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_meta_t is returned by "meta reader" module to the demuxer */
  54 typedef struct demux_meta_t
  55 {
  56     struct vlc_object_t obj;
  57     input_item_t *p_item; /***< the input item that is being read */
  58
  59     vlc_meta_t *p_meta;                 /**< meta data */
  60
  61     int i_attachments;                  /**< number of attachments */
  62     input_attachment_t **attachments;    /**< array of attachments */
  63 } demux_meta_t;
  64
  65 /**
  66  * Control query identifiers for use with demux_t.pf_control
  67  *
  68  * In the individual identifier description, the input stream refers to
  69  * demux_t.s if non-NULL, and the output refers to demux_t.out.
  70  *
  71  * A demuxer is synchronous if it only accesses its input stream and the
  72  * output from within its demux_t callbacks, i.e. demux.pf_demux and
  73  * demux_t.pf_control.
  74  *
  75  * A demuxer is threaded if it accesses either or both input and output
  76  * asynchronously.
  77  *
  78  * An access-demuxer is a demuxer without input, i.e. demux_t.s == NULL).
  79  */
  80 enum demux_query_e
  81 {
  82     /** Checks whether the stream supports seeking.
  83      * Can fail if seeking is not supported (same as returning false).
  84      * \bug Failing should not be allowed.
  85      *
  86      * arg1 = bool * */
  87     DEMUX_CAN_SEEK,
  88
  89     /** Checks whether (long) pause then stream resumption is supported.
  90      * Can fail only if synchronous and <b>not</b> an access-demuxer. The
  91      * underlying input stream then determines if pause is supported.
  92      * \bug Failing should not be allowed.
  93      *
  94      * arg1= bool * */
  95     DEMUX_CAN_PAUSE = 0x002,
  96
  97     /** Whether the stream can be read at an arbitrary pace.
  98      * Cannot fail.
  99      *
 100      * arg1= bool * */
 101     DEMUX_CAN_CONTROL_PACE,
 102
 103     /** Retrieves the PTS delay (roughly the default buffer duration).
 104      * Can fail only if synchronous and <b>not</b> an access-demuxer. The
 105      * underlying input stream then determines the PTS delay.
 106      *
 107      * arg1= vlc_tick_t * */
 108     DEMUX_GET_PTS_DELAY = 0x101,
 109
 110     /** Retrieves stream meta-data.
 111      * Should fail if no meta-data were retrieved.
 112      *
 113      * arg1= vlc_meta_t * */
 114     DEMUX_GET_META = 0x105,
 115
 116     /** Retrieves an estimate of signal quality and strength.
 117      * Can fail.
 118      *
 119      * arg1=double *quality, arg2=double *strength */
 120     DEMUX_GET_SIGNAL = 0x107,
 121
 122     /** Sets the paused or playing/resumed state.
 123      *
 124      * Streams are initially in playing state. The control always specifies a
 125      * change from paused to playing (false) or from playing to paused (true)
 126      * and streams are initially playing; a no-op cannot be requested.
 127      *
 128      * The control is never used if DEMUX_CAN_PAUSE fails.
 129      * Can fail.
 130      *
 131      * arg1= bool */
 132     DEMUX_SET_PAUSE_STATE = 0x200,
 133
 134     /** Seeks to the beginning of a title.
 135      *
 136      * The control is never used if DEMUX_GET_TITLE_INFO fails.
 137      * Can fail.
 138      *
 139      * arg1= int */
 140     DEMUX_SET_TITLE,
 141
 142     /** Seeks to the beginning of a chapter of the current title.
 143      *
 144      * The control is never used if DEMUX_GET_TITLE_INFO fails.
 145      * Can fail.
 146      *
 147      * arg1= int */
 148     DEMUX_SET_SEEKPOINT,        /* arg1= int            can fail */
 149
 150     /** Check which INPUT_UPDATE_XXX flag is set and reset the ones set.
 151      *
 152      * The unsigned* argument is set with the flags needed to be checked,
 153      * on return it contains the values that were reset during the call
 154      *
 155      * arg1= unsigned * */
 156     DEMUX_TEST_AND_CLEAR_FLAGS, /* arg1= unsigned*      can fail */
 157
 158     /** Read the title number currently playing
 159      *
 160      * Can fail.
 161      *
 162      * arg1= int * */
 163     DEMUX_GET_TITLE,            /* arg1= int*           can fail */
 164
 165     /* Read the seekpoint/chapter currently playing
 166      *
 167      * Can fail.
 168      *
 169      * arg1= int * */
 170     DEMUX_GET_SEEKPOINT,        /* arg1= int*           can fail */
 171
 172     /* I. Common queries to access_demux and demux */
 173     /* POSITION double between 0.0 and 1.0 */
 174     DEMUX_GET_POSITION = 0x300, /* arg1= double *       res=    */
 175     DEMUX_SET_POSITION,         /* arg1= double arg2= bool b_precise    res=can fail    */
 176
 177     /* LENGTH/TIME in microsecond, 0 if unknown */
 178     DEMUX_GET_LENGTH,           /* arg1= vlc_tick_t *   res=    */
 179     DEMUX_GET_TIME,             /* arg1= vlc_tick_t *   res=    */
 180     DEMUX_SET_TIME,             /* arg1= vlc_tick_t arg2= bool b_precise   res=can fail    */
 181     /* Normal or original time, used mainly by the ts module */
 182     DEMUX_GET_NORMAL_TIME,      /* arg1= vlc_tick_t *   res= can fail, in that case VLC_TICK_0 will be used as NORMAL_TIME */
 183
 184     /**
 185      * \todo Document
 186      *
 187      * \warning The prototype is different from STREAM_GET_TITLE_INFO
 188      *
 189      * Can fail, meaning there is only one title and one chapter.
 190      *
 191      * arg1= input_title_t ***, arg2=int *, arg3=int *pi_title_offset(0),
 192      * arg4= int *pi_seekpoint_offset(0) */
 193     DEMUX_GET_TITLE_INFO,
 194
 195     /* DEMUX_SET_GROUP_* / DEMUX_SET_ES is only a hint for demuxer (mainly DVB)
 196      * to avoid parsing everything (you should not use this to call
 197      * es_out_Control()).
 198      * If you don't know what to do with it, just IGNORE it: it is safe(r). */
 199     DEMUX_SET_GROUP_DEFAULT,
 200     DEMUX_SET_GROUP_ALL,
 201     DEMUX_SET_GROUP_LIST,       /* arg1= size_t, arg2= const int *, can fail */
 202     DEMUX_SET_ES,               /* arg1= int                        can fail */
 203     DEMUX_SET_ES_LIST,          /* arg1= size_t, arg2= const int * (can be NULL) can fail */
 204
 205     /* Ask the demux to demux until the given date at the next pf_demux call
 206      * but not more (and not less, at the precision available of course).
 207      * XXX: not mandatory (except for subtitle demux) but will help a lot
 208      * for multi-input
 209      */
 210     DEMUX_SET_NEXT_DEMUX_TIME,  /* arg1= vlc_tick_t     can fail */
 211     /* FPS for correct subtitles handling */
 212     DEMUX_GET_FPS,              /* arg1= double *       res=can fail    */
 213
 214     /* Meta data */
 215     DEMUX_HAS_UNSUPPORTED_META, /* arg1= bool *   res can fail    */
 216
 217     /* Attachments */
 218     DEMUX_GET_ATTACHMENTS,      /* arg1=input_attachment_t***, int* res=can fail */
 219
 220     /* RECORD you are ensured that it is never called twice with the same state
 221      * you should accept it only if the stream can be recorded without
 222      * any modification or header addition. */
 223     DEMUX_CAN_RECORD,           /* arg1=bool*   res=can fail(assume false) */
 224     /**
 225      * \todo Document
 226      *
 227      * \warning The prototype is different from STREAM_SET_RECORD_STATE
 228      *
 229      * The control is never used if DEMUX_CAN_RECORD fails or returns false.
 230      * Can fail.
 231      *
 232      * arg1= bool */
 233     DEMUX_SET_RECORD_STATE,
 234
 235     /* II. Specific access_demux queries */
 236
 237     /* DEMUX_CAN_CONTROL_RATE is called only if DEMUX_CAN_CONTROL_PACE has
 238      *  returned false. *pb_rate should be true when the rate can be changed
 239      * (using DEMUX_SET_RATE). */
 240     DEMUX_CAN_CONTROL_RATE,     /* arg1= bool*pb_rate */
 241     /* DEMUX_SET_RATE is called only if DEMUX_CAN_CONTROL_RATE has returned true.
 242      * It should return the value really used in *p_rate */
 243     DEMUX_SET_RATE,             /* arg1= float*p_rate res=can fail */
 244
 245     /** Checks whether the stream is actually a playlist, rather than a real
 246      * stream.
 247      *
 248      * Can fail if the stream is not a playlist (same as returning false).
 249      *
 250      * arg1= bool * */
 251     DEMUX_IS_PLAYLIST,
 252
 253     /* Menu (VCD/DVD/BD) Navigation */
 254     /** Activate the navigation item selected. Can fail */
 255     DEMUX_NAV_ACTIVATE,
 256     /** Use the up arrow to select a navigation item above. Can fail */
 257     DEMUX_NAV_UP,
 258     /** Use the down arrow to select a navigation item under. Can fail */
 259     DEMUX_NAV_DOWN,
 260     /** Use the left arrow to select a navigation item on the left. Can fail */
 261     DEMUX_NAV_LEFT,
 262     /** Use the right arrow to select a navigation item on the right. Can fail */
 263     DEMUX_NAV_RIGHT,
 264     /** Activate the popup Menu (for BD). Can fail */
 265     DEMUX_NAV_POPUP,
 266     /** Activate disc Root Menu. Can fail */
 267     DEMUX_NAV_MENU,            /* res=can fail */
 268     /** Enable/Disable a demux filter
 269      * \warning This has limited support, and is likely to break if more than
 270      * a single demux_filter is present in the chain. This is not guaranteed to
 271      * work in future VLC versions, nor with all demux filters
 272      */
 273     DEMUX_FILTER_ENABLE,
 274     DEMUX_FILTER_DISABLE
 275 };
 276
 277 /*************************************************************************
 278  * Main Demux
 279  *************************************************************************/
 280
 281 VLC_API demux_t *demux_New( vlc_object_t *p_obj, const char *psz_name,
 282                             stream_t *s, es_out_t *out );
 283
 284 static inline void demux_Delete(demux_t *demux)
 285 {
 286     vlc_stream_Delete(demux);
 287 }
 288
 289 VLC_API int demux_vaControlHelper( stream_t *, int64_t i_start, int64_t i_end,
 290                                    int64_t i_bitrate, int i_align, int i_query, va_list args );
 291
 292 VLC_USED static inline int demux_Demux( demux_t *p_demux )
 293 {
 294     if( !p_demux->pf_demux )
 295         return VLC_DEMUXER_SUCCESS;
 296
 297     return p_demux->pf_demux( p_demux );
 298 }
 299
 300 VLC_API int demux_vaControl( demux_t *p_demux, int i_query, va_list args );
 301
 302 static inline int demux_Control( demux_t *p_demux, int i_query, ... )
 303 {
 304     va_list args;
 305     int     i_result;
 306
 307     va_start( args, i_query );
 308     i_result = demux_vaControl( p_demux, i_query, args );
 309     va_end( args );
 310     return i_result;
 311 }
 312
 313 /*************************************************************************
 314  * Miscellaneous helpers for demuxers
 315  *************************************************************************/
 316
 317 #ifndef __cplusplus
 318 static inline void demux_UpdateTitleFromStream( demux_t *demux,
 319     int *restrict titlep, int *restrict seekpointp,
 320     unsigned *restrict updatep )
 321 {
 322     stream_t *s = demux->s;
 323     unsigned title, seekpoint;
 324
 325     if( vlc_stream_Control( s, STREAM_GET_TITLE, &title ) == VLC_SUCCESS
 326      && title != (unsigned)*titlep )
 327     {
 328         *titlep = title;
 329         *updatep |= INPUT_UPDATE_TITLE;
 330     }
 331
 332     if( vlc_stream_Control( s, STREAM_GET_SEEKPOINT,
 333                             &seekpoint ) == VLC_SUCCESS
 334      && seekpoint != (unsigned)*seekpointp )
 335     {
 336         *seekpointp = seekpoint;
 337         *updatep |= INPUT_UPDATE_SEEKPOINT;
 338     }
 339 }
 340 # define demux_UpdateTitleFromStream(demux) \
 341      demux_UpdateTitleFromStream(demux, \
 342          &((demux_sys_t *)((demux)->p_sys))->current_title, \
 343          &((demux_sys_t *)((demux)->p_sys))->current_seekpoint, \
 344          &((demux_sys_t *)((demux)->p_sys))->updates)
 345 #endif
 346
 347 VLC_USED
 348 static inline bool demux_IsPathExtension( demux_t *p_demux, const char *psz_extension )
 349 {
 350     const char *name = (p_demux->psz_filepath != NULL) ? p_demux->psz_filepath
 351                                                        : p_demux->psz_location;
 352     const char *psz_ext = strrchr ( name, '.' );
 353     if( !psz_ext || strcasecmp( psz_ext, psz_extension ) )
 354         return false;
 355     return true;
 356 }
 357
 358 VLC_USED
 359 static inline bool demux_IsContentType(demux_t *demux, const char *type)
 360 {
 361     return stream_IsMimeType(demux->s, type);
 362 }
 363
 364 VLC_USED
 365 static inline bool demux_IsForced( demux_t *p_demux, const char *psz_name )
 366 {
 367    if( p_demux->psz_name == NULL || strcmp( p_demux->psz_name, psz_name ) )
 368         return false;
 369     return true;
 370 }
 371
 372 static inline int demux_SetPosition( demux_t *p_demux, double pos, bool precise,
 373                                      bool absolute)
 374 {
 375     if( !absolute )
 376     {
 377         double current_pos;
 378         int ret = demux_Control( p_demux, DEMUX_GET_POSITION, &current_pos );
 379         if( ret != VLC_SUCCESS )
 380             return ret;
 381         pos += current_pos;
 382     }
 383
 384     if( pos < 0.f )
 385         pos = 0.f;
 386     else if( pos > 1.f )
 387         pos = 1.f;
 388     return demux_Control( p_demux, DEMUX_SET_POSITION, pos, precise );
 389 }
 390
 391 static inline int demux_SetTime( demux_t *p_demux, vlc_tick_t time, bool precise,
 392                                  bool absolute )
 393 {
 394     if( !absolute )
 395     {
 396         vlc_tick_t current_time;
 397         int ret = demux_Control( p_demux, DEMUX_GET_TIME, &current_time );
 398         if( ret != VLC_SUCCESS )
 399             return ret;
 400         time += current_time;
 401     }
 402
 403     if( time < 0 )
 404         time = 0;
 405     return demux_Control( p_demux, DEMUX_SET_TIME, time, precise );
 406 }
 407
 408 /**
 409  * This function will create a packetizer suitable for a demuxer that parses
 410  * elementary stream.
 411  *
 412  * The provided es_format_t will be cleaned on error or by
 413  * demux_PacketizerDestroy.
 414  */
 415 VLC_API decoder_t * demux_PacketizerNew( demux_t *p_demux, es_format_t *p_fmt, const char *psz_msg ) VLC_USED;
 416
 417 /**
 418  * This function will destroy a packetizer create by demux_PacketizerNew.
 419  */
 420 VLC_API void demux_PacketizerDestroy( decoder_t *p_packetizer );
 421
 422 /* */
 423 #define DEMUX_INIT_COMMON() do {            \
 424     p_demux->pf_control = Control;          \
 425     p_demux->pf_demux = Demux;              \
 426     p_demux->p_sys = calloc( 1, sizeof( demux_sys_t ) ); \
 427     if( !p_demux->p_sys ) return VLC_ENOMEM;\
 428     } while(0)
 429
 430 /**
 431  * \defgroup chained_demux Chained demultiplexer
 432  * Demultiplexers wrapped by another demultiplexer
 433  * @{
 434  */
 435
 436 typedef struct vlc_demux_chained_t vlc_demux_chained_t;
 437
 438 /**
 439  * Creates a chained demuxer.
 440  *
 441  * This creates a thread running a demuxer whose input stream is generated
 442  * directly by the caller. This typically handles some sort of stream within a
 443  * stream, e.g. MPEG-TS within something else.
 444  *
 445  * \note There are a number of limitations to this approach. The chained
 446  * demuxer is run asynchronously in a separate thread. Most demuxer controls
 447  * are synchronous and therefore unavailable in this case. Also the input
 448  * stream is a simple FIFO, so the chained demuxer cannot perform seeks.
 449  * Lastly, most errors cannot be detected.
 450  *
 451  * \param parent parent VLC object
 452  * \param name chained demux module name (e.g. "ts")
 453  * \param out elementary stream output for the chained demux
 454  * \return a non-NULL pointer on success, NULL on failure.
 455  */
 456 VLC_API vlc_demux_chained_t *vlc_demux_chained_New(vlc_object_t *parent,
 457                                                    const char *name,
 458                                                    es_out_t *out);
 459
 460 /**
 461  * Destroys a chained demuxer.
 462  *
 463  * Sends an end-of-stream to the chained demuxer, and releases all underlying
 464  * allocated resources.
 465  */
 466 VLC_API void vlc_demux_chained_Delete(vlc_demux_chained_t *);
 467
 468 /**
 469  * Sends data to a chained demuxer.
 470  *
 471  * This queues data for a chained demuxer to consume.
 472  *
 473  * \param block data block to queue
 474  */
 475 VLC_API void vlc_demux_chained_Send(vlc_demux_chained_t *, block_t *block);
 476
 477 /**
 478  * Controls a chained demuxer.
 479  *
 480  * This performs a <b>demux</b> (i.e. DEMUX_...) control request on a chained
 481  * demux.
 482  *
 483  * \note In most cases, vlc_demux_chained_Control() should be used instead.
 484  * \warning As per vlc_demux_chained_New(), most demux controls are not, and
 485  * cannot be, supported; VLC_EGENERIC is returned.
 486  *
 487  * \param query demux control (see \ref demux_query_e)
 488  * \param args variable arguments (depending on the query)
 489  */
 490 VLC_API int vlc_demux_chained_ControlVa(vlc_demux_chained_t *, int query,
 491                                         va_list args);
 492
 493 static inline int vlc_demux_chained_Control(vlc_demux_chained_t *dc, int query,
 494                                             ...)
 495 {
 496     va_list ap;
 497     int ret;
 498
 499     va_start(ap, query);
 500     ret = vlc_demux_chained_ControlVa(dc, query, ap);
 501     va_end(ap);
 502     return ret;
 503 }
 504
 505 /**
 506  * @}
 507  */
 508
 509 /**
 510  * @}
 511  */
 512
 513 #endif