include/vlc_demux.h

   1 /*****************************************************************************
   2  * vlc_demux.h: Demuxer descriptor, queries and methods
   3  *****************************************************************************
   4  * Copyright (C) 1999-2005 the VideoLAN team
   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
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 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 General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  22  *****************************************************************************/
  23
  24 #if !defined( __LIBVLC__ )
  25   #error You are not libvlc or one of its plugins. You cannot include this file
  26 #endif
  27
  28 #ifndef _VLC_DEMUX_H
  29 #define _VLC_DEMUX_H 1
  30
  31 #include <vlc_es.h>
  32 #include <vlc_stream.h>
  33 #include <vlc_es_out.h>
  34
  35 /**
  36  * \defgroup demux Demux
  37  * @{
  38  */
  39
  40 struct demux_t
  41 {
  42     VLC_COMMON_MEMBERS
  43
  44     /* Module properties */
  45     module_t    *p_module;
  46
  47     /* eg informative but needed (we can have access+demux) */
  48     char        *psz_access;
  49     char        *psz_demux;
  50     char        *psz_path;
  51
  52     /* input stream */
  53     stream_t    *s;     /* NULL in case of a access+demux in one */
  54
  55     /* es output */
  56     es_out_t    *out;   /* our p_es_out */
  57
  58     /* set by demuxer */
  59     int (*pf_demux)  ( demux_t * );   /* demux one frame only */
  60     int (*pf_control)( demux_t *, int i_query, va_list args);
  61
  62     /* Demux has to maintain them uptodate
  63      * when it is responsible of seekpoint/title */
  64     struct
  65     {
  66         unsigned int i_update;  /* Demux sets them on change,
  67                                    Input removes them once take into account*/
  68         /* Seekpoint/Title at demux level */
  69         int          i_title;       /* idem, start from 0 (could be menu) */
  70         int          i_seekpoint;   /* idem, start from 0 */
  71     } info;
  72     demux_sys_t *p_sys;
  73 };
  74
  75
  76 /* demux_meta_t is returned by "meta reader" module to the demuxer */
  77 struct demux_meta_t
  78 {
  79     vlc_meta_t *p_meta;                 /**< meta data */
  80
  81     int i_attachments;                  /**< number of attachments */
  82     input_attachment_t **attachments;    /**< array of attachments */
  83 };
  84
  85 enum demux_query_e
  86 {
  87     /* I. Common queries to access_demux and demux */
  88     /* POSITION double between 0.0 and 1.0 */
  89     DEMUX_GET_POSITION,         /* arg1= double *       res=    */
  90     DEMUX_SET_POSITION,         /* arg1= double         res=can fail    */
  91
  92     /* LENGTH/TIME in microsecond, 0 if unknown */
  93     DEMUX_GET_LENGTH,           /* arg1= int64_t *      res=    */
  94     DEMUX_GET_TIME,             /* arg1= int64_t *      res=    */
  95     DEMUX_SET_TIME,             /* arg1= int64_t        res=can fail    */
  96
  97     /* TITLE_INFO only if more than 1 title or 1 chapter */
  98     DEMUX_GET_TITLE_INFO,       /* arg1=input_title_t*** arg2=int*
  99                                    arg3=int*pi_title_offset(0), arg4=int*pi_seekpoint_offset(0) can fail */
 100     /* TITLE/SEEKPOINT, only when TITLE_INFO succeed */
 101     DEMUX_SET_TITLE,            /* arg1= int            can fail */
 102     DEMUX_SET_SEEKPOINT,        /* arg1= int            can fail */
 103
 104     /* DEMUX_SET_GROUP only a hit for demuxer (mainly DVB) to allow not
 105      * reading everything (you should not use this to call es_out_Control)
 106      * if you don't know what to do with it, just IGNORE it, it is safe(r)
 107      * -1 means all group, 0 default group (first es added) */
 108     DEMUX_SET_GROUP,            /* arg1= int            can fail */
 109
 110     /* Ask the demux to demux until the given date at the next pf_demux call
 111      * but not more (and not less, at the precision avaiable of course).
 112      * XXX: not mandatory (except for subtitle demux) but I will help a lot
 113      * for multi-input
 114      */
 115     DEMUX_SET_NEXT_DEMUX_TIME,  /* arg1= int64_t *      can fail */
 116     /* FPS for correct subtitles handling */
 117     DEMUX_GET_FPS,              /* arg1= double *       res=can fail    */
 118
 119     /* Meta data */
 120     DEMUX_GET_META,             /* arg1= vlc_meta_t **  res=can fail    */
 121     DEMUX_HAS_UNSUPPORTED_META, /* arg1= vlc_bool_t *   res can fail    */
 122
 123     /* Attachments */
 124     DEMUX_GET_ATTACHMENTS,      /* arg1=input_attachment_t***, int* res=can fail */
 125
 126     /* II. Specific access_demux queries */
 127     DEMUX_CAN_PAUSE,            /* arg1= vlc_bool_t*    can fail (assume false)*/
 128     DEMUX_SET_PAUSE_STATE,      /* arg1= vlc_bool_t     can fail */
 129
 130     DEMUX_GET_PTS_DELAY,        /* arg1= int64_t*       cannot fail */
 131
 132     /* DEMUX_CAN_CONTROL_PACE returns true (*pb_pace) if we can read the
 133      * data at our pace */
 134     DEMUX_CAN_CONTROL_PACE,     /* arg1= vlc_bool_t*pb_pace    can fail (assume false) */
 135
 136     /* DEMUX_CAN_CONTROL_RATE is called only if DEMUX_CAN_CONTROL_PACE has returned false.
 137      * *pb_rate should be true when the rate can be changed (using DEMUX_SET_RATE)
 138      * *pb_ts_rescale should be true when the timestamps (pts/dts/pcr) have to be rescaled */
 139     DEMUX_CAN_CONTROL_RATE,     /* arg1= vlc_bool_t*pb_rate arg2= vlc_bool_t*pb_ts_rescale  can fail(assume false) */
 140     /* DEMUX_SET_RATE is called only if DEMUX_CAN_CONTROL_RATE has returned true.
 141      * It should return the value really used in *pi_rate */
 142     DEMUX_SET_RATE,             /* arg1= int*pi_rate                                        can fail */
 143
 144     DEMUX_CAN_SEEK,            /* arg1= vlc_bool_t*    can fail (assume false)*/
 145 };
 146
 147 VLC_EXPORT( int,       demux2_vaControlHelper, ( stream_t *, int64_t i_start, int64_t i_end, int i_bitrate, int i_align, int i_query, va_list args ) );
 148
 149 /*************************************************************************
 150  * Miscellaneous helpers for demuxers
 151  *************************************************************************/
 152
 153 static inline vlc_bool_t demux2_IsPathExtension( demux_t *p_demux, const char *psz_extension )
 154 {
 155     const char *psz_ext = strrchr ( p_demux->psz_path, '.' );
 156     if( !psz_ext || strcasecmp( psz_ext, psz_extension ) )
 157         return VLC_FALSE;
 158     return VLC_TRUE;
 159 }
 160
 161 static inline vlc_bool_t demux2_IsForced( demux_t *p_demux, const char *psz_name )
 162 {
 163    if( !p_demux->psz_demux || strcmp( p_demux->psz_demux, psz_name ) )
 164         return VLC_FALSE;
 165     return VLC_TRUE;
 166 }
 167
 168 #define DEMUX_INIT_COMMON() do {            \
 169     p_demux->pf_control = Control;          \
 170     p_demux->pf_demux = Demux;              \
 171     MALLOC_ERR( p_demux->p_sys, demux_sys_t ); \
 172     memset( p_demux->p_sys, 0, sizeof( demux_sys_t ) ); } while(0)
 173
 174 #define STANDARD_DEMUX_INIT_MSG( msg ) do { \
 175     DEMUX_INIT_COMMON();                    \
 176     msg_Dbg( p_demux, msg ); } while(0)
 177
 178 #define DEMUX_BY_EXTENSION( ext ) \
 179     demux_t *p_demux = (demux_t *)p_this; \
 180     if( !demux2_IsPathExtension( p_demux, ext ) ) \
 181         return VLC_EGENERIC; \
 182     DEMUX_INIT_COMMON();
 183
 184 #define DEMUX_BY_EXTENSION_MSG( ext, msg ) \
 185     demux_t *p_demux = (demux_t *)p_this; \
 186     if( !demux2_IsPathExtension( p_demux, ext ) ) \
 187         return VLC_EGENERIC; \
 188     STANDARD_DEMUX_INIT_MSG( msg );
 189
 190 #define DEMUX_BY_EXTENSION_OR_FORCED( ext, module ) \
 191     demux_t *p_demux = (demux_t *)p_this; \
 192     if( !demux2_IsPathExtension( p_demux, ext ) && !demux2_IsForced( p_demux, module ) ) \
 193         return VLC_EGENERIC; \
 194     DEMUX_INIT_COMMON();
 195
 196 #define DEMUX_BY_EXTENSION_OR_FORCED_MSG( ext, module, msg ) \
 197     demux_t *p_demux = (demux_t *)p_this; \
 198     if( !demux2_IsPathExtension( p_demux, ext ) && !demux2_IsForced( p_demux, module ) ) \
 199         return VLC_EGENERIC; \
 200     STANDARD_DEMUX_INIT_MSG( msg );
 201
 202 #define CHECK_PEEK( zepeek, size ) \
 203     if( stream_Peek( p_demux->s , &zepeek, size ) < size ){ \
 204         msg_Dbg( p_demux, "not enough data" ); return VLC_EGENERIC; }
 205
 206 #define CHECK_PEEK_GOTO( zepeek, size ) \
 207     if( stream_Peek( p_demux->s , &zepeek, size ) < size ) { \
 208         msg_Dbg( p_demux, "not enough data" ); goto error; }
 209
 210 #define POKE( peek, stuff, size ) (strncasecmp( (const char *)peek, stuff, size )==0)
 211
 212 #define COMMON_INIT_PACKETIZER( location ) \
 213     location = vlc_object_create( p_demux, VLC_OBJECT_PACKETIZER ); \
 214     location->pf_decode_audio = 0; \
 215     location->pf_decode_video = 0; \
 216     location->pf_decode_sub = 0; \
 217     location->pf_packetize = 0; \
 218
 219 #define INIT_APACKETIZER( location, a,b,c,d ) \
 220     COMMON_INIT_PACKETIZER(location ); \
 221     es_format_Init( &location->fmt_in, AUDIO_ES, \
 222                     VLC_FOURCC( a, b, c, d ) );
 223
 224 #define INIT_VPACKETIZER( location, a,b,c,d ) \
 225     COMMON_INIT_PACKETIZER(location ); \
 226     es_format_Init( &location->fmt_in, VIDEO_ES, \
 227                     VLC_FOURCC( a, b, c, d ) );
 228
 229 /* BEWARE ! This can lead to memory leaks ! */
 230 #define LOAD_PACKETIZER_OR_FAIL( location, msg ) \
 231     location->p_module = \
 232         module_Need( location, "packetizer", NULL, 0 ); \
 233     if( location->p_module == NULL ) \
 234     { \
 235         vlc_object_destroy( location ); \
 236         msg_Err( p_demux, "cannot find packetizer for " # msg ); \
 237         free( p_sys ); \
 238         return VLC_EGENERIC; \
 239     }
 240
 241 #define DESTROY_PACKETIZER( location ) \
 242     if( location->p_module ) module_Unneed( location, location->p_module ); \
 243     vlc_object_destroy( location );
 244
 245 /**
 246  * @}
 247  */
 248
 249 #endif