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