git.sesse.net Git - vlc/blob - modules/demux/ps.c

   1 /*****************************************************************************
   2  * ps.c: Program Stream demux module for VLC.
   3  *****************************************************************************
   4  * Copyright (C) 2004 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
  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., 59 Temple Place - Suite 330, Boston, MA  02111, USA.
  22  *****************************************************************************/
  23
  24 /*****************************************************************************
  25  * Preamble
  26  *****************************************************************************/
  27 #include <stdlib.h>                                      /* malloc(), free() */
  28
  29 #include <vlc/vlc.h>
  30 #include <vlc/input.h>
  31
  32 #include "ps.h"
  33
  34 /* TODO:
  35  *  - re-add pre-scanning.
  36  *  - ...
  37  */
  38
  39 /*****************************************************************************
  40  * Module descriptor
  41  *****************************************************************************/
  42 static int  Open ( vlc_object_t * );
  43 static void Close( vlc_object_t * );
  44
  45 vlc_module_begin();
  46     set_description( _("PS demuxer") );
  47     set_capability( "demux2", 1 );
  48     set_callbacks( Open, Close );
  49     add_shortcut( "ps" );
  50 vlc_module_end();
  51
  52 /*****************************************************************************
  53  * Local prototypes
  54  *****************************************************************************/
  55
  56 struct demux_sys_t
  57 {
  58     ps_track_t  tk[PS_TK_COUNT];
  59
  60     int64_t     i_scr;
  61     int         i_mux_rate;
  62 };
  63
  64 static int Demux  ( demux_t *p_demux );
  65 static int Control( demux_t *p_demux, int i_query, va_list args );
  66
  67 static int      ps_pkt_resynch( stream_t *, uint32_t *pi_code );
  68 static block_t *ps_pkt_read   ( stream_t *, uint32_t i_code );
  69
  70 /*****************************************************************************
  71  * Open
  72  *****************************************************************************/
  73 static int Open( vlc_object_t *p_this )
  74 {
  75     demux_t     *p_demux = (demux_t*)p_this;
  76     demux_sys_t *p_sys;
  77
  78     uint8_t     *p_peek;
  79
  80     if( stream_Peek( p_demux->s, &p_peek, 4 ) < 4 )
  81     {
  82         msg_Err( p_demux, "cannot peek" );
  83         return VLC_EGENERIC;
  84     }
  85
  86     if( p_peek[0] != 0 || p_peek[1] != 0 || p_peek[2] != 1 ||
  87         p_peek[3] < 0xb9 )
  88     {
  89         msg_Warn( p_demux, "this does not look like an MPEG PS stream, "
  90                   "continuing anyway" );
  91     }
  92
  93     /* Fill p_demux field */
  94     p_demux->pf_demux = Demux;
  95     p_demux->pf_control = Control;
  96     p_demux->p_sys = p_sys = malloc( sizeof( demux_sys_t ) );
  97
  98     /* Init p_sys */
  99     p_sys->i_mux_rate = 0;
 100     p_sys->i_scr      = -1;
 101
 102     ps_track_init( p_sys->tk );
 103
 104     /* TODO prescanning of ES */
 105
 106     return VLC_SUCCESS;
 107 }
 108
 109 /*****************************************************************************
 110  * Close
 111  *****************************************************************************/
 112 static void Close( vlc_object_t *p_this )
 113 {
 114     demux_t     *p_demux = (demux_t*)p_this;
 115     demux_sys_t *p_sys = p_demux->p_sys;
 116     int i;
 117
 118     for( i = 0; i < PS_TK_COUNT; i++ )
 119     {
 120         ps_track_t *tk = &p_sys->tk[i];
 121         if( tk->b_seen )
 122         {
 123             es_format_Clean( &tk->fmt );
 124             if( tk->es ) es_out_Del( p_demux->out, tk->es );
 125         }
 126     }
 127
 128     free( p_sys );
 129 }
 130
 131 /*****************************************************************************
 132  * Demux:
 133  *****************************************************************************/
 134 static int Demux( demux_t *p_demux )
 135 {
 136     demux_sys_t *p_sys = p_demux->p_sys;
 137     int i_ret, i_id, i_mux_rate;
 138     uint32_t i_code;
 139     block_t *p_pkt;
 140
 141     i_ret = ps_pkt_resynch( p_demux->s, &i_code );
 142     if( i_ret < 0 )
 143     {
 144         return 0;
 145     }
 146     else if( i_ret == 0 )
 147     {
 148         msg_Warn( p_demux, "garbage at input" );
 149         return 1;
 150     }
 151
 152     if( ( p_pkt = ps_pkt_read( p_demux->s, i_code ) ) == NULL )
 153     {
 154         return 0;
 155     }
 156
 157     switch( i_code )
 158     {
 159     case 0x1b9:
 160         block_Release( p_pkt );
 161         break;
 162
 163     case 0x1ba:
 164         if( !ps_pkt_parse_pack( p_pkt, &p_sys->i_scr, &i_mux_rate ) )
 165         {
 166             es_out_Control( p_demux->out, ES_OUT_SET_PCR, p_sys->i_scr );
 167             if( i_mux_rate > 0 ) p_sys->i_mux_rate = i_mux_rate;
 168         }
 169         block_Release( p_pkt );
 170         break;
 171
 172     case 0x1bb:
 173         if( !ps_pkt_parse_system( p_pkt, p_sys->tk ) )
 174         {
 175             int i;
 176             for( i = 0; i < PS_TK_COUNT; i++ )
 177             {
 178                 ps_track_t *tk = &p_sys->tk[i];
 179
 180                 if( tk->b_seen && !tk->es && tk->fmt.i_cat != UNKNOWN_ES )
 181                 {
 182                     tk->es = es_out_Add( p_demux->out, &tk->fmt );
 183                 }
 184             }
 185         }
 186         block_Release( p_pkt );
 187         break;
 188
 189     case 0x1bc:
 190         /* TODO PSM */
 191         block_Release( p_pkt );
 192         break;
 193
 194     default:
 195         if( (i_id = ps_pkt_id( p_pkt )) >= 0xc0 )
 196         {
 197             ps_track_t *tk = &p_sys->tk[PS_ID_TO_TK(i_id)];
 198
 199             if( !tk->b_seen )
 200             {
 201                 if( !ps_track_fill( tk, i_id ) )
 202                 {
 203                     tk->es = es_out_Add( p_demux->out, &tk->fmt );
 204                 }
 205                 tk->b_seen = VLC_TRUE;
 206             }
 207             if( tk->b_seen && tk->es &&
 208                 !ps_pkt_parse_pes( p_pkt, tk->i_skip ) )
 209             {
 210                 es_out_Send( p_demux->out, tk->es, p_pkt );
 211             }
 212             else
 213             {
 214                 block_Release( p_pkt );
 215             }
 216         }
 217         else
 218         {
 219             block_Release( p_pkt );
 220         }
 221         break;
 222     }
 223
 224     return 1;
 225 }
 226
 227 /*****************************************************************************
 228  * Control:
 229  *****************************************************************************/
 230 static int Control( demux_t *p_demux, int i_query, va_list args )
 231 {
 232     demux_sys_t *p_sys = p_demux->p_sys;
 233     double f, *pf;
 234     int64_t i64, *pi64;
 235
 236     switch( i_query )
 237     {
 238         case DEMUX_GET_POSITION:
 239             pf = (double*) va_arg( args, double* );
 240             i64 = stream_Size( p_demux->s );
 241             if( i64 > 0 )
 242             {
 243                 *pf = (double)stream_Tell( p_demux->s ) / (double)i64;
 244             }
 245             else
 246             {
 247                 *pf = 0.0;
 248             }
 249             return VLC_SUCCESS;
 250
 251         case DEMUX_SET_POSITION:
 252             f = (double) va_arg( args, double );
 253             i64 = stream_Size( p_demux->s );
 254
 255             es_out_Control( p_demux->out, ES_OUT_RESET_PCR );
 256
 257             return stream_Seek( p_demux->s, (int64_t)(i64 * f) );
 258
 259         case DEMUX_GET_TIME:
 260             pi64 = (int64_t*)va_arg( args, int64_t * );
 261             if( p_sys->i_mux_rate > 0 )
 262             {
 263                 *pi64 = (int64_t)1000000 * ( stream_Tell( p_demux->s ) / 50 ) /
 264                     p_sys->i_mux_rate;
 265                 return VLC_SUCCESS;
 266             }
 267             *pi64 = 0;
 268             return VLC_EGENERIC;
 269
 270         case DEMUX_GET_LENGTH:
 271             pi64 = (int64_t*)va_arg( args, int64_t * );
 272             if( p_sys->i_mux_rate > 0 )
 273             {
 274                 *pi64 = (int64_t)1000000 * ( stream_Size( p_demux->s ) / 50 ) /
 275                     p_sys->i_mux_rate;
 276                 return VLC_SUCCESS;
 277             }
 278             *pi64 = 0;
 279             return VLC_EGENERIC;
 280
 281         case DEMUX_SET_TIME:
 282         case DEMUX_GET_FPS:
 283         default:
 284             return VLC_EGENERIC;
 285     }
 286 }
 287
 288 /*****************************************************************************
 289  * Divers:
 290  *****************************************************************************/
 291
 292 /* PSResynch: resynch on a system starcode
 293  *  It doesn't skip more than 512 bytes
 294  *  -1 -> error, 0 -> not synch, 1 -> ok
 295  */
 296 static int ps_pkt_resynch( stream_t *s, uint32_t *pi_code )
 297 {
 298     uint8_t *p_peek;
 299     int     i_peek;
 300     int     i_skip;
 301
 302     if( stream_Peek( s, &p_peek, 4 ) < 4 )
 303     {
 304         return -1;
 305     }
 306     if( p_peek[0] == 0 && p_peek[1] == 0 && p_peek[2] == 1 &&
 307         p_peek[3] >= 0xb9 )
 308     {
 309         *pi_code = 0x100 | p_peek[3];
 310         return 1;
 311     }
 312
 313     if( ( i_peek = stream_Peek( s, &p_peek, 512 ) ) < 4 )
 314     {
 315         return -1;
 316     }
 317     i_skip = 0;
 318
 319     for( ;; )
 320     {
 321         if( i_peek < 4 )
 322         {
 323             break;
 324         }
 325         if( p_peek[0] == 0 && p_peek[1] == 0 && p_peek[2] == 1 &&
 326             p_peek[3] >= 0xb9 )
 327         {
 328             *pi_code = 0x100 | p_peek[3];
 329             return stream_Read( s, NULL, i_skip ) == i_skip ? 1 : -1;
 330         }
 331
 332         p_peek++;
 333         i_peek--;
 334         i_skip++;
 335     }
 336     return stream_Read( s, NULL, i_skip ) == i_skip ? 0 : -1;
 337 }
 338
 339 static block_t *ps_pkt_read( stream_t *s, uint32_t i_code )
 340 {
 341     uint8_t *p_peek;
 342     int      i_peek = stream_Peek( s, &p_peek, 14 );
 343     int      i_size = ps_pkt_size( p_peek, i_peek );
 344
 345     if( i_size <= 6 && p_peek[3] > 0xba )
 346     {
 347         /* Special case, search the next start code */
 348         i_size = 6;
 349         for( ;; )
 350         {
 351             i_peek = stream_Peek( s, &p_peek, i_size + 1024 );
 352             if( i_peek <= i_size + 4 )
 353             {
 354                 return NULL;
 355             }
 356             while( i_size <= i_peek - 4 )
 357             {
 358                 if( p_peek[i_size] == 0x00 && p_peek[i_size+1] == 0x00 &&
 359                     p_peek[i_size+2] == 0x01 && p_peek[i_size+3] >= 0xb9 )
 360                 {
 361                     return stream_Block( s, i_size );
 362                 }
 363                 i_size++;
 364             }
 365         }
 366     }
 367     else
 368     {
 369         /* Normal case */
 370         return  stream_Block( s, i_size );
 371     }
 372
 373     return NULL;
 374 }