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 int  OpenAlt( vlc_object_t * );
  44 static void Close  ( vlc_object_t * );
  45
  46 vlc_module_begin();
  47     set_description( _("PS demuxer") );
  48     set_capability( "demux2", 1 );
  49     set_callbacks( Open, Close );
  50     add_shortcut( "ps" );
  51
  52     add_submodule();
  53     set_description( _("PS demuxer") );
  54     set_capability( "demux2", 9 );
  55     set_callbacks( OpenAlt, Close );
  56 vlc_module_end();
  57
  58 /*****************************************************************************
  59  * Local prototypes
  60  *****************************************************************************/
  61
  62 struct demux_sys_t
  63 {
  64     ps_psm_t    psm;
  65     ps_track_t  tk[PS_TK_COUNT];
  66
  67     int64_t     i_scr;
  68     int         i_mux_rate;
  69 };
  70
  71 static int Demux  ( demux_t *p_demux );
  72 static int Control( demux_t *p_demux, int i_query, va_list args );
  73
  74 static int      ps_pkt_resynch( stream_t *, uint32_t *pi_code );
  75 static block_t *ps_pkt_read   ( stream_t *, uint32_t i_code );
  76
  77 /*****************************************************************************
  78  * Open
  79  *****************************************************************************/
  80 static int Open( vlc_object_t *p_this )
  81 {
  82     demux_t     *p_demux = (demux_t*)p_this;
  83     demux_sys_t *p_sys;
  84
  85     uint8_t     *p_peek;
  86
  87     if( stream_Peek( p_demux->s, &p_peek, 4 ) < 4 )
  88     {
  89         msg_Err( p_demux, "cannot peek" );
  90         return VLC_EGENERIC;
  91     }
  92
  93     if( p_peek[0] != 0 || p_peek[1] != 0 ||
  94         p_peek[2] != 1 || p_peek[3] < 0xb9 )
  95     {
  96         msg_Warn( p_demux, "this does not look like an MPEG PS stream, "
  97                   "continuing anyway" );
  98     }
  99
 100     /* Fill p_demux field */
 101     p_demux->pf_demux = Demux;
 102     p_demux->pf_control = Control;
 103     p_demux->p_sys = p_sys = malloc( sizeof( demux_sys_t ) );
 104
 105     /* Init p_sys */
 106     p_sys->i_mux_rate = 0;
 107     p_sys->i_scr      = -1;
 108
 109     ps_psm_init( &p_sys->psm );
 110     ps_track_init( p_sys->tk );
 111
 112     /* TODO prescanning of ES */
 113
 114     return VLC_SUCCESS;
 115 }
 116
 117 static int OpenAlt( vlc_object_t *p_this )
 118 {
 119     demux_t *p_demux = (demux_t*)p_this;
 120     uint8_t *p_peek;
 121
 122     if( stream_Peek( p_demux->s, &p_peek, 4 ) < 4 )
 123     {
 124         msg_Err( p_demux, "cannot peek" );
 125         return VLC_EGENERIC;
 126     }
 127
 128     if( p_peek[0] != 0 || p_peek[1] != 0 ||
 129         p_peek[2] != 1 || p_peek[3] < 0xb9 )
 130     {
 131         if( !p_demux->b_force ) return VLC_EGENERIC;
 132     }
 133
 134     return Open( p_this );
 135 }
 136
 137 /*****************************************************************************
 138  * Close
 139  *****************************************************************************/
 140 static void Close( vlc_object_t *p_this )
 141 {
 142     demux_t     *p_demux = (demux_t*)p_this;
 143     demux_sys_t *p_sys = p_demux->p_sys;
 144     int i;
 145
 146     for( i = 0; i < PS_TK_COUNT; i++ )
 147     {
 148         ps_track_t *tk = &p_sys->tk[i];
 149         if( tk->b_seen )
 150         {
 151             es_format_Clean( &tk->fmt );
 152             if( tk->es ) es_out_Del( p_demux->out, tk->es );
 153         }
 154     }
 155
 156     ps_psm_destroy( &p_sys->psm );
 157
 158     free( p_sys );
 159 }
 160
 161 /*****************************************************************************
 162  * Demux:
 163  *****************************************************************************/
 164 static int Demux( demux_t *p_demux )
 165 {
 166     demux_sys_t *p_sys = p_demux->p_sys;
 167     int i_ret, i_id, i_mux_rate;
 168     uint32_t i_code;
 169     block_t *p_pkt;
 170
 171     i_ret = ps_pkt_resynch( p_demux->s, &i_code );
 172     if( i_ret < 0 )
 173     {
 174         return 0;
 175     }
 176     else if( i_ret == 0 )
 177     {
 178         msg_Warn( p_demux, "garbage at input" );
 179         return 1;
 180     }
 181
 182     if( ( p_pkt = ps_pkt_read( p_demux->s, i_code ) ) == NULL )
 183     {
 184         return 0;
 185     }
 186
 187     switch( i_code )
 188     {
 189     case 0x1b9:
 190         block_Release( p_pkt );
 191         break;
 192
 193     case 0x1ba:
 194         if( !ps_pkt_parse_pack( p_pkt, &p_sys->i_scr, &i_mux_rate ) )
 195         {
 196             es_out_Control( p_demux->out, ES_OUT_SET_PCR, p_sys->i_scr );
 197             if( i_mux_rate > 0 ) p_sys->i_mux_rate = i_mux_rate;
 198         }
 199         block_Release( p_pkt );
 200         break;
 201
 202     case 0x1bb:
 203         if( !ps_pkt_parse_system( p_pkt, &p_sys->psm, p_sys->tk ) )
 204         {
 205             int i;
 206             for( i = 0; i < PS_TK_COUNT; i++ )
 207             {
 208                 ps_track_t *tk = &p_sys->tk[i];
 209
 210                 if( tk->b_seen && !tk->es && tk->fmt.i_cat != UNKNOWN_ES )
 211                 {
 212                     tk->es = es_out_Add( p_demux->out, &tk->fmt );
 213                 }
 214             }
 215         }
 216         block_Release( p_pkt );
 217         break;
 218
 219     case 0x1bc:
 220         /* msg_Dbg( p_demux, "received PSM"); */
 221         ps_psm_fill( &p_sys->psm, p_pkt, p_sys->tk, p_demux->out );
 222         block_Release( p_pkt );
 223         break;
 224
 225     default:
 226         if( (i_id = ps_pkt_id( p_pkt )) >= 0xc0 )
 227         {
 228             ps_track_t *tk = &p_sys->tk[PS_ID_TO_TK(i_id)];
 229
 230             if( !tk->b_seen )
 231             {
 232                 if( !ps_track_fill( tk, &p_sys->psm, i_id ) )
 233                 {
 234                     tk->es = es_out_Add( p_demux->out, &tk->fmt );
 235                 }
 236                 tk->b_seen = VLC_TRUE;
 237             }
 238             if( tk->b_seen && tk->es &&
 239                 !ps_pkt_parse_pes( p_pkt, tk->i_skip ) )
 240             {
 241                 es_out_Send( p_demux->out, tk->es, p_pkt );
 242             }
 243             else
 244             {
 245                 block_Release( p_pkt );
 246             }
 247         }
 248         else
 249         {
 250             block_Release( p_pkt );
 251         }
 252         break;
 253     }
 254
 255     return 1;
 256 }
 257
 258 /*****************************************************************************
 259  * Control:
 260  *****************************************************************************/
 261 static int Control( demux_t *p_demux, int i_query, va_list args )
 262 {
 263     demux_sys_t *p_sys = p_demux->p_sys;
 264     double f, *pf;
 265     int64_t i64, *pi64;
 266
 267     switch( i_query )
 268     {
 269         case DEMUX_GET_POSITION:
 270             pf = (double*) va_arg( args, double* );
 271             i64 = stream_Size( p_demux->s );
 272             if( i64 > 0 )
 273             {
 274                 *pf = (double)stream_Tell( p_demux->s ) / (double)i64;
 275             }
 276             else
 277             {
 278                 *pf = 0.0;
 279             }
 280             return VLC_SUCCESS;
 281
 282         case DEMUX_SET_POSITION:
 283             f = (double) va_arg( args, double );
 284             i64 = stream_Size( p_demux->s );
 285
 286             es_out_Control( p_demux->out, ES_OUT_RESET_PCR );
 287
 288             return stream_Seek( p_demux->s, (int64_t)(i64 * f) );
 289
 290         case DEMUX_GET_TIME:
 291             pi64 = (int64_t*)va_arg( args, int64_t * );
 292             if( p_sys->i_mux_rate > 0 )
 293             {
 294                 *pi64 = (int64_t)1000000 * ( stream_Tell( p_demux->s ) / 50 ) /
 295                     p_sys->i_mux_rate;
 296                 return VLC_SUCCESS;
 297             }
 298             *pi64 = 0;
 299             return VLC_EGENERIC;
 300
 301         case DEMUX_GET_LENGTH:
 302             pi64 = (int64_t*)va_arg( args, int64_t * );
 303             if( p_sys->i_mux_rate > 0 )
 304             {
 305                 *pi64 = (int64_t)1000000 * ( stream_Size( p_demux->s ) / 50 ) /
 306                     p_sys->i_mux_rate;
 307                 return VLC_SUCCESS;
 308             }
 309             *pi64 = 0;
 310             return VLC_EGENERIC;
 311
 312         case DEMUX_SET_TIME:
 313         case DEMUX_GET_FPS:
 314         default:
 315             return VLC_EGENERIC;
 316     }
 317 }
 318
 319 /*****************************************************************************
 320  * Divers:
 321  *****************************************************************************/
 322
 323 /* PSResynch: resynch on a system starcode
 324  *  It doesn't skip more than 512 bytes
 325  *  -1 -> error, 0 -> not synch, 1 -> ok
 326  */
 327 static int ps_pkt_resynch( stream_t *s, uint32_t *pi_code )
 328 {
 329     uint8_t *p_peek;
 330     int     i_peek;
 331     int     i_skip;
 332
 333     if( stream_Peek( s, &p_peek, 4 ) < 4 )
 334     {
 335         return -1;
 336     }
 337     if( p_peek[0] == 0 && p_peek[1] == 0 && p_peek[2] == 1 &&
 338         p_peek[3] >= 0xb9 )
 339     {
 340         *pi_code = 0x100 | p_peek[3];
 341         return 1;
 342     }
 343
 344     if( ( i_peek = stream_Peek( s, &p_peek, 512 ) ) < 4 )
 345     {
 346         return -1;
 347     }
 348     i_skip = 0;
 349
 350     for( ;; )
 351     {
 352         if( i_peek < 4 )
 353         {
 354             break;
 355         }
 356         if( p_peek[0] == 0 && p_peek[1] == 0 && p_peek[2] == 1 &&
 357             p_peek[3] >= 0xb9 )
 358         {
 359             *pi_code = 0x100 | p_peek[3];
 360             return stream_Read( s, NULL, i_skip ) == i_skip ? 1 : -1;
 361         }
 362
 363         p_peek++;
 364         i_peek--;
 365         i_skip++;
 366     }
 367     return stream_Read( s, NULL, i_skip ) == i_skip ? 0 : -1;
 368 }
 369
 370 static block_t *ps_pkt_read( stream_t *s, uint32_t i_code )
 371 {
 372     uint8_t *p_peek;
 373     int      i_peek = stream_Peek( s, &p_peek, 14 );
 374     int      i_size = ps_pkt_size( p_peek, i_peek );
 375
 376     if( i_size <= 6 && p_peek[3] > 0xba )
 377     {
 378         /* Special case, search the next start code */
 379         i_size = 6;
 380         for( ;; )
 381         {
 382             i_peek = stream_Peek( s, &p_peek, i_size + 1024 );
 383             if( i_peek <= i_size + 4 )
 384             {
 385                 return NULL;
 386             }
 387             while( i_size <= i_peek - 4 )
 388             {
 389                 if( p_peek[i_size] == 0x00 && p_peek[i_size+1] == 0x00 &&
 390                     p_peek[i_size+2] == 0x01 && p_peek[i_size+3] >= 0xb9 )
 391                 {
 392                     return stream_Block( s, i_size );
 393                 }
 394                 i_size++;
 395             }
 396         }
 397     }
 398     else
 399     {
 400         /* Normal case */
 401         return  stream_Block( s, i_size );
 402     }
 403
 404     return NULL;
 405 }