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