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