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