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  * $Id$
   6  *
   7  * Authors: Laurent Aimar <fenrir@via.ecp.fr>
   8  *
   9  * This program is free software; you can redistribute it and/or modify it
  10  * under the terms of the GNU Lesser General Public License as published by
  11  * the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU Lesser General Public License
  20  * along with this program; if not, write to the Free Software Foundation,
  21  * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  22  *****************************************************************************/
  23
  24 #ifndef VLC_DEMUX_H
  25 #define VLC_DEMUX_H 1
  26
  27 #include <stdlib.h>
  28 #include <string.h>
  29
  30 #include <vlc_es.h>
  31 #include <vlc_stream.h>
  32 #include <vlc_es_out.h>
  33
  34 /**
  35  * \defgroup demux Demultiplexer
  36  * \ingroup input
  37  * Demultiplexers (file format parsers)
  38  * @{
  39  * \file
  40  * Demultiplexer modules interface
  41  */
  42
  43 struct demux_t
  44 {
  45     struct vlc_common_members obj;
  46
  47     /* Module properties */
  48     module_t    *p_module;
  49
  50     /* eg informative but needed (we can have access+demux) */
  51     char        *psz_name;
  52     char        *psz_url;
  53     const char  *psz_location;
  54     char        *psz_filepath;
  55
  56     union {
  57         /**
  58          * Input stream
  59          *
  60          * Depending on the module capability:
  61          * - "demux": input byte stream (not NULL)
  62          * - "access_demux": a NULL pointer
  63          * - "demux_filter": undefined
  64          */
  65         stream_t *s;
  66         /**
  67          * Input demuxer
  68          *
  69          * If the module capability is "demux_filter", this is the upstream
  70          * demuxer or demux filter. Otherwise, this is undefined.
  71          */
  72         demux_t *p_next;
  73     };
  74
  75     /* es output */
  76     es_out_t    *out;   /* our p_es_out */
  77
  78     bool         b_preparsing; /* True if the demux is used to preparse */
  79
  80     /* set by demuxer */
  81     int (*pf_demux)  ( demux_t * );   /* demux one frame only */
  82     int (*pf_control)( demux_t *, int i_query, va_list args);
  83
  84     /* Demux has to maintain them uptodate
  85      * when it is responsible of seekpoint/title */
  86     struct
  87     {
  88         unsigned int i_update;  /* Demux sets them on change,
  89                                    Input removes them once take into account*/
  90     } info;
  91     void *p_sys;
  92
  93     /* Weak link to parent input */
  94     input_thread_t *p_input;
  95 };
  96
  97 /* pf_demux return values */
  98 #define VLC_DEMUXER_EOF       0
  99 #define VLC_DEMUXER_EGENERIC -1
 100 #define VLC_DEMUXER_SUCCESS   1
 101
 102 /* demux_t.info.i_update field */
 103 #define INPUT_UPDATE_TITLE      0x0010
 104 #define INPUT_UPDATE_SEEKPOINT  0x0020
 105 #define INPUT_UPDATE_META       0x0040
 106 #define INPUT_UPDATE_TITLE_LIST 0x0100
 107
 108 /* demux_meta_t is returned by "meta reader" module to the demuxer */
 109 typedef struct demux_meta_t
 110 {
 111     struct vlc_common_members obj;
 112     input_item_t *p_item; /***< the input item that is being read */
 113
 114     vlc_meta_t *p_meta;                 /**< meta data */
 115
 116     int i_attachments;                  /**< number of attachments */
 117     input_attachment_t **attachments;    /**< array of attachments */
 118 } demux_meta_t;
 119
 120 /**
 121  * Control query identifiers for use with demux_t.pf_control
 122  *
 123  * In the individual identifier description, the input stream refers to
 124  * demux_t.s if non-NULL, and the output refers to demux_t.out.
 125  *
 126  * A demuxer is synchronous if it only accesses its input stream and the
 127  * output from within its demux_t callbacks, i.e. demux.pf_demux and
 128  * demux_t.pf_control.
 129  *
 130  * A demuxer is threaded if it accesses either or both input and output
 131  * asynchronously.
 132  *
 133  * An access-demuxer is a demuxer without input, i.e. demux_t.s == NULL).
 134  */
 135 enum demux_query_e
 136 {
 137     /** Checks whether the stream supports seeking.
 138      * Can fail if seeking is not supported (same as returning false).
 139      * \bug Failing should not be allowed.
 140      *
 141      * arg1 = bool * */
 142     DEMUX_CAN_SEEK,
 143
 144     /** Checks whether (long) pause then stream resumption is supported.
 145      * Can fail only if synchronous and <b>not</b> an access-demuxer. The
 146      * underlying input stream then determines if pause is supported.
 147      * \bug Failing should not be allowed.
 148      *
 149      * arg1= bool * */
 150     DEMUX_CAN_PAUSE = 0x002,
 151
 152     /** Whether the stream can be read at an arbitrary pace.
 153      * Cannot fail.
 154      *
 155      * arg1= bool * */
 156     DEMUX_CAN_CONTROL_PACE,
 157
 158     /** Retrieves the PTS delay (roughly the default buffer duration).
 159      * Can fail only if synchronous and <b>not</b> an access-demuxer. The
 160      * underlying input stream then determines the PTS delay.
 161      *
 162      * arg1= int64_t * */
 163     DEMUX_GET_PTS_DELAY = 0x101,
 164
 165     /** Retrieves stream meta-data.
 166      * Should fail if no meta-data were retrieved.
 167      *
 168      * arg1= vlc_meta_t * */
 169     DEMUX_GET_META = 0x105,
 170
 171     /** Retrieves an estimate of signal quality and strength.
 172      * Can fail.
 173      *
 174      * arg1=double *quality, arg2=double *strength */
 175     DEMUX_GET_SIGNAL = 0x107,
 176
 177     /** Sets the paused or playing/resumed state.
 178      *
 179      * Streams are initially in playing state. The control always specifies a
 180      * change from paused to playing (false) or from playing to paused (true)
 181      * and streams are initially playing; a no-op cannot be requested.
 182      *
 183      * The control is never used if DEMUX_CAN_PAUSE fails.
 184      * Can fail.
 185      *
 186      * arg1= bool */
 187     DEMUX_SET_PAUSE_STATE = 0x200,
 188
 189     /** Seeks to the beginning of a title.
 190      *
 191      * The control is never used if DEMUX_GET_TITLE_INFO fails.
 192      * Can fail.
 193      *
 194      * arg1= int */
 195     DEMUX_SET_TITLE,
 196
 197     /** Seeks to the beginning of a chapter of the current title.
 198      *
 199      * The control is never used if DEMUX_GET_TITLE_INFO fails.
 200      * Can fail.
 201      *
 202      * arg1= int */
 203     DEMUX_SET_SEEKPOINT,        /* arg1= int            can fail */
 204
 205     /** Check which INPUT_UPDATE_XXX flag is set and reset the ones set.
 206      *
 207      * The unsigned* argument is set with the flags needed to be checked,
 208      * on return it contains the values that were reset during the call
 209      *
 210      * This can can fail, in which case flags from demux_t.info.i_update
 211      * are read/reset
 212      *
 213      * arg1= unsigned * */
 214     DEMUX_TEST_AND_CLEAR_FLAGS, /* arg1= unsigned*      can fail */
 215
 216     /** Read the title number currently playing
 217      *
 218      * Can fail.
 219      *
 220      * arg1= int * */
 221     DEMUX_GET_TITLE,            /* arg1= int*           can fail */
 222
 223     /* Read the seekpoint/chapter currently playing
 224      *
 225      * Can fail.
 226      *
 227      * arg1= int * */
 228     DEMUX_GET_SEEKPOINT,        /* arg1= int*           can fail */
 229
 230     /* I. Common queries to access_demux and demux */
 231     /* POSITION double between 0.0 and 1.0 */
 232     DEMUX_GET_POSITION = 0x300, /* arg1= double *       res=    */
 233     DEMUX_SET_POSITION,         /* arg1= double arg2= bool b_precise    res=can fail    */
 234
 235     /* LENGTH/TIME in microsecond, 0 if unknown */
 236     DEMUX_GET_LENGTH,           /* arg1= int64_t *      res=    */
 237     DEMUX_GET_TIME,             /* arg1= int64_t *      res=    */
 238     DEMUX_SET_TIME,             /* arg1= int64_t arg2= bool b_precise   res=can fail    */
 239
 240     /**
 241      * \todo Document
 242      *
 243      * \warning The prototype is different from STREAM_GET_TITLE_INFO
 244      *
 245      * Can fail, meaning there is only one title and one chapter.
 246      *
 247      * arg1= input_title_t ***, arg2=int *, arg3=int *pi_title_offset(0),
 248      * arg4= int *pi_seekpoint_offset(0) */
 249     DEMUX_GET_TITLE_INFO,
 250
 251     /* DEMUX_SET_GROUP/SET_ES only a hint for demuxer (mainly DVB) to allow not
 252      * reading everything (you should not use this to call es_out_Control)
 253      * if you don't know what to do with it, just IGNORE it, it is safe(r)
 254      * -1 means all group, 0 default group (first es added) */
 255     DEMUX_SET_GROUP,            /* arg1= int, arg2=const vlc_list_t *   can fail */
 256     DEMUX_SET_ES,               /* arg1= int                            can fail */
 257
 258     /* Ask the demux to demux until the given date at the next pf_demux call
 259      * but not more (and not less, at the precision available of course).
 260      * XXX: not mandatory (except for subtitle demux) but will help a lot
 261      * for multi-input
 262      */
 263     DEMUX_SET_NEXT_DEMUX_TIME,  /* arg1= int64_t        can fail */
 264     /* FPS for correct subtitles handling */
 265     DEMUX_GET_FPS,              /* arg1= double *       res=can fail    */
 266
 267     /* Meta data */
 268     DEMUX_HAS_UNSUPPORTED_META, /* arg1= bool *   res can fail    */
 269
 270     /* Attachments */
 271     DEMUX_GET_ATTACHMENTS,      /* arg1=input_attachment_t***, int* res=can fail */
 272
 273     /* RECORD you are ensured that it is never called twice with the same state
 274      * you should accept it only if the stream can be recorded without
 275      * any modification or header addition. */
 276     DEMUX_CAN_RECORD,           /* arg1=bool*   res=can fail(assume false) */
 277     /**
 278      * \todo Document
 279      *
 280      * \warning The prototype is different from STREAM_SET_RECORD_STATE
 281      *
 282      * The control is never used if DEMUX_CAN_RECORD fails or returns false.
 283      * Can fail.
 284      *
 285      * arg1= bool */
 286     DEMUX_SET_RECORD_STATE,
 287
 288     /* II. Specific access_demux queries */
 289
 290     /* DEMUX_CAN_CONTROL_RATE is called only if DEMUX_CAN_CONTROL_PACE has
 291      *  returned false. *pb_rate should be true when the rate can be changed
 292      * (using DEMUX_SET_RATE). */
 293     DEMUX_CAN_CONTROL_RATE,     /* arg1= bool*pb_rate */
 294     /* DEMUX_SET_RATE is called only if DEMUX_CAN_CONTROL_RATE has returned true.
 295      * It should return the value really used in *pi_rate */
 296     DEMUX_SET_RATE,             /* arg1= int*pi_rate                                        can fail */
 297
 298     /** Checks whether the stream is actually a playlist, rather than a real
 299      * stream.
 300      *
 301      * \warning The prototype is different from STREAM_IS_DIRECTORY.
 302      *
 303      * Can fail if the stream is not a playlist (same as returning false).
 304      *
 305      * arg1= bool * */
 306     DEMUX_IS_PLAYLIST,
 307
 308     /* Menu (VCD/DVD/BD) Navigation */
 309     /** Activate the navigation item selected. Can fail */
 310     DEMUX_NAV_ACTIVATE,
 311     /** Use the up arrow to select a navigation item above. Can fail */
 312     DEMUX_NAV_UP,
 313     /** Use the down arrow to select a navigation item under. Can fail */
 314     DEMUX_NAV_DOWN,
 315     /** Use the left arrow to select a navigation item on the left. Can fail */
 316     DEMUX_NAV_LEFT,
 317     /** Use the right arrow to select a navigation item on the right. Can fail */
 318     DEMUX_NAV_RIGHT,
 319     /** Activate the popup Menu (for BD). Can fail */
 320     DEMUX_NAV_POPUP,
 321     /** Activate disc Root Menu. Can fail */
 322     DEMUX_NAV_MENU,            /* res=can fail */
 323     /** Enable/Disable a demux filter
 324      * \warning This has limited support, and is likely to break if more than
 325      * a single demux_filter is present in the chain. This is not guaranteed to
 326      * work in future VLC versions, nor with all demux filters
 327      */
 328     DEMUX_FILTER_ENABLE,
 329     DEMUX_FILTER_DISABLE
 330 };
 331
 332 /*************************************************************************
 333  * Main Demux
 334  *************************************************************************/
 335
 336 /* stream_t *s could be null and then it mean a access+demux in one */
 337 VLC_API demux_t *demux_New( vlc_object_t *p_obj, const char *psz_name,
 338                             const char *psz_path, stream_t *s, es_out_t *out );
 339
 340 VLC_API void demux_Delete( demux_t * );
 341
 342
 343 VLC_API int demux_vaControlHelper( stream_t *, int64_t i_start, int64_t i_end,
 344                                    int64_t i_bitrate, int i_align, int i_query, va_list args );
 345
 346 VLC_USED static inline int demux_Demux( demux_t *p_demux )
 347 {
 348     if( !p_demux->pf_demux )
 349         return VLC_DEMUXER_SUCCESS;
 350
 351     return p_demux->pf_demux( p_demux );
 352 }
 353
 354 VLC_API int demux_vaControl( demux_t *p_demux, int i_query, va_list args );
 355
 356 static inline int demux_Control( demux_t *p_demux, int i_query, ... )
 357 {
 358     va_list args;
 359     int     i_result;
 360
 361     va_start( args, i_query );
 362     i_result = demux_vaControl( p_demux, i_query, args );
 363     va_end( args );
 364     return i_result;
 365 }
 366
 367 /*************************************************************************
 368  * Miscellaneous helpers for demuxers
 369  *************************************************************************/
 370
 371 #ifndef __cplusplus
 372 static inline void demux_UpdateTitleFromStream( demux_t *demux,
 373     int *restrict titlep, int *restrict seekpointp )
 374 {
 375     stream_t *s = demux->s;
 376     unsigned title, seekpoint;
 377
 378     if( vlc_stream_Control( s, STREAM_GET_TITLE, &title ) == VLC_SUCCESS
 379      && title != (unsigned)*titlep )
 380     {
 381         *titlep = title;
 382         demux->info.i_update |= INPUT_UPDATE_TITLE;
 383     }
 384
 385     if( vlc_stream_Control( s, STREAM_GET_SEEKPOINT,
 386                             &seekpoint ) == VLC_SUCCESS
 387      && seekpoint != (unsigned)*seekpointp )
 388     {
 389         *seekpointp = seekpoint;
 390         demux->info.i_update |= INPUT_UPDATE_SEEKPOINT;
 391     }
 392 }
 393 # define demux_UpdateTitleFromStream(demux) \
 394      demux_UpdateTitleFromStream(demux, \
 395          &((demux_sys_t *)((demux)->p_sys))->current_title, \
 396          &((demux_sys_t *)((demux)->p_sys))->current_seekpoint)
 397 #endif
 398
 399 VLC_USED
 400 static inline bool demux_IsPathExtension( demux_t *p_demux, const char *psz_extension )
 401 {
 402     const char *name = (p_demux->psz_filepath != NULL) ? p_demux->psz_filepath
 403                                                        : p_demux->psz_location;
 404     const char *psz_ext = strrchr ( name, '.' );
 405     if( !psz_ext || strcasecmp( psz_ext, psz_extension ) )
 406         return false;
 407     return true;
 408 }
 409
 410 VLC_USED
 411 static inline bool demux_IsContentType(demux_t *demux, const char *type)
 412 {
 413     return stream_IsMimeType(demux->s, type);
 414 }
 415
 416 VLC_USED
 417 static inline bool demux_IsForced( demux_t *p_demux, const char *psz_name )
 418 {
 419    if( p_demux->psz_name == NULL || strcmp( p_demux->psz_name, psz_name ) )
 420         return false;
 421     return true;
 422 }
 423
 424 /**
 425  * This function will create a packetizer suitable for a demuxer that parses
 426  * elementary stream.
 427  *
 428  * The provided es_format_t will be cleaned on error or by
 429  * demux_PacketizerDestroy.
 430  */
 431 VLC_API decoder_t * demux_PacketizerNew( demux_t *p_demux, es_format_t *p_fmt, const char *psz_msg ) VLC_USED;
 432
 433 /**
 434  * This function will destroy a packetizer create by demux_PacketizerNew.
 435  */
 436 VLC_API void demux_PacketizerDestroy( decoder_t *p_packetizer );
 437
 438 /* */
 439 #define DEMUX_INIT_COMMON() do {            \
 440     p_demux->pf_control = Control;          \
 441     p_demux->pf_demux = Demux;              \
 442     p_demux->p_sys = calloc( 1, sizeof( demux_sys_t ) ); \
 443     if( !p_demux->p_sys ) return VLC_ENOMEM;\
 444     } while(0)
 445
 446 /**
 447  * \defgroup chained_demux Chained demultiplexer
 448  * Demultiplexers wrapped by another demultiplexer
 449  * @{
 450  */
 451
 452 typedef struct vlc_demux_chained_t vlc_demux_chained_t;
 453
 454 /**
 455  * Creates a chained demuxer.
 456  *
 457  * This creates a thread running a demuxer whose input stream is generated
 458  * directly by the caller. This typically handles some sort of stream within a
 459  * stream, e.g. MPEG-TS within something else.
 460  *
 461  * \note There are a number of limitations to this approach. The chained
 462  * demuxer is run asynchronously in a separate thread. Most demuxer controls
 463  * are synchronous and therefore unavailable in this case. Also the input
 464  * stream is a simple FIFO, so the chained demuxer cannot perform seeks.
 465  * Lastly, most errors cannot be detected.
 466  *
 467  * \param parent parent VLC object
 468  * \param name chained demux module name (e.g. "ts")
 469  * \param out elementary stream output for the chained demux
 470  * \return a non-NULL pointer on success, NULL on failure.
 471  */
 472 VLC_API vlc_demux_chained_t *vlc_demux_chained_New(vlc_object_t *parent,
 473                                                    const char *name,
 474                                                    es_out_t *out);
 475
 476 /**
 477  * Destroys a chained demuxer.
 478  *
 479  * Sends an end-of-stream to the chained demuxer, and releases all underlying
 480  * allocated resources.
 481  */
 482 VLC_API void vlc_demux_chained_Delete(vlc_demux_chained_t *);
 483
 484 /**
 485  * Sends data to a chained demuxer.
 486  *
 487  * This queues data for a chained demuxer to consume.
 488  *
 489  * \param block data block to queue
 490  */
 491 VLC_API void vlc_demux_chained_Send(vlc_demux_chained_t *, block_t *block);
 492
 493 /**
 494  * Controls a chained demuxer.
 495  *
 496  * This performs a <b>demux</b> (i.e. DEMUX_...) control request on a chained
 497  * demux.
 498  *
 499  * \note In most cases, vlc_demux_chained_Control() should be used instead.
 500  * \warning As per vlc_demux_chained_New(), most demux controls are not, and
 501  * cannot be, supported; VLC_EGENERIC is returned.
 502  *
 503  * \param query demux control (see \ref demux_query_e)
 504  * \param args variable arguments (depending on the query)
 505  */
 506 VLC_API int vlc_demux_chained_ControlVa(vlc_demux_chained_t *, int query,
 507                                         va_list args);
 508
 509 static inline int vlc_demux_chained_Control(vlc_demux_chained_t *dc, int query,
 510                                             ...)
 511 {
 512     va_list ap;
 513     int ret;
 514
 515     va_start(ap, query);
 516     ret = vlc_demux_chained_ControlVa(dc, query, ap);
 517     va_end(ap);
 518     return ret;
 519 }
 520
 521 /**
 522  * @}
 523  */
 524
 525 /**
 526  * @}
 527  */
 528
 529 #endif