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     /* input stream */
  57     stream_t    *s;     /* NULL in case of a access+demux in one */
  58
  59     /* es output */
  60     es_out_t    *out;   /* our p_es_out */
  61
  62     /* set by demuxer */
  63     int (*pf_demux)  ( demux_t * );   /* demux one frame only */
  64     int (*pf_control)( demux_t *, int i_query, va_list args);
  65
  66     /* Demux has to maintain them uptodate
  67      * when it is responsible of seekpoint/title */
  68     struct
  69     {
  70         unsigned int i_update;  /* Demux sets them on change,
  71                                    Input removes them once take into account*/
  72         /* Seekpoint/Title at demux level */
  73         int          i_title;       /* idem, start from 0 (could be menu) */
  74         int          i_seekpoint;   /* idem, start from 0 */
  75     } info;
  76     demux_sys_t *p_sys;
  77
  78     /* Weak link to parent input */
  79     input_thread_t *p_input;
  80 };
  81
  82 /* pf_demux return values */
  83 #define VLC_DEMUXER_EOF       0
  84 #define VLC_DEMUXER_EGENERIC -1
  85 #define VLC_DEMUXER_SUCCESS   1
  86
  87 /* demux_t.info.i_update field */
  88 #define INPUT_UPDATE_TITLE      0x0010
  89 #define INPUT_UPDATE_SEEKPOINT  0x0020
  90 #define INPUT_UPDATE_META       0x0040
  91 #define INPUT_UPDATE_TITLE_LIST 0x0100
  92
  93 /* demux_meta_t is returned by "meta reader" module to the demuxer */
  94 typedef struct demux_meta_t
  95 {
  96     VLC_COMMON_MEMBERS
  97     input_item_t *p_item; /***< the input item that is being read */
  98
  99     vlc_meta_t *p_meta;                 /**< meta data */
 100
 101     int i_attachments;                  /**< number of attachments */
 102     input_attachment_t **attachments;    /**< array of attachments */
 103 } demux_meta_t;
 104
 105 /**
 106  * Control query identifiers for use with demux_t.pf_control
 107  *
 108  * In the individual identifier description, the input stream refers to
 109  * demux_t.s if non-NULL, and the output refers to demux_t.out.
 110  *
 111  * A demuxer is synchronous if it only accesses its input stream and the
 112  * output from within its demux_t callbacks, i.e. demux.pf_demux and
 113  * demux_t.pf_control.
 114  *
 115  * A demuxer is threaded if it accesses either or both input and output
 116  * asynchronously.
 117  *
 118  * An access-demuxer is a demuxer without input, i.e. demux_t.s == NULL).
 119  */
 120 enum demux_query_e
 121 {
 122     /** Checks whether the stream supports seeking.
 123      * Can fail if seeking is not supported (same as returning false).
 124      * \bug Failing should not be allowed.
 125      *
 126      * arg1 = bool * */
 127     DEMUX_CAN_SEEK,
 128
 129     /** Checks whether (long) pause then stream resumption is supported.
 130      * Can fail only if synchronous and <b>not</b> an access-demuxer. The
 131      * underlying input stream then determines if pause is supported.
 132      * \bug Failing should not be allowed.
 133      *
 134      * arg1= bool * */
 135     DEMUX_CAN_PAUSE = 0x002,
 136
 137     /** Whether the stream can be read at an arbitrary pace.
 138      * Cannot fail.
 139      *
 140      * arg1= bool * */
 141     DEMUX_CAN_CONTROL_PACE,
 142
 143     /** Retrieves the PTS delay (roughly the default buffer duration).
 144      * Can fail only if synchronous and <b>not</b> an access-demuxer. The
 145      * underlying input stream then determines the PTS delay.
 146      *
 147      * arg1= int64_t * */
 148     DEMUX_GET_PTS_DELAY = 0x101,
 149
 150     /** Retrieves stream meta-data.
 151      * Should fail if no meta-data were retrieved.
 152      *
 153      * arg1= vlc_meta_t * */
 154     DEMUX_GET_META = 0x105,
 155
 156     /** Retrieves an estimate of signal quality and strength.
 157      * Can fail.
 158      *
 159      * arg1=double *quality, arg2=double *strength */
 160     DEMUX_GET_SIGNAL = 0x107,
 161
 162     /** Sets the paused or playing/resumed state.
 163      *
 164      * Streams are initially in playing state. The control always specifies a
 165      * change from paused to playing (false) or from playing to paused (true)
 166      * and streams are initially playing; a no-op cannot be requested.
 167      *
 168      * The control is never used if DEMUX_CAN_PAUSE fails.
 169      * Can fail.
 170      *
 171      * arg1= bool */
 172     DEMUX_SET_PAUSE_STATE = 0x200,
 173
 174     /** Seeks to the beginning of a title.
 175      *
 176      * The control is never used if DEMUX_GET_TITLE_INFO fails.
 177      * Can fail.
 178      *
 179      * arg1= int */
 180     DEMUX_SET_TITLE,
 181
 182     /** Seeks to the beginning of a chapter of the current title.
 183      *
 184      * The control is never used if DEMUX_GET_TITLE_INFO fails.
 185      * Can fail.
 186      *
 187      * arg1= int */
 188     DEMUX_SET_SEEKPOINT,        /* arg1= int            can fail */
 189
 190     /* I. Common queries to access_demux and demux */
 191     /* POSITION double between 0.0 and 1.0 */
 192     DEMUX_GET_POSITION = 0x300, /* arg1= double *       res=    */
 193     DEMUX_SET_POSITION,         /* arg1= double arg2= bool b_precise    res=can fail    */
 194
 195     /* LENGTH/TIME in microsecond, 0 if unknown */
 196     DEMUX_GET_LENGTH,           /* arg1= int64_t *      res=    */
 197     DEMUX_GET_TIME,             /* arg1= int64_t *      res=    */
 198     DEMUX_SET_TIME,             /* arg1= int64_t arg2= bool b_precise   res=can fail    */
 199
 200     /**
 201      * \todo Document
 202      *
 203      * \warning The prototype is different from STREAM_GET_TITLE_INFO
 204      *
 205      * Can fail, meaning there is only one title and one chapter.
 206      *
 207      * arg1= input_title_t ***, arg2=int *, arg3=int *pi_title_offset(0),
 208      * arg4= int *pi_seekpoint_offset(0) */
 209     DEMUX_GET_TITLE_INFO,
 210
 211     /* DEMUX_SET_GROUP/SET_ES only a hint for demuxer (mainly DVB) to allow not
 212      * reading everything (you should not use this to call es_out_Control)
 213      * if you don't know what to do with it, just IGNORE it, it is safe(r)
 214      * -1 means all group, 0 default group (first es added) */
 215     DEMUX_SET_GROUP,            /* arg1= int, arg2=const vlc_list_t *   can fail */
 216     DEMUX_SET_ES,               /* arg1= int                            can fail */
 217
 218     /* Ask the demux to demux until the given date at the next pf_demux call
 219      * but not more (and not less, at the precision available of course).
 220      * XXX: not mandatory (except for subtitle demux) but will help a lot
 221      * for multi-input
 222      */
 223     DEMUX_SET_NEXT_DEMUX_TIME,  /* arg1= int64_t        can fail */
 224     /* FPS for correct subtitles handling */
 225     DEMUX_GET_FPS,              /* arg1= double *       res=can fail    */
 226
 227     /* Meta data */
 228     DEMUX_HAS_UNSUPPORTED_META, /* arg1= bool *   res can fail    */
 229
 230     /* Attachments */
 231     DEMUX_GET_ATTACHMENTS,      /* arg1=input_attachment_t***, int* res=can fail */
 232
 233     /* RECORD you are ensured that it is never called twice with the same state
 234      * you should accept it only if the stream can be recorded without
 235      * any modification or header addition. */
 236     DEMUX_CAN_RECORD,           /* arg1=bool*   res=can fail(assume false) */
 237     /**
 238      * \todo Document
 239      *
 240      * \warning The prototype is different from STREAM_SET_RECORD_STATE
 241      *
 242      * The control is never used if DEMUX_CAN_RECORD fails or returns false.
 243      * Can fail.
 244      *
 245      * arg1= bool */
 246     DEMUX_SET_RECORD_STATE,
 247
 248     /* II. Specific access_demux queries */
 249
 250     /* DEMUX_CAN_CONTROL_RATE is called only if DEMUX_CAN_CONTROL_PACE has returned false.
 251      * *pb_rate should be true when the rate can be changed (using DEMUX_SET_RATE)
 252      * *pb_ts_rescale should be true when the timestamps (pts/dts/pcr) have to be rescaled */
 253     DEMUX_CAN_CONTROL_RATE,     /* arg1= bool*pb_rate arg2= bool*pb_ts_rescale  can fail(assume false) */
 254     /* DEMUX_SET_RATE is called only if DEMUX_CAN_CONTROL_RATE has returned true.
 255      * It should return the value really used in *pi_rate */
 256     DEMUX_SET_RATE,             /* arg1= int*pi_rate                                        can fail */
 257
 258     /** Checks whether the stream is actually a playlist, rather than a real
 259      * stream.
 260      *
 261      * \warning The prototype is different from STREAM_IS_DIRECTORY.
 262      *
 263      * Can fail if the stream is not a playlist (same as returning false).
 264      *
 265      * arg1= bool * */
 266     DEMUX_IS_PLAYLIST,
 267
 268     /* Menu (VCD/DVD/BD) Navigation */
 269     /** Activate the navigation item selected. Can fail */
 270     DEMUX_NAV_ACTIVATE,
 271     /** Use the up arrow to select a navigation item above. Can fail */
 272     DEMUX_NAV_UP,
 273     /** Use the down arrow to select a navigation item under. Can fail */
 274     DEMUX_NAV_DOWN,
 275     /** Use the left arrow to select a navigation item on the left. Can fail */
 276     DEMUX_NAV_LEFT,
 277     /** Use the right arrow to select a navigation item on the right. Can fail */
 278     DEMUX_NAV_RIGHT,
 279     /** Activate the popup Menu (for BD). Can fail */
 280     DEMUX_NAV_POPUP,
 281 };
 282
 283 /*************************************************************************
 284  * Main Demux
 285  *************************************************************************/
 286
 287 /* stream_t *s could be null and then it mean a access+demux in one */
 288 VLC_API demux_t *demux_New( vlc_object_t *p_obj, const char *psz_name,
 289                             const char *psz_path, stream_t *s, es_out_t *out );
 290
 291 VLC_API void demux_Delete( demux_t * );
 292
 293
 294 VLC_API int demux_vaControlHelper( stream_t *, int64_t i_start, int64_t i_end,
 295                                    int64_t i_bitrate, int i_align, int i_query, va_list args );
 296
 297 VLC_USED static inline int demux_Demux( demux_t *p_demux )
 298 {
 299     if( !p_demux->pf_demux )
 300         return 1;
 301
 302     return p_demux->pf_demux( p_demux );
 303 }
 304
 305 VLC_API int demux_vaControl( demux_t *p_demux, int i_query, va_list args );
 306
 307 static inline int demux_Control( demux_t *p_demux, int i_query, ... )
 308 {
 309     va_list args;
 310     int     i_result;
 311
 312     va_start( args, i_query );
 313     i_result = demux_vaControl( p_demux, i_query, args );
 314     va_end( args );
 315     return i_result;
 316 }
 317
 318 /*************************************************************************
 319  * Miscellaneous helpers for demuxers
 320  *************************************************************************/
 321
 322 static inline void demux_UpdateTitleFromStream( demux_t *demux )
 323 {
 324     stream_t *s = demux->s;
 325     unsigned title, seekpoint;
 326
 327     if( stream_Control( s, STREAM_GET_TITLE, &title ) == VLC_SUCCESS
 328      && title != (unsigned)demux->info.i_title )
 329     {
 330         demux->info.i_title = title;
 331         demux->info.i_update |= INPUT_UPDATE_TITLE;
 332     }
 333
 334     if( stream_Control( s, STREAM_GET_SEEKPOINT, &seekpoint ) == VLC_SUCCESS
 335      && seekpoint != (unsigned)demux->info.i_seekpoint )
 336     {
 337         demux->info.i_seekpoint = seekpoint;
 338         demux->info.i_update |= INPUT_UPDATE_SEEKPOINT;
 339     }
 340 }
 341
 342 VLC_USED
 343 static inline bool demux_IsPathExtension( demux_t *p_demux, const char *psz_extension )
 344 {
 345     const char *name = (p_demux->psz_file != NULL) ? p_demux->psz_file
 346                                                    : p_demux->psz_location;
 347     const char *psz_ext = strrchr ( name, '.' );
 348     if( !psz_ext || strcasecmp( psz_ext, psz_extension ) )
 349         return false;
 350     return true;
 351 }
 352
 353 VLC_USED
 354 static inline bool demux_IsContentType(demux_t *demux, const char *type)
 355 {
 356     char *mime = stream_ContentType(demux->s);
 357     if (mime == NULL)
 358         return false;
 359
 360     size_t len = strlen(type);
 361     bool ok = strncasecmp(mime, type, len) == 0
 362            && memchr("\t ;", (unsigned char)mime[len], 4) != NULL;
 363
 364     free(mime);
 365     return ok;
 366 }
 367
 368 VLC_USED
 369 static inline bool demux_IsForced( demux_t *p_demux, const char *psz_name )
 370 {
 371    if( !p_demux->psz_demux || strcmp( p_demux->psz_demux, psz_name ) )
 372         return false;
 373     return true;
 374 }
 375
 376 /**
 377  * This function will create a packetizer suitable for a demuxer that parses
 378  * elementary stream.
 379  *
 380  * The provided es_format_t will be cleaned on error or by
 381  * demux_PacketizerDestroy.
 382  */
 383 VLC_API decoder_t * demux_PacketizerNew( demux_t *p_demux, es_format_t *p_fmt, const char *psz_msg ) VLC_USED;
 384
 385 /**
 386  * This function will destroy a packetizer create by demux_PacketizerNew.
 387  */
 388 VLC_API void demux_PacketizerDestroy( decoder_t *p_packetizer );
 389
 390 /* */
 391 #define DEMUX_INIT_COMMON() do {            \
 392     p_demux->pf_control = Control;          \
 393     p_demux->pf_demux = Demux;              \
 394     p_demux->p_sys = calloc( 1, sizeof( demux_sys_t ) ); \
 395     if( !p_demux->p_sys ) return VLC_ENOMEM;\
 396     } while(0)
 397
 398 /**
 399  * @}
 400  */
 401
 402 #endif