include/vlc_access.h

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