************************************************************/
  40 static int  Open ( vlc_object_t * );
  41 static void Close( vlc_object_t * );
  42
  43 vlc_module_begin ()
  44     set_category( CAT_INPUT )
  45     set_subcategory( SUBCAT_INPUT_DEMUX )
  46     set_description( N_("MPEG-I/II video demuxer" ) )
  47     set_capability( "demux", 5 )
  48     set_callbacks( Open, Close )
  49     add_shortcut( "mpgv" )
  50 vlc_module_end ()
  51
  52 /*****************************************************************************
  53  * Local prototypes
  54  *****************************************************************************/
  55 typedef struct
  56 {
  57     bool  b_start;
  58
  59     es_out_id_t *p_es;
  60
  61     decoder_t *p_packetizer;
  62 } demux_sys_t;
  63
  64 static int Demux( demux_t * );
  65 static int Control( demux_t *, int, va_list );
  66
  67 #define MPGV_PACKET_SIZE 4096
  68
  69 /*****************************************************************************
  70  * Close: frees unused data
  71  *****************************************************************************/
  72 static void Close( vlc_object_t * p_this )
  73 {
  74     demux_t     *p_demux = (demux_t*)p_this;
  75     demux_sys_t *p_sys = p_demux->p_sys;
  76
  77     demux_PacketizerDestroy( p_sys->p_packetizer );
  78     free( p_sys );
  79 }
  80
  81 static int CheckMPEGStartCode( const uint8_t *p_peek )
  82 {
  83     switch( p_peek[3] )
  84     {
  85         case 0x00:
  86             if( (p_peek[5] & 0x38) == 0x00 )
  87                 return VLC_EGENERIC;
  88             break;
  89         case 0xB0:
  90         case 0xB1:
  91         case 0xB6:
  92             return VLC_EGENERIC;
  93         default:
  94             if( p_peek[3] > 0xB9 )
  95                 return VLC_EGENERIC;
  96             break;
  97     }
  98     return VLC_SUCCESS;
  99 }
 100
 101 /*****************************************************************************
 102  * Open: initializes demux structures
 103  *****************************************************************************/
 104 static int Open( vlc_object_t * p_this )
 105 {
 106     demux_t     *p_demux = (demux_t*)p_this;
 107     demux_sys_t *p_sys;
 108     bool   b_forced = false;
 109
 110     const uint8_t *p_peek;
 111
 112     es_format_t  fmt;
 113
 114     if( vlc_stream_Peek( p_demux->s, &p_peek, 8 ) < 8 )
 115     {
 116         msg_Dbg( p_demux, "cannot peek" );
 117         return VLC_EGENERIC;
 118     }
 119
 120     if( p_demux->obj.force )
 121         b_forced = true;
 122
 123     if( p_peek[0] != 0x00 || p_peek[1] != 0x00 || p_peek[2] != 0x01 )
 124     {
 125         if( !b_forced ) return VLC_EGENERIC;
 126
 127         msg_Err( p_demux, "this doesn't look like an MPEG ES stream, continuing" );
 128     }
 129
 130     if( CheckMPEGStartCode( p_peek ) != VLC_SUCCESS )
 131     {
 132         if( !b_forced ) return VLC_EGENERIC;
 133         msg_Err( p_demux, "this seems to be a system stream (PS plug-in ?), but continuing" );
 134     }
 135     p_demux->pf_demux  = Demux;
 136     p_demux->pf_control= Control;
 137     p_demux->p_sys     = p_sys = malloc( sizeof( demux_sys_t ) );
 138     p_sys->b_start     = true;
 139     p_sys->p_es        = NULL;
 140
 141     /* Load the mpegvideo packetizer */
 142     es_format_Init( &fmt, VIDEO_ES, VLC_CODEC_MPGV );
 143     p_sys->p_packetizer = demux_PacketizerNew( p_demux, &fmt, "mpeg video" );
 144     if( !p_sys->p_packetizer )
 145     {
 146         free( p_sys );
 147         return VLC_EGENERIC;
 148     }
 149
 150     /* create the output */
 151     p_sys->p_es = es_out_Add( p_demux->out, &fmt );
 152     if( p_sys->p_es == NULL )
 153     {
 154         Close( p_this );
 155         return VLC_EGENERIC;
 156     }
 157
 158     return VLC_SUCCESS;
 159 }
 160
 161 /*****************************************************************************
 162  * Demux: reads and demuxes data packets
 163  *****************************************************************************
 164  * Returns -1 in case of error, 0 in case of EOF, 1 otherwise
 165  *****************************************************************************/
 166 static int Demux( demux_t *p_demux )
 167 {
 168     demux_sys_t  *p_sys = p_demux->p_sys;
 169     block_t *p_block_in, *p_block_out;
 170     bool b_eof = false;
 171
 172     if( ( p_block_in = vlc_stream_Block( p_demux->s, MPGV_PACKET_SIZE ) ) == NULL )
 173     {
 174         b_eof = true;
 175     }
 176
 177     if( p_block_in )
 178     {
 179         p_block_in->i_pts =
 180         p_block_in->i_dts = ( p_sys->b_start ) ? VLC_TICK_0 : VLC_TICK_INVALID;
 181     }
 182
 183     while( (p_block_out = p_sys->p_packetizer->pf_packetize( p_sys->p_packetizer,
 184                                                              p_block_in ? &p_block_in : NULL )) )
 185     {
 186         p_sys->b_start = false;
 187
 188         while( p_block_out )
 189         {
 190             block_t *p_next = p_block_out->p_next;
 191
 192             es_out_SetPCR( p_demux->out, p_block_out->i_dts );
 193
 194             p_block_out->p_next = NULL;
 195             es_out_Send( p_demux->out, p_sys->p_es, p_block_out );
 196
 197             p_block_out = p_next;
 198         }
 199     }
 200     return (b_eof) ? VLC_DEMUXER_EOF : VLC_DEMUXER_SUCCESS;
 201 }
 202
 203 /*****************************************************************************
 204  * Control:
 205  *****************************************************************************/
 206 static int Control( demux_t *p_demux, int i_query, va_list args )
 207 {
 208     /* demux_sys_t *p_sys  = p_demux->p_sys; */
 209     /* FIXME calculate the bitrate */
 210     if( i_query == DEMUX_SET_TIME )
 211         return VLC_EGENERIC;
 212     else
 213         return demux_vaControlHelper( p_demux->s,
 214                                        0, -1,
 215                                        0, 1, i_query, args );
 216 }
 217