modules/demux/mpeg/mpgv.c

   1 /*****************************************************************************
   2  * mpgv.c : MPEG-I/II Video demuxer
   3  *****************************************************************************
   4  * Copyright (C) 2001-2004 the VideoLAN team
   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 #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 struct demux_sys_t
  56 {
  57     bool  b_start;
  58
  59     es_out_id_t *p_es;
  60
  61     decoder_t *p_packetizer;
  62 };
  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  * Open: initializes demux structures
  71  *****************************************************************************/
  72 static int Open( vlc_object_t * p_this )
  73 {
  74     demux_t     *p_demux = (demux_t*)p_this;
  75     demux_sys_t *p_sys;
  76     bool   b_forced = false;
  77
  78     const uint8_t *p_peek;
  79
  80     es_format_t  fmt;
  81
  82     if( stream_Peek( p_demux->s, &p_peek, 4 ) < 4 )
  83     {
  84         msg_Err( p_demux, "cannot peek" );
  85         return VLC_EGENERIC;
  86     }
  87
  88     if( p_demux->b_force )
  89         b_forced = true;
  90
  91     if( p_peek[0] != 0x00 || p_peek[1] != 0x00 || p_peek[2] != 0x01 )
  92     {
  93         if( !b_forced ) return VLC_EGENERIC;
  94
  95         msg_Err( p_demux, "this doesn't look like an MPEG ES stream, continuing" );
  96     }
  97
  98     if( p_peek[3] > 0xb9 )
  99     {
 100         if( !b_forced ) return VLC_EGENERIC;
 101         msg_Err( p_demux, "this seems to be a system stream (PS plug-in ?), but continuing" );
 102     }
 103
 104     p_demux->pf_demux  = Demux;
 105     p_demux->pf_control= Control;
 106     p_demux->p_sys     = p_sys = malloc( sizeof( demux_sys_t ) );
 107     p_sys->b_start     = true;
 108     p_sys->p_es        = NULL;
 109
 110     /* Load the mpegvideo packetizer */
 111     es_format_Init( &fmt, VIDEO_ES, VLC_CODEC_MPGV );
 112     p_sys->p_packetizer = demux_PacketizerNew( p_demux, &fmt, "mpeg video" );
 113     if( !p_sys->p_packetizer )
 114     {
 115         free( p_sys );
 116         return VLC_EGENERIC;
 117     }
 118
 119     /* create the output */
 120     es_format_Init( &fmt, VIDEO_ES, VLC_CODEC_MPGV );
 121     p_sys->p_es = es_out_Add( p_demux->out, &fmt );
 122
 123     return VLC_SUCCESS;
 124 }
 125
 126 /*****************************************************************************
 127  * Close: frees unused data
 128  *****************************************************************************/
 129 static void Close( vlc_object_t * p_this )
 130 {
 131     demux_t     *p_demux = (demux_t*)p_this;
 132     demux_sys_t *p_sys = p_demux->p_sys;
 133
 134     demux_PacketizerDestroy( p_sys->p_packetizer );
 135     free( p_sys );
 136 }
 137
 138 /*****************************************************************************
 139  * Demux: reads and demuxes data packets
 140  *****************************************************************************
 141  * Returns -1 in case of error, 0 in case of EOF, 1 otherwise
 142  *****************************************************************************/
 143 static int Demux( demux_t *p_demux )
 144 {
 145     demux_sys_t  *p_sys = p_demux->p_sys;
 146     block_t *p_block_in, *p_block_out;
 147
 148     if( ( p_block_in = stream_Block( p_demux->s, MPGV_PACKET_SIZE ) ) == NULL )
 149     {
 150         return 0;
 151     }
 152
 153     if( p_sys->b_start )
 154     {
 155         p_block_in->i_pts =
 156         p_block_in->i_dts = VLC_TS_0;
 157     }
 158     else
 159     {
 160         p_block_in->i_pts =
 161         p_block_in->i_dts = VLC_TS_INVALID;
 162     }
 163
 164     while( (p_block_out = p_sys->p_packetizer->pf_packetize( p_sys->p_packetizer, &p_block_in )) )
 165     {
 166         p_sys->b_start = false;
 167
 168         while( p_block_out )
 169         {
 170             block_t *p_next = p_block_out->p_next;
 171
 172             es_out_Control( p_demux->out, ES_OUT_SET_PCR, p_block_out->i_dts );
 173
 174             p_block_out->p_next = NULL;
 175             es_out_Send( p_demux->out, p_sys->p_es, p_block_out );
 176
 177             p_block_out = p_next;
 178         }
 179     }
 180     return 1;
 181 }
 182
 183 /*****************************************************************************
 184  * Control:
 185  *****************************************************************************/
 186 static int Control( demux_t *p_demux, int i_query, va_list args )
 187 {
 188     /* demux_sys_t *p_sys  = p_demux->p_sys; */
 189     /* FIXME calculate the bitrate */
 190     if( i_query == DEMUX_SET_TIME )
 191         return VLC_EGENERIC;
 192     else
 193         return demux_vaControlHelper( p_demux->s,
 194                                        0, -1,
 195                                        0, 1, i_query, args );
 196 }
 197