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