include/vlc_demux.h

   1 /*****************************************************************************
   2  * vlc_demux.h: Demuxer descriptor, queries and methods
   3  *****************************************************************************
   4  * Copyright (C) 1999-2005 VLC authors and VideoLAN
   5  *
   6  * Authors: Laurent Aimar <fenrir@via.ecp.fr>
   7  *
   8  * This program is free software; you can redistribute it and/or modify it
   9  * under the terms of the GNU Lesser General Public License as published by
  10  * the Free Software Foundation; either version 2.1 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  16  * GNU Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public License
  19  * along with this program; if not, write to the Free Software Foundation,
  20  * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  21  *****************************************************************************/
  22
  23 #ifndef VLC_DEMUX_H
  24 #define VLC_DEMUX_H 1
  25
  26 #include <stdlib.h>
  27 #include <string.h>
  28
  29 #include <vlc_es.h>
  30 #include <vlc_stream.h>
  31 #include <vlc_es_out.h>
  32
  33 /**
  34  * \defgroup demux Demultiplexer
  35  * \ingroup input
  36  * Demultiplexers (file format parsers)
  37  * @{
  38  * \file
  39  * Demultiplexer modules interface
  40  */
  41
  42 /* pf_demux return values */
  43 #define VLC_DEMUXER_EOF       0
  44 #define VLC_DEMUXER_EGENERIC -1
  45 #define VLC_DEMUXER_SUCCESS   1
  46
  47 /* DEMUX_TEST_AND_CLEAR flags */
  48 #define INPUT_UPDATE_TITLE      0x0010
  49 #define INPUT_UPDATE_SEEKPOINT  0x0020
  50 #define INPUT_UPDATE_META       0x0040
  51 #define INPUT_UPDATE_TITLE_LIST 0x0100
  52
  53 /* Demux module descriptor helpers */
  54 #define add_file_extension(ext) add_shortcut("ext-" ext)
  55
  56 /* demux_meta_t is returned by "meta reader" module to the demuxer */
  57 typedef struct demux_meta_t
  58 {
  59     struct vlc_object_t obj;
  60     input_item_t *p_item; /***< the input item that is being read */
  61
  62     vlc_meta_t *p_meta;                 /**< meta data */
  63
  64     int i_attachments;                  /**< number of attachments */
  65     input_attachment_t **attachments;    /**< array of attachments */
  66 } demux_meta_t;
  67
  68 /**
  69  * Control query identifiers for use with demux_t.pf_control
  70  *
  71  * In the individual identifier description, the input stream refers to
  72  * demux_t.s if non-NULL, and the output refers to demux_t.out.
  73  *
  74  * A demuxer is synchronous if it only accesses its input stream and the
  75  * output from within its demux_t callbacks, i.e. demux.pf_demux and
  76  * demux_t.pf_control.
  77  *
  78  * A demuxer is threaded if it accesses either or both input and output
  79  * asynchronously.
  80  *
  81  * An access-demuxer is a demuxer without input, i.e. demux_t.s == NULL).
  82  */
  83 enum demux_query_e
  84 {
  85     /** Checks whether the stream supports seeking.
  86      * Can fail if seeking is not supported (same as returning false).
  87      * \bug Failing should not be allowed.
  88      *
  89      * arg1 = bool * */
  90     DEMUX_CAN_SEEK,
  91
  92     /** Checks whether (long) pause then stream resumption is supported.
  93      * Can fail only if synchronous and <b>not</b> an access-demuxer. The
  94      * underlying input stream then determines if pause is supported.
  95      * \bug Failing should not be allowed.
  96      *
  97      * arg1= bool * */
  98     DEMUX_CAN_PAUSE = 0x002,
  99
 100     /** Whether the stream can be read at an arbitrary pace.
 101      * Cannot fail.
 102      *
 103      * arg1= bool * */
 104     DEMUX_CAN_CONTROL_PACE,
 105
 106     /** Retrieves the PTS delay (roughly the default buffer duration).
 107      * Can fail only if synchronous and <b>not</b> an access-demuxer. The
 108      * underlying input stream then determines the PTS delay.
 109      *
 110      * arg1= vlc_tick_t * */
 111     DEMUX_GET_PTS_DELAY = 0x101,
 112
 113     /** Retrieves stream meta-data.
 114      * Should fail if no meta-data were retrieved.
 115      *
 116      * arg1= vlc_meta_t * */
 117     DEMUX_GET_META = 0x105,
 118
 119     /** Retrieves an estimate of signal quality and strength.
 120      * Can fail.
 121      *
 122      * arg1=double *quality, arg2=double *strength */
 123     DEMUX_GET_SIGNAL = 0x107,
 124
 125     /** Retrieves the demuxed content type
 126      * Can fail if the control is not implemented
 127      *
 128      * arg1= int* */
 129     DEMUX_GET_TYPE = 0x109,
 130
 131     /** Sets the paused or playing/resumed state.
 132      *
 133      * Streams are initially in playing state. The control always specifies a
 134      * change from paused to playing (false) or from playing to paused (true)
 135      * and streams are initially playing; a no-op cannot be requested.
 136      *
 137      * The control is never used if DEMUX_CAN_PAUSE fails.
 138      * Can fail.
 139      *
 140      * arg1= bool */
 141     DEMUX_SET_PAUSE_STATE = 0x200,
 142
 143     /** Seeks to the beginning of a title.
 144      *
 145      * The control is never used if DEMUX_GET_TITLE_INFO fails.
 146      * Can fail.
 147      *
 148      * arg1= int */
 149     DEMUX_SET_TITLE,
 150
 151     /** Seeks to the beginning of a chapter of the current title.
 152      *
 153      * The control is never used if DEMUX_GET_TITLE_INFO fails.
 154      * Can fail.
 155      *
 156      * arg1= int */
 157     DEMUX_SET_SEEKPOINT,        /* arg1= int            can fail */
 158
 159     /** Check which INPUT_UPDATE_XXX flag is set and reset the ones set.
 160      *
 161      * The unsigned* argument is set with the flags needed to be checked,
 162      * on return it contains the values that were reset during the call
 163      *
 164      * arg1= unsigned * */
 165     DEMUX_TEST_AND_CLEAR_FLAGS, /* arg1= unsigned*      can fail */
 166
 167     /** Read the title number currently playing
 168      *
 169      * Can fail.
 170      *
 171      * arg1= int * */
 172     DEMUX_GET_TITLE,            /* arg1= int*           can fail */
 173
 174     /* Read the seekpoint/chapter currently playing
 175      *
 176      * Can fail.
 177      *
 178      * arg1= int * */
 179     DEMUX_GET_SEEKPOINT,        /* arg1= int*           can fail */
 180
 181     /* I. Common queries to access_demux and demux */
 182     /* POSITION double between 0.0 and 1.0 */
 183     DEMUX_GET_POSITION = 0x300, /* arg1= double *       res=    */
 184     DEMUX_SET_POSITION,         /* arg1= double arg2= bool b_precise    res=can fail    */
 185
 186     /* LENGTH/TIME in microsecond, 0 if unknown */
 187     DEMUX_GET_LENGTH,           /* arg1= vlc_tick_t *   res=    */
 188     DEMUX_GET_TIME,             /* arg1= vlc_tick_t *   res=    */
 189     DEMUX_SET_TIME,             /* arg1= vlc_tick_t arg2= bool b_precise   res=can fail    */
 190     /* Normal or original time, used mainly by the ts module */
 191     DEMUX_GET_NORMAL_TIME,      /* arg1= vlc_tick_t *   res= can fail, in that case VLC_TICK_0 will be used as NORMAL_TIME */
 192
 193     /**
 194      * \todo Document
 195      *
 196      * \warning The prototype is different from STREAM_GET_TITLE_INFO
 197      *
 198      * Can fail, meaning there is only one title and one chapter.
 199      *
 200      * arg1= input_title_t ***, arg2=int *, arg3=int *pi_title_offset(0),
 201      * arg4= int *pi_seekpoint_offset(0) */
 202     DEMUX_GET_TITLE_INFO,
 203
 204     /* DEMUX_SET_GROUP_* / DEMUX_SET_ES is only a hint for demuxer (mainly DVB)
 205      * to avoid parsing everything (you should not use this to call
 206      * es_out_Control()).
 207      * If you don't know what to do with it, just IGNORE it: it is safe(r). */
 208     DEMUX_SET_GROUP_DEFAULT,
 209     DEMUX_SET_GROUP_ALL,
 210     DEMUX_SET_GROUP_LIST,       /* arg1= size_t, arg2= const int *, can fail */
 211     DEMUX_SET_ES,               /* arg1= int                        can fail */
 212     DEMUX_SET_ES_LIST,          /* arg1= size_t, arg2= const int * (can be NULL) can fail */
 213
 214     /* Ask the demux to demux until the given date at the next pf_demux call
 215      * but not more (and not less, at the precision available of course).
 216      * XXX: not mandatory (except for subtitle demux) but will help a lot
 217      * for multi-input
 218      */
 219     DEMUX_SET_NEXT_DEMUX_TIME,  /* arg1= vlc_tick_t     can fail */
 220     /* FPS for correct subtitles handling */
 221     DEMUX_GET_FPS,              /* arg1= double *       res=can fail    */
 222
 223     /* Meta data */
 224     DEMUX_HAS_UNSUPPORTED_META, /* arg1= bool *   res can fail    */
 225
 226     /* Attachments */
 227     DEMUX_GET_ATTACHMENTS,      /* arg1=input_attachment_t***, int* res=can fail */
 228
 229     /* RECORD you are ensured that it is never called twice with the same state
 230      * you should accept it only if the stream can be recorded without
 231      * any modification or header addition. */
 232     DEMUX_CAN_RECORD,           /* arg1=bool*   res=can fail(assume false) */
 233     /**
 234      * \todo Document
 235      *
 236      * \warning The prototype is different from STREAM_SET_RECORD_STATE
 237      *
 238      * The control is never used if DEMUX_CAN_RECORD fails or returns false.
 239      * Can fail.
 240      *
 241      * arg1= bool */
 242     DEMUX_SET_RECORD_STATE,
 243
 244     /* II. Specific access_demux queries */
 245
 246     /* DEMUX_CAN_CONTROL_RATE is called only if DEMUX_CAN_CONTROL_PACE has
 247      *  returned false. *pb_rate should be true when the rate can be changed
 248      * (using DEMUX_SET_RATE). */
 249     DEMUX_CAN_CONTROL_RATE,     /* arg1= bool*pb_rate */
 250     /* DEMUX_SET_RATE is called only if DEMUX_CAN_CONTROL_RATE has returned true.
 251      * It should return the value really used in *p_rate */
 252     DEMUX_SET_RATE,             /* arg1= float*p_rate res=can fail */
 253
 254     /* Menu (VCD/DVD/BD) Navigation */
 255     /** Activate the navigation item selected. Can fail */
 256     DEMUX_NAV_ACTIVATE,
 257     /** Use the up arrow to select a navigation item above. Can fail */
 258     DEMUX_NAV_UP,
 259     /** Use the down arrow to select a navigation item under. Can fail */
 260     DEMUX_NAV_DOWN,
 261     /** Use the left arrow to select a navigation item on the left. Can fail */
 262     DEMUX_NAV_LEFT,
 263     /** Use the right arrow to select a navigation item on the right. Can fail */
 264     DEMUX_NAV_RIGHT,
 265     /** Activate the popup Menu (for BD). Can fail */
 266     DEMUX_NAV_POPUP,
 267     /** Activate disc Root Menu. Can fail */
 268     DEMUX_NAV_MENU,            /* res=can fail */
 269     /** Enable/Disable a demux filter
 270      * \warning This has limited support, and is likely to break if more than
 271      * a single demux_filter is present in the chain. This is not guaranteed to
 272      * work in future VLC versions, nor with all demux filters
 273      */
 274     DEMUX_FILTER_ENABLE,
 275     DEMUX_FILTER_DISABLE
 276 };
 277
 278 /*************************************************************************
 279  * Main Demux
 280  *************************************************************************/
 281
 282 VLC_API demux_t *demux_New( vlc_object_t *p_obj, const char *psz_name,
 283                             stream_t *s, es_out_t *out );
 284
 285 static inline void demux_Delete(demux_t *demux)
 286 {
 287     vlc_stream_Delete(demux);
 288 }
 289
 290 VLC_API int demux_vaControlHelper( stream_t *, int64_t i_start, int64_t i_end,
 291                                    int64_t i_bitrate, int i_align, int i_query, va_list args );
 292
 293 VLC_API int demux_Demux( demux_t *p_demux ) VLC_USED;
 294 VLC_API int demux_vaControl( demux_t *p_demux, int i_query, va_list args );
 295
 296 static inline int demux_Control( demux_t *p_demux, int i_query, ... )
 297 {
 298     va_list args;
 299     int     i_result;
 300
 301     va_start( args, i_query );
 302     i_result = demux_vaControl( p_demux, i_query, args );
 303     va_end( args );
 304     return i_result;
 305 }
 306
 307 /*************************************************************************
 308  * Miscellaneous helpers for demuxers
 309  *************************************************************************/
 310
 311 #ifndef __cplusplus
 312 static inline void demux_UpdateTitleFromStream( demux_t *demux,
 313     int *restrict titlep, int *restrict seekpointp,
 314     unsigned *restrict updatep )
 315 {
 316     stream_t *s = demux->s;
 317     unsigned title, seekpoint;
 318
 319     if( vlc_stream_Control( s, STREAM_GET_TITLE, &title ) == VLC_SUCCESS
 320      && title != (unsigned)*titlep )
 321     {
 322         *titlep = title;
 323         *updatep |= INPUT_UPDATE_TITLE;
 324     }
 325
 326     if( vlc_stream_Control( s, STREAM_GET_SEEKPOINT,
 327                             &seekpoint ) == VLC_SUCCESS
 328      && seekpoint != (unsigned)*seekpointp )
 329     {
 330         *seekpointp = seekpoint;
 331         *updatep |= INPUT_UPDATE_SEEKPOINT;
 332     }
 333 }
 334 # define demux_UpdateTitleFromStream(demux) \
 335      demux_UpdateTitleFromStream(demux, \
 336          &((demux_sys_t *)((demux)->p_sys))->current_title, \
 337          &((demux_sys_t *)((demux)->p_sys))->current_seekpoint, \
 338          &((demux_sys_t *)((demux)->p_sys))->updates)
 339 #endif
 340
 341 VLC_USED
 342 static inline bool demux_IsPathExtension( demux_t *p_demux, const char *psz_extension )
 343 {
 344     const char *name = (p_demux->psz_filepath != NULL) ? p_demux->psz_filepath
 345                                                        : p_demux->psz_location;
 346     const char *psz_ext = strrchr ( name, '.' );
 347     if( !psz_ext || strcasecmp( psz_ext, psz_extension ) )
 348         return false;
 349     return true;
 350 }
 351
 352 VLC_USED
 353 static inline bool demux_IsContentType(demux_t *demux, const char *type)
 354 {
 355     return stream_IsMimeType(demux->s, type);
 356 }
 357
 358 VLC_USED
 359 static inline bool demux_IsForced( demux_t *p_demux, const char *psz_name )
 360 {
 361    if( p_demux->psz_name == NULL || strcmp( p_demux->psz_name, psz_name ) )
 362         return false;
 363     return true;
 364 }
 365
 366 static inline int demux_SetPosition( demux_t *p_demux, double pos, bool precise,
 367                                      bool absolute)
 368 {
 369     if( !absolute )
 370     {
 371         double current_pos;
 372         int ret = demux_Control( p_demux, DEMUX_GET_POSITION, &current_pos );
 373         if( ret != VLC_SUCCESS )
 374             return ret;
 375         pos += current_pos;
 376     }
 377
 378     if( pos < 0.f )
 379         pos = 0.f;
 380     else if( pos > 1.f )
 381         pos = 1.f;
 382     return demux_Control( p_demux, DEMUX_SET_POSITION, pos, precise );
 383 }
 384
 385 static inline int demux_SetTime( demux_t *p_demux, vlc_tick_t time, bool precise,
 386                                  bool absolute )
 387 {
 388     if( !absolute )
 389     {
 390         vlc_tick_t current_time;
 391         int ret = demux_Control( p_demux, DEMUX_GET_TIME, &current_time );
 392         if( ret != VLC_SUCCESS )
 393             return ret;
 394         time += current_time;
 395     }
 396
 397     if( time < 0 )
 398         time = 0;
 399     return demux_Control( p_demux, DEMUX_SET_TIME, time, precise );
 400 }
 401
 402 /**
 403  * This function will create a packetizer suitable for a demuxer that parses
 404  * elementary stream.
 405  *
 406  * The provided es_format_t will be cleaned on error or by
 407  * demux_PacketizerDestroy.
 408  */
 409 VLC_API decoder_t * demux_PacketizerNew( demux_t *p_demux, es_format_t *p_fmt, const char *psz_msg ) VLC_USED;
 410
 411 /**
 412  * This function will destroy a packetizer create by demux_PacketizerNew.
 413  */
 414 VLC_API void demux_PacketizerDestroy( decoder_t *p_packetizer );
 415
 416 /* */
 417 #define DEMUX_INIT_COMMON() do {            \
 418     p_demux->pf_control = Control;          \
 419     p_demux->pf_demux = Demux;              \
 420     p_demux->p_sys = calloc( 1, sizeof( demux_sys_t ) ); \
 421     if( !p_demux->p_sys ) return VLC_ENOMEM;\
 422     } while(0)
 423
 424 /**
 425  * \defgroup chained_demux Chained demultiplexer
 426  * Demultiplexers wrapped by another demultiplexer
 427  * @{
 428  */
 429
 430 typedef struct vlc_demux_chained_t vlc_demux_chained_t;
 431
 432 /**
 433  * Creates a chained demuxer.
 434  *
 435  * This creates a thread running a demuxer whose input stream is generated
 436  * directly by the caller. This typically handles some sort of stream within a
 437  * stream, e.g. MPEG-TS within something else.
 438  *
 439  * \note There are a number of limitations to this approach. The chained
 440  * demuxer is run asynchronously in a separate thread. Most demuxer controls
 441  * are synchronous and therefore unavailable in this case. Also the input
 442  * stream is a simple FIFO, so the chained demuxer cannot perform seeks.
 443  * Lastly, most errors cannot be detected.
 444  *
 445  * \param parent parent VLC object
 446  * \param name chained demux module name (e.g. "ts")
 447  * \param out elementary stream output for the chained demux
 448  * \return a non-NULL pointer on success, NULL on failure.
 449  */
 450 VLC_API vlc_demux_chained_t *vlc_demux_chained_New(vlc_object_t *parent,
 451                                                    const char *name,
 452                                                    es_out_t *out);
 453
 454 /**
 455  * Destroys a chained demuxer.
 456  *
 457  * Sends an end-of-stream to the chained demuxer, and releases all underlying
 458  * allocated resources.
 459  */
 460 VLC_API void vlc_demux_chained_Delete(vlc_demux_chained_t *);
 461
 462 /**
 463  * Sends data to a chained demuxer.
 464  *
 465  * This queues data for a chained demuxer to consume.
 466  *
 467  * \param block data block to queue
 468  */
 469 VLC_API void vlc_demux_chained_Send(vlc_demux_chained_t *, block_t *block);
 470
 471 /**
 472  * Controls a chained demuxer.
 473  *
 474  * This performs a <b>demux</b> (i.e. DEMUX_...) control request on a chained
 475  * demux.
 476  *
 477  * \note In most cases, vlc_demux_chained_Control() should be used instead.
 478  * \warning As per vlc_demux_chained_New(), most demux controls are not, and
 479  * cannot be, supported; VLC_EGENERIC is returned.
 480  *
 481  * \param query demux control (see \ref demux_query_e)
 482  * \param args variable arguments (depending on the query)
 483  */
 484 VLC_API int vlc_demux_chained_ControlVa(vlc_demux_chained_t *, int query,
 485                                         va_list args);
 486
 487 static inline int vlc_demux_chained_Control(vlc_demux_chained_t *dc, int query,
 488                                             ...)
 489 {
 490     va_list ap;
 491     int ret;
 492
 493     va_start(ap, query);
 494     ret = vlc_demux_chained_ControlVa(dc, query, ap);
 495     va_end(ap);
 496     return ret;
 497 }
 498
 499 /**
 500  * @}
 501  */
 502
 503 /**
 504  * @}
 505  */
 506
 507 #endif