include/vlc_access.h

   1 /*****************************************************************************
   2  * vlc_access.h: Access descriptor, queries and methods
   3  *****************************************************************************
   4  * Copyright (C) 1999-2006 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_ACCESS_H
  25 #define VLC_ACCESS_H 1
  26
  27 /**
  28  * \file
  29  * This file defines functions and definitions for access object
  30  */
  31
  32 #include <vlc_block.h>
  33
  34 /**
  35  * \defgroup access Access
  36  * @{
  37  */
  38
  39 enum access_query_e
  40 {
  41     /* capabilities */
  42     ACCESS_CAN_SEEK,        /* arg1= bool*    cannot fail */
  43     ACCESS_CAN_FASTSEEK,    /* arg1= bool*    cannot fail */
  44     ACCESS_CAN_PAUSE,       /* arg1= bool*    cannot fail */
  45     ACCESS_CAN_CONTROL_PACE,/* arg1= bool*    cannot fail */
  46
  47     /* */
  48     ACCESS_GET_PTS_DELAY = 0x101,/* arg1= int64_t*       cannot fail */
  49     /* */
  50     ACCESS_GET_TITLE_INFO,  /* arg1=input_title_t*** arg2=int*      res=can fail */
  51     /* Meta data */
  52     ACCESS_GET_META,        /* arg1= vlc_meta_t **                  res=can fail */
  53
  54     /* */
  55     ACCESS_GET_CONTENT_TYPE,/* arg1=char **ppsz_content_type                       res=can fail */
  56
  57     /* */
  58     ACCESS_GET_SIGNAL,      /* arg1=double *pf_quality, arg2=double *pf_strength   res=can fail */
  59
  60     /* */
  61     ACCESS_SET_PAUSE_STATE = 0x200, /* arg1= bool           can fail */
  62
  63     /* */
  64     ACCESS_SET_TITLE,       /* arg1= int            can fail */
  65     ACCESS_SET_SEEKPOINT,   /* arg1= int            can fail */
  66
  67     /* Special mode for access/demux communication
  68      * XXX: avoid to use it unless you can't */
  69     ACCESS_SET_PRIVATE_ID_STATE = 0x1000, /* arg1= int i_private_data, bool b_selected    res=can fail */
  70     ACCESS_SET_PRIVATE_ID_CA,             /* arg1= int i_program_number, uint16_t i_vpid, uint16_t i_apid1, uint16_t i_apid2, uint16_t i_apid3, uint8_t i_length, uint8_t *p_data */
  71     ACCESS_GET_PRIVATE_ID_STATE,          /* arg1=int i_private_data arg2=bool *          res=can fail */
  72 };
  73
  74 struct access_t
  75 {
  76     VLC_COMMON_MEMBERS
  77
  78     /* Module properties */
  79     module_t    *p_module;
  80
  81     /* Access name (empty if non forced) */
  82     char        *psz_access;
  83     char        *psz_location; /**< Location (URL with the scheme stripped) */
  84     char        *psz_filepath; /**< Local file path (if applicable) */
  85
  86     /* Access can fill this entry to force a demuxer
  87      * XXX: fill it once you know for sure you will succeed
  88      * (if you fail, this value won't be reseted */
  89     char        *psz_demux;
  90
  91     /* pf_read/pf_block is used to read data.
  92      * XXX A access should set one and only one of them */
  93     ssize_t     (*pf_read) ( access_t *, uint8_t *, size_t );  /* Return -1 if no data yet, 0 if no more data, else real data read */
  94     block_t    *(*pf_block)( access_t * );                  /* return a block of data in his 'natural' size, NULL if not yet data or eof */
  95
  96     /* Called for each seek.
  97      * XXX can be null */
  98     int         (*pf_seek) ( access_t *, uint64_t );         /* can be null if can't seek */
  99
 100     /* Used to retreive and configure the access
 101      * XXX mandatory. look at access_query_e to know what query you *have to* support */
 102     int         (*pf_control)( access_t *, int i_query, va_list args);
 103
 104     /* Access has to maintain them uptodate */
 105     struct
 106     {
 107         unsigned int i_update;  /* Access sets them on change,
 108                                    Input removes them once take into account*/
 109
 110         uint64_t     i_size;    /* Write only for access, read only for input */
 111         uint64_t     i_pos;     /* idem */
 112         bool         b_eof;     /* idem */
 113
 114         int          i_title;    /* idem, start from 0 (could be menu) */
 115         int          i_seekpoint;/* idem, start from 0 */
 116     } info;
 117     access_sys_t *p_sys;
 118
 119     /* Weak link to parent input */
 120     input_thread_t *p_input;
 121 };
 122
 123 static inline int access_vaControl( access_t *p_access, int i_query, va_list args )
 124 {
 125     if( !p_access ) return VLC_EGENERIC;
 126     return p_access->pf_control( p_access, i_query, args );
 127 }
 128
 129 static inline int access_Control( access_t *p_access, int i_query, ... )
 130 {
 131     va_list args;
 132     int     i_result;
 133
 134     va_start( args, i_query );
 135     i_result = access_vaControl( p_access, i_query, args );
 136     va_end( args );
 137     return i_result;
 138 }
 139
 140 static inline void access_InitFields( access_t *p_a )
 141 {
 142     p_a->info.i_update = 0;
 143     p_a->info.i_size = 0;
 144     p_a->info.i_pos = 0;
 145     p_a->info.b_eof = false;
 146     p_a->info.i_title = 0;
 147     p_a->info.i_seekpoint = 0;
 148 }
 149
 150 /**
 151  * This function will return the parent input of this access.
 152  * It is retained. It can return NULL.
 153  */
 154 VLC_API input_thread_t * access_GetParentInput( access_t *p_access ) VLC_USED;
 155
 156 #define ACCESS_SET_CALLBACKS( read, block, control, seek ) \
 157     do { \
 158         p_access->pf_read = (read); \
 159         p_access->pf_block = (block); \
 160         p_access->pf_control = (control); \
 161         p_access->pf_seek = (seek); \
 162     } while(0)
 163
 164 #define STANDARD_READ_ACCESS_INIT \
 165     do { \
 166         access_InitFields( p_access ); \
 167         ACCESS_SET_CALLBACKS( Read, NULL, Control, Seek ); \
 168         p_sys = p_access->p_sys = calloc( 1, sizeof( access_sys_t ) ); \
 169         if( !p_sys ) return VLC_ENOMEM;\
 170     } while(0);
 171
 172 #define STANDARD_BLOCK_ACCESS_INIT \
 173     do { \
 174         access_InitFields( p_access ); \
 175         ACCESS_SET_CALLBACKS( NULL, Block, Control, Seek ); \
 176         p_sys = p_access->p_sys = calloc( 1, sizeof( access_sys_t ) ); \
 177         if( !p_sys ) return VLC_ENOMEM; \
 178     } while(0);
 179
 180 /**
 181  * @}
 182  */
 183
 184 #endif