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_category( CAT_INPUT );
  49     set_subcategory( SUBCAT_INPUT_DEMUX );
  50     set_capability( "demux2", 1 );
  51     set_callbacks( Open, Close );
  52     add_shortcut( "ps" );
  53
  54     add_submodule();
  55     set_description( _("PS demuxer") );
  56     set_capability( "demux2", 9 );
  57     set_callbacks( OpenAlt, Close );
  58 vlc_module_end();
  59
  60 /*****************************************************************************
  61  * Local prototypes
  62  *****************************************************************************/
  63
  64 struct demux_sys_t
  65 {
  66     ps_psm_t    psm;
  67     ps_track_t  tk[PS_TK_COUNT];
  68
  69     int64_t     i_scr;
  70     int         i_mux_rate;
  71 };
  72
  73 static int Demux  ( demux_t *p_demux );
  74 static int Control( demux_t *p_demux, int i_query, va_list args );
  75
  76 static int      ps_pkt_resynch( stream_t *, uint32_t *pi_code );
  77 static block_t *ps_pkt_read   ( stream_t *, uint32_t i_code );
  78
  79 /*****************************************************************************
  80  * Open
  81  *****************************************************************************/
  82 static int Open( vlc_object_t *p_this )
  83 {
  84     demux_t     *p_demux = (demux_t*)p_this;
  85     demux_sys_t *p_sys;
  86
  87     uint8_t     *p_peek;
  88
  89     if( stream_Peek( p_demux->s, &p_peek, 4 ) < 4 )
  90     {
  91         msg_Err( p_demux, "cannot peek" );
  92         return VLC_EGENERIC;
  93     }
  94
  95     if( p_peek[0] != 0 || p_peek[1] != 0 ||
  96         p_peek[2] != 1 || p_peek[3] < 0xb9 )
  97     {
  98         msg_Warn( p_demux, "this does not look like an MPEG PS stream, "
  99                   "continuing anyway" );
 100     }
 101
 102     /* Fill p_demux field */
 103     p_demux->pf_demux = Demux;
 104     p_demux->pf_control = Control;
 105     p_demux->p_sys = p_sys = malloc( sizeof( demux_sys_t ) );
 106
 107     /* Init p_sys */
 108     p_sys->i_mux_rate = 0;
 109     p_sys->i_scr      = -1;
 110
 111     ps_psm_init( &p_sys->psm );
 112     ps_track_init( p_sys->tk );
 113
 114     /* TODO prescanning of ES */
 115
 116     return VLC_SUCCESS;
 117 }
 118
 119 static int OpenAlt( vlc_object_t *p_this )
 120 {
 121     demux_t *p_demux = (demux_t*)p_this;
 122     uint8_t *p_peek;
 123
 124     if( stream_Peek( p_demux->s, &p_peek, 4 ) < 4 )
 125     {
 126         msg_Err( p_demux, "cannot peek" );
 127         return VLC_EGENERIC;
 128     }
 129
 130     if( p_peek[0] != 0 || p_peek[1] != 0 ||
 131         p_peek[2] != 1 || p_peek[3] < 0xb9 )
 132     {
 133         if( !p_demux->b_force ) return VLC_EGENERIC;
 134     }
 135
 136     return Open( p_this );
 137 }
 138
 139 /*****************************************************************************
 140  * Close
 141  *****************************************************************************/
 142 static void Close( vlc_object_t *p_this )
 143 {
 144     demux_t     *p_demux = (demux_t*)p_this;
 145     demux_sys_t *p_sys = p_demux->p_sys;
 146     int i;
 147
 148     for( i = 0; i < PS_TK_COUNT; i++ )
 149     {
 150         ps_track_t *tk = &p_sys->tk[i];
 151         if( tk->b_seen )
 152         {
 153             es_format_Clean( &tk->fmt );
 154             if( tk->es ) es_out_Del( p_demux->out, tk->es );
 155         }
 156     }
 157
 158     ps_psm_destroy( &p_sys->psm );
 159
 160     free( p_sys );
 161 }
 162
 163 /*****************************************************************************
 164  * Demux:
 165  *****************************************************************************/
 166 static int Demux( demux_t *p_demux )
 167 {
 168     demux_sys_t *p_sys = p_demux->p_sys;
 169     int i_ret, i_id, i_mux_rate;
 170     uint32_t i_code;
 171     block_t *p_pkt;
 172
 173     i_ret = ps_pkt_resynch( p_demux->s, &i_code );
 174     if( i_ret < 0 )
 175     {
 176         return 0;
 177     }
 178     else if( i_ret == 0 )
 179     {
 180         msg_Warn( p_demux, "garbage at input" );
 181         return 1;
 182     }
 183
 184     if( ( p_pkt = ps_pkt_read( p_demux->s, i_code ) ) == NULL )
 185     {
 186         return 0;
 187     }
 188
 189     switch( i_code )
 190     {
 191     case 0x1b9:
 192         block_Release( p_pkt );
 193         break;
 194
 195     case 0x1ba:
 196         if( !ps_pkt_parse_pack( p_pkt, &p_sys->i_scr, &i_mux_rate ) )
 197         {
 198             /* done later on to work around bad vcd/svcd streams */
 199             /* es_out_Control( p_demux->out, ES_OUT_SET_PCR, p_sys->i_scr ); */
 200             if( i_mux_rate > 0 ) p_sys->i_mux_rate = i_mux_rate;
 201         }
 202         block_Release( p_pkt );
 203         break;
 204
 205     case 0x1bb:
 206         if( !ps_pkt_parse_system( p_pkt, &p_sys->psm, p_sys->tk ) )
 207         {
 208             int i;
 209             for( i = 0; i < PS_TK_COUNT; i++ )
 210             {
 211                 ps_track_t *tk = &p_sys->tk[i];
 212
 213                 if( tk->b_seen && !tk->es && tk->fmt.i_cat != UNKNOWN_ES )
 214                 {
 215                     tk->es = es_out_Add( p_demux->out, &tk->fmt );
 216                 }
 217             }
 218         }
 219         block_Release( p_pkt );
 220         break;
 221
 222     case 0x1bc:
 223         /* msg_Dbg( p_demux, "received PSM"); */
 224         ps_psm_fill( &p_sys->psm, p_pkt, p_sys->tk, p_demux->out );
 225         block_Release( p_pkt );
 226         break;
 227
 228     default:
 229         if( (i_id = ps_pkt_id( p_pkt )) >= 0xc0 )
 230         {
 231             ps_track_t *tk = &p_sys->tk[PS_ID_TO_TK(i_id)];
 232
 233             if( !tk->b_seen )
 234             {
 235                 if( !ps_track_fill( tk, &p_sys->psm, i_id ) )
 236                 {
 237                     tk->es = es_out_Add( p_demux->out, &tk->fmt );
 238                 }
 239                 tk->b_seen = VLC_TRUE;
 240             }
 241
 242             /* The popular VCD/SVCD subtitling WinSubMux does not
 243              * renumber the SCRs when merging subtitles into the PES */
 244             if( tk->b_seen &&
 245                 ( tk->fmt.i_codec == VLC_FOURCC('o','g','t',' ') ||
 246                   tk->fmt.i_codec == VLC_FOURCC('c','v','d',' ') ) )
 247             {
 248                 p_sys->i_scr = -1;
 249             }
 250
 251             if( p_sys->i_scr > 0 )
 252                 es_out_Control( p_demux->out, ES_OUT_SET_PCR, p_sys->i_scr );
 253
 254             p_sys->i_scr = -1;
 255
 256             if( tk->b_seen && tk->es &&
 257                 !ps_pkt_parse_pes( p_pkt, tk->i_skip ) )
 258             {
 259                 es_out_Send( p_demux->out, tk->es, p_pkt );
 260             }
 261             else
 262             {
 263                 block_Release( p_pkt );
 264             }
 265         }
 266         else
 267         {
 268             block_Release( p_pkt );
 269         }
 270         break;
 271     }
 272
 273     return 1;
 274 }
 275
 276 /*****************************************************************************
 277  * Control:
 278  *****************************************************************************/
 279 static int Control( demux_t *p_demux, int i_query, va_list args )
 280 {
 281     demux_sys_t *p_sys = p_demux->p_sys;
 282     double f, *pf;
 283     int64_t i64, *pi64;
 284
 285     switch( i_query )
 286     {
 287         case DEMUX_GET_POSITION:
 288             pf = (double*) va_arg( args, double* );
 289             i64 = stream_Size( p_demux->s );
 290             if( i64 > 0 )
 291             {
 292                 *pf = (double)stream_Tell( p_demux->s ) / (double)i64;
 293             }
 294             else
 295             {
 296                 *pf = 0.0;
 297             }
 298             return VLC_SUCCESS;
 299
 300         case DEMUX_SET_POSITION:
 301             f = (double) va_arg( args, double );
 302             i64 = stream_Size( p_demux->s );
 303
 304             es_out_Control( p_demux->out, ES_OUT_RESET_PCR );
 305
 306             return stream_Seek( p_demux->s, (int64_t)(i64 * f) );
 307
 308         case DEMUX_GET_TIME:
 309             pi64 = (int64_t*)va_arg( args, int64_t * );
 310             if( p_sys->i_mux_rate > 0 )
 311             {
 312                 *pi64 = (int64_t)1000000 * ( stream_Tell( p_demux->s ) / 50 ) /
 313                     p_sys->i_mux_rate;
 314                 return VLC_SUCCESS;
 315             }
 316             *pi64 = 0;
 317             return VLC_EGENERIC;
 318
 319         case DEMUX_GET_LENGTH:
 320             pi64 = (int64_t*)va_arg( args, int64_t * );
 321             if( p_sys->i_mux_rate > 0 )
 322             {
 323                 *pi64 = (int64_t)1000000 * ( stream_Size( p_demux->s ) / 50 ) /
 324                     p_sys->i_mux_rate;
 325                 return VLC_SUCCESS;
 326             }
 327             *pi64 = 0;
 328             return VLC_EGENERIC;
 329
 330         case DEMUX_SET_TIME:
 331         case DEMUX_GET_FPS:
 332         default:
 333             return VLC_EGENERIC;
 334     }
 335 }
 336
 337 /*****************************************************************************
 338  * Divers:
 339  *****************************************************************************/
 340
 341 /* PSResynch: resynch on a system starcode
 342  *  It doesn't skip more than 512 bytes
 343  *  -1 -> error, 0 -> not synch, 1 -> ok
 344  */
 345 static int ps_pkt_resynch( stream_t *s, uint32_t *pi_code )
 346 {
 347     uint8_t *p_peek;
 348     int     i_peek;
 349     int     i_skip;
 350
 351     if( stream_Peek( s, &p_peek, 4 ) < 4 )
 352     {
 353         return -1;
 354     }
 355     if( p_peek[0] == 0 && p_peek[1] == 0 && p_peek[2] == 1 &&
 356         p_peek[3] >= 0xb9 )
 357     {
 358         *pi_code = 0x100 | p_peek[3];
 359         return 1;
 360     }
 361
 362     if( ( i_peek = stream_Peek( s, &p_peek, 512 ) ) < 4 )
 363     {
 364         return -1;
 365     }
 366     i_skip = 0;
 367
 368     for( ;; )
 369     {
 370         if( i_peek < 4 )
 371         {
 372             break;
 373         }
 374         if( p_peek[0] == 0 && p_peek[1] == 0 && p_peek[2] == 1 &&
 375             p_peek[3] >= 0xb9 )
 376         {
 377             *pi_code = 0x100 | p_peek[3];
 378             return stream_Read( s, NULL, i_skip ) == i_skip ? 1 : -1;
 379         }
 380
 381         p_peek++;
 382         i_peek--;
 383         i_skip++;
 384     }
 385     return stream_Read( s, NULL, i_skip ) == i_skip ? 0 : -1;
 386 }
 387
 388 static block_t *ps_pkt_read( stream_t *s, uint32_t i_code )
 389 {
 390     uint8_t *p_peek;
 391     int      i_peek = stream_Peek( s, &p_peek, 14 );
 392     int      i_size = ps_pkt_size( p_peek, i_peek );
 393
 394     if( i_size <= 6 && p_peek[3] > 0xba )
 395     {
 396         /* Special case, search the next start code */
 397         i_size = 6;
 398         for( ;; )
 399         {
 400             i_peek = stream_Peek( s, &p_peek, i_size + 1024 );
 401             if( i_peek <= i_size + 4 )
 402             {
 403                 return NULL;
 404             }
 405             while( i_size <= i_peek - 4 )
 406             {
 407                 if( p_peek[i_size] == 0x00 && p_peek[i_size+1] == 0x00 &&
 408                     p_peek[i_size+2] == 0x01 && p_peek[i_size+3] >= 0xb9 )
 409                 {
 410                     return stream_Block( s, i_size );
 411                 }
 412                 i_size++;
 413             }
 414         }
 415     }
 416     else
 417     {
 418         /* Normal case */
 419         return  stream_Block( s, i_size );
 420     }
 421
 422     return NULL;
 423 }